ChemWiki - User contributions [en]

It07:DIBAL

2007-11-30T13:24:31Z

Fj106: /* Safety Information */

=DIBAL Di-IsoButyl Aluminium Hydride=
[[Image:DIBAL1.png]]

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[Image:DIBAL1.png|200px|{{PAGENAME}}]] 
|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| Di-Isobutyl Aluminium Hydride

|-
| Other names
| DIBAL, DIBAL-H, DIBAH, DIBALH
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| [(CH3)2CHCH2]2AlH
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| [H][Al]CC(C)C.CCC(C)C
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 142.22
|-
| Appearance
| Clear, colourless liquid
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 1191-15-7
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| 0.798 g/cm³ 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 255.15 K 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| 389.15-391.15 K
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| Corrosive, highly flammable. 
|-
|-
|-
|-
|-

|-
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Liquid
|-
|-
|-
|-
|-
|-
|-
|}

==Introduction==
DIBAL has rapidly established itself as a reducing agent of choice in organic synthesis. It is most effective at reducing electron-rich carbonyl groups and has largely replaced the use of metal hydrides (including LiAlH4 and NaBH4) due to economic advantages. It demonstrates increased selectivity and a considerably lower cost per reducing equivalent. It is also a particularly easy-handling material as it is a liquid that is miscible in many solvents.
DIBAL exists as a dimer due to increased stabilisation:
[[Image:DIBAL6.png]]

==Reduction of Esters to Aldehydes using DIBAL==

Chemists often come across a problem when reducing an ester to an aldehyde. This is because the aldehyde product is more susceptible to reduction than the starting ester and therefore the reduction process continues to the next oxidation level – to the alcohol.
DIBAL, however, can be used as a reagent that will carry out this reduction in 1 step and stops at the aldehyde without further reduction.

[[Image:Ester3.png]]

At -70oC the tetrahedral intermediate is stable. It collapses to the aldehyde on aqueous work-up (slow quenching with methanol followed by full quenching with water), but by this stage excess DIBAL has been destroyed so as to prevent any further reduction.

==Reduction of Nitriles to Aldehydes using DIBAL==

[[Image:Nitrile3.png]]

Mechanism:

i. The first step of this mechanism involves an acid-base reaction between a lone pair of electrons on N with the AL in DIBAL.

ii. The second step involves the transfer of a hydride ion from DIBAL to the C of the nitrile group.

iii. The final step is the hydrolysis of the aluminium complex which results in the formation of the desired aldehyde.

==Safety Information==
Neat DIBAL is pyrophoric (capable of igniting spontaneously in air), and its solutions react violently with water, oxygen and other related compounds. It should always be handled with care in a fume hood.

===Potential Health Effects===

*Eye: Causes eye burns.
*Skin: Causes skin burns.
*Ingestion: Causes gastrointestinal tract burns.
*Inhalation: Harmful if inhaled. Causes chemical burns to the respiratory tract.

NOTE: Only use dry chemical to extinguish DIBAL-induced fires. DO NOT USE WATER.

==References==

It07:DIBAL

2007-11-30T13:17:27Z

Fj106: /* Introduction */

Carbon Dioxide

2007-11-30T12:52:04Z

Fj106: /* General */

== General ==


</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[Image:{{PAGENAME}}.jpg|200px|{{PAGENAME}}]] 
|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| Carbon Dioxide

|-
| Other names
| Carbonic acid gas; carbonic anhydride; dry ice (in solid state)
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| CO2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| O=C=O
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 44.0095(14) g/mol
|-
| Appearance
| Colourless gas
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 124-38-9
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| 1,600 kg/m in solid state; 1.98 kg/m³ in gaseous state
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| 1.45 kg/m³
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 194.65 K 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| 195 K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| 0.07 cP at 195 °C9
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| Linear 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| Not available 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| Asphyxiant in high concentrations 
|-
| [[NFPA 704]]
| None
|-
| [[Flash point]]
| None
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}
{{Chem-Data_Structure}}

Carbon dioxide is a chemical compound made up from two oxygen atoms covalently bonded to a single carbon atom. At room temperature and pressure, carbon dioxide exists as a gas. The chemical formula for carbon dioxide is CO2.
Most commonly, carbon dioxide is used up in one of the most important processes of life, photosynthesis. It is used to form glucose, water vapour and oxygen as a by-product, which is the same oxygen available to humans for respiration, where the opposite gas transfer takes place, and carbon dioxide is released, while oxygen is taken up. Additional carbon dioxide is also created by the combustion of fossil fuels or vegetable matter, among other chemical processes.
Carbon dioxide is referred to as a green house gas, as it traps radiation from the sun to keep heat from fully escaping. Due to the fact that it absorbs in the infra red region of light, and because of its atmospheric life time, it plays a major role in the carbon cycle.

== Physical and Chemical Properties ==

Carbon dioxide is a colourless and odourless gas. At standard temperature and pressure, carbon dioxide has a density of 1.98kg/m³, which is about one and half times greater than that of air. The VSEPR theory predicts that carbon is bonded from two double bonds, one from each oxygen leaving two sets of lone pairs on each of the oxygen, which best arranges best itself to a linear shape due to electron repulsion. The molecule has no electrical dipole, and because it’s fully oxidised, it is reasonably reactive and non flammable, but can be used as support in the combustion of certain metals like magnesium.

Carbon dioxide has some interesting effects in the human body. It has been proven that if carbon dioxide is inhaled at concentrations higher than the normal atmospheric levels, it can produce s stinging sensation in the nose and throat, and a sour taste in the mouth. This is the result of carbon dioxide dissolving the mucous membranes and saliva, which forms a very solution of carbonic acid. This sensation also occurs at an attempt to stifle a burp after drinking a carbonated drink.

[[Image:Dry_Ice.jpg|150px]]

At a low temperature of about 194.64 K, carbon dioxide changes from a solid to a gaseous phase through the process of sublimation. It’s commonly referred to as dry ice, and was first observed by a French chemist called Charles Thilorier in 1825. There are however other forms of solid carbon dioxide are known today. One of them is the amorphous glass like form which can be formed under very strong pressure. This form of glass is known as carbonia, which was produced by cooling heated carbon dioxide at extreme pressure (of about 400,000 atm) in a diamond anvil. The research established that carbon dioxide could exist in a glass form just like other elements in Group 14, such as silicon and germanium. However due to its instability, the carbon dioxide glass sublimed back to gas when exposed at standard conditions.

Liquid carbon dioxide only forms at pressures above 5.1 atm. The triple point of carbon dioxide is approximately 518 kPa at 218.55 K and the critical point is 7,821 kPa at 306.25 K (data from the phase diagram).

[[Image:CO2.jpg|150px|align="center"]]

== Uses: ==

Carbon dioxide is widely used in many industries, and has important roles in the food, oil, and chemical industry.

== Industrial production: ==

Carbon dioxide in the atmosphere:

Carbon Dioxide

2007-11-30T12:38:47Z

Fj106: /* General */

== General ==


</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[Image:{{PAGENAME}}.jpg|200px|{{PAGENAME}}]] 
|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| Carbon Dioxide

|-
| Other names
| Carbonic acid gas; carbonic anhydride; dry ice (in solid state)
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| CO2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| O=C=O
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 44.0095(14) g/mol
|-
| Appearance
| colorless gas
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 124-38-9
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| 1,600 kg/m in solid state; 1.98 kg/m³ in gaseous state
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| 1.45 kg/m³
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| {{{Mp}}} K 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| 195 K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| 0.07 cP at 195 °C9
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}
{{Chem-Data_Structure}}

Carbon dioxide is a chemical compound made up from two oxygen atoms covalently bonded to a single carbon atom. At room temperature and pressure, carbon dioxide exists as a gas. The chemical formula for carbon dioxide is CO2.
Most commonly, carbon dioxide is used up in one of the most important processes of life, photosynthesis. It is used to form glucose, water vapour and oxygen as a by-product, which is the same oxygen available to humans for respiration, where the opposite gas transfer takes place, and carbon dioxide is released, while oxygen is taken up. Additional carbon dioxide is also created by the combustion of fossil fuels or vegetable matter, among other chemical processes.
Carbon dioxide is referred to as a green house gas, as it traps radiation from the sun to keep heat from fully escaping. Due to the fact that it absorbs in the infra red region of light, and because of its atmospheric life time, it plays a major role in the carbon cycle.

== Physical and Chemical Properties ==

Carbon dioxide is a colourless and odourless gas. At standard temperature and pressure, carbon dioxide has a density of 1.98kg/m³, which is about one and half times greater than that of air. The VSEPR theory predicts that carbon is bonded from two double bonds, one from each oxygen leaving two sets of lone pairs on each of the oxygen, which best arranges best itself to a linear shape due to electron repulsion. The molecule has no electrical dipole, and because it’s fully oxidised, it is reasonably reactive and non flammable, but can be used as support in the combustion of certain metals like magnesium.

Carbon dioxide has some interesting effects in the human body. It has been proven that if carbon dioxide is inhaled at concentrations higher than the normal atmospheric levels, it can produce s stinging sensation in the nose and throat, and a sour taste in the mouth. This is the result of carbon dioxide dissolving the mucous membranes and saliva, which forms a very solution of carbonic acid. This sensation also occurs at an attempt to stifle a burp after drinking a carbonated drink.

[[Image:Dry_Ice.jpg|150px]]

At a low temperature of about 194.64 K, carbon dioxide changes from a solid to a gaseous phase through the process of sublimation. It’s commonly referred to as dry ice, and was first observed by a French chemist called Charles Thilorier in 1825. There are however other forms of solid carbon dioxide are known today. One of them is the amorphous glass like form which can be formed under very strong pressure. This form of glass is known as carbonia, which was produced by cooling heated carbon dioxide at extreme pressure (of about 400,000 atm) in a diamond anvil. The research established that carbon dioxide could exist in a glass form just like other elements in Group 14, such as silicon and germanium. However due to its instability, the carbon dioxide glass sublimed back to gas when exposed at standard conditions.

Liquid carbon dioxide only forms at pressures above 5.1 atm. The triple point of carbon dioxide is approximately 518 kPa at 218.55 K and the critical point is 7,821 kPa at 306.25 K (data from the phase diagram).

[[Image:CO2.jpg|150px|align="center"]]

== Uses: ==

Carbon dioxide is widely used in many industries, and has important roles in the food, oil, and chemical industry.

== Industrial production: ==

Carbon dioxide in the atmosphere:

It07:Jacobsen

2007-11-30T12:33:33Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts (0.25–10 mol %) with sodium hypochlorite (bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
</inlineContents>
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| Not Available 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| Miscible in water 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| Not Available
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| Not Available
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| Not Available
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| Not Available 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| Harmful by skin contact or inhalation 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| N/A
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

Reaction Scheme [[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-30T12:27:42Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts (0.25–10 mol %) with sodium hypochlorite (bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| Harmful by skin contact or inhalation 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| N/A
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

Reaction Scheme [[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T17:07:54Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts (0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

Reaction Scheme [[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T17:05:43Z

Fj106: /* The Jacobsen-Katsuki Epoxidation */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

Reaction Scheme [[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T17:05:06Z

Fj106: /* The Jacobsen-Katsuki Epoxidation */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

Reaction Scheme [[Image:Jacobsen_katsuki_epoxidation.gif|550px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T17:04:21Z

Fj106: /* The Jacobsen-Katsuki Epoxidation */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|700px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T17:02:38Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
<jmolApplet>
<size>300</size>
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T17:01:40Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T17:00:22Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T16:59:26Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
</inlineContents>
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<jmol>
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<size>200</size><name>fixed</name>
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<uploadedFileContents>17373.pdb</uploadedFileContents>
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T16:57:09Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T16:56:32Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Jacobsen Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T16:55:20Z

Fj106: /* Jacobsen Catalyst Synthesis */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Jacobsen Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T16:53:58Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
</inlineContents>
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

Jacobsen Catalyst:[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

First Catalyst:[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T16:51:23Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalystnew.gif]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalystnew.gif]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

File:Jacobsen 1stCatalystnew.gif

2007-11-29T16:50:41Z

Fj106:

File:Jacobsen Catalystnew.gif

2007-11-29T16:50:18Z

Fj106:

It07:Jacobsen

2007-11-29T16:46:02Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst.gif]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T16:35:23Z

Fj106: /* Jacobsen Catalyst Synthesis */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T16:34:25Z

Fj106: /* Jacobsen Catalyst Synthesis */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step, 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

Synthesis route: [[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

===Hazards===

Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T16:31:11Z

Fj106: /* Jacobsen Catalyst Synthesis */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
</inlineContents>
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<size>200</size><name>fixed</name>
<script>zoom 80; cpk -25;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<uploadedFileContents>17373.pdb</uploadedFileContents>
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

[[Image:Jacobsen_Synthesis.gif]]

The diimine 2 (aka “Jacobsen’s ligand”) is formed by adding 3,5-di-tert-butyl-2-hydroxybenzaldehyde (dissolved in hot ethanol) to a refluxing solution of diaminocyclohexane salt 1 and potassium carbonate dissolved in a mixture of ethanol and water. After formation of the diimine, the reaction mixture is cooled in an ice bath. The crude solid product is then collected by vacuum filtration and dissolved in dichloromethane and washed with water and brine. Drying with sodium sulfate and evaporation of the solvent affords the diimine 2 as a yellow solid.

In the final step of the synthesis of Jacobsen’s catalyst (3), manganese(II) acetate is added to a refluxing solution of the diimine 2 in ethanol. Air is then bubbled through the reaction mixture to oxidize the manganese, producing a dark brown solution. The reaction is monitored by thin-layer chromatography and after the ligand has disappeared the air is discontinued and lithium chloride is added. The solvent is removed using a rotary evaporator and the residue dissolved in dichloromethane then washed with water and saturated sodium chloride (brine). After the dichloromethane layer is dried (Na2SO4), heptane is added and the dichloromethane (but not the heptane) is removed via rotary evaporation. The resulting dark brown solid is collected by vacuum filtration and allowed to dry in air.

Hazards
Occasionally fumes can be observed propagating from the top of the condenser when air is bubbled through the refluxing reaction mixture during production of Jacobsen’s catalyst. Therefore, this procedure should be done under a fumehood. Deuterochloroform and aromatic epoxides are suspected carcinogenics and should be handled with proper care.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

File:Jacobsen Synthesis.gif

2007-11-29T16:29:08Z

Fj106:

File:Jacobsen Synthesis.JPG

2007-11-29T16:25:56Z

Fj106:

It07:Jacobsen

2007-11-29T15:47:17Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T15:45:19Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T15:14:27Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T15:13:07Z

Fj106:

= '''Jacobsen's Epoxidation Catalyst''' =

The Jacobsen's catalyst, which was awarded the Fluka Prize "Reagent of the Year" in 1994, is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

Unlike many modern organometallic reagents (which are toxic, carcinogenic, etc), the Jacobsen's Catalyst is relatively safe and easy to use (even by organic students beginners). It is stable in air and water and is typically used only in small amounts(0.25–10 mol %) with sodium hypochlorite(bleach) as it is an ultimate oxidant. The catalyst is commercially available, but its preparation is simple and easy enough to understand.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==Jacobsen Catalyst Synthesis==

In the first step 1,2-diaminocyclohexane is purified and resolved by crystallization of the salt formed with L-tartaric acid. As the hot reaction mixture cools, product crystallizes from the reaction mixture. The crude product is collected and recrystallized from water.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T15:11:44Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

It07:Jacobsen

2007-11-29T14:40:35Z

Fj106: /* Mode of oxygen transfer */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

Two-step catalytic cycle: [[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T14:37:08Z

Fj106: /* Mode of oxygen transfer */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

[[Image:Salen_cycle.gif]]

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

File:Salen cycle.gif

2007-11-29T14:35:56Z

Fj106:

It07:Jacobsen

2007-11-29T14:35:28Z

Fj106: /* Mode of oxygen transfer */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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<title>Pentahelicene</title><color>black</color>
<size>200</size><name>fixed</name>
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see diagram below). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T14:34:27Z

Fj106: /* The Jacobsen-Katsuki Epoxidation */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|500px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T14:32:19Z

Fj106: /* The Jacobsen-Katsuki Epoxidation */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
<jmolApplet>
<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif|150px]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T14:30:36Z

Fj106: /* The Jacobsen-Katsuki Epoxidation */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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<jmol>
<jmolApplet>
<title>Pentahelicene</title><color>black</color>
<size>200</size><name>fixed</name>
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

[[Image:Jacobsen_katsuki_epoxidation.gif]]

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

File:Jacobsen katsuki epoxidation.gif

2007-11-29T14:29:28Z

Fj106:

It07:Jacobsen

2007-11-29T14:28:27Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T14:27:06Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T14:26:35Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG|align="center"]]

The first Salen catalyst introduced by Jacobsen was:

|align="center"[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T14:26:03Z

Fj106: /* '''Jacobsen's Epoxidation Catalyst''' */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
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<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG|align="center"]]

The first Salen catalyst introduced by Jacobsen was:

|align="center"]][[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T14:16:25Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
<color>white</color>
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<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

It07:Jacobsen

2007-11-29T14:15:22Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

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<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

[[Image:Jacobsen_1stCatalyst.JPG]]

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

File:Jacobsen 1stCatalyst.JPG

2007-11-29T14:14:24Z

Fj106:

It07:Jacobsen

2007-11-29T13:56:42Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
</inlineContents>
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<jmol>
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<title>Pentahelicene</title><color>black</color>
<size>200</size><name>fixed</name>
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst1.JPG]]

The first Salen catalyst introduced by Jacobsen was:

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com

File:Jacobsen Catalyst1.JPG

2007-11-29T13:55:47Z

Fj106:

It07:Jacobsen

2007-11-27T17:56:01Z

Fj106: /* 2D Structure of the Molecule */

= '''Jacobsen's Epoxidation Catalyst''' =

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | 

<jmol>
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<size>300</size>
<color>white</color>
<script>zoom 80; cpk on;frame 1; move 10 -20 10 0 0 0 0 0 3; delay 1;</script>
<inlineContents>HEADER NONAME 19-Nov-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 19-Nov-07 0 NONE 4
ATOM 1 Cl 0 -1.805 0.548 1.202 0.00 0.00 Cl+0
ATOM 2 Mn 0 -0.055 -0.636 0.753 0.00 0.00 Mn+0
ATOM 3 O 0 1.374 -1.675 0.525 0.00 0.00 O+0
ATOM 4 C 0 2.525 -1.003 0.343 0.00 0.00 C+0
ATOM 5 C 0 3.615 -1.841 0.035 0.00 0.00 C+0
ATOM 6 C 0 3.399 -3.330 -0.041 0.00 0.00 C+0
ATOM 7 C 0 4.719 -4.020 -0.388 0.00 0.00 C+0
ATOM 8 C 0 2.896 -3.842 1.310 0.00 0.00 C+0
ATOM 9 C 0 2.362 -3.640 -1.123 0.00 0.00 C+0
ATOM 10 C 0 4.870 -1.334 -0.199 0.00 0.00 C+0
ATOM 11 C 0 5.088 0.033 -0.136 0.00 0.00 C+0
ATOM 12 C 0 6.461 0.597 -0.397 0.00 0.00 C+0
ATOM 13 C 0 6.906 0.220 -1.812 0.00 0.00 C+0
ATOM 14 C 0 6.421 2.120 -0.264 0.00 0.00 C+0
ATOM 15 C 0 7.450 0.021 0.619 0.00 0.00 C+0
ATOM 16 C 0 4.042 0.871 0.166 0.00 0.00 C+0
ATOM 17 C 0 2.753 0.376 0.414 0.00 0.00 C+0
ATOM 18 C 0 1.700 1.353 0.688 0.00 0.00 C+0
ATOM 19 N 0 1.700 2.564 0.203 0.00 0.00 N+0
ATOM 20 C 0 0.468 3.316 0.464 0.00 0.00 C+0
ATOM 21 H 0 -0.118 2.609 1.131 0.00 0.00 H+0
ATOM 22 C 0 0.565 4.583 1.208 0.00 0.00 C+0
ATOM 23 C 0 0.751 5.863 0.407 0.00 0.00 C+0
ATOM 24 C 0 -0.489 5.944 -0.509 0.00 0.00 C+0
ATOM 25 C 0 -0.380 4.734 -1.422 0.00 0.00 C+0
ATOM 26 C 0 -0.364 3.402 -0.799 0.00 0.00 C+0
ATOM 27 H 0 0.177 2.723 -1.536 0.00 0.00 H+0
ATOM 28 N 0 -1.647 2.707 -0.618 0.00 0.00 N+0
ATOM 29 C 0 -1.508 1.410 -0.724 0.00 0.00 C+0
ATOM 30 C 0 -2.587 0.438 -0.541 0.00 0.00 C+0
ATOM 31 C 0 -3.914 0.842 -0.404 0.00 0.00 C+0
ATOM 32 C 0 -4.909 -0.097 -0.230 0.00 0.00 C+0
ATOM 33 C 0 -6.343 0.345 -0.090 0.00 0.00 C+0
ATOM 34 C 0 -6.417 1.871 -0.175 0.00 0.00 C+0
ATOM 35 C 0 -7.178 -0.270 -1.215 0.00 0.00 C+0
ATOM 36 C 0 -6.889 -0.118 1.262 0.00 0.00 C+0
ATOM 37 C 0 -4.593 -1.446 -0.185 0.00 0.00 C+0
ATOM 38 C 0 -3.282 -1.860 -0.320 0.00 0.00 C+0
ATOM 39 C 0 -2.951 -3.330 -0.279 0.00 0.00 C+0
ATOM 40 C 0 -4.236 -4.136 -0.082 0.00 0.00 C+0
ATOM 41 C 0 -2.289 -3.740 -1.596 0.00 0.00 C+0
ATOM 42 C 0 -1.992 -3.605 0.881 0.00 0.00 C+0
ATOM 43 C 0 -2.270 -0.929 -0.491 0.00 0.00 C+0
ATOM 44 O 0 -0.981 -1.342 -0.616 0.00 0.00 O+0
ATOM 45 H 0 5.458 -3.799 0.382 0.00 0.00 H+0
ATOM 46 H 0 4.563 -5.098 -0.443 0.00 0.00 H+0
ATOM 47 H 0 5.078 -3.656 -1.351 0.00 0.00 H+0
ATOM 48 H 0 1.955 -3.350 1.557 0.00 0.00 H+0
ATOM 49 H 0 2.739 -4.919 1.255 0.00 0.00 H+0
ATOM 50 H 0 3.634 -3.621 2.080 0.00 0.00 H+0
ATOM 51 H 0 2.720 -3.276 -2.085 0.00 0.00 H+0
ATOM 52 H 0 2.205 -4.718 -1.178 0.00 0.00 H+0
ATOM 53 H 0 1.421 -3.149 -0.875 0.00 0.00 H+0
ATOM 54 H 0 5.688 -2.000 -0.432 0.00 0.00 H+0
ATOM 55 H 0 6.201 0.630 -2.536 0.00 0.00 H+0
ATOM 56 H 0 7.899 0.627 -2.001 0.00 0.00 H+0
ATOM 57 H 0 6.934 -0.865 -1.907 0.00 0.00 H+0
ATOM 58 H 0 6.104 2.389 0.744 0.00 0.00 H+0
ATOM 59 H 0 7.414 2.528 -0.453 0.00 0.00 H+0
ATOM 60 H 0 5.716 2.530 -0.988 0.00 0.00 H+0
ATOM 61 H 0 7.478 -1.064 0.524 0.00 0.00 H+0
ATOM 62 H 0 8.443 0.429 0.430 0.00 0.00 H+0
ATOM 63 H 0 7.132 0.290 1.626 0.00 0.00 H+0
ATOM 64 H 0 4.217 1.936 0.213 0.00 0.00 H+0
ATOM 65 H 0 0.925 1.136 1.413 0.00 0.00 H+0
ATOM 66 H 0 -0.342 4.691 1.802 0.00 0.00 H+0
ATOM 67 H 0 1.403 4.500 1.901 0.00 0.00 H+0
ATOM 68 H 0 0.787 6.725 1.073 0.00 0.00 H+0
ATOM 69 H 0 1.660 5.806 -0.191 0.00 0.00 H+0
ATOM 70 H 0 -1.402 5.890 0.084 0.00 0.00 H+0
ATOM 71 H 0 -0.469 6.863 -1.094 0.00 0.00 H+0
ATOM 72 H 0 -1.219 4.765 -2.117 0.00 0.00 H+0
ATOM 73 H 0 0.534 4.839 -2.006 0.00 0.00 H+0
ATOM 74 H 0 -0.510 1.045 -0.974 0.00 0.00 H+0
ATOM 75 H 0 -4.163 1.892 -0.433 0.00 0.00 H+0
ATOM 76 H 0 -6.027 2.200 -1.138 0.00 0.00 H+0
ATOM 77 H 0 -7.454 2.190 -0.074 0.00 0.00 H+0
ATOM 78 H 0 -5.822 2.308 0.627 0.00 0.00 H+0
ATOM 79 H 0 -7.125 -1.357 -1.155 0.00 0.00 H+0
ATOM 80 H 0 -8.215 0.050 -1.114 0.00 0.00 H+0
ATOM 81 H 0 -6.788 0.060 -2.179 0.00 0.00 H+0
ATOM 82 H 0 -6.294 0.319 2.063 0.00 0.00 H+0
ATOM 83 H 0 -7.926 0.201 1.363 0.00 0.00 H+0
ATOM 84 H 0 -6.836 -1.205 1.322 0.00 0.00 H+0
ATOM 85 H 0 -5.376 -2.176 -0.043 0.00 0.00 H+0
ATOM 86 H 0 -4.919 -3.940 -0.908 0.00 0.00 H+0
ATOM 87 H 0 -3.997 -5.199 -0.053 0.00 0.00 H+0
ATOM 88 H 0 -4.707 -3.844 0.857 0.00 0.00 H+0
ATOM 89 H 0 -1.374 -3.165 -1.737 0.00 0.00 H+0
ATOM 90 H 0 -2.050 -4.803 -1.567 0.00 0.00 H+0
ATOM 91 H 0 -2.972 -3.543 -2.423 0.00 0.00 H+0
ATOM 92 H 0 -2.464 -3.313 1.819 0.00 0.00 H+0
ATOM 93 H 0 -1.753 -4.668 0.910 0.00 0.00 H+0
ATOM 94 H 0 -1.077 -3.030 0.740 0.00 0.00 H+0
CONECT 1 2 0 0 0 NONE 99
CONECT 2 1 44 3 0 NONE 100
CONECT 3 2 4 0 0 NONE 101
CONECT 4 3 17 5 0 NONE 102
CONECT 5 4 6 10 0 NONE 103
CONECT 6 5 7 8 9 NONE 104
CONECT 7 6 45 46 47 NONE 105
CONECT 8 6 48 49 50 NONE 106
CONECT 9 6 51 52 53 NONE 107
CONECT 10 5 11 54 0 NONE 108
CONECT 11 10 12 16 0 NONE 109
CONECT 12 11 13 14 15 NONE 110
CONECT 13 12 55 56 57 NONE 111
CONECT 14 12 58 59 60 NONE 112
CONECT 15 12 61 62 63 NONE 113
CONECT 16 11 17 64 0 NONE 114
CONECT 17 16 4 18 0 NONE 115
CONECT 18 17 19 65 0 NONE 116
CONECT 19 18 20 0 0 NONE 117
CONECT 20 19 21 22 26 NONE 118
CONECT 22 20 23 66 67 NONE 119
CONECT 23 22 24 68 69 NONE 120
CONECT 24 23 25 70 71 NONE 121
CONECT 25 24 26 72 73 NONE 122
CONECT 26 20 27 25 28 NONE 123
CONECT 28 26 29 0 0 NONE 124
CONECT 29 28 30 74 0 NONE 125
CONECT 30 29 43 31 0 NONE 126
CONECT 31 30 32 75 0 NONE 127
CONECT 32 31 33 37 0 NONE 128
CONECT 33 32 34 35 36 NONE 129
CONECT 34 33 76 77 78 NONE 130
CONECT 35 33 79 80 81 NONE 131
CONECT 36 33 82 83 84 NONE 132
CONECT 37 32 38 85 0 NONE 133
CONECT 38 37 39 43 0 NONE 134
CONECT 39 38 40 41 42 NONE 135
CONECT 40 39 86 87 88 NONE 136
CONECT 41 39 89 90 91 NONE 137
CONECT 42 39 92 93 94 NONE 138
CONECT 43 38 30 44 0 NONE 139
CONECT 44 43 2 0 0 NONE 140
END NONE 141
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|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1

|-
| Other names
| Mn Salen Ligand
Jacobsen's Epoxidation Catalyst
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C36H52ClMnN2O2
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| Cl[Mn]123OC(C(C(C)(C)C)=CC(C(C)(C)C)=C5)=C5C=[N@]1[C@](CCCC6)([H])[C@@]6([H])[N@]2=CC(C=C(C(C)(C)C)C=C4C(C)(C)C)=C4O3
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 635.21208 gmol-1
|-
| Appearance
| Dark brown powder
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 138124-32-0
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| {{{Density}}} g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 330-332 oC 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| {{{Bp}}} K
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''a) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''b) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki>D] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| {{{Fp}}}°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant εr], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic data]]
| Phase behaviour Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | Except where noted otherwise, data are given for materials in their [[standard state|standard state (at 25 °C, 100 kPa)]] [[wikipedia:Chemical infobox|Infobox disclaimer and references]]
|-
|}

The Jacobsen's catalyst, which won the 1994 "Reagent of the Year", is an important catalyst widely used in the Jacobsen-Katsuki Epoxidation. This catalyst consists of a chiral salen ligand complexed with Manganese (III). It has the ability to convert cis-substituted olefins into chiral epoxides with high enantiomeric selectivity (usually with enantiomeric excesses of more than 90%, and sometimes even up to 98%!). It's also widely used in industry because only a few percent of the catalyst is needed, and common household bleach can be used as an oxidant. The Jacobsen catalyst could then be recycled and regenerated, so less chemical waste is produced.

==2D Structure of the Molecule==

The Jacobsen epoxidation catalyst is actually a molecule with the IUPAC name, N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine]manganese(III)]chloride 1 and has the following structure:

[[Image:Jacobsen_Catalyst.gif|500px]]

The first Salen catalyst introduced by Jacobsen was:

This then undergoes change to become the Jacobsen catalyst we all know and love today. It is a convenient tool and its now most widely used to synthesize the key side chain in the anti-tumour drug, Taxol.

The catalyst is produced in wide-scale quantities. It is quite simple to prepare this catalyst for a large-scale production. Its advantage is that only a few percent of the catalyst is used while using the common, low-cost everyday bleach. This produces less chemical waste, which is an important aspect in industry.

==The Jacobsen-Katsuki Epoxidation==

The reaction scheme for the Jacobsen-Katsuki epoxidation is as follows:

===Mechanism===
The mechanistic route for this reaction has two related but distinct aspects: the mode of oxygen transfer and the method of chiral induction. Since this is quite a new substance, neither aspect is fully understood.

====Mode of oxygen transfer====

The oxygen transfer occurs by a two-step catalytic cycle (see Figure 1). In the first step, the oxidant (in this case, bleach) transfers oxygen to the MnIII catalyst in such a way that the oxygen orientates itself in a site normal to the Salen ligand. The Mn is thus oxidised from a +3 oxidation state to a +5 oxidation state. The activated oxygen is then delivered to the alkene to form an epoxide. This cycle is supported by observations that several oxidants have been used with identical selectivity, as opposed to assisted transfer by a complex aggregate. This reaction consumes stoichiometric quantities of the oxidant during the process of converting an alkene to an epoxide. The related salen complex then shows incorporation of oxygen from in situ labelled water, so this does not occur by exchange with the oxidant or epoxide.

==References==

#T. Linker (Angew. Chem. Int. Ed., 1997, 36, 2060)
#Hanson, John. J. Chem. Educ. 2001 78 1266.
#http://www.organic-chemistry.org/namedreactions/jacobsen-katsuki-epoxidation.shtm
#http://www.ch.ic.ac.uk/ectoc/echet96/hyperwave/0000013f.html
#http://www.chemexper.com
#http://www.sigmaaldrich.com