Catalytic asymmetric hydrogenation using a [2.2]paracyclophane based chiral 1,2,3-triazol-5-ylidene–Pd complex under ambient conditions and 1 atmosphere of H<sub>2</sub>
Chiral 1,2,3-triazol-5-ylidene–Pd complexes with the planar chiral [2.2]paracyclophane wing tip group have been synthesized and structurally characterized. The complex with a labile acetonitrile co-ligand is an excellent catalyst for chemoselective hydrogenation of alkynes and alkenes and enantioselective hydrogenation of prochiral alkenes at ambient conditions and 1.0 atmosphere of H2.
Axially Asymmetric Phosphorus Compound and Production Method Thereof
申请人:Tanaka Ken
公开号:US20090227805A1
公开(公告)日:2009-09-10
Problem to be Solved: To provide an axially asymmetric optically active biarylphosphorus compound that can easily produced without the step of optical resolution which was almost indispensable in conventional methods.
Solution: A method for producing an axially asymmetric phosphorus compound represented by the general formula (1), comprising a cycloaddition reaction of a compound having a triple bond with the use of a catalyst containing rhodium metal and an optically active bisphosphine.
(In the formula, J is an oxygen atom, a sulfur atom or BH
3
; R
1
and R
2
independently are an alkyl, cycloalkyl, aryl, alkoxy and aryloxy group; a1 and a2 independently are 0 or 1; R
3
to R
10
independently are an alkyl, cycloalkyl, aryl, alkoxy and aryloxy group; two among R
3
to R
10
may form a ring;
and * is axial asymmetry.)
Inverted Supercritical Carbon Dioxide/Aqueous Biphasic Media for Rhodium-Catalyzed Hydrogenation Reactions
作者:Katja Burgemeister、Giancarlo Franciò、Volker H. Gego、Lasse Greiner、Herbert Hugl、Walter Leitner
DOI:10.1002/chem.200601717
日期:2007.3.26
supercritical carbon dioxide (scCO(2))/aqueousbiphasic system has been used as reaction media for Rh-catalysed hydrogenation of polar substrates. Chiral and achiral CO(2)-philic catalysts were efficiently immobilised in scCO(2) as the stationary phase, while the polar substrates and products were contained in water as the mobile phase. Notably, product separation and catalyst recycling were conducted without
Supramolecular chiral dendritic monophosphites assembled by hydrogen bonding and their use in the Rh-catalyzed asymmetric hydrogenation
作者:Yong Li、Yan-Mei He、Zhi-Wei Li、Feng Zhang、Qing-Hua Fan
DOI:10.1039/b823047a
日期:——
A new type of supramolecular chiral dendritic monophosphite ligands has been prepared via a hydrogen-bonding assembly. The Rh complexes of these supramolecular ligands have been successfully applied in the asymmetric hydrogenation of enamides and dehydroamino acid derivatives with good enantioselectivities, which are comparable to those obtained from the free monophosphite ligands. The supramolecular catalyst could be easily recycled viasolvent precipitation.
Heterogeneous catalytic hydrogenation of olefinic substrates by poly-NAP
作者:Rob ter Halle、Emmanuelle Schulz、Michel Spagnol、Marc Lemaire
DOI:10.1016/s0040-4039(00)00377-4
日期:2000.4
With our previously described poly-NAP, various olefinic substrates were reduced with selectivities comparable to those obtained by BINAP. For substrates which contained a methyl ester, the selectivities were higher than those observed for their carboxylic acid analogues.