A chemo-enzymatic route to diastereoisomers of 2-methyl-1-phenyl-1,3-butanediol: the dual role of microorganisms
摘要:
Diastereoisomers (1S,2R,3S)-, (1R,2R,3S)-, (IR,2S,3S)- and (1S,2S,3S)-2-methyl-1-phenyl-1,3-butanediols were prepared by simple and convenient strategies using two different chemo-enzymatic approaches for the reduction of racemic 2-methyl-1-phenyl-1, 3-butanedione, both involving in situ racemization. The first method comprised a one-pot microbial reduction coupled with a chemical reduction, while in the second method, stepwise chemo-enzymatic reductions were performed. (c) 2006 Elsevier Ltd. All rights reserved.
Catalytic asymmetric synthesis of β-hydroxy ketones by palladium-catalyzed asymmetric 1,4-disilylation of α,β-unsaturated ketones
作者:Yonetatsu Matsumoto、Tamio Hayashi、Yoshihiko Ito
DOI:10.1016/s0040-4020(01)80758-4
日期:1994.1
1,4-Disilylation of β,β-unsaturatedketones with 1,1-dichloro-l-phenyl-2,2,2-trimethyldisilane proceeded in the presence of phosphine-palladium catalysts in benzene. High enantio-selectivity (up to 92%) was observed in the disilylation with dichloro[(R)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl]palladium(II) as a catalyst (0.5 mol %). The disilylation products, 1-(trimethyisilyloxy)-3-(dichlorophenylsilyl)propenes
Synthesis of Valuable Chiral Intermediates by Isolated Ketoreductases: Application in the Synthesis of α-Alkyl-β-hydroxy Ketones and 1,3-Diols
作者:Dimitris Kalaitzakis、J. David Rozzell、Ioulia Smonou、Spiros Kambourakis
DOI:10.1002/adsc.200606185
日期:2006.9
and in two examples both ketones were reduced to the 1,3-diol. By replacing the α-alkyl substituent with the OAc group, 1-keto-2,3-diols, as well as 1,2,3-triols were synthesized in high optical purities. These enzymatic reactions provide a simple, highly stereoselective and quantitative method for the synthesis of different diastereomers of valuable chiralsynthonsfrom non-chiral, easily accessible
Enantioselective Monoreduction of 2-Alkyl-1,3-diketones Mediated by Chiral Ruthenium Catalysts. Dynamic Kinetic Resolution
作者:Florence Eustache、Peter I. Dalko、Janine Cossy
DOI:10.1021/ol025527q
日期:2002.4.1
The reduction of 2-alkyl-1,3-diketones using (R,R)- or (S,S)-RuCl[N-(tosyl)-1,2-diphenylethylenediamine](p-cymene) in the presence of formic acid and triethylamine affords syn-2-alkyl-3-hydroxy ketones as the major products with high enantioselectivity. [reaction: see text]