Stereochemical Control in Microbial Reduction. XXVIII. Asymmetric Reduction of<i>α</i>,<i>β</i>-Unsaturated Ketones with Bakers’ Yeast
作者:Yasushi Kawai、Kentarou Saitou、Kouichi Hida、Duc Hai Dao、Atsuyoshi Ohno
DOI:10.1246/bcsj.69.2633
日期:1996.9
Bakers’ yeastreduction of α,β-unsaturated ketones affords optically active saturated ketones contaminated by allylic and saturated alcohols as minor components. Stereoselectivity of the reduction of carbon–carbon double bond strongly depends on the structure of β-aryl substituent. The bakers’ yeastreduction of β-phenyl enones gives saturated ketones in moderate stereoselectivity. Stereoselectivity
Primary allylic amines with enantiomeric excesses from 97 to >99% were prepared by asymmetric transfer hydrogenation of α,β-unsaturated N-(tert-butylsulfinyl)ketimines followed by removal of the sulfinyl group. The effect caused by different substituents at the C═C bond and at the iminic carbon atom on the chemoselectivity of the reduction was studied. The desired enantiomer of the final allylic amine
Extractive biocatalysis in the asymmetric reduction of α-alkyl, β-aryl enones by Baker’s yeast
作者:Rafaela M. Silva、Laura T. Okano、J. Augusto R. Rodrigues、Giuliano C. Clososki
DOI:10.1016/j.tetasy.2017.05.009
日期:2017.7
We prepared various chiral alpha-alkyl, beta-aryl ketones with good to excellent enantiomeric excess through the Baker's yeast asymmetric double-bond reduction of the corresponding alpha,beta-unsaturated substrates adsorbed onto the resin Amberlite XAD-7. This methodology was compatible with substrates bearing both electron-donating and withdrawing groups attached to the aromatic ring. Elongation of the alpha-alkyl substituent of the starting material strongly affected the reactivity and enantioselectivity of the reaction. (C) 2017 Elsevier Ltd. All rights reserved.