Stereocomplementary asymmetric bioreduction of boron-containing ketones mediated by alcohol dehydrogenases
摘要:
Optically active boron-containing alcohols were prepared via the stereoselective reduction of the corresponding carbonyl compounds by alcohol dehydrogenases. Depending on the substrate, both (R)-alcohols and (S)-alcohols were obtained with excellent enantioselectivity (up to >99% ee) employing either ADH-A or LB-ADH. (C) 2011 Elsevier Ltd. All rights reserved.
Iridium-Catalyzed Enantioselective Allylic Substitution with Aqueous Solutions of Nucleophiles
作者:Tobias Sandmeier、F. Wieland Goetzke、Simon Krautwald、Erick M. Carreira
DOI:10.1021/jacs.9b05830
日期:2019.8.7
The iridium-catalyzed asymmetric allylic substitution under biphasic conditions is reported. This approach allows the use of various unstable and/or volatile nucleophiles including hydrazines, methyl-amine, t-butyl hydroperoxide, N-hydroxylamine, α-chloroacetaldehyde and glutaraldehyde. This transformation pro-vides rapid access to a broad range of products from simple starting materials in good yields
报道了双相条件下铱催化的不对称烯丙基取代。这种方法允许使用各种不稳定和/或挥发性亲核试剂,包括肼、甲胺、叔丁基过氧化氢、N-羟胺、α-氯乙醛和戊二醛。这种转变提供了从简单的起始材料以良好的产率和高达 > 99% ee 和 20:1 dr 快速获得广泛产品的途径。此外,这些产品可以有效地加工成多种环状和非环状化合物,最多可带有四个立体中心。
Formaldehyde <i>N</i>,<i>N</i>-Dialkylhydrazones as Neutral Formyl Anion Equivalents in Iridium-Catalyzed Asymmetric Allylic Substitution
作者:Simon Breitler、Erick M. Carreira
DOI:10.1021/jacs.5b01951
日期:2015.4.29
The use of formaldehydeN,N-dialkylhydrazones as neutral C1-nucleophiles in the iridium-catalyzed substitution of allylic carbonates is described for two processes. Kinetic resolution or, alternatively, stereospecific substitution affords configurationally stable α,α-disubstituted aldehyde hydrazones in high enantiomeric excess and yield. This umpolung approach allows for the construction of optically