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.
Highly efficient and practical hydroboration of alkenes has been catalyzed by an inexpensive and air-stable cobalt(II) coordination polymer (CP) in the presence of KOtBu. Complete conversion of alkenes to alkylboronates were performed within just 5 min with low catalyst loading (0.025 mol %), achieving the record high turnover frequencies of up to 47 520 h–1. For a range of vinylarenes, unusual Markovnikov
在KO t Bu存在下,廉价且空气稳定的钴(II)配位聚合物(CP)催化了烯烃的高效,实用的硼氢化反应。在短短5分钟内以低催化剂负载量(0.025 mol%)将烯烃完全转化为烷基硼酸酯,实现了高达47 520 h –1的创纪录高周转率。对于一定范围的乙烯基芳烃,观察到了异常的马尔可夫尼科夫选择性。
Lipase-Catalyzed Highly Enantioselective Kinetic Resolution of Boron-Containing Chiral Alcohols
作者:Leandro H. Andrade、Thiago Barcellos
DOI:10.1021/ol901091f
日期:2009.7.16
to obtain optically pure boron compounds is described. The kinetic resolution of boron-containing chiral alcohols via enantioselective transesterification catalyzed by lipases was studied. Aromatic, allylic, and aliphatic secondary alcohols containing a boronate ester or boronic acid group were resolved by lipase from Candida antartica (CALB), and excellent E values (E > 200) and high enantiomeric excesses