Kinetic resolution of racemic halohydrins, precursors of optically active di- and trialkyl-substituted epoxides, with lipase from Pseudomonas sp.
摘要:
Asymmetric acetylation of racemic halohydrins with vinyl acetate catalyzed by lipase from Pseudomonas sp. afforded the optically active beta-halo alcohols 1 and acetates 2 in high enantiomeric excess (68 to > 98%). The enzymatic kinetic resolution was performed on the preparative scale and the halo alcohols 1 and acetates 2 led to the optically active epoxides 3 after base treatment. (C) 1997 Elsevier Science Ltd.
作者:Christopher A. Discolo、Eric E. Touney、Sergey V. Pronin
DOI:10.1021/jacs.9b10645
日期:2019.11.6
Asymmetric intramolecular hydrofunctionalization of tertiary allylic alcohols is described. This metal hydride-mediated catalytic radical-polar crossover reaction delivers corresponding epoxides in good to high enantioselectivity and constitutes the first example of asymmetric hydrogen atom transfer-initiated process. A series of modified cobalt salen complexes has proven optimal for achieving good