Catalytic Asymmetric α-Chlorination of 3-Acyloxazolidin-2-one with a Trinary Catalytic System
作者:Yoshitaka Hamashima、Tatsuya Nagi、Ryo Shimizu、Teruhisa Tsuchimoto、Mikiko Sodeoka
DOI:10.1002/ejoc.201100453
日期:2011.7
Direct asymmetric α-chlorination of aryl acetic acid derivatives was achieved with a novel trinary activation system consisting of a catalytic amount of NiCl2/(R)-BINAP, Et3SiOTf, and a tertiary amine base. The reaction smoothly afforded the chlorinated compound in good yield with up to 89 % ee. Application of this reaction to a less acidic crotonic acid derivative gave the β,γ-unsaturated α-chlorinated
使用由催化量的 NiCl2/(R)-BINAP、Et3SiOTf 和叔胺碱组成的新型三元活化系统实现了芳基乙酸衍生物的直接不对称 α-氯化。反应平稳地以良好的收率得到氯化化合物,ee 高达 89%。将该反应应用于酸性较低的巴豆酸衍生物,通过在 γ 位去质子化得到 β,γ-不饱和 α-氯化化合物。