Catalytic Enantioselective Methylene C(sp<sup>3</sup>)–H Hydroxylation Using a Chiral Manganese Complex/Carboxylic Acid System
作者:Qiangsheng Sun、Wei Sun
DOI:10.1021/acs.orglett.0c03585
日期:2020.12.18
direct C–H hydroxylation in a highly diastereo- and enantioselective manner is still a challenging goal. This reaction is mainly hindered by the potential for overoxidation of the generated alcohols as well as low stereoselectivity. Herein, we present an enantioselective benzylic C–H hydroxylation catalyzed by a manganese complex, H2O2, and a carboxylic acid in 2,2,2-trifluoroethanol. The benzylic alcohols
实现高度非对映和对映选择性的直接C–H羟基化仍然是一个挑战性的目标。该反应主要受到所产生的醇的过度氧化的可能性以及低的立体选择性的阻碍。在本文中,我们介绍了在2,2,2-三氟乙醇中由锰配合物H 2 O 2和羧酸催化的对映选择性苄基C–H羟基化反应。苯甲醇具有出色的非对映选择性(高达> 95:5)和对映选择性(高达95%ee)。作为这项工作的重点,可以通过调整羧酸添加剂的量来实现C–H羟基化的非对映选择性。