Catalytic α-Deracemization of Ketones Enabled by Photoredox Deprotonation and Enantioselective Protonation
作者:Chenhao Zhang、Anthony Z. Gao、Xin Nie、Chen-Xi Ye、Sergei I. Ivlev、Shuming Chen、Eric Meggers
DOI:10.1021/jacs.1c06637
日期:2021.8.25
deprotonation, followed by enantioselective protonation. The principle of microscopic reversibility, which has previously rendered this strategy elusive, is overcome by a photoredox deprotonation through single electron transfer and subsequent hydrogen atom transfer (HAT). Specifically, the irradiation of racemic pyridylketones in the presence of a single photocatalyst and a tertiary amine provides nonracemic
该研究报告了在单个反应中通过去质子化,然后对映选择性质子化,在 α 位带有立体中心的酮的催化去外消旋化。先前使该策略难以捉摸的微观可逆性原理被通过单电子转移和随后的氢原子转移 (HAT) 进行的光氧化还原去质子化所克服。具体而言,在单一光催化剂和叔胺存在下外消旋吡啶基酮的辐照可提供对映体过量高达 97% 的非外消旋羰基化合物。光催化剂收集可见光,诱导氧化还原过程,并负责不对称诱导,而胺作为单电子供体、HAT 试剂和质子源。