Mechanistically Guided Design of an Efficient and Enantioselective Aminocatalytic α-Chlorination of Aldehydes
作者:George Hutchinson、Carla Alamillo-Ferrer、Jordi Burés
DOI:10.1021/jacs.1c02997
日期:2021.5.12
The enantioselective aminocatalytic α-chlorination of aldehydes is a challenging reaction because of its tendency to proceed through neutral intermediates in unselective pathways. Herein we report the rational shift to a highly selective reaction pathway involving charged intermediates using hexafluoroisopropanol as solvent. This change in mechanism has enabled us to match and improve upon the yields
醛的对映选择性氨基催化 α-氯化是一个具有挑战性的反应,因为它倾向于在非选择性途径中通过中性中间体进行。在这里,我们报告了向高选择性反应途径的合理转变,该反应途径涉及使用六氟异丙醇作为溶剂的带电中间体。这种机制的变化使我们能够匹配和改进先前方法显示的产率和对映选择性,同时使用更便宜的氨基催化剂和氯化剂,催化剂用量减少 80-95%,温度方便,反应时间更短。