Wang Jing, Wang Tingting, Du Hongguang, Chen Ning, Xu Jiaxi, Yang Zhanhui
Department of Organic Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
J Org Chem. 2023 Sep 1;88(17):12572-12584. doi: 10.1021/acs.joc.3c01294. Epub 2023 Aug 18.
An iridium-catalyzed and phenol-directed deoxygenation of benzylic alcohols comes as an alternative access to 4-alkylphenols, featuring low catalyst loading (/ up to 20,000, TOF up to 12,400 h), high functionality compatibility, and excellent site-selectivity. The applications in late-stage modification of steroids and gram-scale total synthesis of a extract are highlighted. Mechanistically, the intermediacy of quinone methide controls the site-selectivity, and the formation of iridium hydride serves as the rate-limiting step.
铱催化且苯酚导向的苄醇脱氧反应为制备4-烷基苯酚提供了一种替代方法，其特点是催化剂负载量低（高达1/20000）、官能团兼容性高以及位点选择性优异。文中重点介绍了该反应在甾体后期修饰和提取物克级全合成中的应用。从机理上讲，醌甲基化物中间体控制着位点选择性，而氢化铱的形成是限速步骤。
