Site‐Selective Electrochemical Benzylic C−H Amination

作者：Zhong‐Wei Hou, Dingjin Liu, Peng Xiong, Xiao‐Li Lai, Jinshuai Song, Hai‐Chao Xu · 发表于：Angewandte Chemie · 年份：2020 · DOI：10.1002/ange.202013478 · 被引用次数：54 · 研究领域：Radical Photochemical Reactions、Catalytic C–H Functionalization Methods、Sulfur-Based Synthesis Techniques

Abstract C−H/N‐H cross‐coupling is an ideal strategy to synthesize various amines but remains challenging owing to the requirement for sacrificial chemical oxidants and the difficulty in controlling the regio‐ and chemo‐selectivity. Herein we report a site‐selective electrochemical amination reaction that can convert benzylic C−H bonds into C‐N linkages via H 2 evolution without need for external oxidants or metal catalysts. The synthetic strategy involves anodic cleavage of benzylic C−H to form a carbocation intermediate, which is then trapped with an amine nucleophile leading to C−N bond formation. Key to the success is to include HFIP as a co‐solvent to modulate the oxidation potentials of the alkylbenzene substrate and the aminated product to avoid overoxidation of the latter.