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 H2 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.
Keywords: C−H amination; C−H functionalization; cross-dehydrogenative coupling; electrochemistry; oxidation.
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