Photo‐ and Rh‐Promoted Cross‐Coupling Reactions of α‐Hydroxy Aryl Ketones via Cleavage of Carbon–Carbon σ‐Bonds

ABSTRACT The cross‐coupling reaction of α‐hydroxy aryl ketones with aryl bromides to give biaryls via cleavage of C─C σ‐bonds was achieved utilizing a Rh catalyst under photoirradiation conditions. The reaction is initiated by the photoinduced Norrish type I reaction of aryl ketones to generate aroyl radicals, which are captured by the Rh catalyst to be decarbonylated and coupled with aryl radicals generated from aryl bromides. The reaction was further applied to an arylative ring‐opening reaction of 1,4‐epoxy‐1,4‐dihydronaphthalene derivatives. This work demonstrates new synthetic utility of aryl ketones as aryl sources in cross coupling reactions.