Cobalt-Catalyzed, Imine-Directed Olefin Hydroarylation under Grignard-Free Conditions

Abstract

We report here that a cobalt catalyst generated from a cobalt(II) salt and a ligand using magnesium metal is capable of promoting hydroarylation reactions through chelation-assisted C−H activation. With the appropriate choice of the ligand and other reaction conditions, ketimine- or aldimine-directed branched selective hydroarylations of styrenes and ketimine-directed hydroarylations of vinylsilane have been achieved. The reported catalytic systems may serve as more convenient alternatives to previously developed catalytic systems employing Grignard reagents as reducing agents.