Efficient Synthesis of Phthalimides via Cobalt-Catalyzed C(sp(2))-H Carbonylation of Benzoyl Hydrazides with Carbon Monoxide

A cobalt-catalyzed C-H carbonylation of benzoyl hydrazides has been developed by using 2-(1-methylhydrazinyl)pyridine as the bidentate directing group. This transformation is mild, efficient, operationally simple, and highly functional-group-tolerant. The protocol has generated a broad range of phthalimide derivatives in good to excellent yields. The ligand moiety can be readily removed through hydrogenolysis.