Cobalt-Catalyzed Aerobic Aminocyclization of Unsaturated Amides for the Synthesis of Functionalized ?- and d-Lactams

We report the cobalt-catalyzed aminocyclization of unsaturated N-acyl sulfonamides in the presence of oxygen to provide ?- and d-lactam aldehydes. Use of an optically active cobalt catalyst resulted in the formation of enantiomerically enriched ?-and d-lactam alcohols. The ?-lactam aldehydes and alcohols obtained were elaborated into useful building blocks.