Synthesis of 2H-Azirines via Iodine-Mediated Oxidative Cyclization of Enamines

A facile and practical oxidative cyclization reaction of enamines to 2H-azirines has been developed, employing molecular iodine. The features of the present synthetic approach include no use of transition metals, mild reaction conditions, and simplicity of operation. Under the optimal reaction conditions, a variety of 2H-azirine derivatives were synthesized from simple and readily accessible enamine precursors in an efficient and scalable fashion.