Pd/PC-Phos-Catalyzed Enantioselective Intermolecular Denitrogenative Cyclization of Benzotriazoles with Allenes and N-Allenamides.

Reported herein is an asymmetric Pd/PC-Phos-catalyzed denitrogenative cyclization of benzotriazoles with allenes and N-allenamides, representing the first example of enantioselective denitrogenative cyclizations of benzotriazoles. A series of optically active 3-methyleneindolines were obtained in good yields with high ee values. The use of inexpensive and readily available starting materials, high regio- and enantioselectivity, a broad substrate scope, mild reaction conditions, no need for base, as well as versatile functionalization of the 3-methyleneindolines make this approach attractive.