Rh(II)-Catalyzed formation of pyrrolo[2,3-b]quinolines from azide-methylenecyclopropanes and isonitriles.

Azide-methylenecyclopropanes (azide-MCPs) underwent an intermolecular cyclization with isonitriles catalyzed by a Rh(II) complex to produce a series of pyrrolo[2,3-b]quinolines in moderate to good yields via carbodiimide intermediates. Moreover, synthetic applications of these products to construct structurally novel and useful heterocycles have also been achieved.