Rh-Catalyzed Reactions of 3-Diazoindolin-2-imines: Synthesis of Pyridoindoles and Tetrahydrofuropyrroloindoles

Abstract

The rhodium-catalyzed reactions of 3-diazoindolin-2-imines with furans and dihydrofuran furnished 9H-pyrido[2,3-b]indoles and tetrahydrofuro[3',2':4,5]pyrrolo[2,3-b]indoles, respectively. A cascade reaction mechanism involving an α-imino rhodium carbene intermediate is proposed. The starting materials are readily available, and the procedure is facile and efficient.