Easy synthesis of imidazo[1,5-a]indol-3-ones through Rh(iii)-catalyzed C–H allenylation/annulation

Abstract

A highly efficient and regioselective synthesis of imidazo[1,5-a]indol-3-ones has been developed via a sequential C–H allenylation/annulation starting from easily available N-methoxycarbamoyl indoles and propargyl alcohols, in which the propargyl alcohols served as a C1 synthon. This strategy displays excellent regioselectivity, high atom economy and tolerates a broad substrate scope.