Copper-catalyzed cascade C–N coupling/C–H amination: one pot synthesis of imidazo[1,2-b]indazole

Abstract

We report an efficient synthesis of imidazo[1,2-b]indazole starting from 2-(2H-indazol-2-yl)aniline with aryl/heteroaryl/aliphatic bromide. This novel transformation involves a one-pot Cu-catalyzed cascade process combining C–N coupling between 2-(2H-indazol-2-yl)aniline and aryl/heteroaryl/aliphatic bromide followed by intramolecular C–H amination to afford the desired compounds in good yields.