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

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.