Palladium-Catalyzed Dual C(sp2)-H Functionalization of Indole-2-carboxamides Involving a 1,2-Acyl Migration: A Synthesis of Indolo[3,2- c]quinolinones.

A novel Pd/Cu catalytic system to construct indolo[3,2- c]quinolinones has been developed starting from indole-2-carboxamides. Substrates were transformed into indolo[3,2- c]quinolinones through dual C(sp2)-H functionalization of the indole moiety and arene, in which a carbonyl 1,2-migration was involved. The corresponding products were obtained in moderate to excellent yields with a wide substrate scope.