Synthesis of N-Fused Polycyclic Indoles via Ligand-Free Palladium-Catalyzed Annulation/Acyl Migration Reaction

An efficient synthesis of N-fused polycyclic indoles by a palladium-catalyzed annulation/acyl migration cascade reaction is described. The reaction is ligand-free, scalable, and provides access to a diverse range of useful indole scaffolds from readily available starting materials. Supporting mechanistic studies indicate that the reaction likely proceeds via an intramolecular α-arylation mechanism. The synthetic utility of this protocol is...