Regioselectivity on the Palladium-Catalyzed Intramolecular Cyclization of Indole Derivatives

Abstract
Indole 2-carboxamide derivatives 4 underwent palladium-catalyzed intramolecular cyclization reactions to afford beta-carbolinones or pyrazino[1,2-a]indoles according to different reaction pathways. The complete regioselectivity of the reactions was obtained in different reaction conditions.