Discovery and Enantioselective Synthesis of Tetra-Substituted Methylene Oxindole Atropisomers by Palladium-Catalyzed Domino Cyclization

Abstract

The discovery of atropisomers with unique skeletal structures is important for the development of chiral catalysts, ligands, drugs, and materials. Herein, we report the development of palladium-catalyzed enantioselective domino cyclization chemistry for generating tetra-substituted methylene oxindole atropisomers. A set of rarely reported oxindole–indole atropisomers was synthesized in high yields, with ( Z )-stereoselectivities and good enantioselectivities under mild reaction conditions. Importantly, the formed oxindole–indole atropisomer motif could be transferred between Z - and E -alkenes that interconverts four different isomeric states in a fixed sequence upon light irradiation.