Pd-Catalyzed enantioselective synthesis of 2-methyl-3-methyleneindoline

A Pd-catalyzed enantioselective synthesis of 2-methyl-3-methyleneindoline in up to 89% yield and 84% ee from racemic vinyl benzoxazinanones has been developed with the help of (R,R)-BenzP* ligand. Mechanism studies support the formation of palladacyclobutane as the key intermediate via C2 attack to pi-allyl Pd complex. The beta-hydride elimination provides a new reaction pathway for the palladacyclobutane. (C) 2020 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

This method allows for the high-yielding and highly selective synthesis of 2-methyl-3-methyleneindoline using the (R,R)-BenzP* ligand and Pd catalysis. Mechanistic studies indicate the formation of palladacyclobutane as a key intermediate, with beta-hydride elimination providing a new reaction pathway.