Ligand-free Pd-catalyzed double Heck reaction of N-(o-bromoaryl)acrylamides with α-F/CF3-acrylates.

Abstract

Herein, we have demonstrated an operationally simple Pd-catalyzed double-Heck reaction between N-(o-bromoaryl)acrylamide derivatives and α-fluoro/trifluoromethyl acrylates to enable monofluoro/trifluoromethyl alkene tethered 3,3-disubstituted oxindoles in a stereoselective manner. Remarkably, the reaction proceeds well without any external ligand in an open-air atmosphere. Control experiments and spectroscopic analysis are performed to understand the reaction mechanism.