Chelate-Assisted Oxidative Coupling Reaction of Arylamides and Unactivated Alkenes: Mechanistic Evidence for Vinyl C−H Bond Activation Promoted by an Electrophilic Ruthenium Hydride Catalyst

The cationic ruthenium hydride complex [(η6-C6H6)(PCy3)(CO)RuH]+BF4− was found to be a highly regioselective catalyst for the oxidative C−H coupling reaction of aryl-substituted amides and unactivated alkenes to give o-alkenylamide products. The kinetic and spectroscopic analyses support a mechanism involving a rapid vinyl C−H activation followed by a rate-limiting C−C bond formation step.