Aerobic Intramolecular Oxidative Amination of Alkenes Catalyzed by NHC-Coordinated Palladium Complexes

Palladium(II) complexes bearing a single N-heterocyclic carbene ligand serve as effective catalysts for the aerobic oxidative cyclization of alkenes with pendant sulfonamides. The use of carboxylic acid cocatalysts (AcOH and PhCO2H) often leads to significant improvements in catalyst stability and product yield and enables catalytic turnover to be achieved with air, rather than pure oxygen gas, as the source of O2.