Supported Palladium Nanoparticles Catalyzed Ortho-Directed C–C Coupling Reaction via a Pd0/PdII/PdIV Catalytic Cycle

Catalyzed by supported palladium nanoparticles, an ortho-directed C–C coupling reaction between 2-phenylpyridines and aldehydes has been developed for the selective synthesis of aromatic ketones. The catalyst is recovered and used for five times with the conversion of 2-phenylpyridine holding above 44% after recycling five times. The XPS analysis of the catalyst before and after reaction suggested that the reaction might be performed via a Pd0/PdII/PdIV catalytic cycle that began with Pd0.