N-Heterocyclic Carbene/Palladium-Catalyzed Suzuki-Miyaura Cross-Coupling Reactions in Aqueous Medium

In this study, a series of ether-functionalized benzimidazolium salts as N-heterocyclic carbene (NHC) ligands were synthesized and their structures characterized by 1H NMR, 13C NMR, FT-IR, and elemental analysis techniques. The in situ formed [PdX2(NHC)2] complexes from the interaction of Pd(OAc)2 with NHC ligands were used as catalyst in the Suzuki-Miyaura cross-coupling reactions between phenylboronic acid and aryl chlorides under mild reaction conditions in aqueous media. In situ formed [PdX2(NHC)2] catalysts showed high catalytic activity for electron-donating, electron-drawing or sterically hindered aryl chlorides