Palladium catalyst immobilized on functionalized hyper-crosslinked polymers with 8-hydroxyquinoline as monomer for Suzuki-Miyaura coupling reactions

Abstract

Abstract An efficient and stable palladium species catalyst immobilized on functionalised hyper-crosslinked polymers (HCPs-Pd) has been successfully developed and applied in the Suzuki-Miyaura coupling reaction of diverse types of aromatic halides with aromatic boric acid in this work. The results demonstrated that HCPs-Pd exhibited high catalytic activity, which benefited from the microporous structure of the catalyst guaranteed high dispersibility of active palladium, and high specific surface area, large pore volume, good chemical stability. Under optimal reaction conditions, 93.0% of biphenyl yield in the Suzuki-Miyaura reaction with bromobenzene (C6H5Br) and phenylboric acid (C6H7BO2) as raw material was obtained. The good stability of the HCPs-Pd catalyst was verified by five cycles experiments. Perhaps this work provides new insights into the high-yield preparation of biphenyl aromatic compounds employing HCPs-Pd as an efficient and stable catalyst in the Suzuki-Miyaura reaction.