Polyvinylpyridine-supported palladium nanoparticles: An efficient catalyst for Suzuki-Miyaura coupling reactions

Palladium nanoparticles (Pd NPs) synthesized by the metal vapor synthesis technique were supported on poly(4-vinylpyridine) 2% cross-linked with divinylbenzene (Pd/PVPy). Transmission electron microscopy revealed the presence of small metal nanoparticles (dm = 2.9 nm) highly dispersed on the PVPy. The Pd/PVPy system showed high catalytic efficiency in Suzuki-Miyaura carbon-carbon coupling reactions of both non-activated and deactivated aromatic iodides and bromides with aryl boronic acids, carried out under an air atmosphere. The high turnover of the catalyst and the ability of the PVPy resin to retain active Pd species are highlighted. By comparing the catalytic performances of Pd/PVPy with those observed by using commercially available Pd-based supported catalysts, the reported system showed higher selectivity and lower Pd leaching.