Palladium catalyst based on polyvinylpyrrolidone-silica hybrid support was prepared and exhibited excellent activity and stability in copper, amine and phosphine-free Sonogashira-Hagihara and Suzuki-Miyaura cross-coupling reactions. The polymeric catalyst was applied efficiently in the coupling reactions of chloro (as well as iodo) and bromoarenes. Elemental analysis of Pd by inductively coupled plasma (ICP) and hot filtration test revealed low leaching of the metal into solution from the supported system. The catalyst could be reused many times in repeated cycles without significant decline in its activity.
Keywords
organic-inorganic hybrid support; polyvinylpyrrolidone-grafted silica; palladium nanoparticles; Sonogashira reaction; Suzuki reaction
