Pd @ PEG-PU polymer networks: A convenient catalyst for hydrogenation and Suzuki coupling reactions

Polyethyleneglycol-polyurethane (PEG-PU) polymer network films with sodium tetrachloropalladate were fabricated by solution casting technique. The incorporated palladium ions were reduced using sodium borohydride to obtain zero-valent (metallic) palladium in the films. These films were characterized by X-ray diffraction, Fourier transform-infra red spectroscopy, atomic absorption spectroscopy and X-ray photoelectron spectroscopy for their structure and chemical composition. The films containing palladium metal are found to be highly efficient toward hydrogenation of a number of unsaturated organic compounds and Suzuki coupling reactions of haloarenes. The novelty of this catalyst system is the incorporation of palladium in the polymer network that renders the catalyst system's reusability because there is no leaching of the metal from the polymer matrix and as the catalyst system is in the form of a compact film it can be easily separated from the reaction mixture and can be reused. (C) 2010 Elsevier B.V. All rights reserved.