Reusable functionalized polysiloxane-supported palladium catalyst for Suzuki–Miyaura cross-coupling

Palladium catalyst, obtained in the reaction of PdCl2(cod) with poly[(3-N-imidazolopropyl)methylsiloxane-co-dimethylsiloxane], was used in the Suzuki–Miyaura cross-coupling of aryl bromides with phenylboronic acid. Catalytic reactions, performed at 40–80 °C in water or 2-propanol/water mixture, led to high yields of 2-methylbiphenyl with TOF up to 25,000 h−1. In recycling experiments, excellent results were obtained in eight subsequent runs. With application of microwave heating, more than 95% of product was formed under mild conditions and short time. XRD, TEM, and XPS methods evidenced the presence of Pd(0) nanoparticles bonded to the polysiloxane support. Their important role in the catalytic process was indicated by the results of mercury poisoning test.