Silica-supported palladium complex: An efficient, highly selective and reusable organic–inorganic hybrid catalyst for the synthesis of E-stilbenes

Abstract

A novel, highly efficient and reusable palladium based catalyst has been synthesized by covalent grafting of diphenyldiketone–monothiosemicarbazone on silica gel followed by metallation with palladium chloride, and the resulting organic–inorganic hybrid material was found to be highly effective catalyst for Suzuki-Miyaura cross-coupling reaction of various aryl halides with alkenyl boronic acid to give stilbenes. The catalyst was characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray fluorescence (ED-XRF), BET surface area analysis, solid-state 13C CPMAS NMR spectroscopy, atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM) and elemental analysis. High turnover frequency, mild reaction conditions, high selectivity for E-stilbenes, and easy recovery and reusability of the catalyst renders the present protocol highly indispensable to address the industrial prerequisites and environmental concerns.