Palladium-Schiff Base Complex Immobilized Covalently on Magnetic Nanoparticles as an Efficient and Recyclable Catalyst for Heck and Suzuki Cross-Coupling Reactions

Abstract

A new palladium-Schiff base complex immobilized covalently on magnetic nanoparticles (Pd-imino-Py-γ-Fe₂O₃) was synthesized via the reaction of chloro-functionalized γ-Fe₂O₃ with iminopyridine followed by the reaction with palladium acetate. Characterization of Pd-imino-Py-γ-Fe₂O₃ was carried out by various techniques such as XRD, SEM, TEM, FT-IR, TGA, ICP, XPS, VSM and elemental analysis. Pd-imino-Py-γ-Fe₂O₃ was successfully applied as a magnetically recyclable heterogeneous catalyst in Heck and Suzuki cross-coupling reactions of various aryl halides (iodide, bromides and chlorides as challenging substrates) with olefins and phenylboronic acid, respectively. The synthesized catalyst was separated easily by using an external magnet and recycled eight runs without appreciable loss of its catalytic activity and leaching of the significant quantity of Pd.