Construction of Pd Complex Immobilized on Magnetic Nanoparticles as an Efficient Nanocatalyst for Preparation of Diaryl Ketones

A novel and efficient nanomagnetic palladium catalyst [Fe₃O₄@SiO₂-Schiff base-Pd(0)] has been fabricated by attaching of a Pd (0) complex to magnetic nanoparticles through cheap, simple, and readily available chemicals. The as-fabricated Fe₃O₄@SiO₂-Schiff base-Pd(0) nanomaterial was fully characterized by a number of spectroscopic techniques including FT-IR, SEM, TEM, EDX, XRD, VSM, TGA, elemental mapping and ICP-OES. The catalytic activity of the Fe₃O₄@SiO₂-dipyridine-Pd nanocatalyst was investigated in the formation of C=O bonds through Suzuki coupling carbonylative reactions (the Suzuki cross-coupling of N–Ac amides by N−C cleavage). Under this method, aromatic benzamides and boronic acids with both electron-donating and electron-withdrawing substituents exhibit high reactivity and generate the corresponding diaryl ketones with high yields. The high efficiency and the ability to be recovered and reused for at least up to 8 consecutive runs are superior properties of the Fe₃O₄@SiO₂-Schiff base-Pd(0) catalyst.