Schiff-base transition metal complexes fabricated on magnetic nanoparticles as efficient and reusable catalysts in Suzuki reaction

Schiff- bases are widely studied because of increasing recognition of their role in catalytic systems. On other hand, magnetic nanoparticles (MNPs) can be used as heterogeneous support in catalytic reactions due to their unique features such as easy and clean separation of catalysts1-3. A simple, efficient, and less expensive protocol for the phosphine-free C-C coupling reactions has been reported in the presence of Schiff-base complexs of Zr or Cu ions supported on Fe3O4 MNPs (M–Schiff‑base@MNPs). The structure of these catalysts has been characterized by various techniques such as SEM, EDS, WDX, FT-IR, XRD, TGA, AAS, and VSM. The SEM images of this catalyst demonstrate that the particles size is less than 50 nm in diameter. The Suzuki reaction was carried out in green solvent using phenylboronic acid reagent. The formation of carbon-carbon bond have been frequently employed in the synthesis of natural products, agrochemicals, pharmaceuticals, biologically active compounds and advanced materials. VSM curve of the catalysts show that these catalysts can be recovered using an external magnet; therefore, these catalysts can be reused for several times without significant loss of its catalytic efficiency or metals leaching. Also, all products were obtained in high TOF numbers, which reveals these catalysts have high activity in the case of C-C coupling reactions.

Keywords:

Zr , Cu Magnetic nanoparticles , Suzuki reaction , biphenyl , Schiff‑base