Supported organometallic palladium catalyst into mesoporous channels of magnetic MCM-41 nanoparticles for phosphine-free C-C coupling reactions

Magnetic MCM-41 nanoparticles were synthesized via Fe3O4-doped into mesoporous channels of MCM-41 nanoparticles and further, a new organometallic complex of palladium was supported on its inner surface (Pd-imi@MCM-41/Fe3O4). This immobilized catalyst was applied as highly efficient, heterogeneous and magnetically recoverable nanocatalyst in the various C-C coupling reactions such as Suzuki-Miyaura and Mizoroki-Heck reactions under phosphine-free conditions at atmospheric pressure. This catalyst has advantages of both magnetic nanoparticles and mesoporous materials. The structure of prepared nanomaterial has been characterized by various techniques such as N-2 adsorption-desorption isotherms, TEM, SEM, EDS, WDX, FT-IR, XRD, TGA, ICP, AAS, and VSM. SEM images of this catalyst demonstrate that the particles size are less than 100 nm in diameter. VSM curve of the catalyst shows that this catalyst can be recovered using an external magnet; therefore, this catalyst can be reused for several times without significant loss of its catalytic efficiency or palladium leaching. Also, all products were obtained in high TON and TOF numbers, which reveals this catalyst has high activity and selectivity in described coupling reactions. Heterogeneity and stability of this nanocatalyst were confirmed by hot filtration test and AAS technique.