Highly efficient polymer-stabilized palladium heterogeneous catalyst: Synthesis, characterization and application for Suzuki-Miyaura and Mizoroki-Heck coupling reactions

A suitable approach to stabilize palladium nanoparticles (Pd NPs), with an average diameter of 3-4 nm, on magnetic polymer is described. A new magnetic polymer containing 4 '-(4-hydroxyphenyl)-2,2 ':6 ',2 ''-terpyridine (HPTPy) ligand was prepared by the polymerization of itaconic acid (ITC) as a monomer and trimethylolpropane triacrylate (TMPTA) as a cross-linker and fully characterized. Pd NPs embedded on the magnetic polymer were successfully applied in Suzuki-Miyaura and Mizoroki-Heck coupling reactions under low palladium loading conditions, and provided the corresponding products with excellent yields (up to 98%) and high catalytic activities (TOF up to 257 hr(-1)). Also, the catalyst can be easily separated and reused for at least consecutive five times with a small drop in catalytic activity.