Synthesis Of MCM-41-supported Palladium And Rhodium Complexes And Their Applications In Organic Synthesis

Part 1:Diphosphino-functionalized MCM-41 anchored palladium(II) complex [MCM-41-2P-Pd(II)] was conveniently synthesized from commercially available and cheap 3-aminopropyltriethoxysilane via immobilization on MCM-41, followed by reacting with diphenylphosphinomethanol and palladium chloride. It was found that MCM-41-2P-Pd(II) can efficiently catalyze the formylation of aryl iodides and bromides using sodium formate as hydride source under an atmospheric pressure of carbon monoxide. The results show that the catalyst exhibited high activity and selectivity and can be recovered and recycled by a simple filtration of the reaction solution for many trials without any decrease in activity.Part 2 : MCM-41-supported tridentate nitrogen palladium(II) complex (MCM-41-3N-PdCl₂) was conveniently prepared from commercially available and cheap 3-(2-aminoethylamino)propyltrimethoxysilane via immobilization on MCM-41, followed by reacting with pyridine-2-carboxaldehyde and palladium chloride. Its catalytic performance in Suzuki coupling reaction of aryl bromides with arylboronic acids was studied. It was found that MCM-41-3N-PdCl₂ can efficiently catalyze the Suzuki coupling reactions of aryl bromides with arylboronic acids under air. The results show that the catalyst exhibited high activity and selectivity and can be recovered and recycled by a simple filtration of the reaction solution and used for at least 10 times without any decrease in activity.Part 3:Diphosphino-functionalized MCM-41 anchored rhodium (I) complex [MCM-41-2P-Rh(I)] was conveniently synthesized by the reaction of MCM-41-2P with Wilkinson catalyst RhCl(PPh₃)₃. Its catalytic performance in hydrophosphonylation of alkynes was studied. The results show that the catalytic activity of MCM-41-2P-Rh(I) is comparable to that RhCl(PPh₃)₃ and this rhodium catalyst can be recovered and reused many times without any decrease in activity.