Synthesis Of Heterogeneous Mn(Ⅲ) Salen Catalysts Axially Immobilized Onto The Sulfomethylated ZSPP And Their Application For Asymmetric Epoxidation

Heterogeneous asymmetric catalysis has received considerable attention in the area of catalysis. The suitable supports for chiral ligand are the most important for heterogeneous asymmetric catalysis. Zirconium oligo-chloromethyl-polystyrenyl phosphonate-phosphate (ZSPP) is a new type of organic-inorganic hybrids material developed by our group. ZSPP particles have many caves, channels and pores with different shapes and sizes This kind of organic-inorganic hybrid materials has high thermal stability, acid and base stabilities, which can be used as a new kind of support material posessing advantages of organic-inorganic supports.We synthesised three sulphomethanated ZCMSPP supports used sodium sulfite , formaldehyde sodium bisulfite, Hydroxyethanesulphonic acid sodium, and sucessfully axially immobilized chiral Mn(III) salen complex onto the modified ZSPP. All the immobilized chiral salen Mn(III) catalysts were characterized by FT-IR, diffusion reflection UV-Vis, AAS, N₂ volumetric adsorption, SEM, TEM and TG. We supposed a possible model for catalysts. We have studied these catalysts' catalytic performace in asymmetric epoxidation of styrene,α-methylstyrene and indene respectively. The effect of factors such as amount of catalyts, co-catalyst, the reaction time, the reaction temperature and axial length on asymmetric epoxidation of styrene was investigated. These supported chiral catalysts showed a little lower chiral induction (ee 64-67%) and conversion (Con., 85%) for asymmetric epoxidation of styrene in presence of NMO as axial ligands with m-CPBA as oxidant. After 5th using , the catalytic performance has little descrease.