Synthesis Of Chiral Mn(Salen) Axially Immobilized Onto Hydroxylated ZPS-IPPA By Phenoxyl Group And Catalytic Epoxidation Of Olefins On The Cayalyst

The heterogeneous asymmetric catalysis has received more and more attention in recent years.Among all the reactions,the heterogeneous asymmetric epoxidation is the most impressive.Linear styrene-isopropenyl phosphonic acid copolymer was newly synthesized by free radical reaction in solution with isopropenyl phosphonic acid and styrene.Ulteriorly,a new kind of catalyst support material,Zirconium poly (styrene-isopropenyl phosphonate)-phosphate,was synthesized.The benzene rings of ZPS-IPPA were hydroxylated or after chloromethylization,grafted with hydroquinone and resorcin respectively.Thus,three kind of functionalized ZPS-IPPA were synthesized as ZHPS-IPPA,ZPS-IPPA-qu,ZPS-IPPA-re,which reacted with homogeneous Mn(salen)catalyst to obtain four kinds of heterogeneous catalysts.TEM and SEM analysis show that ZPS-IPPA has special layer microstructure and channels,holes and cavums,which are all in nanometer scale.It can be concluded from TG curve that the heterogeneous catalysts have excellent thermal stability and are stable under 180℃.The effect of approach of functionalizing ZPS-IPPA and special microstructure on the asymmetry epoxidation of styrene,α-methylstyrene and indene is studied.It was found that increasing length of chain between ZPS-IPPA and active centre of Mn(salen)catalyst can keep the spacial structure of homogeneous Mn(salen) catalyst,obtaining excellent catalytic abilities.Especially,in epoxidation ofα-methylstyrene catalyzed by catalyst3 in NaClO-PPNO catalysis system,95.0%ee was obtained,showing the special microstructure of ZPS-IPPA has special inducing effect, leading to chiral inducing effect in epoxidation of unfunctionalized olefins.What is more,the effect has selectivity to substrate.Catalyst3,which has the best catalytical ability,was chosen to investigate the recycling ability in NaClO-PPNO catalysis system. The catalytical ability of heterogeneous catalyst didn't decrease apparently after eight recycles,obtaining above 55.0%ee,showing it has excellent stability.