Synthesis Of Chiral Polymers With Side Groups Of Binaphthol And The Primary Application In Asymmetric Catalysis

Asymmetric optically active structures characteristic of natural chiral macromolecules play a key role in maintaining both metabolism and evolution of normal life.Compared with small molecule catalysts,chiral polymers have the advantages of separating,purifying and recycling easily.Inspired by these advantages,scientists have paid special attention to the design and construction of new optically active polymers,and studied their unique physical and chemical properties and functions,and made significant progress.Many excellent results have been obtained in the field of asymmetric catalysis and polymers based on binaphthyl.At present,there are few reports on the epoxy and alkyne-derived binaphthyl polymers in the field of asymmetric catalysis.The specific action details of this paper is as follows:?1?Using?S?-BINOL as raw material,the phenolic hydroxyl group is protected by chloromethyl methyl ether?MOM?.Then,the hydrogen is exchanged by lithium in the presence of n-butyllithium,and by formylated to obtain ?S?-1. ?S,S?-3-?2,3-epoxypropoxy?methyl-2,2'-bis?methoxymethoxy?-1,1'-binaphthol ??S?-2? was obtained by reduction of ?S?-1 with sodium borohydride.?S?-2 is further reacted with ?S?-epichlorohydrin to give an epoxy monomer ?S?-3.Finally,the epoxy monomer ?S?-3 was polymerized by anion ?using KOH as initiator?,and the chiral polyether poly-1 was obtained by deprotection with concentrated hydrochloric acid.The chiral polyether Poly-1 was obtained by deprotection with concentrated hydrochloric acid and then characterized Poly-1.?2?Three chiral binaphthol-derived alkyne monomers binaphthol-derived alkyne monomers was designed and synthesized,?S?-6–ethynyl-2,2'–hydroxyl-1,1'-binaphthyl ??S?-7?),?S?-6-??N-ethynyl?amine?-2,2'-dimethoxymethoxy-1,1'-binaphthyl ??S?-9? and ?S?-3-??acetylene?Oxy?methyl)-2,2'-dihydroxy-1,1'-binaphthyl ??S?-11?.Under the co-catalysis of Et3N/[Rh?nbd?Cl]2,the monomers were coordination polymerizated to obtain the corresponding polymers Poly-2,Poly-3 and Poly-4.The newly synthesized polymer was characterized by NMR spectrum,a polarimeter,GPC.?3?We used newly synthesized chiral polymers poly[?S,S?-3-?2,3-epoxypropoxy?methyl-2,2'-bis?methoxymethoxy?-1,1'-binaphthyl] ?Poly-1?,poly[?S?-6-ethynyl-2,2'-hydroxy-1,1'-binaphthyl] ?Poly-2?and poly[?S?-3-??ethynyloxy?methyl?-2,2'-dihydroxy-1,1'-binaphthyl] ?Poly-4? as chiral ligands to chelate with ZnEt₂ to form a chiral self-supporting catalyst,and then use the obtained catalyst to inducte asymmetric epoxidation of?,?-unsaturated ketones.The experimental results show that Poly-1 has the best chiral induction effect in this reaction.Moreover,The target products of high yield and good enantioselectivity?ee value up to 99%?can be obtained under mild conditions.And the substrate of the reaction is universal.We also studied the recycling and reuse of ligands.It was found that the catalyst did not significantly reduce its chiral induction and catalytic activity after repeated use.?4?We tried the template reaction with two synthesized newly chiral polyacetylenes ?Poly-2 and Poly-4?:Asymmetric addition reaction of Et3Al to p-Methoxybenzaldehyde.By the chiral induction of the reaction with Poly-2 can gave an addition product having an ee value of 65%,and Poly-4 can obtained an addition product having an ee value of 75%.