Synthesis Of A Novel Type Of Bifunctional Phase-Thransfer Catalysts Derived From Cinchona Alkaloid And Their Application In Asymmetric Catalysis Reactions

In this paper, eight novel phase-transfer catalysts (Id1-4d1,1d2-4d2) had been synthesized by using cinchona alkaloids as raw materials through several steps:Mistunobu reaction, Boc-protection, nucleophilic substitution and Boc-deprotection. The composition and structure was characterized and ascertained by1H NMR,13C NMR and IR.These chiral phase-transfer catalysts were derived from the first generation of cinchona alkaloids phase-transfer catalyst by transformation of hydroxyl group into amino group, and resulted in the better catalytic performance than that of the third generation of cinchona alkaloids phase-transfer catalyst. In the asymmetric alkylation of N-diphenylmethylene-glycine tert-butyl ester, the effects of solvent, temperature, categories and concentrations of base, the dosage of catalyst on catalytic performance had been investigated in detail. Under the optimum reaction conditions:2d2, ether as solvent, S/C=10, KOH aq (50%),-40℃,12h, the excellent catalytic performances (86-99%yield and87.3-95.6%ee) were found in the alkylation of N-diphenylmethylene-glycine tert-butyl ester with bromoalkane derivatives.