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以单(6-O-p-甲苯磺酰基)-β-环糊精为原料,通过亲核取代反应合成了5个未见文献报道的环状氨基醇修饰β-环糊精CD-1～CD-5,收率36%～68%,其结构经过1H NMR,13C NMR和ESI-MS进行表征确认.将这些β-环糊精衍生物CD-1～CD-5作为Na2MoO4的配体,应用于H2O2不对称氧化苯甲硫醚,研究结果显示,反应介质的pH值对该反应体系的对映选择性具有较大影响.较佳配体CD-4在pH 7.0,1 mol/L CH3COONa-HCl中,诱导Na2MoO4催化H2O2不对称氧化苯甲硫醚,ee值为21.25%.通过2D-1H ROESY NMR表征,表明制约CD-1～CD-5在诱导Na2MoO4催化H2O2不对称氧化苯甲硫醚反应中ee值提高的主要因素为CD-1～CD-5的分子内自包结行为,并且该自包结状态也从量子化学计算方面得到了证实.
Five novel cyclodextrin-modified β-cyclodextrin CD-1 ~ CD-1 complexes were synthesized by nucleophilic substitution using mono (6-Op-tosyl) 5, the yield was 36% ~ 68% .The structure was confirmed by 1H NMR, 13C NMR and ESI-MS.The CD-1 ~ CD-5 derivatives were used as ligands of Na2MoO4 H2O2 asymmetric oxidation of anisole, the results show that the pH of the reaction medium has a greater impact on the enantioselectivity of the reaction system.Preferred ligand CD-4 at pH 7.0,1 mol / L CH3COONa-HCl , Inducing asymmetric anisole oxidation of H2O2 catalyzed by Na2MoO4 with the ee value of 21.25%. The 2D-1H ROESY NMR characterization indicated that the reaction of CD-1 ~ CD-5 on the induction of H2O2 asymmetric oxidation of anisole by Na2MoO4 The main factor for the increase in ee is the intramolecular self-entangling behavior of CD-1 to CD-5, and the self-entrapment state is also confirmed from quantum chemical calculations.