手性β-氨基醇催化α,β-不饱和酮的不对称环氧化反应

将以烯烃为原料通过Sharpless不对称双羟化等多步反应合成的8种手性β-氨基醇, 作为有机小分子催化剂, 用于催化α,β-不饱和酮的不对称环氧化反应．考察了影响对映选择性的催化剂结构、催化剂用量、氧化剂种类、溶剂、反应温度等因素．结果表明, 当催化剂用量为30 mol%、氧化剂为TBHP(叔丁基过氧化氢)、正己烷溶剂、在室温下、以(1S,2R)-(＋)-1,2-二苯基-2-甲氨基乙醇(3)作催化剂时, 所得环氧化物的对映体过量最高为70% ee, 产率最高为84%.

Asymmetric Epoxidation of α,β-Enones Catalyzed by Chiral β-Aminoalcohols

Starting from correspongding olefins, eight chiral β-aminoalcohols were synthesized by Sharpless asymmetric dihydroxylation and applied in the organocatalytic asymmetric epoxidation of α,β-enones. The effects of the amount of catalysts, the structure of catalysts, oxidant, solvent and reaction temperature on enantioselectivity were also studied. When the amount of catalyst was 30 mol% relative to α,β-enones, tert-butyl hydroperoxide (TBHP) as oxidant, hexane as a solvent at room temperature, (1S,2R)-1,2-diphenyl- 2-(N-methyl)aminoethanol (3) has been successfully applied as catalyst in asymmetric epoxidation of α,β-enones with the yield up to 84% and enantiomeric excesses up to 70%.