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以离子液体[bm im]PF6为反应溶剂,乙酸乙烯酯为酰基供体,考察了脂肪酶Candida antarcticaB催化外消旋仲醇的动力学拆分。主要考察了有机碱和无机碱对拆分反应的影响,结果发现,在反应底物中加入三乙胺或吡啶,能够极大地提高脂肪酶的活性和对映选择性,当底物邻甲氧基-α-苯乙醇和1-(2-萘基)乙醇在拆分时加入吡啶后,脂肪酶的对映选择性是未加入有机碱时的5~8倍,分别从E=65提高到E=525和从E=209提高到E=1 059,因此,可高对映选择性地获得邻甲氧基-α-苯乙醇和1-(2-萘基)乙醇的手性单体。随着吡啶加入量的增加,脂肪酶的对映选择性有所下降,因此,有机碱的最佳加入量为0.01 mol,原因可能是在该加入量下,脂肪酶达到了最佳pH,即处于活性构象,从而具有较高的活性和对映选择性。
Taking ionic liquid [bm im] PF6 as reaction solvent and vinyl acetate as acyl donor, the kinetic resolution of racemic secondary alcohol catalyzed by Candida antarctica B was investigated. The effects of organic bases and inorganic bases on the resolution were investigated. It was found that the addition of triethylamine or pyridine to the reaction substrate can greatly increase the activity and enantioselectivity of the lipase. When the substrate is o-methoxy The enantioselectivity of lipase was 5-8 times higher than that without organic base when base-α-phenylethyl alcohol and 1- (2-naphthyl) ethanol were added into the pyridine during the resolution, respectively from E = 65 to E = 525 and from E = 209 to E = 1059, chiral monomers of o-methoxy- [alpha] -phenylethanol and 1- (2-naphthyl) ethanol can therefore be obtained with high enantioselectivity. With the increase of the amount of pyridine, the enantioselectivity of lipase decreased. Therefore, the best addition amount of organic base was 0.01 mol, probably because lipase reached the optimum pH at the added amount, that is, In the active conformation, which has a higher activity and enantioselectivity.