不对称催化合成手性泛解酸内酯的研究进展

泛解酸内酯是合成D-泛酸钙和D-泛醇的重要中间体，国内主要采用生物拆分法，虽取得一定进展，但存在底物浓度偏低、反应条件苛刻、光学纯度不高和催化剂活性不强等问题。化学不对称合成法成为近年来制备手性泛内酯的研究热点。根据手性源的不同，介绍过渡金属配合物催化不对称还原酮基泛内酯，过渡金属配合物催化羟醛缩合反应,有机小分子及其衍生物不对称催化羟醛缩合反应并经还原内酯化合成泛内酯以及光学活性化合物作为反应底物或非手性底物中加入手性助剂的合成手性泛内酯工艺。其中，有机小分子催化乙醛酸酯与醛的反应表现出良好的催化效果，且催化剂易得，反应条件温和，操作简单。缩合产物的收率和对映选择性均不高，设计具有高活性和高选择性的有机小分子手性催化剂是今后研究的重点。

Progress in the asymmetric synthesis of chiral pantolactone

Pantolactone is an important intermediate for synthesis of D-calcium pantothenate and D-panthenol.Biological separation is the main synthetic method of chiral pantolactone in China,but it still has the following problems：relatively low substrate concentration,harsh reaction conditions,low optical purity and weak catalytic activity.Therefore,chemical asymmetric synthesis of chiral pantolactone become a hotspot in recent years.Using different chiral centres,the synthesis processes of pantolactone were introduced by asymmetric hydrogenation of ketopantolactone using transition metal complexes as the catalysts,asymmetric aldol reaction using transition metal complexes and small organic molecules as well as their derivatives as the catalysts,and optical activity of reactants and chiral induction by adding small amount of chiral additive to the achiral reagent.Small organic molecules exhibited high catalytic activity in the reaction of aldehydes and glyoxylate,which had the advantages of easily obtained catalysts,mild reaction conditions and simple operation.But the yield of and enantioselectivity to the condensation products were low.Development of chiral catalysts with high activity and high selectivity are the research focus in future.