多相手性催化是合成手性化合物的有效途径之一,开发高活性、高选择性的多相手性催化剂并应用于不对称催化反应是兼具基础科学和应用科学背景的重要研究方向.本文综述了近年来具有代表性的固体表面上、纳米孔道内以及手性乳液体系中的多相手性催化研究进展,着重对本实验室近年来在该领域中的探索研究进行了介绍,涉及的重要手性催化反应包括氢化、氢转移、氢甲酰化、环氧化、环氧化物水解动力学拆分、Aldol反应和Diels—Alder反应等.我们的研究表明,手性修饰纳米粒子催化剂上的手性氢化反应可以获得95%ee以上的手性选择性以及高达20000h1的TOF,手性氢甲酰化反应得到90%ee的手性选择性;在手性催化剂组装的乳液体系中,催化不对称Aldol反应获得高达99%ee的手性选择性,催化活性得到显著提升,乳液氢转移反应的TOF可达3×10^5h^-1;在纳米孔中多个手性环氧化反应的例子显示出孔道效应能够显著提高手性选择性,并发现在纳米反应器中的环氧化物水解动力学拆分反应显示出催化剂协同活化效应,使催化反应的活性大幅度提高.本文还讨论了表面、界面上以及孔道中的催化剂组装、孔道限阈以及多中心协同效应等因素对多相手性催化反应性能的影响.
Heterogeneous chiral catalysis is one of the potential strategies for the synthesis of chiral chemicals. To develop high efficient and selective heterogeneous ehiral catalysts is of both scientific interests and application potentials. In this review, we present the research progress of heterogeneous chiral catalysis on surfaces, in nanopores, and with emulsions and mainly focuses on the recent progresses on chiral hydrogenation, hydrogen transfer, hydroformylation, epoxidation, hydrolytic kinetics resolution, Aldol reaction, Diels-Alder reaction, enzyme catalytic reaction, etc. made in this laboratory. The chirally modified nanoeatalysts can catalyze hydrogenation of a-ketoester with 20 000 h 1 TOF and more than 95 % ee; up to 90 % ee can be obtained for the hy- droformylation on ehirally modified Rh nanocatalysts. Asymmetric Aldol reaction in chiral emulsion gives 99% ee and increased activity. Up to 3 × 10^5 h^- 1 TOF can be achieved for emulsion hydrogen transfer. The pore effects can remarkably improve the catalytic performance for a few chiral epoxidation reactions in nanopores. An obvious cooperative activation effect was found for the hydrolytic kinetics resolution of epoxides in nanoreactors, which results in the increased catalytic activity. Several crucial factors such as catalyst assembly, pore confine- ment, and cooperative activation effects, which may influence the catalytic performance, are discussed.