原子单分散的手性金原子簇及其催化不对称反应的立体选择性效应

目前金属催化剂催化不对称反应过程中，手性的中心主要来自于手性配体，手性溶剂, 手性反应剂或者生物酶等来诱导不对称反应，而金属本身是非手性的。Au28, Au38, Au102, Au130, Au133等一系列含有手性异构体的金原子簇的成功制备，说明金原子簇可以通过其原子的空间排列实现金属具有手性的特性。本项目我们将通过实验手段获得化学计量的高纯度的手性金原子簇, 深入研究左手性和右手性金原子簇的原子排列空间结构在催化不对称反应中对催化历程和产物的影响；研究簇中处于不同空间位置的金原子在活化和作用反应物分子，以及提供立体选择性中所起的作用；对比手性金属诱导的不对称反应和手性配体诱导的不对称反应的本质区别。这些研究将会解决目前催化反应中金属催化剂本身是非手性的问题，为不对称催化技术带来新的研究思路，丰富不对称合成方法和技术。

Currently, almost all metal catalysts are not intrinsically chiral, and the stereoselective catalysis can be often achieved when the reaction is carried out in a chiral environment, e.g., involving enzymes, chiral precursors, transition metal complexes with chiral ligands or chiral solvents. Successful determination of crystal structures of atomically precise gold nanoclusters has gained significant interest, especially intrinsic chirality of Au28, Au38, Au102, Au130, and Au133 was found. It suggests that chiral gold can be obtained via the atomic packing of gold atoms. Herein, we will gain the stoichiometric chiral Aun nanocluster via the separation of the enantiomers by HPLC, and investigate the stereoselective performance of left-hand isomer and right-hand isomer in the process of asymmetric catalytic reactions. We will explore the effect of chiral gold atoms on the different sites such as on the shell or in the core on the activating and reacting with reactant molecules, as well as on the stereoselective selectivity toward products. We will compare the intrinsic distinction between chiral Aun nanoclusters and chiral ligands which induce the asymmetric processes. The work will be crucial to make a breakthrough in the acquisition of chrial metal catalysts for asymmetric technology, and will provide some guidelines for asymmetric chemical reactions.