新型多孔共价有机框架的手性结构设计、构筑及催化性能

Due to their high stability, large surface area, diverse and tunable structure, covalent organic frameworks (COFs) provide as a new platform for chiral science. However, it still remains a big challenge to construct chiral functional COFs effectively. In this project, based on chiral phosphoric acids of Binol, Biphenol, Spirobindan and Taddol, enantiopure bidentate and multidentate organic monomers with different structures and condensation groups (e.g. aldehyde, amine, hydrazine, hydrazone and nitrile functionalities) will be designed and synthesized. Based on the principles of reticular chemistry, micro- and mesoporous COFs bearing chiral phosphoric acids will be constructed through dynamic covalent chemistry approaches (Schiff-base condensation and self-condensation of nitrile compound, etc.). Precise construction and efficient control of chiral spatial structures and functionalities of COFs will be realized, and new strategies and approaches for chiral COFs synthesis will be established. Chiral phosphoric acids that are immobilized in COFs will be utilized to promote a variety of important organic reactions, and their efficiency, selectivity and uniqueness will be extensively studied to develop new generation of heterogeneous asymmetric catalyst systems. By using molecular dynamic simulation and calculation, the principle of chiral induction, transmission, amplification and regulation within the confined spaces will be studied and the design concept of functional porous materials for enantioselective processes will be well established, which can greatly promote the development of chiral science.

共价有机框架(COFs)因具有稳定性高、比表面积大和结构类型丰富等特点，为发展手性科学提供了一个崭新的平台，如何实现手性功能COFs的精准构筑是目前亟待解决的问题。本项目以光学活性稳定的联苯酚、联萘酚、螺二氢茚和酒石酸类二醇等衍生的手性磷酸类催化剂为骨架, 设计合成结构和缩聚能力不同的双齿和多齿桥连有机单体(如醛、胺、肼、腙和氰基等)；基于网状化学的设计原则，利用单体之间的动态共价键反应（席夫碱缩合和氰基自聚等）制备含手性磷酸的微孔和介孔COFs, 实现对其手性结构的精准构筑和功能调控，建立手性COFs合成的新方法和新路线。研究负载手性磷酸的不对称催化活性、选择性和独特性，发展多相不对称反应催化新方法，制备高效稳定的固体手性催化剂；结合分子动力学模拟和计算研究限阈空间的手性诱导、传递、放大和调控的规律，发展手性功能多孔材料的设计理念，促进手性化学和材料的发展。

以具有优异不对称诱导功能的手性联萘、联苯和螺环等骨架为平台，设计构筑了系列结构稳定的多孔手性共价有机框架、金属-有机框架及二维分子材料；根据材料的孔道结构和功能特征，研究了它们的不对称催化、手性识别与分离及手性传感等性能，发展了制备手性晶态多孔材料的新方法和新策略，实现了分子水平上对材料结构和功能的有效调控，创建了基于晶态多孔材料的手性功能新体系，揭示了限域体系中不对称诱导的特点和规律。. 1. 发展了利用共价有机框架调节分子催化剂对映选择性的有效方法。将手性联萘分子催化剂组装进三维共价有机框架，框架化使羟基的布朗斯特酸性得到了显著增强，COF的空间位阻与孔道内的限域效应可在底物和骨架之间提供优先的次级相互作用，从而实现了对邻氨基苯甲酰胺与芳香醛的缩合反应的高对映选择性催化，而相应的均相小分子催化剂却无法诱导生成手性产物。2. 首次创建了基于共价有机框架的不对称光催化体系，基于三苯胺单体的三维共价有机框架与手性MacMillan催化剂整合后能有效催化醛的不对称α-烷基化反应，在可见光照射下催化得到目标产物的对映选择性高达94%，为共价有机框架在不对称光催化中的应用奠定了坚实的基础。3. 成功构筑了C-C键和C=C键连接的手性共价有机框架以及悬挂不同手性小分子催化剂的手性共价有机框架，创建了具有特色的手性诱导、物质传输和催化转化等功能手性新体系，促进了手性科学和技术的发展。. 在Nature., J. Am. Chem. Soc., Angew. Chem. Int. Ed和Chem等期刊发表 SCI 论文54篇，研究工作被Nature, J. Am. Chem. Soc.等选作研究亮点进行专题报道。