新型单原子钯催化剂的制备及在sp2 C-H活化反应中的应用

Single atom catalysis has become one of the frontiers in the field of catalytic research because of its catalytic performance and both homogeneous and heterogeneous catalytic properties. The inert bond activation conversion of small molecules, such as methane and carbon dioxide, shows excellent catalytic performance. It is expected to be applied to the construction of C-heterogeneity bonds of aromatics activated by hydrocarbon, and become a new strategy for the efficient catalytic conversion of aromatics. However, there has not been any relevant report. This project is intended to focus on the activation of Csp2 at the aromatic site. The design of graphene supported monoatomic palladium catalyst was carried out, focusing on the scientific problem of "the interaction between the local atoms at the surface of the monatomic catalyst and the high efficiency oriented Csp2 activation region". Study on preparation and highly selective hydrocarbon bond activation and catalytic mechanism. 1. Taking the precise design and construction of catalyst as the key control point, the method of preparing monoatomic palladium catalyst with uniform loading, large load and controllable distribution was discussed. 2. The mechanism and regulation of substrate molecules acting on the surface of monoatomic palladium catalyst were studied. 3. The bond formation rule is used to guide the efficient preparation of purine compounds with high biological activity, and to provide a new efficient catalytic strategy for the directional synthesis of new purine compounds based on C-H bond activation.

单原子催化因其催化的高效性及兼具均相和非均相催化特性而成为催化研究领域的前沿方向之一，在甲烷、二氧化碳等小分子的惰性键活化转化中表现出优越的催化性能，有望拓展应用于芳烃碳氢活化、C-杂键的构建，成为芳烃高效催化转化的新策略，而目前尚未有文献报导。本项目拟以芳烃Csp2活化为重点，围绕“单原子催化剂表界面局域原子与高效定向Csp2活化区域之间的作用规律”这一科学问题，深入开展石墨烯负载单原子钯催化剂的设计、制备与高选择性碳氢键活化及催化机理研究：1.以催化剂的精准设计与构建为关键控制点，探讨光化学制备负载均匀、载量较大和分布可控的单原子钯催化剂的方法；2.以苯基间位碳氢高选择性活化为研究对象，开展底物分子在单原子钯催化剂表面作用机制和调控规律的研究；3. 将形成的成键规律用于指导具有高生物活性的嘌呤类化合物的高效制备，为基于C-H键活化的定向合成新型嘌呤类化合物提供新型高效催化方法。

底物适用性广，催化活性高，结构稳定的单原子金属催化剂是高效非均相催化反应的关键。本课题针对嘌呤衍生物合成过程中存在成键反应难以实现和活化位点难以控制等问题，以芳香环上C(sp2)-H活化反应为研究对象，开展了系列均相催化有机反应，研究各种因素，如温度、溶剂、反应时间和添加剂对偶联反应活性及选择性的影响，将其应用于具有生物活性含氮杂环的高效合成及修饰，探讨了相关机理和成键规律，以寻求高选择性C(sp2)-H活化转化为其他碳杂键的最佳催化体系。针对单原子催化剂在非均相反应中存在催化活性低、稳定性差、易发生团聚和回收难等问题，开展了非均相催化反应结合计算化学研究了相关催化剂的回收和循环问题。为更好的研究催化剂固体表界面特性与环境和外场的相互作用机制等问题，设计以光条件下催化剂固体表界面特性为研究对象，开展了系列测试及表征，研究催化剂与底物的配位及构效关系。结合上述实验规律及结论，设计了系列单原子钯催化剂并将其应用于催化合成中。