基于可见光诱导单电子转移的钌催化σ活化及芳烃间位多样化修饰

Ruthenium-catalyzed σ-activation has been recognized as a distinctive strategy to the challenging meta-selective diversification of arenes. However, the reaction conditions are relatively harsh. To solve the problem, the applicant proposed a new ruthenium-catalyzed σ-activation strategy by introducing photo-induced single-electron transfer into the reaction system. Pilot study demonstrated that the white light irradiation could promote ruthenium-catalyzed meta-alkylation of 2-phenylpyridine, suggesting the feasibility of the presumption. Contributing factors will be systematicly investigated to establish the highly efficient reaction system. To overcome the bottleneck of the reaction process, the influence of additives on ortho-C(sp2)-H activation as well as the influence of directing groups and ligands on C-Ru intermediate’s stability will be studied in detail. Then, the applicability of the reaction system in the modification of functional group substituted arenes, chiral molecules, and hetero/fused arenes will be investigated. Moreover, new cross-system strategy will be investigated to achieve the regio-controllable modification of arenes on multiple sites. By merging visible light-catalysis and ruthenium-catalyzed σ-activation, this project will provide a promising strategy to achieve the meta-selective C(sp2)-H functionalization with broad scope, arming the precise modification of arenes with more sustainable synthetic methodologies.

钌催化的σ活化为芳烃多样化修饰中的间位选择性难题提供了颇具特色的解决方案，但是反应条件较为苛刻。对此，申请人提出引入可见光诱导的单电子转移过程，构建新型的钌催化σ活化体系。预实验显示白光能够促进钌催化的2-苯基吡啶间位烷基化，初步证实了上述构想的可行性。本项目将系统性考察反应体系各组成要素的影响，针对影响反应进程的瓶颈问题，重点考察添加剂对邻位C(sp2)-H活化的影响以及导向基团和配体对C-Ru中间体稳定性的影响，根据实验结果分析总结规律，实现反应体系的优化。在该策略的应用性研究中，将考察反应体系对官能团、手性反应物以及杂、稠环的应用性，并将探索新型跨催化体系的设计方案，实现区域选择性可调控的芳烃多位点修饰。本项目的研究将融合可见光催化与钌催化的σ活化，有望实现条件温和、应用广泛的间位C(sp2)-H官能团化反应，为芳烃的多样化修饰提供更多绿色合成方法学手段。

基于可见光诱导单电子转移的钌催化σ活化（光/钌催化σ活化反应）为芳烃的精准多样化修饰提供了颇具特色的解决方案。按照预定研究计划，项目组进行了光/钌催化σ活化的反应机理研究，光/钌催化σ活化反应体系的适用性研究，以及芳烃“一锅法”多位点修饰研究。在光/钌催化σ活化的反应机理研究中，项目组从钌催化C-H活化、光催化生成自由基、以及钌催化C-H活化/光生自由基偶合三个角度系统性考察了反应体系各组成要素的影响，优化构建了高效的光/钌催化σ活化反应体系。在光/钌催化σ活化反应体系的适用性研究中，项目组发展了多种杂芳环化合物的区域选择性C-H官能团化策略。在芳烃“一锅法”多位点修饰研究中，项目组发展了光/钌催化σ活化与传统的过渡金属催化的联用策略。通过本项目的研究，发展了多种高效的芳烃修饰策略，对于绿色合成化学的发展具有重要意义。

内容获取失败，请点击重试