“叔膦-季鏻鎓Lewis酸”双功能配体修饰的Ru定向催化胺与合成气的甲基化反应研究

胺与合成气（CO/H2）的甲基化反应是经中间产物甲酰胺“一锅法”制备甲基胺的新路线，但制约该方法有效实施的问题是：CO对甲酰胺加氢活性物种的毒害；甲酰胺不同加氢途径之间的选择性调控。本项目提出构建三齿“叔膦-季鏻鎓Lewis酸”双功能配体的策略，其修饰Ru催化体系协同促进胺与CO的甲酰化反应及随后的甲酰胺加氢反应。其优势在于：含有吸电子性取代基的叔膦基团促进加氢活性物种的生成与稳定，实现合成气氛围下的胺甲基化反应；季鏻鎓Lewis酸基团协同Ru-P基团催化甲酰胺的C-O途径定向加氢，高选择性制备甲基胺。在此基础上，考察配体的电子效应对催化活性物种生成与稳定的作用规律，研究不同功能基团在反应各步中的作用机制、剖析功能基团之间的协同效应，探究双功能Ru催化体系下串联反应的机理，并以离子液体为溶剂实现催化剂的循环使用，为胺与合成气甲基化反应中高效双功能Ru催化剂的研究和发展提供新思路、新方案。

The methylation of amines with syngas (CO/H2) is a new route for the “one-pot” synthesis of methylamines through formamide. The active species of hydrogenation denatured by CO atmosphere, the poor selectivity caused by two hydrogenation pathways of the formamide, inhibited the development of the tandem reaction. Herein, we propose a new strategy to construct bi-functional ligands with different electronic effects. The Ru catalysts modified by the bi-functional ligands could promote the formylation of amines and the subsequent hydrogenation of formylation synergically. The introduced phosphines with electron-withdrawing groups could facilitate the formation and stability of species to catalyze the tandem reaction in syngas atmosphere. The introduced phosphoniums groups could convert formamide to methylamines via C-O pathway, in order to improve the selectivity of the reaction. Then, the influence of electronic effects of ligands on the formation and stability of active species will be investigated, the mechanism of the different functional groups in the bi-functional ligand will be studied, the synergistic catalytic effects of different functional groups will be analyzed, the mechanism of the methylation of amines catalyzed by bi-functional Ru catalysts will be explored, the ionic liquid will be used as solvent to fulfil the recovery and recycling of the Ru-catalysts in the reaction. Moreover, the project provides new ideas and new solutions for the research and development of efficient bi-functional Ru catalysts in the methylation of amines with syngas.