在温和的反应条件下开发用于反应的高效,廉价和可循环使用的催化剂是绿色化学中非常有吸引力的主题。在本文中,研究了一系列碱性离子液体(ILs)作为通过环状碳酸酯水解合成邻位二醇的催化剂,以改善这种合成方法。详细研究了IL结构,环状碳酸酯与水的摩尔比以及各种反应参数对催化性能的影响。发现一种简单的无卤两性离子催化剂1,3-二甲基咪唑-2-羧酸盐具有很高的活性(时空产率为1086 h -1),并具有优异的选择性,可用于制备乙二醇。碳酸亚乙酯的水解。该催化剂可以重复使用六次而不会明显降低催化活性。同样,它适用于多种环状碳酸酯,以高产率和高选择性生产它们相应的邻位二醇。根据实验结果,核磁共振光谱和理论计算,提出了一种可能的催化循环方法。该反应方案为化学合成替代传统的碱性或碱性ILs开辟了新的可能性。
Highly Active and Robust Metalloporphyrin Catalysts for the Synthesis of Cyclic Carbonates from a Broad Range of Epoxides and Carbon Dioxide
作者:Chihiro Maeda、Junta Shimonishi、Ray Miyazaki、Jun-ya Hasegawa、Tadashi Ema
DOI:10.1002/chem.201600164
日期:2016.5.4
metalloporphyrins with quaternary ammonium bromides (nucleophiles) at the meta, para, or ortho positions of meso‐phenyl groups were synthesized as catalysts for the formation of cycliccarbonatesfromepoxides and carbondioxide under solvent‐free conditions. The meta‐substituted catalysts exhibited high catalytic performance, whereas the para‐ and ortho‐substituted catalysts showed moderate and low activity
Microwave-Assisted Synthesis of Tris-Anderson Polyoxometalates for Facile CO<sub>2</sub> Cycloaddition
作者:Wei-Dong Yu、Yin Zhang、Yu-Yang Han、Bin Li、Sai Shao、Le-Ping Zhang、Hong-Ke Xie、Jun Yan
DOI:10.1021/acs.inorgchem.1c00019
日期:2021.3.15
(NH4)4[ZnMo6O18(C4H8NO3)(OH)3]·4H2O (1), (NH4)4[CuMo6O18(C4H8NO3)(OH)3]·4H2O (2), (TBA)3(NH4)[ZnMo6O17(C5H9O3)2(OH)]·10H2O (3) (TBA = n-C16H36N), and (NH4)4[CuMo6O18(C5H9O3)2]·16H2O (4), were synthesized by a microwave-assisted method. Single-crystal X-ray diffraction revealed that 1 and 2 contained a tris (trihydroxyl organic compounds) ligand grafted on one side, while two tris ligands were grafted on two sides to
四个新的tris-Anderson多金属氧酸盐(POMs)(NH 4)4 [ZnMo 6 O 18(C 4 H 8 NO 3)(OH)3 ]·4H 2 O(1),(NH 4)4 [CuMo 6 O 18(C 4 H 8 NO 3)(OH)3 ]·4H 2 O(2),(TBA)3(NH 4)[ZnMo 6 O 17(C 5 H 9 O 3)2(OH)]·10H 2 O(3)(TBA = n -C 16 H 36 N)和(NH 4)4 [CuMo 6 O 18(C 5 H 9 O 3)2 ]·16H 2 O (4)是通过微波辅助法合成的。X射线单晶衍射表明,1和2的一侧接有一个tris(三羟基有机化合物)配体,而两侧的两个tris配体接枝了,在3和3中形成χ/δ和δ/δ异构体。分别为4。首次获得χ/δ异构体3的1 H和13 C NMR光谱,其中6个亚甲基在1 H NMR光谱中显示6个峰,在13
Catalytic Non-redox Carbon Dioxide Fixation in Cyclic Carbonates
作者:Saravanan Subramanian、Julius Oppenheim、Doyun Kim、Thien S. Nguyen、Wahyu M.H. Silo、Byoungkook Kim、William A. Goddard、Cafer T. Yavuz
DOI:10.1016/j.chempr.2019.10.009
日期:2019.12
selectivity for a range of substrates under ambient conditions and without the need for co-catalysts, metals, solvent, or pressure. COP-222 is recyclable and has been demonstrated to retain complete retention of activity for over 15 cycles. Moreover, it is scalable to at least a kilogram scale. We determined the reaction mechanism by using quantum mechanics (density functional theory), showing that it involves
Hydrogenation of CO<sub>2</sub>
-Derived Carbonates and Polycarbonates to Methanol and Diols by Metal-Ligand Cooperative Manganese Catalysis
作者:Viktoriia Zubar、Yury Lebedev、Luis Miguel Azofra、Luigi Cavallo、Osama El-Sepelgy、Magnus Rueping
DOI:10.1002/anie.201805630
日期:2018.10.8
The first base‐metal‐catalysed hydrogenation of CO2‐derived carbonates to alcohols is presented. The reaction proceeds under mild conditions in the presence of a well‐defined manganese complex with a loading as low as 0.25 mol %. The non‐precious‐metal homogenous catalytic system provides an indirect route for the conversion of CO2 into methanol with the co‐production of value‐added (vicinal) diols
Gel catalysts have been developed based on dynamic covalent chemistry and post-modification methods for improved chemical stability and catalytic activity.