1,1,3,3-四烷基胍羰基钴离子液体:高效可循环利用的环氧化合物羰基化反应催化新材料（英文）

发布时间：2018-04-30 14:30

本文选题：羰基钴离子液体 + 羰基化反应　；参考：《催化学报》2017年05期

【摘要】：离子液体因其所独有的物理化学性质如蒸气压低、热稳定性好以及结构和性能的可调性等优点而备受关注.四羰基钴阴离子是多种重要均相催化反应的催化活性物种,含有四羰基钴阴离子的金属有机离子液体有效结合了羰基金属和离子液体各自的特点和优势,作为一类新颖而且重要的功能化离子液体,受到国内外研究者的青睐.2001年,Dyson等首次报道了一种室温下为液态的羰基钴金属有机离子液体[bmim][Co(CO)_4],为四羰基钴阴离子离子液体的研究开创了先河.此后,有关羰基钴金属有机离子液体的催化应用研究也相继报道.目前[CnPy][Co(CO)_4]以及[bmim][Co(CO)_4]在环氧化合物的羰基化反应中已有报道,但该类催化剂的催化活性特别是循环使用性能有待进一步提高.胍盐具有阳离子电荷分散程度高、热稳定性和化学稳定性高、三个氮原子上的基团可以调节等特点,使得胍盐离子液体的设计、合成和应用研究受到国内外学者关注.由于其自身结构特点,氮原子上有取代氢可以和含F,O,N底物作用形成氢键,并且氮原子上取代烷基之间作用使阳离子的平面结构发生变化,使得与三个氮原子相连的碳原子处于缺电子状态,使阳离子表现出Lewis酸性.所以其在环氧化合物氢酯基化反应中可起到稳定四羰基钴阴离子以及活化环氧化合物的作用.基于此,本文以较高收率合成了四种新型的1,1,3,3-四烷基胍羰基钴金属有机离子液体:1,1-二甲基-3,3-二乙基胍羰基钴(3a),1,1-二甲基-3,3-二正丁基胍羰基钴(3b),1,1-二甲基-3,3-四亚甲基胍羰基钴(3c),1,1-二甲基-3,3-五亚甲基胍羰基钴(3d).通过红外光谱、紫外-可见光谱、1H核磁共振谱、13C核磁共振谱、高分辨质谱、差示量热扫描仪和热重分析对该类化合物进行了结构确认及性质研究.这四种催化剂,特别是3a,在环氧化合物的氢酯基化反应中表现出优异的催化性能,在无需任何助剂的情况下具有较好的催化活性及底物适用性.此外,以不同构型的环氧丙烷为反应底物,氢酯基化反应结果显示:在该催化体系作用下,产物的构型与底物保持一致,没有发生消旋.尤其值得指出的是,催化剂3a在环氧丙烷的氢酯基化反应中表现出了优异的循环稳定性能,在循环使用6次后依然可以获得较好的转化率(91%)和选择性(94%).
[Abstract]:Ionic liquids have attracted much attention due to their unique physical and chemical properties such as vapor depression, good thermal stability, and structural and performance tunability. Tetracarbonyl cobalt anion is an important catalytic active species for homogeneous catalytic reactions. Metal organic ionic liquids containing tetracarbonyl cobalt anions effectively combine the characteristics and advantages of carbonyl metals and ionic liquids. As a class of novel and important functional ionic liquids, In 2001, Dyson et al reported for the first time that a carbonyl cobalt metal organic ionic liquid [bmim] [Co(CO)_4] was liquid at room temperature, which opened the way for the study of tetracarbonyl cobalt anionic liquid. Since then, the catalytic application of carbonyl cobalt organometallic ionic liquids has been reported one after another. At present, [CnPy] [Co(CO)_4] and [bmim] [Co(CO)_4] have been reported in the carbonylation of epoxides, but the catalytic activity of this kind of catalysts, especially the performance of recycling, needs to be further improved. Guanidine salt has the characteristics of high cationic charge dispersion, high thermal stability and chemical stability, and the groups on the three nitrogen atoms can be adjusted. Therefore, the design, synthesis and application of guanidine salt ionic liquids have attracted much attention at home and abroad. Because of its own structural characteristics, substituted hydrogen on nitrogen atoms can form hydrogen bonds with FN substrates, and the plane structure of cations can be changed by the interaction of substituted alkyl groups in nitrogen atoms. The carbon atoms linked to the three nitrogen atoms are in an electron-deficient state and the cations exhibit Lewis acidity. So it can stabilize the cobalt tetracarbonyl anion and activate the epoxy compound in the hydroesterification of epoxy compound. Based on this, In this paper, four new cobalt organic ionic liquids, 1: 1- dimethyl-3-diethylguanidine-3-dimethyl-3- Ding Ji-guanidine carbonyl-cobalt 3b1- dimethyl-3- trimethylguanidine carbonyl cobalt trimethylidene were synthesized in a high yield. The results show that the organic ionic liquids: 1: 1- 1-dimethyl-3-diethylguanidine-3-diethylguanidine carbonyl cobalt (3b1- 1)-dimethyl-3-trimethylguanidine-3-tetrachloromethylguanidine carbonyl cobalt Dimethyl- 3-methylene guanidine carbonyl cobalt trioxide. The structures and properties of these compounds were confirmed by IR, 1H NMR, high resolution mass spectrometry, differential scanning calorimetry and thermogravimetric analysis. These four catalysts, especially 3a, showed excellent catalytic performance in the hydroesterification of epoxy compounds, and showed good catalytic activity and substrate applicability without any additives. In addition, using propylene oxide with different configurations as the reaction substrate, the results of hydroesterification showed that the configuration of the product was consistent with that of the substrate, and no racemic reaction took place. It is especially worth pointing out that the catalyst 3a exhibits excellent cyclic stability in the hydroesterification of propylene oxide, and a good conversion of 91g) and selectivity can be obtained after six cycles.
【作者单位】：中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室;中国科学院大学;
【基金】：supported by the National Natural Science Foundation of China(21373248,21673260,21133011)~~
【分类号】：O643.36;O645.1

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