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New pyridinium-functionalized metalloporphyrins MEtPpBr4 (M = Zn2+, Co2+, Ni2+, Cu2+; EtPp = 5, 10, 15, 20-tetra(4-(3-(N-ethyl-4-pyridyl)pyrazolyl)phenyl)porphyrin) were synthesized as bifunctional catalysts for the cycloaddition reactions of epoxides and CO2. The effects of catalyst loading, CO2 pressure, reaction temperature and time on catalytic activity were investigated. ZnEtPpBr4 ( 1 ) and CoEtPpBr4 ( 2 ) exhibited efficient activities in the cycloaddition reactions of various epoxides with CO2 as at 120 °C under 2 MPa of CO2 pressure without solvent. Most of corresponding cyclic carbonates could be obtained in almost quantitative yields and > 99.9% selectivity with molar ratio of epoxide/catalyst 2222 after 8 hr of reaction. 相似文献
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Salen-complex-mediated formation of cyclic carbonates by cycloaddition of CO2 to epoxides 总被引:1,自引:0,他引:1
Decortes A Castilla AM Kleij AW 《Angewandte Chemie (International ed. in English)》2010,49(51):9822-9837
Metal complexes of salen ligands are an important class of compounds, and they have been widely studied in the past. Among their successful catalytic applications, the synthesis of cyclic carbonates by the coupling reaction of epoxides with CO(2) has received increased attention; this is mostly due to the importance of using a greenhouse gas as a feedstock for the synthesis of useful molecules. Herein the most relevant past and present research surrounding this topic is presented. 相似文献
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Titanocene dichloride (Cp2TiCl2)/KI was developed to be an efficient catalytic system for the cycloaddition of CO2 to epoxides to synthesize relevant cyclic carbonates from epoxides and CO2. Various influencing factors on the coupling reaction, such as co‐catalyst, temperature, CO2 pressure and reaction time, were investigated. The optimal reaction conditions were KI as co‐catalyst, 150 °C reaction temperature, 12 atm CO2 pressure and 4 h reaction time using THF as solvent for the synthesis of propylene carbonate in 98% yield. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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研究了超临界二氧化碳中α-氨基酸催化二氧化碳与环氧化物环加成反应合成环状碳酸酯,发现组氨酸的催化活性最高.在二氧化碳压力为8MPa、反应温度130℃、反应时间48h、组氨酸加入量为0.8mol%的条件下,二氧化物可以顺利的与各种环氧化物反应,以高的选择性和产率生成相应的环状碳酸酯. 相似文献
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Dongsheng Bai Guangjian Wang Fang Ma Juangang Wang Kuai Wang Zijing Yang 《应用有机金属化学》2014,28(11):814-817
Synthesis of cyclic carbonates from CO2 and terminal epoxides catalyzed by Mg, Ca and In BINOL complexes was achieved without organic solvents. Effects of temperature, CO2 pressure, reaction time and co‐catalyst on the cycloaddition were investigated. Propylene carbonate was obtained under a CO2 pressure of 1.2 MPa within 10 hours in a yield of 98% catalyzed by Ca–BINOL at 120°C. The order of catalytic activity of the metal center is Ca > In > Mg. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Extraction of lanthanides from aqueous solution by using room-temperature ionic liquid and supercritical carbon dioxide in conjunction 总被引:2,自引:0,他引:2
Mekki S Wai CM Billard I Moutiers G Burt J Yoon B Wang JS Gaillard C Ouadi A Hesemann P 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(6):1760-1766
For the first time, the study of a three-step extraction system of water/ionic liquid/supercritical CO2 has been performed. Extraction of trivalent lanthanum and europium from an aqueous nitric acid solution to a supercritical CO2 phase via an imidazolium-based ionic liquid phase is demonstrated, and extraction efficiencies higher than 87 % were achieved. The quantitative extraction is obtained by using different fluorinated beta-diketones with and without the addition of tri(n-butyl)phosphate. The complexation phenomenon occurring in the room-temperature ionic-liquid (RTIL) phase was evidenced by using luminescence spectroscopy. 相似文献
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The synthesis of cyclic carbonates from epoxides and carbon dioxide catalyzed by cyanocobalamin and n‐Bu4NI system was achieved under 0.8 MPa CO2 pressure at 140°C without organic solvents. Propylene carbonate was obtained in 99% yield within 6 h under the optimized reaction conditions. The cyanocobalamin catalyst could be recycled with water and retained moderate catalytic activity. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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《化学:亚洲杂志》2017,12(17):2271-2277
Development of inexpensive, easily prepared, non‐toxic, and efficient catalysts for the cycloaddition of CO2 with epoxides to synthesize five‐membered cyclic carbonates is a very attractive topic in the field of CO2 transformation. In this work, we conducted the first work on the cycloaddition of CO2 with epoxides to produce cyclic carbonates catalyzed by a binary catalyst system consisting of KI and boron phosphate (BPO4), which are both inexpensive and non‐toxic, and various corresponding cyclic carbonates could be produced with high yields (93–99 %) at 110 °C with a CO2 pressure of 4 MPa under solvent‐free conditions. In the BPO4/KI catalyst system, BPO4, a Brønsted and Lewis acid hybrid, played the role of activating the epoxy ring through the formation of hydrogen bonds with Brønsted acidic sites and the interaction with Lewis acidic sites simultaneously, and thus enhanced the activity of KI for the cycloaddition of CO2 with epoxides significantly. Additionally, the activity of the BPO4/KI catalyst system showed no noticeable decrease after being reused five times, indicating that the BPO4 was stable under the reaction conditions. 相似文献
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在乙腈体系中,以不同的乙酸盐作催化剂,研究了CO2与二醇合成环状碳酸酯的反应.乙腈在反应过程中不仅是溶剂,而且还起到了脱水剂的作用,促进了反应的进行.以1,2-丙二醇为反应物对催化剂进行筛选,发现无水乙酸锌具有最高的催化活性.在无水乙酸锌上考察了二氧化碳和不同二醇的反应,结果表明,五元环碳酸酯的产率明显高于六元环碳酸酯,其中碳酸丙烯酯的产率最高.以1,2-丙二醇为反应基质,无水乙酸锌为催化剂,确定了最佳反应条件,1,2-丙二醇100 mmol,乙睛10 mL,催化剂2.5 mmol,反应压力10 MPa,温度170 ℃,反应12 h.在此条件下,碳酸丙烯酯的产率达到了24.2%,1,2-丙二醇的转化率为38.9%. 相似文献
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Promotion of Ionic Liquid to Dimethyl Carbonate Synthesis from Methanol and Carbcn Dioxide 总被引:2,自引:0,他引:2
Promotion of ionic liquid, 1-ethyl-3-methylimidazolium bromide (emimBr), to the synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide in the presence of potassium carbonate and less amount of methyl iodide under mild conditions was investigated. The results showed that the high selectivity and raised yield of DMC was achieved due to the addition of emimBr in the reaction system. And effect of several reaction conditions such as temperature, pressure and amount of emimBr was discussed. 相似文献
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Atsushi SudoYosuke Morioka Eri KoizumiFumio Sanda Takeshi Endo 《Tetrahedron letters》2003,44(43):7889-7891
Cycloaddition of aziridine with carbon dioxide was successfully catalyzed by alkali metal halide or tetraalkylammonium halide to give the corresponding 5-membered cyclic urethane, 1,3-oxazolidin-2-one, selectively. The reaction can be performed at ambient temperature under atmospheric pressure. Analoguous reaction of aziridine with carbon disulfide also successfully gave the corresponding 5-membered cyclic dithiourethane, 1,3-thioxazolidine-2-thione. 相似文献
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Frontispiece: Highly Active and Robust Metalloporphyrin Catalysts for the Synthesis of Cyclic Carbonates from a Broad Range of Epoxides and Carbon Dioxide
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Dr. Chihiro Maeda Junta Shimonishi Ray Miyazaki Prof. Jun‐ya Hasegawa Prof. Tadashi Ema 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19)
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Ciriminna R Hesemann P Moreau JJ Carraro M Campestrini S Pagliaro M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(20):5220-5224
The replacement of toxic Cr(VI) for O2 and of chlorinated solvents for supercritical carbon dioxide (or ionic liquids) in the oxidation of alcohols remains hindered by the low selectivity and activity of the current heterogeneous catalysts. Using an integrated approach that combines sol-gel entrapped perruthenate as aerobic catalyst, an encapsulated ionic liquid as solubility promoter, and scCO2 as the reaction solvent, we have developed a system capable of rapidly converting different alcohols into carbonyl compounds with complete selectivity, including substrates which are otherwise difficult to oxidise. The methodology is generally applicable and may easily be extended to other waste-free, catalytic syntheses of fine chemicals. 相似文献
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He J Wu T Zhang Z Ding K Han B Xie Y Jiang T Liu Z 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(24):6992-6997
The catalytic activity of polyaniline-HX (X=I, Br, Cl) (PANI-HI, PANI-HBr, PANI-HCl) for the cycloaddition of CO2 to propylene oxide (PO) to produce propylene carbonate (PC) was studied for the first time. It was shown that all the PANI salts were active for the reaction, and PANI-HI was most active and selective. On the basis of the preliminary results, the effect of the reaction conditions on the cycloadditions of CO2 to propylene oxide and epichlorohydrin was further investigated by using PANI-HI as the catalyst. The results indicated that the optimized temperature was around 115 degrees C. The maxima occurred in yield versus pressure curves at about 5 MPa for both substrates. Complete conversion was achieved in 3 h for epichlorohydrin and 6 h for propylene oxide at 115 degrees C and 5 MPa. With propylene oxide as the substrate, the reusability of PANI-HI was evaluated and no loss of catalytic activity was detectable after the catalyst had been reused five times. The catalyst was characterized by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), which provided further evidence for the high stability of the catalyst. We believe that the catalyst has great potential for industrial applications because it has some unusual advantages, such as its easy preparation, high activity, selectivity, stability, low cost, and simple separation from products. 相似文献
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Javier Martínez Dr. José A. Castro‐Osma Amy Earlam Dr. Carlos Alonso‐Moreno Prof. Antonio Otero Dr. Agustín Lara‐Sánchez Prof. Michael North Dr. Antonio Rodríguez‐Diéguez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9850-9862
New aluminium scorpionate based complexes have been prepared and used for the synthesis of cyclic carbonates from epoxides and carbon dioxide. Bimetallic aluminium(heteroscorpionate) complexes 9 – 14 were synthesised in very high yields. The single‐crystal X‐ray structures of 12 and 13 confirm an asymmetric κ2‐NO‐μ‐O arrangement in a dinuclear molecular disposition. These bimetallic aluminium complexes were investigated as catalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide in the presence of ammonium salts. Under the optimal reaction conditions, complex 9 in combination with tetrabutylammonium bromide acts as a very efficient catalyst system for the conversion of both monosubstituted and internal epoxides into the corresponding cyclic carbonates showing broad substrate scope. Complex 9 and tetrabutylammonium bromide is the second most efficient aluminium‐based catalyst system for the reaction of internal epoxides with carbon dioxide. A kinetic study has been carried out and showed that the reactions were first order in complex 9 and tetrabutylammonium bromide concentrations. Based on the kinetic study, a catalytic cycle is proposed. 相似文献