90136-73-5Relevant academic research and scientific papers
Biomass-derived metal-organic hybrids for CO2 transformation under ambient conditions
Guo, Shien,Han, Buxing,Li, Dongyang,Liu, Zhimin,Wang, Huan,Wu, Yunyan,Zhang, Jing,Zhao, Yanfei,Zhao, Zhijuan,Zuo, Shouwei
, p. 2846 - 2851 (2020)
The fabrication of catalysts that can activate CO2 under ambient conditions is very interesting but challenging. Metal-organic hybrids (MOHs) have promising applications in catalysis, and their fabrication from renewable resources is very attractive. Herein, we report a simple protocol to fabricate metal-organic hybrids (MOHs) from chitosan, phytic acid and ZnCl2, obtaining mesoporous MOH-Zn possessing-OH,-NH2, and-PO4 groups. The resulting MOH-Zn shows excellent activity for CO2 activation and enables the cyclization of epoxides with CO2 to proceed under ambient conditions, affording a high turnover frequency of 7.8 h-1. The high performance of MOH-Zn originates from the synergistic effects among multi-functional sites in the catalysts.
N-Heterocyclic carbene-nitrogen molybdenum catalysts for utilization of CO2
Chen, Fei,Tao, Sheng,Liu, Ning,Dai, Bin
, (2021/01/19)
Three new N-heterocyclic carbene-nitrogen molybdenum complex was synthesized, and its catalytic activity was evaluated in the cycloaddition of epoxides with CO2. The molybdenum complex combined with tetrabutyl ammonium iodide (TBAI) resulted in a catalytic system for efficient conversion of a wide range of terminal and internal epoxides under 80 °C and 5–7 bar pressure for CO2. The cooperative catalysis mechanism between molybdenum complex and TBAI was elucidated, in which molybdenum complex was used as Lewis acid, and TBAI was employed as nucleophilic reagent. In addition, the NHC-Mo catalytic system was also successfully applied for the direct carboxylation of terminal alkynes with CO2.
Cycloaddition of carbon dioxide and epoxides catalyzed by rare earth metal complexes bearing a Trost ligand
Cheng, Jun,Lu, Chengrong,Zhao, Bei
, p. 13096 - 13103 (2021/08/04)
A series of rare earth metal complexes (Sm (1), Eu (2), Y (3), Yb (4), and Lu (5)) based on Trost ligands were synthesized and well characterized, and catalyzed the cycloaddition of carbon dioxide and epoxides successfully. The combination of 1 mol% Sm-based complex1with 2 mol% tetrabutylammonium bromide (TBAB) was proved to be the optimal catalyst system for the formation of the monosubstituted cyclic carbonate at 70 °C under the atmospheric pressure. While for the more challenging disubstituted epoxides, the adduct cyclic carbonates were successfully obtained when the pressure of CO2was elevated to 0.7 MPa.
Catalytic, Kinetic, and Mechanistic Insights into the Fixation of CO2 with Epoxides Catalyzed by Phenol-Functionalized Phosphonium Salts
Hu, Yuya,Wei, Zhihong,Frey, Anna,Kubis, Christoph,Ren, Chang-Yue,Spannenberg, Anke,Jiao, Haijun,Werner, Thomas
, p. 363 - 372 (2020/11/30)
A series of hydroxy-functionalized phosphonium salts were studied as bifunctional catalysts for the conversion of CO2 with epoxides under mild and solvent-free conditions. The reaction in the presence of a phenol-based phosphonium iodide proceeded via a first order rection kinetic with respect to the substrate. Notably, in contrast to the aliphatic analogue, the phenol-based catalyst showed no product inhibition. The temperature dependence of the reaction rate was investigated, and the activation energy for the model reaction was determined from an Arrhenius-plot (Ea=39.6 kJ mol?1). The substrate scope was also evaluated. Under the optimized reaction conditions, 20 terminal epoxides were converted at room temperature to the corresponding cyclic carbonates, which were isolated in yields up to 99 %. The reaction is easily scalable and was performed on a scale up to 50 g substrate. Moreover, this method was applied in the synthesis of the antitussive agent dropropizine starting from epichlorohydrin and phenylpiperazine. Furthermore, DFT calculations were performed to rationalize the mechanism and the high efficiency of the phenol-based phosphonium iodide catalyst. The calculation confirmed the activation of the epoxide via hydrogen bonding for the iodide salt, which facilitates the ring-opening step. Notably, the effective Gibbs energy barrier regarding this step is 97 kJ mol?1 for the bromide and 72 kJ mol?1 for the iodide salt, which explains the difference in activity.
Synthesis of carbonates from CO2 and epoxides catalyzed by the system of N-heterocyclic carbene, hydrogen bond donor, CrCl2, and tetrabutylammonium bromide
Zhang, Kuikui,Liu, Zhenbang,Liu, Ning
, (2021/07/10)
A three-component catalytic system including pyridine-bridged benzimidazolium salts, CrCl2, and tetrabutylammonium bromide (TBAB) was developed. Based on the control experiments and spectroscopic measurements, the role of the three components in the catalytic process was clarified, in which benzimidazolium salts were used as N-heterocyclic carbene precursor, a new Cr complex generating from the coordination of CrCl2 with pyridine nitrogen and pyrazole nitrogen bearing benzimidazolium salts was employed as hydrogen bond donor, TBAB was used as nucleophilic reagent, respectively. Under mild conditions (50°C and 1?bar CO2), the terminal epoxides displayed high reactivity in the three-component catalytic system. The catalytic system showed also high catalytic activity for the internal epoxides by increasing the temperature and CO2 pressure and/or prolonging the reaction time.
Method for preparing cyclic carbonate by immobilizing CO2 under catalysis of organic boric acid
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Paragraph 0197-0202, (2021/06/22)
The invention discloses a synthesis method for synergistically catalyzing carbon dioxide immobilization through weak Lewis acid phenylboronic acid and tetrabutylammonium bromide. According to the method, CO2 is immobilized by epoxide, and a cyclic carbonate product is generated. The method comprises the following step: under the concerted catalysis of phenylboronic acid and tetrabutylammonium bromide, performing reaction on epoxide as shown in a formula IV, a formula V or a formula VI and carbon dioxide to respectively obtain a cyclic carbonate product as shown in a formula I, a formula II or a formula III. According to the method, raw materials are convenient and easy to obtain, reaction conditions are mild, operation is easy and convenient, and the yield can reach 97%.
Microwave-Assisted Synthesis of Tris-Anderson Polyoxometalates for Facile CO2Cycloaddition
Yu, Wei-Dong,Zhang, Yin,Han, Yu-Yang,Li, Bin,Shao, Sai,Zhang, Le-Ping,Xie, Hong-Ke,Yan, Jun
supporting information, p. 3980 - 3987 (2021/04/07)
Four new tris-Anderson polyoxometalates (POMs), (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 form χ/δand δ/δisomers in 3 and 4, respectively. 1H and 13C NMR spectra of the χ/δisomer 3 were obtained for the first time, with six methylenes showing six peaks in the 1H NMR spectrum and only four peaks in the 13C NMR spectrum. Mass spectrometry monitoring revealed that during the microwave-assistant process the tris ligand can graft onto POMs to form 1, while tris directly coordinates with metallic heteroatoms to form isopolymolybdates during the conventional reflux synthesis process. In addition, 1-4 can catalyze CO2 with epoxides into cyclic carbonates with high selectivity and yields at an atmospheric pressure of CO2, which is lower than the pressure of CO2 in other catalysis using POMs as catalysts. Furthermore, 1-4 showed good catalytic stability and cycling properties. Mechanism studies substantiated POMs cocatalyzed with Br- to improve the catalytic yields.
Catalytic Formation of Cyclic Carbonates using Gallium Aminotrisphenolate Compounds and Comparison to their Aluminium Congeners: A Combined Experimental and Computational Study
álvarez-Miguel, Lucía,Burgoa, Jesús Damián,Mosquera, Marta E. G.,Hamilton, Alex,Whiteoak, Christopher J.
, p. 4099 - 4110 (2021/08/23)
This work reports on the use of gallium aminotrisphenolate compounds as catalysts for the synthesis of cyclic carbonates from epoxides and CO2. The results show that they are highly active, and more so than the corresponding aluminium congeners. The catalyst system is applicable at low and elevated temperatures across a wide substrate scope including terminal, internal, multiple and fully deuterated epoxides. Applying low catalyst loadings has allowed for a TON of 344,000 to be obtained, highlighting their stability. A DFT investigation has confirmed that the gallium catalysts have lower energetic profiles compared to the aluminium congeners. Measurement of the Lewis acidity of both the gallium and aluminium aminotrisphenolate compounds using the Gutmann-Beckett method provides the experimental proof that the gallium compounds are more Lewis acidic than their aluminium congeners. Finally, Ab-Initio Molecular Dynamic (AIMD) simulations have investigated and quantified the dynamic behaviour of the catalytic systems, highlighting an important increase in fluxionality in some cases which helps to explain the increase in catalytic activity.
Efficient conversion of CO2into cyclic carbonates at room temperature catalyzed by Al-salen and imidazolium hydrogen carbonate ionic liquids
Hu, Xingbang,Liu, Jia,Liu, Ying,Yang, Guoqiang,Zhang, Dejin,Zhang, Zhibing
supporting information, p. 4509 - 4515 (2020/08/10)
A novel process for the efficient synthesis of cyclic carbonates from CO2 and epoxides at room temperature in the absence of a solvent has been achieved by using Al-salen complexes as catalysts and imidazolium hydrogen carbonate ionic liquids ([CnCmIm][HCO3]) as cocatalysts. As a halide ion-free cocatalyst, [CnCmIm][HCO3] showed higher catalytic reactivity compared to traditional halogen-containing quaternary ammonium salts (such as (nBu)4NBr) and organic bases. The catalytic system can be used for the cycloaddition of a series of substrates with good to excellent yields at room temperature in the absence of a solvent. Besides, the catalytic system can be easily recycled at least four times without significant loss of catalytic activity. A possible mechanism was proposed, in which Al-salen and carbene activate the epoxides and CO2 respectively.
A Phosphonium Ylide as a Ligand for [3 + 2] Coupling Reactions of Epoxides with Heterocumulenes under Mild Conditions
Hashimoto, Kousuke,Mori, Yoko,Suga, Hiroyuki,Toda, Yasunori
, p. 10980 - 10987 (2020/09/23)
The potential of carbonyl-stabilized phosphonium ylides as ligands for novel catalysis was explored. We found that the combination of phosphonium ylides and metal halide salts efficiently catalyzed the reaction of epoxides with carbon dioxide under mild c
