40492-31-7Relevant academic research and scientific papers
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.
Heterobimetallic rare earth metal-zinc catalysts for reactions of epoxides and CO2under ambient conditions
Yin, Kuan,Hua, Linyan,Qu, Liye,Yao, Quanyou,Wang, Yaorong,Yuan, Dan,You, Hongpeng,Yao, Yingming
, p. 1453 - 1464 (2021/02/09)
Four homodinuclear rare earth metal (RE) complexes1-4bearing a multidentate diglycolamine-bridged bis(phenolate) ligand were synthesized. In addition, seven heterobimetallic RE-Zn complexes5-11were prepared through a one-pot strategy. In these heterobimetallic complexes, two RE centers are bridged by either Zn(OAc)2or Zn(OBn)2moieties. All complexes were characterized by single crystal X-ray diffraction, elemental analysis, IR spectroscopy, and multinuclear NMR spectroscopy (in the case of diamagnetic complexes1,4,7and11). Moreover, the multi-nuclear structures of complexes4and11in solution were also studied by1H DOSY spectroscopy. These complexes were applied in catalyzing the coupling reaction of carbon dioxide (CO2) with epoxides. Zn(OAc)2- and Zn(OBn)2-bridged heterobimetallic complexes showed comparable catalytic activities under ambient conditions and were more active than monometallic RE complexes. Significant synergistic effect in heterobimetallic complexes is observed. Mono-substituted epoxides were converted into cyclic carbonates under 1 atm CO2at 25 °C in 88-96% yields, whereas di-substituted epoxides reacted under 1 atm CO2at higher temperatures in 40-80% yields.
A Strained Ion Pair Permits Carbon Dioxide Fixation at Atmospheric Pressure by C-H H-Bonding Organocatalysis
Xu, Jiaxi,Xian, Anmei,Li, Zhenjiang,Liu, Jingjing,Zhang, Zhihao,Yan, Rui,Gao, Luoyu,Liu, Bo,Zhao, Lili,Guo, Kai
, p. 3422 - 3432 (2021/02/27)
The cycloadditions of carbon dioxide into epoxides to afford cyclic carbonates by H-bond donor (HBD) and onium halide (X) cocatalysis have emerged as a key strategy for CO2 fixation. However, if the HBD is also a halide receptor, the two will quench each other, decreasing the catalytic activity. Here, we propose a strained ion pair tris(alkylamino)cyclopropenium halide (TAC·X), in which TAC repels X. TAC possesses a positively charged cyclopropenium core that makes the vicinal C-H or N-H a nonclassical HBD. The interionic strain within TAC·X makes TAC a more electrophilic HBD, allowing it to activate the oxygen of the epoxide and making X more nucleophilic and better able to attack the methylene carbon of the epoxide. NMR titration spectra and computational studies were employed to probe the mechanism of the cycloaddition of CO2 to epoxides reactions under the catalysis of TAC·X. The 1H and 13C{1H}NMR titration spectra of the catalyst with the epoxide substrate unambiguously confirmed H-bonding between TAC and the epoxide. DFT computational studies identified the transition states in the ring-opening of the epoxide (TS1) and in the ring-closure of the cyclic carbonate (TS2).
The catalytic system ‘Rhodamine B/additive’ for the chemical fixation of CO2
Wu, Feng-tian,Wu, Ling,Cui, Chun-na
, (2021/02/09)
The catalytic system ‘Rhodamine B/additive’ was introduced to promote the CO2 reactions. We synthesized various cyclic carbonates in good to excellent yields under the catalysis of rhodamine B and TBAB. A variety of 2-oxazolidinone derivatives were obtained in the presence of rhodamine B and DBU.
Fixation of CO2 into Cyclic Carbonates by Halogen-Bonding Catalysis
Yan, Rui,Chen, Kai,Li, Zhenjiang,Qu, Yuanyuan,Gao, Luoyu,Tong, Haoying,Li, Yongqiang,Li, Jie,Hu, Yongzhu,Guo, Kai
, p. 738 - 744 (2020/11/30)
Halogen bonding, parallel to hydrogen bonding, was introduced into the catalytic cycloaddition of carbon dioxide into epoxide (CCE) reactions. A series of halogen-bond donor (XBD) catalysts of N-iodopyridinium halide featured with N?I bond were synthesized and evaluated in CCE reactions. The optimal XBD catalyst, 4-(dimethylamino)-N-iodopyridinium bromide ([DMAPI]Br), under screened conditions at 100 °C, ambient pressure, and 1 mol % catalyst loading, realized 93 % conversion of styrene oxide into cyclic carbonate in 6 h. The substrate scope was successfully extended with excellent yields (mostly ≥93 %) and quantitative selectivity (more than 99 %). 1H NMR spectroscopy of the catalyst [DMAPI]Br on substrate epoxide certified that the N?I bond directly coordinated with the epoxide oxygen. A plausible mechanism of halogen-bonding catalysis was proposed, in which the DMAPI cation functioned as halogen-bond donor to activate the epoxide, and the counter anion bromide attacked the methylene carbon to initiate the ring-opening of the epoxide. CCE reactions promoted by N-iodopyridinium halide, exemplify a first case of halogen-bonding catalysis in epoxide activation and CO2 transformation.
Conversion of dilute CO2to cyclic carbonates at sub-atmospheric pressures by a simple indium catalyst
Baalbaki, Hassan A.,Roshandel, Hootan,Hein, Jason E.,Mehrkhodavandi, Parisa
, p. 2119 - 2129 (2021/04/09)
The transformation of CO2to value added commodity chemicals presents an impactful strategy to obtain products that are less dependent on fossil fuels. In this study, indium tribromide (InBr3) mixed with tetrabutylammonium bromide (NBu4Br) co-catalyst has been identified as a simple, highly efficient catalyst for the synthesis of cyclic carbonates from epoxides and CO2at sub-atmospheric pressures, room temperature, and under solvent-free conditions. The InBr3/NBu4Br catalytic system is tolerant toward different functional groups with high conversions and >99% selectivity for cyclic carbonate without resorting to high pressures and temperatures. Moreover, a combination ofin situIR, NMR spectroscopy, and substrate labelling experiments enabled the proof of key catalytic steps and detection of reaction intermediates to elucidate the reaction mechanism. This technology represents a potential scalable system for the utilization of waste CO2
Synthesis method of cyclic carbonate
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Paragraph 0074-0075, (2021/05/19)
The invention discloses a preparation method of cyclic carbonate, and belongs to the technical field of green catalytic synthesis. According to the invention, epoxide and carbon dioxide are catalyzed by the catalyst to obtain cyclic carbonate, the synthesis method is simple and low in cost, the catalyst has the characteristics of no metal and no halogen, and the reaction condition is mild.
A Porous Copper-Organic Framework Assembled by [Cu12] Nanocages: Highly Efficient CO2Capture and Chemical Fixation and Theoretical DFT Calculations
Wang, Wen-Min,Wang, Wan-Ting,Wang, Mei-Ying,Gu, Ai-Ling,Hu, Tian-Ding,Zhang, Ya-Xin,Wu, Zhi-Lei
, p. 9122 - 9131 (2021/06/27)
A new porous copper-organic framework assembled from 12-nuclear [Cu12] nanocages {[Cu2(L4-)(H2O)2]·4DMA·2H2O}n (1) (H4L = 5,5′-(butane-1,4-diyl)-bis(oxy)-diisophthalic acid) was successfully prepared and structurally characterized. Compound 1 feathering of a 3D framework with two types of 1D nanotubular channels and a large specific surface area can effectively enrich various harmful dyes. Additionally, due to the carbon dioxide (CO2) interactions with open Cu(II) sites and the electron-rich ether oxygen atoms of ligand in 1, it exhibits a highly selective CO2 uptake. Interestingly, 1 can effectively catalyze the cycloaddition reaction of CO2 with various epoxides under mild conditions, which is ascribed to the Lewis acid Cu(II) sites in the framework of 1. Importantly, 1 acting as a heterogeneous catalyst can be recycled at least 10 times without an obvious loss of catalytic activity, and the CO2 cycloaddition mechanism was further uncovered by density functional theory (DFT) calculations. This study can greatly enrich the MOF catalysts system of CO2 conversion and also provide a valuable guidance for the design of efficient MOFs catalysts.
Self-assembled bimetallic aluminum-salen catalyst for the cyclic carbonates synthesis
Abboud, Khalil A.,Hahm, Hyungwoo,Hong, Sukwon,Kim, Seyong,Park, Jongwoo,Seong, Wooyong
supporting information, (2021/07/21)
Bimetallic bis-urea functionalized salen-aluminum catalysts have been developed for cyclic carbonate synthesis from epoxides and CO2. The urea moiety provides a bimetallic scaffold through hydrogen bonding, which expedites the cyclic carbonate formation reaction under mild reaction conditions. The turnover frequency (TOF) of the bis-urea salen Al catalyst is three times higher than that of a μ-oxo-bridged catalyst, and 13 times higher than that of a monomeric salen aluminum catalyst. The bimetallic reaction pathway is suggested based on urea additive studies and kinetic studies. Additionally, the X-ray crystal structure of a bis-urea salen Ni complex supports the self-assembly of the bis-urea salen metal complex through hydrogen bonding.
