- Chemical fixation of CO2 to cyclic carbonate catalyzed by new environmental- friendly bifunctional bis-Β-cyclodextrin derivatives
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In present work, three amino-bridged biomass bis-β-cyclodextrins (bis-β-CDs) and eight bifunctionalized bis-β-CDs derivatives were designed and synthesized as environmental friendly catalysts to fix CO2. Both the bridged bis-β-CDs 1a-3a/potassium halide and haloalkane functionalized bis-β-CDs 1b-8b were poven to be efficient catalytic systems for the solvent-free coupling reaction of CO2 and epoxides. After systematic investigation, the optimized conditions of (120 °C, 4 MPa, 0.14mol% 1a, 1.25mol% KI, 2 h) have been established for dual catalytic system 1a/KI and the excellent yield (94%) with high selectivity (99%) can be achieved for the cycloaddition of CO2 and propylene oxide. Furthermore, after functionalization with alkyl halides, bis-β-CD derivative 1b-8b as sigle bifunctional catalyst exhibited better activity under milder optimal conditions of (110 °C, 2 MPa, 0.125mol% 1b and 4 h). Moreover, these bifunctional catalysts are also applicable to a variety of epoxides (including diepoxides) and good catalytic performances were abtained for producing the corresponding cyclic carbonates in most cases. Furthermore, this catalyst can be reused at least for five times without significant activity decrease. Finally, a possible mechanism including the activation of both epoxide and CO2 was proposed based on the literatures and experimental results.
- Peng, Jing,Wang, Sheng,Yang, Hai-Jian,Ban, Binru,Wei, Zidong,Wang, Lihua,Bo, Lei
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- Crosslinked Resin-Supported Bifunctional Organocatalyst for Conversion of CO2 into Cyclic Carbonates
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The development of solvent-free, metal-free, recyclable organic catalysts is required for the current chemical fixation of carbon dioxide converted into cyclic carbonates. With the goal of reducing the cost, time, and energy consumption for the coupling reaction of CO2 and epoxides, a series of highly active heterogeneous catalysts, based on a thiourea and quaternary ammonium salt system, are synthesized by using a thiol-ene click reaction under ultraviolet light. Benefitting from synergistic interactions of the electrophilic center (thiourea) and the nucleophilic site (ammonium bromide), the catalysts exhibit excellent catalytic selectivity (99 %) for the cycloaddition of carbon dioxide with a diverse range of epoxides under mild conditions (1.2 MPa, 100 °C). Moreover, the catalyst can be easily recycled by facile filtration and reused for 5 times without noticeable loss of activity and selectivity. This work provides a potential heterogeneous catalyst for the conversion of carbon dioxide into high value-added chemicals with the combined advantages of low cost, easy recovery, and satisfactory catalytic properties.
- Dong, Tongfeng,Li, Bo,Wu, Guang-Peng,Yang, Guan-Wen,Zhang, Yao-Yao,Zheng, Yu-Jia
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- Metal-Organic Frameworks with Tb4 Clusters as Nodes: Luminescent Detection of Chromium(VI) and Chemical Fixation of CO2
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Two multifunctional metal-organic frameworks based on cubane-like tetrahedron Tb4 clusters as nodes have been synthesized and characterized. Compound 1 exhibits a 2D lanthanide-organic framework with Tb4 clusters as nodes, and compound 2 possesses a 3D framework with Tb4 clusters and Mn2+ as nodes. Interestingly, luminescent investigations on them reveal that the two compounds can act as recyclable luminescent probes for chromium(VI) anion species and the corresponding detection limit can reach 10-7 mol/L. Furthermore, 1 and 2 own efficient catalytic activity for the chemical fixation of CO2 with epoxides under mild conditions. Importantly, they both can be recycled at least three times without compromising the activity.
- Dong, Jie,Xu, Hang,Hou, Sheng-Li,Wu, Zhi-Lei,Zhao, Bin
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- Zeolitic Tetrazolate-Imidazolate Frameworks with SOD Topology for Room Temperature Fixation of CO2 to Cyclic Carbonates
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Presented here is an SOD-type zeolitic tetrazolate-imidazolate framework (ZTIF-8) based on 5-methyltetrazole (5-Hmtz) and 2-methyimidazole (2-Hmim) ligands. Owing to the uncoordinated N-sites on the framework, ZTIF-8 has shown high chemical fixation of CO2 to cyclic carbonates at room temperature and ambient pressure.
- Li, Min-Yu,Wang, Fei,Zhang, Jian
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- New lanthanide(iii) coordination polymers: Synthesis, structural features, and catalytic activity in CO2 fixation
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A new series of lanthanide coordination polymers formulated as [Ln(μ-L)(μ3-L)(H2O)]nXn (Ln/X = Er/Cl (1), Er/Br (2), Tm/Cl (3), Tm/Br (4), Yb/Cl (5), and Yb/Br (6); L = 1,3-bis(4-carboxyphenyl) imidazolium carboxylate(1+)) were solvothermally generated and fully characterized. Single-crystal X-ray diffraction analysis shows that all products possess isomorphous structures that are composed of cationic 1D double chains with encapsulated halide anions. From a topological perspective, such 1D chains can be classified as a binodal 3,5-connected net with a unique topology defined by the point symbol of (3·42)(32·42·53·62·7). All products 1-6 feature a remarkable thermal stability and were applied as highly active heterogeneous catalysts for the coupling reactions between halogenated propylene oxides and CO2 to give the corresponding cyclic carbonates. The reaction conditions, substrate and catalyst scope, and mechanistic features of this catalytic transformation were investigated. High products yields (up to 98%), elevated TONs (up to 3920) or TOFs (up to 326 h-1) were attained under mild reaction conditions. In addition, catalyst 6 can be recycled at least eight times with no loss of catalytic activity.
- Xu, Cong,Liu, Yan,Wang, Li,Ma, Jingxin,Yang, Lizi,Pan, Fu-Xin,Kirillov, Alexander M.,Liu, Weisheng
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- Robust multivariate metal-porphyrin frameworks for efficient ambient fixation of CO2 to cyclic carbonates
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A family of multivariate metal-organic frameworks (MOFs) with three-kinds of orderly distributed metals were designed and successfully synthesized by combining metalloporphyrin sheets and pentafluoride (NbOF5)2? pillars. Benefiting from the cooperative nature of open-metal-sites (OMSs) within porphyrins, specific pore-sizes, coupled with fluorine-rich electrostatic environments, the fabricated materials demonstrated high affinity toward CO2, and good catalytic performance, structural robustness, and good recyclability for the conversion of epoxides and CO2 to cyclic carbonates at room temperature and 1 atm pressure.
- He, Liang,Nath, Jayanta Kumar,Lin, Qipu
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- Synthesis of carbonates from CO2 and epoxides catalyzed by the system of N-heterocyclic carbene, hydrogen bond donor, CrCl2, and tetrabutylammonium bromide
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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.
- Zhang, Kuikui,Liu, Zhenbang,Liu, Ning
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- Aluminium based binary catalytic system for the solvent free conversion of CO2 to carbonates with high activity and selectivity
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An easily prepared and low-cost aluminium based metal complex catalyst was prepared using kojic acid (Hkoj) as a ligand, and this developed oxo-coordinated Al(koj)3 complex showed high activity and selectivity for the CO2 fixation reaction with epoxides under mild conditions without any organic solvents. Various cyclic carbonates were obtained in excellent yields (up to 99%). This stable catalytically active Al(koj)3 has strong Lewis acidity for the activation of epoxides, and meanwhile the hydroxy group in Al(koj)3 may play a role in boosting the catalytic activity through possible hydrogen bonding interactions with the epoxide.
- Ma, Ran,Sun, Haojie,Cui, Yuanzhi
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- A Mechanochemical-Assisted Synthesis of Boron, Nitrogen Co-Doped Porous Carbons as Metal-Free Catalysts
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A green and convenient solid-state method assisted by mechanical energy is employed for the synthesis of boron (B) and nitrogen (N) co-doped porous carbons (B,N-Cs). Glutamic acid (Glu) and boric acid (H3BO3) are used as the N-containing carbon precursor and boron source, respectively. This method is easy to perform and proved to be efficient towards co-doping B and N into the carbon matrix with high contents of B (7 atom %) and N (10 atom %). By adjusting the molar ratio of H3BO3 to Glu, the surface chemical states of B and N could be readily modulated. When increasing H3BO3 dosage, the pore size of B,N-Cs could be tuned ranging from micropores to mesopores with a Brunauer–Emmett–Teller (BET) surface area up to 940 m2 g?1. Finally, the B,N-Cs were applied as metal-free catalysts for the cycloaddition of CO2 to epoxides, which outperform the N-doped carbon catalyst (NC-900) and the physically mixed catalyst of NC-900/B4C. The enhanced activity is attributed to the cooperative effect between B and N sites. X-ray photoelectron spectroscopy (XPS) analysis reveals that BN3 in the B,N-Cs serves as a critical active site for the cooperative catalysis.
- Zhao, Li-Yuan,Dong, Xiao-Ling,Chen, Jun-Yue,Lu, An-Hui
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- Amino acids/superbases as eco-friendly catalyst system for the synthesis of cyclic carbonates under metal-free and halide-free conditions
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An eco-friendly and efficient binary catalyst system of superbases and amino acids was developed for the synthesis of cyclic carbonates from epoxides and CO2 under metal-free and halide-free conditions. Among the various amino acids and superbases systems tested, the L-histidine/1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) system achieved the highest conversion of propylene oxide and selectivity of propylene carbonate. The effect of various reaction parameters was evaluated. A possible catalyst mechanism for L-histidine synergized with DBU in the ring opening of epoxide and DBU introduced CO2 activation. The process herein represents a green, simple, and cost-effective route for the chemical fixation of CO2 into cyclic carbonates.
- Qi, Yaqiong,Cheng, Weiguo,Xu, Fei,Chen, Shengli,Zhang, Suojiang
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- Fixation of atmospheric CO2as C1-feedstock by nickel(ii) complexes
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The development of molecular catalysts for the activation and conversion of atmospheric carbon dioxide (CO2) into a value-added product is a great challenge. A series of nickel(ii) complexes, [Ni(L)(CH3CN)3](BPh4)2,1-4of diazepane based ligands, 4-methyl-1-[(pyridin-2-yl-methyl)]-1,4-diazepane (L1), 4-methyl-1-[2-(pyridine-2-yl)ethyl]-1,4-diazepane (L2), 4-methyl-1-[(quinoline-2-yl)-methyl]-1,4-diazepane (L3) and 1-[(4-methoxy-3,5-dimethyl-pyridin-2-yl)methyl]-4-methyl-1,4-diazepane (L4), have been synthesized and characterized as catalysts for the activation of atmospheric CO2. The single-crystal X-ray structure of1shows a distorted octahedral geometry with acis-β configuration around the NiN6coordination sphere. All the complexes are used as catalysts for the conversion of atmospheric CO2and epoxides into cyclic carbonates at 1 atmosphere (atm) pressure and in the presence of Et3N. Catalyst4was found to be the most efficient catalyst and showed a 31% formation of cyclic carbonates with a TON of 620 under 1 atm air as the CO2source. This yield was enhanced to 94% with a TON of 1880 under 1 atm pure CO2gas and it is the highest catalytic efficiency known for nickel(ii)-based catalysts. Catalyst4enabled the transformation of a wide range of epoxides (eight examples) into corresponding cyclic carbonates with excellent selectivity (>99%) and yields of 59-94% and 11-31% under pure CO2and atmospheric CO2, respectively. The catalytic efficiency is strongly influenced by the electronic nature of the complexes. The CO2fixation reactions without an epoxide substrate led to the formation of the carbonate bridged dinuclear nickel(ii) complexes [(LNiII)2CO3](BPh4)21a-4a, which are speculated as catalytically active intermediates. The formation of these species was accompanied by the formation of new absorption bands around 592-681 nm and was further confirmed by the ESI-MS and IR spectral studies. The molecular structures of these carbonate-bridged key intermediates were determined by X-ray analysis. The structures contain two Ni2+-centers bridgedviaa carbonate ion that originated from CO2. Distorted square pyramidal geometries are adopted around each Ni(ii) center. All these results support that CO2fixation reactions occurviaCO2-bound nickel key intermediates.
- Mayilmurugan, Ramasamy,Muthuramalingam, Sethuraman,Velusamy, Marappan
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- Hemilabile N-heterocyclic carbene and nitrogen ligands on Fe (II) catalyst for utilization of CO2 into cyclic carbonate
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Six Fe (II) complexes were synthesized based on the concept of the hemilability of hybrid ligands, and their catalytic behaviors and performances were evaluated for the fixation of CO2 via the cycloaddition of epoxides. The catalytic potential of the Fe (II) complexes, in combination with bis(triphenylphosphoranylidene)ammonium chloride, have been proved to achieve the efficient conversion in some challenging substrates such as internal, disubstituted epoxides, oxetanes, and fatty acid-derived epoxides for synthesis of cyclic carbonates under the mild reaction conditions. Ultraviolet–visible and in situ Fourier transform infrared spectroscopy experiments as well as our previous coordination of Ni complexes studies revealed that the origin of activity of Fe (II) complexes might be attributed to the trans effect between N-heterocyclic carbene ligands and pyridine nitrogen donors.
- Chen, Fei,Tao, Sheng,Liu, Ning,Guo, Cheng,Dai, Bin
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- DIASTEREOSELECTIVE FORMATION OF CYCLIC CARBONATES BY CYCLIZATION OF ALKENYLOXYCARBONYLOXY RADICALS
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The alkenyloxycarbonyloxy radical (8) derived from trans-hex-2-en-1-ol via the N-hydroxypyridin-2-thione carbonate (4) undergoes fast (kc > 4.0 x 108 s-1 at 80 deg C) cyclization exclusively in the exo mode to give a cyclic radical (9) which is converted into products (6, 7) by diastereoselective SH2 reactions; radicals derived from homoallylic alcohols behave similarly.
- Beckwith, Athelstan L. J.,Davison, G. E.
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- Dinuclear [OSSO]-Fe complexes for the reaction of CO2with epoxides
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A dinuclear iron-based catalytic system, bearing a new alkyl-bridged bis-[OSSO]-type ligand, for the coupling of CO2with epoxides is reported. A turnover frequency up to 1680 h?1was recorded for propylene carbonate formation. A bimetallic cooperative reaction mechanism is proposed on the basis of kinetic analyses. These results give insights into the development of more efficient catalysts.
- Capacchione, Carmine,D'Aniello, Sara,Della Monica, Francesco,Lamparelli, David Hermann,Paradiso, Veronica,Rieger, Bernhard
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- Availability of other aliphatic polycarbonates derived from geometric isomers of butene oxide and carbon dioxide coupling reactions
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In this study, we investigate the selectivity for copolymer versus cyclic carbonate production from the coupling of isomeric forms of butene oxide with carbon dioxide in the presence of binary and bifunctional cobalt(III) and chromium(III) salicylaldimine catalysts. Use of the less problematic 1-butene oxide has previously been reported to preferentially afford copolymer from its coupling with CO2. Of the epoxides, cis- and trans-2-butene oxide and isobutene oxide, only cis-2-butene oxide was shown to selectively provide polycarbonate, with both cobalt(III) catalysts being more effective than their chromium(III) analogues. The binary chromium catalyst system produced both cis- and trans-cyclic carbonates from the cycloaddition of CO2 and cis-2-butene oxide, whereas, the corresponding cobalt(III) catalyst selectively yielded 75.4% copolymer at 40 °C with the remaining product being trans-cyclic carbonate. In this instance, the trans-cyclic carbonate results from copolymer degradation, consistent with the observation that depolymerization of the copolymer derived from CO2 and cis-2-butene oxide affords trans-cyclic carbonate exclusively. By way of contrast, both bifunctional catalysts were efficient at producing copolymers with selectivities of 100% (40 °C) and 79% (70 °C) for the cobalt and chromium catalysts, respectively. The glass transition temperature (Tg) of poly(trans-2-butene carbonate) derived from the completely alternating copolymerization of CO2 and cis-2-butene oxide was found to be 68 °C, some 30 deg higher than poly(propylene carbonate). Furthermore, it was shown to have a significantly lower % elongation-to-break value than poly(propylene carbonate).
- Darensbourg, Donald J.,Chung, Wan-Chun
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- Thiourea-Based Bifunctional Ionic Liquids as Highly Efficient Catalysts for the Cycloaddition of CO2 to Epoxides
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Abstract: A series of thiourea-based ionic liquids (TBILs) were developed as efficient catalysts for the synthesis of cyclic carbonates by the cycloaddition of CO2 with epoxides under metal-, cocatalyst- and solvent-free conditions. Different substituted groups including electron donating and withdrawing groups were introduced onto the para-position of the aromatic ring in cation of TBILs. The effect of the catalyst structures on the reaction activity was systematically investigated. Among the ionic liquids, TBIL3 with substituted OCH3 group showed the best performance with 99% propylene oxide conversion as well as 99% propylene carbonate selectivity under mild conditions (1.5?MPa, 130 °C and 3?h) without any co-solvent. It was demonstrated that two secondary amine groups of the thiourea unit could dually activate the epoxides and CO2 and have a synergetic effect with the halide anion. Graphical Abstract: [Figure not available: see fulltext.].
- Xu, Fei,Cheng, Weiguo,Yao, Xiaoqian,Sun, Jian,Sun, Wei,Zhang, Suojiang
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- Polar group and defect engineering in a metal-organic framework: Synergistic promotion of carbon dioxide sorption and conversion
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Abstract A sulfone-functionalized metal-organic framework (MOF), USTC-253, has been synthesized that exhibits a much higher CO2 uptake capacity (168-182 %) than the corresponding unfurnished MOFs. The introduction of trifluoroacetic acid (TFA) during the synthesis of USTC-253 affords defect-containing USTC-253-TFA with exposed metal centers, which has an increased CO2 uptake (167 %) compared to pristine USTC-253. USTC-253-TFA exhibits a very high ideal adsorption solution theory selectivity (S=75) to CO2 over N2 at 298K. In addition, USTC-253-TFA demonstrates good catalytic activity and recyclability in the cycloaddition of CO2 and epoxide at room temperature under 1bar CO2 pressure as a result of the presence of Lewis and Bronsted acid sites, which were evaluated by diffuse reflectance infrared Fourier transform spectroscopy with a CO probe molecule. We propose that the CO2 adsorption capability has a positive correlation with the catalytic performance toward CO2 conversion.
- Jiang, Zhuo-Rui,Wang, Hengwei,Hu, Yingli,Lu, Junling,Jiang, Hai-Long
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- An efficient and recyclable tetraoxo-coordinated zinc catalyst for the cycloaddition of epoxides with carbon dioxide at atmospheric pressure
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An efficient and recyclable catalytic system of a Zn(O)4-coordinated complex e.g. 2-hydroxypyridine N-oxide zinc(ii), Zn(OPO)2 and tetrabutylammonium iodide (TBAI) was developed for the cyclic carbonate synthesis from epoxides and CO2 without the use of any organic solvents. This easily prepared, low-toxic Zn(OPO)2 may have a strong Lewis acidity for the activation of epoxides and exhibited high activity (TOF up to 22 000 h-1) even at a CO2 pressure as low as 1 bar with a broad substrate scope. Furthermore, the catalyst can be easily recovered and reused five times without a significant loss of its catalytic activity.
- Ma, Ran,He, Liang-Nian,Zhou, Yue-Biao
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- 8-Hydroxyquinolates of trivalent metals as new catalysts for the reaction of CO2 with epoxides
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Tris(8-hydroxyquinolates) of aluminum(III), chromium(III), and iron(III) in the presence of triphenylphosphine oxide efficiently catalyze the formation of alkylenecarbonates by the reaction of CO2 with oxiranes, viz., propylene oxide, but-2-ene oxides, and isobutylene oxide. The catalytic system is active at 140-170 deg C and a CO2 pressure of 15-100 atm.
- Lermontov, S. A.,Velikokhat'ko, T. N.,Golovin, E. Yu.,Zavel'skii, V. O.
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- Self-Assembly of Luminescent Lanthanide Mesocates as Efficient Catalysts for Transforming Carbon Dioxide into Cyclic Carbonates
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Four dinuclear lanthanide mesocates were fabricated through a spontaneous self-assembly method, and the formation of these complexes was well studied by their absorption and emission spectra. These stable complexes were also found to exhibit superior performance in catalyzing the coupling reaction between epoxides and CO2 with excellent recyclability. Moreover, the catalysts could be prepared on large scale. Moreover, the Yb and Lu complexes featured emissions in the near-infrared and visible regions, respectively, and their intensities and lifetimes could be used for identification purposes. Thus, this new approach can be used to construct promising lanthanide complexes as efficient catalysts and it identifies the possibility to better study a catalytic reaction with a luminescent catalyst.
- Han, Qingxin,Wang, Li,Shi, Zhaohua,Xu, Cong,Dong, Zhe,Mou, Zuolin,Liu, Weisheng
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- Cooperative calcium-based catalysis with 1,8-diazabicyclo[5.4.0]-undec-7-ene for the cycloaddition of epoxides with CO2 at atmospheric pressure
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A bifuncational catalytic system consisting of CaBr2 and 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) was developed for the efficient fixation of CO2 with epoxides to cyclic carbonates. Such a dual catalysis facilitates the reaction to proceed smoothly at atmospheric CO2 pressure, presumably due to the simultaneous activation of CO2 by DBU and epoxides by CaBr2. In addition, the activation role of CaBr2 was also studied using density functional theory (DFT) calculations. A plausible mechanism involving the DBU-CO2 adduct-assisted ring opening path and the bromide anion-promoted ring opening path is proposed, in combination with the activation of epoxides by the calcium cation. This process represents a simple, cost-effective and biocompatible route to obtain cyclic carbonates from CO2 under mild conditions, especially at atmospheric CO2 pressure.
- Liu, Xi,Zhang, Shuai,Song, Qing-Wen,Liu, Xiao-Fang,Ma, Ran,He, Liang-Nian
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- Pyridine-bridged bifunctional organocatalysts for the synthesis of cyclic carbonates from carbon dioxide
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Hydroxyl- and carboxyl-functionalized imidazolium halides are used as efficient bifunctional organocatalysts for the synthesis of cyclic carbonates from CO2 and epoxides under mild reaction conditions. Control experiments suggest that the cycloaddition reaction is realized by the combination of the nucleophilic halide anions with hydroxyl and carboxyl groups as hydrogen bond donors. Moreover, the bifunctional organocatalysts can be easily recycled five times by simple filtration; however, a loss of activity was observed.
- Liu, Quan-Yao,Shi, Lei,Liu, Ning
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- Boron-doped melamine-derived carbon nitrides tailored by ionic liquids for catalytic conversion of CO2 into cyclic carbonates
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A new approach to tailoring edge active groups of graphitic carbon nitrides for catalytic conversion of CO2 into cyclic carbonates was proposed in this work. To improve the catalytic performance, boron-doped melamine-derived graphitic carbon nitrides (MCNB) with numerous exposed edge defects were prepared by using 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4) as the soft template and boron source. Different mass ratios of BmimBF4 to melamine were explored for MCNB preparation, MCNB(x) (x is the mass ratio) with different polymerization degree, pore structure and boron doping content were obtained, and the relationship between MCNB properties and the corresponding catalytic activity was then investigated. With low polymerization degree, abundant meso-macroporous structure and small amounts of boron (1.59 atm%) doped in the skeleton, MCNB(0.01) exhibited better catalytic performance and could be suitable for various epoxide substrates with the yield of cyclic carbonates up to 89.0% at 130°C in 6 h. According to the XPS analysis and DFT calculation results, the active centers were confirmed to be the partially-condensed amino groups in edge defects, which were enhanced by moderate doping of boron in the skeleton.
- Su, Qian,Yao, Xiaoqian,Cheng, Weiguo,Zhang, Suojiang
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- Zinc 2-: N -methyl N-confused porphyrin: An efficient catalyst for the conversion of CO2 into cyclic carbonates
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A zinc 2-N-methyl N-confused porphyrin (Zn(NCP)Cl) catalyst was developed for the solvent-free synthesis of cyclic carbonates from epoxides and CO2. Zn(NCP)Cl exhibited very high catalytic activity. Using this catalyst, a series of epoxides have been converted into the corresponding cyclic carbonates in high yields and selectivity (>99%). The turnover frequency (TOF) value reached 266667 h-1 for the conversion of CO2 with epichlorohydrin into cyclic carbonate at 120 °C and an initial CO2 pressure of 1.7 MPa within 3 h. Furthermore, an almost quantitative cyclic carbonate product was achieved under atmospheric CO2 within 24 h. X-ray structural analysis of Zn(NCP)Cl reveals that the Zn2+ ion is four-coordinate, surrounded by three nitrogen atoms from the N-confused porphyrin and a chlorine atom. Due to the strong electron-withdrawing ability of chloride, zinc shows strong acidity, thereby enhancing its ability to activate epoxide. Density functional theory calculations (DFT) suggest that the ring-opening of epoxide is the rate-determining step of the catalytic cycle.
- Ge, Yuansheng,Cheng, Guoe,Xu, Nanfeng,Wang, Weizhou,Ke, Hanzhong
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- Nano-sized polydopamine-based biomimetic catalyst for the efficient synthesis of cyclic carbonates
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Polydopamine (PDA) is a biocompatible and biomimetic material. Herein, nano-sized PDA sphere was prepared and the combination of alkali metal halide and PDA was investigated as a catalyst for the synthesis of cyclic carbonates from epoxide and carbon dioxide. It was found that the activity of PDA could be obviously enhanced in the presence of alkali metal salts. After reaction, the catalyst and the products could be separated easily, and the catalyst was reusable. The origin of the high catalytic efficiency and the reaction mechanism were also discussed.
- Yang, Zifeng,Sun, Jian,Liu, Xiaomin,Su, Qian,Liu, Ying,Li, Qian,Zhang, Suojiang
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- Cycloaddition of carbon dioxide and epoxides catalyzed by rare earth metal complexes bearing a Trost ligand
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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.
- Cheng, Jun,Lu, Chengrong,Zhao, Bei
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p. 13096 - 13103
(2021/08/04)
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- Radii-dependent self-assembly polynuclear lanthanide complexes as catalysts for CO2transformation into cyclic carbonates
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Multidentate acylhydrazone ligand dinuclear and pentanuclear complexes were constructed with the lighter lanthanide ions (La3+, Pr3+, and Eu3+) and the heavier lanthanide ions (Tb3+ and Er3+), respectively, which indicated the structural change of polynuclear lanthanide complexes is controlled by the ionic radii of Ln3+ ions. In addition, these polynuclear lanthanide complexes as catalysts in combination with tetrabutylammonium bromide (TBAB) as a co-catalyst displayed excellent catalytic performance for CO2 conversion to obtain cyclic carbonates with a wide scope of substrates and high selectivity under solvent-free conditions. This journal is
- Chen, Changjuan,Zhang, Aijiang
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p. 20155 - 20163
(2021/12/02)
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- Heterobimetallic rare earth metal-zinc catalysts for reactions of epoxides and CO2under ambient conditions
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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.
- Yin, Kuan,Hua, Linyan,Qu, Liye,Yao, Quanyou,Wang, Yaorong,Yuan, Dan,You, Hongpeng,Yao, Yingming
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p. 1453 - 1464
(2021/02/09)
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- Catalytic, Kinetic, and Mechanistic Insights into the Fixation of CO2 with Epoxides Catalyzed by Phenol-Functionalized Phosphonium Salts
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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.
- Hu, Yuya,Wei, Zhihong,Frey, Anna,Kubis, Christoph,Ren, Chang-Yue,Spannenberg, Anke,Jiao, Haijun,Werner, Thomas
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p. 363 - 372
(2020/11/30)
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- N-Heterocyclic carbene-nitrogen molybdenum catalysts for utilization of CO2
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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.
- Chen, Fei,Tao, Sheng,Liu, Ning,Dai, Bin
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- Method for catalytically synthesizing cyclic carbonate based on multi-active-center type ionic liquid
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The invention discloses a method for catalytically synthesizing cyclic carbonate based on multi-active-center type ionic liquid. A series of multi-active-center type ionic liquids are designed, efficient conversion of cyclic carbonate can be achieved in a short time under the condition that the use amount of the ionic liquids is very small in the reaction, and the stability and the activity of theionic liquids are superior to those of single-active-center type ionic liquids. The method is characterized by comprising two stages: an ionic liquid synthesis stage and a catalytic cycloaddition reaction stage. In the synthesis stage of the ionic liquid, the reaction is carried out in a nitrogen atmosphere, the reaction temperature is 20-200 DEG C, the reaction pressure is normal pressure, and the reaction time is 1-48 hours, so that the multi-active-center type ionic liquid is obtained; wherein the catalytic cycloaddition reaction stage comprises that the ionic liquid is adopted as a catalyst, the reaction temperature is 30-180 DEG C, the reaction pressure is 0.1-8 MPa, the reaction time is 0.25-24 h, the product cyclic carbonate is obtained, and the anion of the ionic liquid can promote the ring opening of the epoxy compound in the process. The catalytic process has the following advantages that through the design of a multi-active center site structure, efficient conversion of thereaction is achieved, meanwhile, cyclic carbonate can also be used as a raw material source of efficient chemicals such as downstream dimethyl carbonate and ethylene glycol, and good economical efficiency and energy saving performance are achieved.
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Paragraph 0065; 0109-0111
(2021/01/29)
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- Method for preparing cyclic carbonate by immobilizing CO2 under catalysis of organic boric acid
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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%.
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Paragraph 0191-0196
(2021/06/22)
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- Microwave-Assisted Synthesis of Tris-Anderson Polyoxometalates for Facile CO2Cycloaddition
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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.
- Yu, Wei-Dong,Zhang, Yin,Han, Yu-Yang,Li, Bin,Shao, Sai,Zhang, Le-Ping,Xie, Hong-Ke,Yan, Jun
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supporting information
p. 3980 - 3987
(2021/04/07)
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- Catalytic Formation of Cyclic Carbonates using Gallium Aminotrisphenolate Compounds and Comparison to their Aluminium Congeners: A Combined Experimental and Computational Study
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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.
- álvarez-Miguel, Lucía,Burgoa, Jesús Damián,Mosquera, Marta E. G.,Hamilton, Alex,Whiteoak, Christopher J.
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p. 4099 - 4110
(2021/08/23)
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- CO2 fixation by cycloaddition of mono/disubstituted epoxides using acyl amide decorated Co(II) MOF as a synergistic heterogeneous catalyst
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Dual ligand 3D MOF {[Co(BDC)(L)]·2H2O.xG}n (CoMOF-2; G = guest) was synthesized via simple room temperature stirring method. Bulk Phase purity of CoMOF-2 was assessed by various physicochemical methods including X‐ray diffraction (XRD). CO2 adsorption isotherms indicate that activated CoMOF-2 is efficient in CO2 uptake, which has been utilized for the CO2-Epoxide cycloaddition. The catalytic ability of CoMOF-2 as a binary catalyst revealed excellent results for variety of monosubstituted epoxide under solvent‐free conditions (1 bar/40 °C/12 h). Interestingly CoMOF-2/KI also showed great potential as a heterogeneous catalyst for disubstituted epoxide (10 bar/120 °C/24 h) with high yields/selectivity. The catalytic efficiency of the present investigation for scantly explored disubstituted epoxide is better/on par with the earlier reports and the recyclability of the catalyst is an added advantage. Probable mechanism for the catalytic reaction is deduced and verified the representative energy profile for cycloaddition of CO2-Cyclohexane oxide (CHO) by DFT calculation.
- Patel, Parth,Parmar, Bhavesh,Pillai, Renjith S.,Ansari, Amamudin,Khan, Noor-ul H.,Suresh, Eringathodi
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- Efficient conversion of CO2into cyclic carbonates at room temperature catalyzed by Al-salen and imidazolium hydrogen carbonate ionic liquids
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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.
- Hu, Xingbang,Liu, Jia,Liu, Ying,Yang, Guoqiang,Zhang, Dejin,Zhang, Zhibing
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supporting information
p. 4509 - 4515
(2020/08/10)
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- Efficient Solvent-Free Synthesis of Cyclic Carbonates from the Cycloaddition of Carbon Dioxide and Epoxides Catalyzed by New Imidazolinium Functionalized Metal Complexes Under 0.1?MPa
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Abstract: A series of imidazolinium functionalized metal complexes were prepared as efficient and recyclable homogeneous catalysts for the synthesis of cyclic carbonates via the coupling reaction of carbon dioxide and epoxides in the absence of co-catalysts and solvent. Due to the synergistic effect between the metal center as Lewis acid and the imidazolinium groups with halide anions as Lewis base, these catalysts exhibited excellent catalytic capability. Particularly, high turnover frequency (TOF) values of (1174, 1240 and 1262?h?1) for bifunctional catalysts (2c, 2i and 2j, respectively) were achieved via adjusting reaction parameters. These catalysts also showed excellent catalytic performances under atmospheric pressure. Recyclability test showed that this kind of bifunctional catalyst can be easily recovered and reused for at least five times without dramatic loss of activity and selectivity. The optimum reaction conditions were also screened as (120?°C, 1.0?MPa CO2 and 2?h). The catalyst could also be applied to a variety of substrates and be used for a long time with high catalytic activities. We also performed the Kinetic studies, which suggested that the activity of catalysts following the order I? > Br? > Cl?. Moreover, a plausible reaction mechanism by imidazolinium functionalized metal complexes was proposed. Graphic Abstract: [Figure not available: see fulltext.].
- Zhang, Qian,Yu, Peng,Lei, Bo,Yang, Hai-Jian,Hu, Juncheng,Wang, Lihua,Zhou, Tengfei,Jiang, Qingqing,Zhu, Junjiang,Han, Buxing
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p. 2537 - 2548
(2020/03/11)
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- Rational Design of Cobalt Complexes Based on the trans Effect of Hybrid Ligands and Evaluation of their Catalytic Activity in the Cycloaddition of Carbon Dioxide with Epoxide
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A series of cobalt complexes are presented as effective catalysts for the synthesis of cyclic carbonates from epoxides and CO2. The catalytic potentials of the cobalt complexes, in combination with tetrabutylammonium bromide, have been demonstrated to solve some challenges in the synthesis of cyclic carbonates, including the room-temperature conversion of terminal epoxides and activation-challenging substrates such as internal epoxides and fatty acid derived epoxides. A key factor in the success of the strategy is the use of cobalt complexes that are prepared on the basis of the trans effect of hybrid ligands. The trans effect between N-heterocyclic carbenes and acetylacetone has been proved by a number of spectroscopic measurements, including UV-vis, ESI-MS, EPR, and in situ FT-IR and by DFT calculations; these support the notion that acetylacetone prefers to dissociate from the cobalt center, which will result in one coordination site for the activation of a substrate molecule at the cobalt atom and thus give rise to high reactivity.
- Bu, Qingqing,Dai, Bin,Liu, Ning,Liu, Qiuli,Song, Wen-Yue,Wei, Donghui
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p. 3546 - 3561
(2020/11/02)
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- Linear Metal-Organic Frameworks Based on Bis(1-Benzotriazolyl)methane and Zinc and Copper Nitrates
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Abstract: Complexes {[(Zn(Bbtm)(H2O)4](NO3)2}n (I) and [Cu(Вbtm)(NO3)2]n (II) are formed due to the reactions of solutions of zinc and copper(II) nitrates with the bis(1,1'-1,2,3-benzotriazolyl)methane ligand (Bbtm). Their crystal structures are determined by X-ray diffraction analysis (CIF files ССDС nos. 1963126 (I) and 1963127 (II)). Complex I is a linear metal-organic framework (1D-MOF) in which the octahedral coordination of the central atom is provided by four water molecules and two nitrogen atoms of two Bbtm molecules in the trans position. In the structure of complex II, the coordination sphere of copper contains two nitrogen atoms of the Вbtm ligands and four oxygen atoms of two nitrate anions, one of which is bridging like the Вbtm ligand. This makes it possible to describe the structure of complex II as 3D-MOF. The luminescence spectra are recorded for earlier undescribed compound I. The emission maximum is observed at 363?nm. Compound I is also tested as a catalyst for the cycloaddition of СО2 to epoxides. The synthesized MOF efficiently catalyzes the cycloaddition reactions for both monosubstituted and disubstituted epoxides.
- Belousov, Yu. A.,Bezzubov, S. I.,Bondarenko, G. N.,Ganina, O. G.,Goncharenko, V. E.,Taidakov, I. V.
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p. 805 - 811
(2020/12/14)
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- A non-metal Acen-H catalyst for the chemical fixation of CO2 into cyclic carbonates under solvent- and halide-free mild reaction conditions
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A metal-free Acen-H catalyst was effectively synthesized by a single step reflux method and successfully tested for the cycloaddition of CO2 with epoxides to synthesize cyclic carbonates. The Acen-H catalyst exhibited high activity and selectivity for the cycloaddition reaction in the absence of co-catalysts (halides) and solvents at mild reaction conditions of a reaction temperature of 110 °C and a reaction pressure of 1 MPa. Under the optimized reaction conditions, some of the epoxides were successfully converted into corresponding cyclic carbonates with a highest yield of ~98.5%. The composition and structure of the homogeneous catalyst was then systematically evaluated and the reaction kinetics and a plausible reaction mechanism for the cycloaddition of CO2 with epoxides were proposed. The density functional theory (DFT) calculation provided a corroborated elucidation for the proposed mechanism. The catalytic activity of the Acen-H catalyst was found to be originated from the active hydrogen bond donors (-O-H, =N---H) and imino groups present (-N=) in it, which played a synergistic role in the adsorption and activation of reactants as confirmed by the DFT studies. The structural characteristics of the catalyst was found to be crucial for the cycloaddition of CO2 with epoxides.
- Chen, Shiyu,Jia, Qingming,Liu, Yi,Pudukudy, Manoj,Shan, Shaoyun,Wang, Junya,Yue, Zhongxiao,Zhao, Wenbo
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- Synthesis of cyclic carbonates by ruthenium(VI) bis -imido porphyrin/TBACl-catalyzed reaction of epoxide with CO2
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The catalytic activity of the ruthenium(VI) bis-imido porphyrin complex/TBACl binary system in promoting the CO2 cycloaddition to epoxides forming cyclic carbonates is here reported. The system was very efficient in catalyzing the conversion of differently substituted epoxides under mild experimental conditions (100 degC and 0.6 MPa of CO2). Even if the sole TBACl resulted active under the optimized experimental conditions, the addition of ruthenium species was fundamental to maximizing the reaction productivity both in terms of epoxide conversions and cyclic carbonate selectivities. A preliminary mechanistic study indicated a positive role of ruthenium imido nitrogen atom in activating carbon dioxide.
- Damiano, Caterina,Sonzini, Paolo,Intrieri, Daniela,Gallo, Emma
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p. 809 - 816
(2020/01/21)
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- Self-assembly of tetranuclear 3d-4f helicates as highly efficient catalysts for CO2cycloaddition reactions under mild conditions
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A series of novel asymmetry 3d-4f helicates Zn3LnL4 (H2L = N-(2-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino)ethyl)-2-hydroxybenzamide, Ln = Dy(1), Gd(2), Er(3)) were successfully constructed via selective incorporation of groups with different coordination capabilities. These helicates with the well-defined conformation demonstrate high catalytic efficiency in converting CO2 to cyclic carbonates under mild conditions. Particularly, Zn3ErL4 showed superior catalytic performance with high catalytic activity (TOF up to 38?000 h-1) and extraordinary selectivity (up to 99%) across the wide substrate scope. Meanwhile, these 3d-4f helicates showed stable catalytic performance without being influenced by the moisture and air. The results presented herein highlight an important consideration for constructing heterometallic and asymmetric complexes for catalyzing CO2 conversion.
- Chen, Wanmin,Gao, Guoshu,Liu, Weisheng,Wang, Li,Yang, Huan
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p. 10270 - 10277
(2020/08/17)
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- Efficient catalytic conversion of terminal/internal epoxides to cyclic carbonates by porous Co(ii) MOF under ambient conditions: Structure-property correlation and computational studies
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A mixed ligand three-dimensional neutral porous framework, {[Co(OBA)(L)]xG}n (CoMOF-1) (H2OBA = 4,4′-oxybis(benzoic acid); L = (E)-N′-(pyridin-4-ylmethylene)isonicotinohydrazide; G = DMF, EtOH, MeOH, H2O), was successfully synthesized via a hydrothermal and reflux method. The activated MOF (CoMOF-1′) not only showed good affinity toward CO2 molecules, but also exhibited a good catalytic performance for CO2 conversion with a variety of terminal and internal epoxides. Grand Canonical Monte Carlo (GCMC) simulation proved the strong interactions of CO2 molecules with the amide functional groups of the MOF. The Lewis acidity of the Co(ii) centers endowed by the weakly chelated carboxylate from the OBA ligand and Lewis basicity originating from the acylamide functionality of the pyridyl-based Schiff base ligand L favored the efficient solvent-free cycloaddition reaction of CO2 with different epoxides. Strikingly, CoMOF-1′ exhibited good catalytic efficiency for CO2 coupled with various terminal epoxides at ambient temperature and pressure (1 bar, 60 °C, 12 h) and with a variety of internal epoxides at moderate reaction conditions (30 bar, 100 °C, and 8 h) with good yield and recyclability. Further, the binary heterogeneous catalyst showed good chemical stability, easy separation and recyclability (6 cycles) without a noticeable decrease in activity. To the best of our knowledge, this is the first investigation on a neutral porous MOF as a potential heterogeneous solvent-free catalyst toward CO2 utilization for internal epoxide under moderate reaction conditions. Based on the structural evidence, a plausible mechanism for the cycloaddition reaction was proposed, which is further reinforced by the relative energy of each stage obtained from periodic Density Functional Theory (DFT) calculations.
- Parmar, Bhavesh,Patel, Parth,Pillai, Renjith S.,Kureshy, Rukhsana I.,Khan, Noor-Ul H.,Suresh, Eringathodi
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supporting information
p. 2884 - 2894
(2019/02/12)
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- PROCESS FOR PREPARING CARBONATES BY ADDITION OF CO2 WITH AN EPOXIDE
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The invention relates to a process for preparing cyclic organic carbonates, characterized in that an epoxide is initially charged in the presence of CO2 and then a catalyst is added.
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Page/Page column 38-39
(2020/01/08)
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- Transfer hydrogenation of cyclic carbonates and polycarbonate to methanol and diols by iron pincer catalysts
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Herein, we report the first example on the use of an earth-abundant metal complex as the catalyst for the transfer hydrogenation of cyclic carbonates to methanol and diols. The advantage of this method is the use of isopropanol as the hydrogen source, thus avoiding the handling of flammable hydrogen under high pressure. The reaction offers an indirect route for the reduction of CO2 to methanol. In addition, poly(propylene carbonate) was converted to methanol and propylene glycol. This methodology can be considered as an attractive opportunity for the chemical recycling of polycarbonates.
- Liu, Xin,De Vries, Johannes G.,Werner, Thomas
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p. 5248 - 5255
(2019/10/11)
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- Synthesis of Homo- And Heteronuclear Rare-Earth Metal Complexes Stabilized by Ethanolamine-Bridged Bis(phenolato) Ligands and Their Application in Catalyzing Reactions of CO2 and Epoxides
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A series of homonuclear rare-earth (RE) metal complexes (1Y, 2Yb, 3Nd, and 4La) and heteronuclear RE-Zn complexes (1Y-Zn, 3Nd-Zn, and 5Sm-Zn) stabilized by ethanolamine-bridged bis(phenolato) ligands was prepared and structurally characterized. Heteronuclear complexes are assembled through bridging acetate ligands, and their formation and characterization add to the diversity of 3d-4f complexes. Their activities in mediating reactions of CO2 and epoxides were evaluated and compared. Heteronuclear RE-Zn complexes found application in the copolymerization of cyclohexene oxide and CO2, giving rise to acetate-group-capped copolymers. Homonuclear complexes showed good activity in catalyzing the cycloaddition of variously monosubstituted epoxides and CO2 (1 bar), generating cyclic carbonates in 65-96% yield. For sterically hindered disubstituted epoxides, good yields of 60-91% were achieved in the presence of 10 bar CO2
- Hua, Linyan,Li, Baoxia,Han, Cuiting,Gao, Pengfei,Wang, Yaorong,Yuan, Dan,Yao, Yingming
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p. 8775 - 8786
(2019/07/03)
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- Zinc single atoms on N-doped carbon: An efficient and stable catalyst for CO2 fixation and conversion
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The cycloaddition of epoxides and carbon dioxide represents a straightforward and atom-efficient method for synthesis of cyclic carbonates and utilization of CO2. So far, homogeneous metal complexes have been mainly applied for such transformations. Here, we describe the synthesis of novel heterogeneous Zn-based catalysts, which were conveniently prepared by pyrolysis of an active-carbon-supported phenanthroline-ligated Zn(OAc)2 complex. Detail structural characterizations proved the existence of single zinc sites in the active material. Compared to a Zn-based nanoparticle (Zn-NP) catalyst, the resulting single metal atom catalyst (SAC) displayed improved activity and stability for the cycloaddition of epoxides. By applying the optimal catalyst, a variety of carbonates were successfully obtained in high yields with good functional group tolerance.
- Cui, Xinjiang,Dai, Xingchao,Surkus, Annette-Enrica,Junge, Kathrin,Kreyenschulte, Carsten,Agostini, Giovanni,Rockstroh, Nils,Beller, Matthias
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p. 1679 - 1685
(2019/11/11)
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- Cu-MOF-Catalyzed Carboxylation of Alkynes and Epoxides
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The catalytic activity of copper-containing heterogeneous catalysts, in particular metal-organic frameworks, zeolites, and alumina-supported nanoparticles, in the carboxylation of terminal alkynes and oxiranes has been evaluated. Temperature dependences of these reactions have been studied.
- Beletskaya, I. P.,Bondarenko, G. N.,Ganina, O. G.,Isaeva, V. I.,Kustov, L. M.
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p. 1813 - 1820
(2020/02/03)
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- Efficient Catalysts In situ Generated from Zinc, Amide and Benzyl Bromide for Epoxide/CO2 Coupling Reaction at Atmospheric Pressure
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Herein, in situ generated efficient catalysts were designed for fixation of CO2 to cyclic carbonates under mild conditions. Zinc bromide and N,N-dibenzyl-N,N-dimethylammonium bromide, being proved as active catalyst species, were in situ generated from cheap Zn powder, dimethyl formamide and benzyl bromide, and catalyzed the cycloaddition reaction of CO2 and various terminal epoxides in moderate to excellent yields at 80 °C and atmospheric pressure of CO2. The protocol circumvents the preparation of active catalysts, simultaneously possesses good catalytic activity under mild conditions.
- Zhang, Shuai,Han, Feng,Yan, Shaorui,He, Mingyue,Miao, Chengxia,He, Liang-Nian
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p. 1311 - 1316
(2019/01/09)
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- Halide-Free and Bifunctional One-Component Catalysts for the Coupling of Carbon Dioxide and Epoxides
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In this paper, we first report a new class of halide-free and bifunctional one-component catalysts for the coupling of CO2 with epoxides. The catalysts do not need halide-based additives or tethered salts attached to the ligand when used for this coupling reaction. As the halide-free and bifunctional one-component catalysts, we chose nonionic and monomeric tetracarbonylchromium(0), tetracarbonylmolybdenum(0), and tetracarbonyltungsten(0) complexes chelated by modified ethylenediamines, namely N,N-dimethylethylenediamine, N,N′-dimethylethylenediamine, N,N,N′-trimethylethylenediamine, and N,N,N′,N′-tetramethylethylenediamine. A simple mixture of M(CO)6 (M = Cr, Mo, and W) with the modified ethylenediamines shows only one-third of the activity achieved with the tetracarbonyl metal complexes precoordinated to the corresponding modified ethylenediamines. Increasing the number of methyl substituents on the nitrogen atoms of the ethylenediamine derivatives as well as the chromium metal center in the metal carbonyl complex significantly enhanced the catalytic activity. Thus, among the 12 catalysts tested, tetracarbonyl(tetramethylethylenediamine)chromium(0) exhibited the best catalytic activity under the same reaction conditions. Various terminal and internal epoxides were easily converted into the corresponding cyclic carbonates using this chromium system. Calculations based on density functional theory were also carried out to elucidate the mechanism of the coupling reaction.
- Kim, Yoseph,Ryu, Seol,Cho, Woolee,Kim, Min,Park, Myung Hwan,Kim, Youngjo
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supporting information
p. 5922 - 5931
(2019/05/08)
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- Polymeric ionic liquids tailored by different chain groups for the efficient conversion of CO2 into cyclic carbonates
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To realize a high utilization ratio and easy recyclability of catalysts, polymeric ionic liquids as heterogeneous catalysts are tailored for the transformation of CO2 into cyclic carbonates. Herein, six types of self-polymerized polymeric ionic liquids are successfully synthesized by changing the substitutions. Amongst those catalysts, hydroxyl-rich polymeric ionic liquids, especially P(DMAEMA-EtOH)Br, exhibit the highest conversion (96%) to propyl carbonate, which is almost comparable to the reactivity of the bulk ionic liquid. Not only does the presence of a hydroxyl group considerably boost the reactivity, but it also enhances the thermal stability. Molecular dynamics calculations and XPS analysis confirm that the ability of P(DMAEMA-EtOH)Br to combine with epoxide is equivalent to that of its monomer. Dynamic light scattering data reveal that decreasing the hydrodynamic radius of the polymer particles contributes to greater exposure of active sites, resulting in high reactivity. In addition, synergistic catalysis mechanisms are proposed on the basis of the H-NMR studies. This eco-friendly process using polymeric ionic liquids provides a promising catalyst to convert CO2 into value-added chemicals.
- Ying, Ting,Tan, Xin,Su, Qian,Cheng, Weiguo,Dong, Li,Zhang, Suojiang
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p. 2352 - 2361
(2019/05/21)
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- Scorpionate Catalysts for Coupling CO2 and Epoxides to Cyclic Carbonates: A Rational Design Approach for Organocatalysts
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Novel scorpionate-type organocatalysts capable of effectively coupling carbon dioxide and epoxides under mild conditions to afford cyclic propylene carbonates were developed. On the basis of a combined experimental and computational study, a precise mechanistic proposal was developed and rational optimization strategies were identified. The epoxide ring-opening, which requires an iodide as a nucleophile, was enhanced by utilizing an immonium functionality that can form an ion pair with iodide, making the ring-opening process intramolecular. The CO2 activation and cyclic carbonate formation were catalyzed by the concerted action of two hydrogen bonds originating from two phenolic groups placed at the claw positions of the scorpionate scaffold. Electronic tuning of the hydrogen bond donors allowed to identify a new catalyst that can deliver >90% yield for a variety of epoxide substrates within 7 h at room temperature under a CO2 pressure of only 10 bar, and is highly recyclable.
- Hong, Mannkyu,Kim, Yoseph,Kim, Hyejin,Cho, Hee Jin,Baik, Mu-Hyun,Kim, Youngjo
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p. 9370 - 9380
(2018/06/29)
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- Cooperative Multifunctional Organocatalysts for Ambient Conversion of Carbon Dioxide into Cyclic Carbonates
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A series of pincer-type compounds possessing an N-heterocyclic carbene precursor and a carboxyl group as proton transfer agent were synthesized and used as organocatalysts for the cycloaddition of epoxides with CO2. In this context, we have demonstrated the high activity of these one-component organocatalysts in the CO2 transformation to cyclic carbonates under ambient conditions (room temperature, 1 bar of CO2). The catalytic potential of these multifunctional organocatalysts on challenging internal epoxides is particularly deserving of mention because organocatalysts that are able to mediate the cycloaddition reaction of internal epoxides with CO2 under mild conditions remain scarce. The intramolecular synergistic activation mechanism was elucidated by control experiments and DFT calculations.
- Liu, Ning,Xie, Ya-Fei,Wang, Chuan,Li, Shi-Jun,Wei, Donghui,Li, Min,Dai, Bin
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p. 9945 - 9957
(2018/10/15)
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- Zinc–Azatrane Complexes as Efficient Catalysts for the Conversion of Carbon Dioxide into Cyclic Carbonates
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Three Zn complexes based on the N4-tris(2-aminoethyl)amine (tren) chelating ligand and presenting a C3-symmetrical axis were synthesized and successfully applied in the coupling of CO2 with terminal and internal epoxides. These complexes proved to be efficient catalysts if associated with tetrabutylammonium iodide, even at a low catalyst loading (0.005 mol %) or at room temperature, and allowed the production of cyclic carbonates in good to high yields. Variation of the substitution pattern on the tren ligand was shown to impact the catalyst performance greatly, and the highest turnover number (TON) (up to 11 200) was achieved with the less sterically hindered methyl-substituted ZnII–azatrane complex. These binary Zn–azatrane/NBu4I catalytic systems could be applied to a wide range of epoxide substrates, including the more challenging internal epoxides. Moreover, although soluble in the reaction medium, Zn–azatrane catalysts could be easily recovered and reused up to three times without any substantial loss in activity, proving their robustness under the reaction conditions.
- Bousquet, Benjamin,Martinez, Alexandre,Dufaud, Véronique
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p. 843 - 848
(2018/01/27)
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- Novel hydrazine-bridged covalent triazine polymer for CO2 capture and catalytic conversion
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Carbon dioxide (CO2) capture and catalytic conversion has become an attractive and challenging strategy for CO2 utilization since it is an abundant, inexpensive, and renewable C1 resource and a main greenhouse gas. Herein, a novel hydrazine-bridged covalent triazine polymer (HB-CTP) was first designed and synthesized through simple polymerization of cyanuric chloride with 2,4,6-trihydrazinyl-1,3,5-triazine. The resultant HB-CTP exhibited good CO2 capture capacity (8.2 wt%, 0 °C, and 0.1 MPa) as well as satisfactory recyclability after five consecutive adsorption-desorption cycles. Such a polymer was subsequently employed as a metal-free heterogeneous catalyst for the cyclo-addition of CO2 with various epoxides under mild and solvent-free conditions, affording cyclic carbonates with good to excellent yields (67%–99%) and high functional-group tolerance. The incorporation of hydrazine linkages into HB-CTP's architecture was suggested to play the key role in activating epoxides through hydrogen bonding. Moreover, HB-CTP can be reused at least five times without significant loss of its catalytic activity.
- Liu, Anhua,Zhang, Jinju,Lv, Xiaobing
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p. 1320 - 1328
(2018/07/13)
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- Solvent-dependent variations of both structure and catalytic performance in three manganese coordination polymers
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Three new manganese 4′-(3,5-dicarboxyphenyl)-2,2′:6′,2′′′-terpyridine (H2DATP) metal-organic framework materials have been generated through regulating the ratios of a binary solvent mixture (DMA/H2O) under solvothermal conditions. Compound 1 {[Mn2(DATP)(HDATP)(H2O)4](OH)·10H2O}n displaying a one-dimensional (1D) chainlike structure was crystallized from the DMA/H2O mixture with a molar ratio of 1:1, while the two-dimensional (2D) layer species, {[Mn(DATP)(H2O)]·2H2O}n (2) was produced by increasing the ratio of DMA/H2O to 5:1. Interestingly, the crystallization in pure DMA yields a three-dimensional (3D) interpenetrating network {[Mn(DATP)]·4H2O}n (3), featuring higher solvent stability and pH stability than compounds 1 and 2. It is proved that solvent not only influences the structural transformation process of crystals but also has a significant effect on their properties. These three compounds present different catalytic performances in the CO2 cycloaddition to epoxides with various substituent groups into corresponding cyclic carbonates, and only 3 can serve as an efficient and recyclable catalyst at mild temperature.
- Kang, Xiao-Min,Wang, Wen-Min,Yao, Lin-Hong,Ren, Hong-Xia,Zhao, Bin
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supporting information
p. 6986 - 6994
(2018/06/01)
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- Naturally occurring gallic acid derived multifunctional porous polymers for highly efficient CO2 conversion and I2 capture
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Assembly of naturally occurring building blocks into functional materials is of great importance. Herein, we utilized plant-derived polyphenols as building blocks to prepare porous organic polymers (POPs) with multifunctional sites, and a typical POP (denoted as GA-azo-POP) could be achieved from gallic acid through an azo-coupling strategy. As a superior support, GA-azo-POP supported Ag nanoparticles could efficiently catalyze the carboxylative cyclization of propargyl alcohols with CO2 with a very low usage of Ag (0.14 mol%). Meanwhile, the GA-azo-POP showed a high capacity for I2 adsorption (up to 287 mg g-1), which was higher than that of the reported solid materials at a similar I2 concentration. More interestingly, after adsorbing I2, the GA-azo-POP could efficiently catalyze the formation of cyclic carbonates from CO2. The excellent performance of the GA-azo-POP resulted from the co-existence of aromatic, azo, and phenolic OH functional groups and its porous structure.
- Xie, Chao,Song, Jinliang,Wu, Haoran,Hu, Yue,Liu, Huizhen,Yang, Youdi,Zhang, Zhanrong,Chen, Bingfeng,Han, Buxing
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p. 4655 - 4661
(2018/10/23)
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- Recyclable Single-Component Rare-Earth Metal Catalysts for Cycloaddition of CO2 and Epoxides at Atmospheric Pressure
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Ionic rare-earth metal complexes 1-4 bearing an imidazolium cation were synthesized, which, as single-component catalysts, showed good activity in catalyzing cyclic carbonate synthesis from epoxides and CO2. In the presence of 0.2 mol % catalyst, monosubstituted epoxides bearing different functional groups were converted into cyclic carbonates in 60-97% yields under atmospheric pressure. In addition, bulky/internal epoxides with low reactivity yielded cyclic carbonates in 40-95% yields. More importantly, the readily available samarium complex 2 was reused for six successive cycles without any significant loss in its catalytic activity. This is the first recyclable rare-earth metal-based catalyst in cyclic carbonate synthesis.
- Zhao, Zhiwen,Qin, Jie,Zhang, Chen,Wang, Yaorong,Yuan, Dan,Yao, Yingming
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p. 4568 - 4575
(2017/04/26)
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- Poly(ethylene glycol)s as Ligands in Calcium-Catalyzed Cyclic Carbonate Synthesis
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Herein the use of CaI2 in combination with poly(ethylene glycol) dimethyl ether (PEG DME 500) as an efficient catalyst system for the addition of CO2 to epoxides is reported. This protocol is based on a nontoxic and abundant metal in conjunction with a polymeric ligand. Fifteen terminal epoxides were converted at room temperature to give the desired products in yields up to 99 %. Notably, this system was also effective for the synthesis of twelve challenging internal carbonates in yields up to 98 %.
- Steinbauer, Johannes,Werner, Thomas
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p. 3025 - 3029
(2017/08/18)
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- Highly Efficient and Convenient Supported Ionic Liquid TiCl5-DMIL@SiO2@Fe3O4-Catalyzed Cycloaddition of CO2 and Epoxides to Cyclic Carbonates
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Abstract: A series of silica coated magnetic nanoparticles supported ILs were prepared, characterized and their catalytic performances in cycloaddition of CO2 to epoxides were investigated. The influences of various reaction parameters including catalyst selection, catalyst amount, reaction time, and reaction temperature were studied. Research shows that TiCl5-DMIL@SiO2@Fe3O4 could be used as the highest efficient catalyst in cycloaddition of CO2 and epoxides to gives the corresponding cyclic carbonates. Good to excellent yields were achieved for this reaction under mild conditions. The heterogeneous supported catalyst is easily recoverable by filtration, and could be used for five consecutive runs without significant loss in catalytic activity.
- Hu, Yu Lin,Xing, Rong
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p. 1453 - 1463
(2017/05/16)
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- An in situ formed Ca2+-crown ether complex and its use in CO2-fixation reactions with terminal and internal epoxides
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Herein we report an efficient catalytic system based on readily available calcium iodide and 18-crown-6 ether for the atom economical addition of CO2 to epoxides. 1H NMR experiments revealed the selective in situ formation of a crown ether complex. This catalyst allows the conversion of various terminal epoxides under 1 atm CO2 pressure even at room temperature. Remarkably, a broad range of internal epoxides with various substitution patterns and substituents were smoothly converted which confirms the high efficiency and capability of the protocol. Notably, most of the internal carbonates were synthesized in high yields and diastereoselectivities of up to ≥99%. Furthermore, this system operates under solvent-free conditions without any co-catalysts e.g. onium salts.
- Steinbauer,Spannenberg,Werner
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supporting information
p. 3769 - 3779
(2017/08/26)
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- An Efficient and Versatile Lanthanum Heteroscorpionate Catalyst for Carbon Dioxide Fixation into Cyclic Carbonates
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A new lanthanum heteroscorpionate complex has shown exceptional catalytic activity for the synthesis of cyclic carbonates from epoxides and carbon dioxide. This catalyst system also promotes the reaction of bio-based epoxides to give an important class of bis(cyclic carbonates) that can be further used for the production of bio-derived non-isocyanate polyurethanes. The catalytic process requires low catalyst loading and mild reaction conditions for the synthesis of a wide range of cyclic carbonates.
- Martínez, Javier,Fernández-Baeza, Juan,Sánchez-Barba, Luis F.,Castro-Osma, José A.,Lara-Sánchez, Agustín,Otero, Antonio
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p. 2886 - 2890
(2017/07/25)
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