107-98-2Relevant articles and documents
One-step synthesis of dimethyl carbonate from carbon dioxide, propylene oxide and methanol over alkali halides promoted by crown ethers
Li, Lei,Shi, Shikai,Song, Li,Guo, Liping,Wang, Yifei,Ma, Hongxia,Hou, Jie,Wang, Haidong
, p. 231 - 236 (2015)
Crown ethers (i.e. [2,4]-dibenzo-18-crown-6 (DBC), 18-crown-6, 15-crown-5 and 12-crown-4) show obvious co-catalytic effect for alkali halides catalyzing one-step synthesis of dimethyl carbonate (DMC) from CO2, propylene oxide and methanol. Especially, the DMC yield of KCl catalyst promoted by DBC can increase by more than five times and reach about 40% under mild reaction conditions (i.e., low mole ratio of methanol and epoxieds: 7:3, low initial pressure of CO2: 1.5 MPa, reaction temperature: 140 °C, time: 10 h). The optimized molar ratio of KCl to DBC is 2: 1. Due to the good complexing ability between DBC and K+, KCl and DBC formed an organometallic complex. Actually, DBC can not only promote the reaction rate and equilibrium of cycloaddition and transesterification reactions, but also prevent side reaction. Importantly, DBC can conveniently achieve high recovery ratio and show excellent reusability.
Tunable synthesis of propylene glycol ether from methanol and propylene oxide under ambient pressure
Bai, Yu,Cai, Qinghai,Wang, Xiaoguang,Lu, Bin
, p. 386 - 390 (2011)
A series of basic and acidic ionic liquids, 1-butyl-3-methylimidazolium hydroxide (BMIMOH), 1-acetyl-3-methylimidazolium chloride (AcMIMCl) and AcMIMCl-FeCl3, or analogues of AcMIMCl, namely 1-potassium acetate-3-methylimidazolium chloride (KAcMIMCl), 1-potassium (sodium, ammonium) acetate-3-methylimidazolium hydroxides (KAcMIMOH, NaAcMIMOH and NH 4AcMIMOH), were prepared and used as catalysts for catalytic synthesis of propylene glycol ether via reaction of propylene oxide (PO) with methanol under mild reaction conditions. KAcMIMOH exhibited outstanding catalytic performance with 94.2% of conversion of PO and 99.1% of selectivity to 1-methoxy-2-propanol (MP-2) at 60°C and ambient pressure for 4 h. However, AcMIMCl-FeCl3 showed a good catalysis performance with high selectivity to 2-methoxy-1-propanol (MP-1). The tunable synthesis of MP-2 or MP-1 catalyzed by basic compound KAcMIMOH or acidic ionic liquid AcMIMCl-FeCl3 was realized.
Ionic-Liquid-Based Heterogeneous Covalent Triazine Framework Cobalt Catalyst for the Direct Synthesis of Methyl 3-Hydroxybutyrate from Propylene Oxide
Rajendiran, Senkuttuvan,Park, Kwangho,Lee, Kwangyeol,Yoon, Sungho
, p. 7270 - 7277 (2017)
β-Hydroxy esters are considered as potential building blocks for the production of fine chemicals and potential drug molecules in various industries. Developing an efficient and recyclable catalyst for the synthesis of β-hydroxy esters is challenging. Her
One-pot two-step process for direct propylene oxide production catalyzed by bi-functional Pd(Au)@TS-1 materials
Prieto, Alejandro,Palomino, Miguel,Díaz, Urbano,Corma, Avelino
, p. 73 - 84 (2016)
Different bi-functional materials (Pd(Au)@TS-1) based on metallic nanoparticles supported onto active nanocrystalline titanium silicalite (TS-1) zeolites were synthesized, characterized and used as recyclable heterogeneous catalysts for direct propylene oxide production from hydrogen, oxygen and propylene through one-pot two-step consecutive process. These catalysts allowed carrying out the combined reaction where metallic nanoparticles catalyzed the formation of in situ H2O2 that was the necessary intermediate for propylene epoxidation catalyzed by active TS-1 nanocrystalline support. Several variables were considered such as use of supercritical CO2 conditions, modifiable content of metallic species, and presence of additional co-solvents, surface acidity inhibitors and H2O2 stabilizers. Reusability and stability of the bi-functional catalyst was showed through consecutive catalytic cycles.
Supported ionic liquids on solid materials as catalysts for the synthesis of propylene glycol methyl ether
Haa, Minh Ngoc,Whiting, Roger,Han, Sheng,Wang, Yuhong
, p. 2722 - 2728 (2013)
Ionic liquid 1,1,3,3-tetramethylguanidium lactate was immobilized on three solid supports, MCM-41, silica-gel and attapulgite (Atta), by different methods. The prepared materials were used to catalyze the reaction of propylene oxide and methanol to produce propylene glycol methyl ether. 1-Methoxy-2-propanol was the predominant product. The influence of the amount of the catalyst, molar ratio of the reactants, reaction temperature and time on the yield and selectivity was studied. The three catalysts proved to be efficient reusable catalysts for the reaction.
Effect of propylene glycol monomethyl ether and rust impurities on TS-1 deactivation in propylene epoxidation
Li, Yi-Chuan,Shen, Ben-Xian,Zhao, Ji-Gang
, p. 169 - 174 (2013)
The properties of TS-1 catalyst in continuous reaction of propylene epoxidation, as well as the effects of by-product propylene glycol monomethyl ether (PGME) on catalytic performance, was investigated in a low-pressure fixed bed reactor with chemical pure methanol as solvent. As the rust could be doped from the pipings and solvent containers, its impact on catalyst deactivation was then studied by using industrial-grade methanol. Finally the catalyst before and after deactivation was contrastively characterized by means of micro-structure analysis, TPD and TPR. The results showed that self-developed TS-1 catalyst performed well in the reaction, and the by-product propylene glycol monomethyl ether would not depress the catalytic activity in 80 h. The presence of rust could not only block active sites leading to partial loss of activity, but also increase the surface acidity, which would induce side reactions and decrease the selectivity of propylene oxide.
Tuning Zr12O22 Node Defects as Catalytic Sites in the Metal-Organic Framework hcp UiO-66
Chen, Xi,Gates, Bruce C.,Lyu, Yinghui,Qiao, Xu,Wang, Zhengyan,Yang, Dong
, p. 2906 - 2914 (2020)
Defects in metal-organic frameworks (MOFs) play important roles in MOF reactivity and catalysis. Now, we report evidence of the reactivity and the quantitative characterization of the missing linker defects on the Zr12O22 nodes in the MOF hcp UiO-66 (these are paired Zr6O8 nodes bridged by OH groups) and those on the Zr6O8 nodes of the MOF UiO-66. The defect sites catalyze the ring-opening reactions of epoxides with alcohols, and new sites formed by removal of bridging OH groups on the Zr12O22 nodes also participate in the catalysis. The hcp UiO-66 was synthesized from UiO-66 and from molecular precursors, and, under various synthesis conditions, the nodes incorporated acetate ligands, where linkers were missing, and the number of these ligands was controlled by the synthesis conditions. These ligands are inhibitors of the catalytic reactions, and their removal by reaction with, for example, methanol (to form, for example, methyl acetate) preceded catalysis on the defect sites. The former MOF incorporated more defect sites than the latter, correspondingly being a more active catalyst. The defect sites on the Zr12O22 nodes are 2-6 times more active per site than those on the isolated Zr6O8 nodes, with the node-bridging OH groups increasing the catalytic activity of the neighboring node defect sites because new sites are formed by their removal. The results help point the way to the design and control of catalytic sites on metal oxide-like MOF nodes by tuning of the number and reactivity of the defect sites.
Selectivity controlled transformation of carbon dioxide into a versatile bi-functional multi-carbon oxygenate using a physically mixed ruthenium-iridium catalyst
Chatterjee, Abhijit,Chatterjee, Maya,Kawanami, Hajime,Kitta, Mitsunori
, p. 4719 - 4731 (2021)
To mitigate environmental concern and energy issues, the conversion of carbon dioxide (CO2) to valuable and useful carbon chemicals offers a promising strategy for the development of a carbon neutral economy. The utilization of inert CO2as a building block in the synthesis of multi-carbon (>2) oxygenated compounds, specifically propylene glycol methyl ether (PGME; C4H10O2), produced annually at a multi-million-ton scale from petroleum-based propylene oxide is of particular interest because of its multifaceted industrial and commercial applications. Herein, we present a simple and straightforward system that uses CO2in compressed form as the C1 feedstock for the synthesis of PGME by direct hydrogenation and subsequent C-C coupling without any other sacrificial reagents. In addition, we combine experimental results with DFT calculations to elucidate the synergistic contributions of two catalytic metals (Ru and Ir) to activation of CO2for hydrogenation and consequent mediation of the C-C bond formation leading to the generation of PGME. Taken together, our findings suggest that the strategy presented herewith may serve as a starting point for the development of a sustainable chemical synthesis platform for multi-carbon oxygenates by utilizing CO2as the starting material.
Ketone-alcohol hydrogen-transfer equilibria: Is the biooxidation of halohydrins blocked?
Bisogno, Fabricio R.,Garcia-Urdiales, Eduardo,Valdes, Haydee,Lavandera, Ivan,Kroutil, Wolfgang,Suarez, Dimas,Gotor, Vicente
, p. 11012 - 11019 (2010)
To ensure the quasi-irreversibility of the oxidation of alcohols coupled with the reduction of ketones in a hydrogen-transfer (HT) fashion, stoichiometric amounts of a-halo carbonyl compounds have been employed as hydrogen acceptors. The reason that these substrates lead to quasi-quantitative conversions has been tacitly attributed to both thermodynamic and kinetic effects. To provide a clear rationale for this behavior, we investigate herein the redox equilibrium of a selected series of ketones and 2-propanol by undertaking a study that combines experimental and theoretical approaches. First, the activity of the (R)-specific alcohol dehydrogenase from Lactobacillus brevis (LBADH) with these substrates was studied. The docking of acetophenone/(R)-l-phenyethanol and a-chloroacetophenone/(S)-2-chloro- lphenylethanol in the active site of the enzyme confirms that there seems to be no structural reason for the lack of reactivity of halohydrins. This assumption is confirmed by the fact that the corresponding aluminum-catalyzed Meerwein-Ponndorf-Verley-Oppenauer (MPVO) reactions afford similar conversions to those obtained with LBADH, showing that the observed reactivity is independent of the catalyst employed. While the initial rates of the enzymatic reductions and the IR v(C=0) values contradict the general belief that electron-withdrawing groups increase the electrophilicity of the carbonyl group, the calculated βG values of the isodesmic redox transformations of these series of ketones/alcohols with 2-propanol/acetone support the thermodynamic control of the reaction. As a result, a general method to predict the degree of conversion obtained in the HT-reduction process of a given ketone based on the IR absorption band of the carbonyl group is proposed, and a strategy to achieve the HT oxidation of halohydrins is also shown.
A novel strategy for constructing mesoporous solid superbase catalysts: Bimetallic Al-La oxides supported on SBA-15 modified with KF
Liu, Ning,Wu, Zhimin,Li, Meng,Li, Shanshan,Li, Yongfei,Yu, Rongdong,Pan, Langsheng,Liu, Yuejin
, p. 725 - 733 (2017)
Bimetallic Al-La oxides were conjointly precoated on SBA-15 prior to the introduction of potassium fluoride to achieve solid superbases at low temperature by a modified wetness impregnation method. This breaks the tradition of decomposition of KNO3 at high temperature and gives rise to a new approach to generating superbasic sites on SBA-15. The physico-chemical characteristics of the prepared KF/Al-La@SBA-15 materials were investigated using FT-IR, XRD, TG-DTG, N2 adsorption-desorption, TEM, SEM-EDS, acid-base titration, Hammett indicators and CO2-TPD measurements. The results demonstrated that the addition of Al species promoted the dispersion behavior of La species inside the channels, and the bimetallic species could synergistically protect the mesoporous structures of SBA-15 against KF corrosion. With increasing Al content, KF/Al-La@SBA-15 exhibited a long-range ordering of the pores with relatively narrow pore size distribution as well as high specific surface area. The research results showed that the KF/Al-La@SBA-15 (0.4) catalyst possessed a total basicity up to 0.79 mmol g-1 and superbasicity with a strength of 26.5. The catalytic activity of the prepared materials was evaluated in the ring-opening reaction of propylene oxide with methanol. Compared with the SBA-15 supported monometallic oxide (Al or La) catalysts, KF/Al-La@SBA-15 (0.4) exhibited the highest catalytic activity for the ring-opening reaction of propylene oxide with methanol. This is associated with the synergistic effects between Al and La species and the high dispersion of active components on the SBA-15 support.
