107-98-2Relevant articles and documents
Venkatasubramanian,Thiagarajan
, p. 694 (1969)
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.
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
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.
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.
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.
Fluorine-modified Mg-Al mixed oxides: A solid base with variable basic sites and tunable basicity
Wu, Gongde,Wang, Xiaoli,Wei, Wei,Sun, Yuhan
, p. 107 - 113 (2010)
The fluorine-modified Mg-Al mixed oxides were synthesized by thermal decomposition of the fluorine-containing Mg-Al hydrotalcites, and their physicochemical properties were characterized by ICP, TGA, XRD, FTIR, CO2-TPD and N2 adsorption/desorption techniques. It was found that weak basic sites were gradually transformed into moderate and strong basic sites during thermal decomposition, and thus weak basic sites (OH- groups), moderate basic sites (Mg-O, Mg-F and Al-O pairs) and strong basic sites (coordinatively unsaturated F- and O2- ions) were all produced in the as-prepared samples. Furthermore, the basicity of moderate basic sites could be controlled by the change of fluorine content, which caused the change in the amounts of Mg-F pairs. In the synthesis of propylene glycol methyl ether from methanol and propylene oxide, the base-catalytic performance of the obtained samples was shown to be closely associated with their moderate basic sites.
Chemo- and Regioselective Reductions of Functionalized Epoxides by Bu3SnH/Bu3SnI-Phosphine Oxide
Kawakami, Takayo,Tanizawa, Daisuke,Shibata, Ikuya,Baba, Akio
, p. 9357 - 9360 (1995)
A novel reagent, Bu3SnH/Bu3SnI-phosphine oxide, reduced functionalized epoxides to the corresponding alcohols in high chemo- and regioselectivities.
Selective decomposition of hydrogen peroxide in the epoxidation effluent of the HPPO process
Blanco-Brieva, Gema,De Frutos-Escrig, M. Pilar,Martín, Hilario,Campos-Martin, Jose M.,Fierro, Jose L.G.
, p. 168 - 172 (2012)
This work describes the selective H2O2 decomposition in the exit stream of the epoxidation reactor employed in the Hydrogen Peroxide-Propylene Oxide (HPPO) process. Pd/Al2O3 and Pt/Al2O3 catalysts were tested. The effects of the reaction temperature and the pH of the solution on catalyst performance were investigated. It was found that the Pt catalyst is much more active than its Pd counterpart. An increase in the temperature and the pH of the solution resulted in an increase in the H2O2 decomposition rate; however, a parallel increase of by-products from PO was also observed. Working with a Pt/Al2O3 catalyst under optimized reaction conditions (333 K, pH = 7), hydrogen peroxide can be completely decomposed at reaction times of 120 min with no by-products produced from propylene oxide.
Synthesis of propylene glycol methyl ether catalyzed by MCM-41
Liang, Shuguang,Zhou, Yinxi,Liu, Huizhen,Jiang, Tao,Han, Buxing
, p. 891 - 897 (2011)
In this work, we found that MCM-41 prepared using cetyltrimethyl ammonium bromide (CTAB) as the template could be used as a heterogeneous catalyst for the reaction of methanol with propylene oxide to produce propylene glycol methyl ether. 1-Methoxy-2-propanol was the predominant product. The influence of ratio of the reactants, reaction temperature, and time on the yield and selectivity was studied. The as-prepared MCM-41 proved to be an efficient and reusable catalyst, and the separation of the catalyst form the product was very easy.
Low-Temperature Preparation of a Mesoporous Silica Superbase by Employing the Multifunctionality of a La2O3 Interlayer
Liu, Ning,Wu, Zhimin,Li, Meng,Li, Shanshan,Luo, Zhantao,Li, Yongfei,Pan, Langsheng,Liu, Yuejin
, p. 1641 - 1647 (2017)
A simple and effective approach for the preparation of the solid superbasic La2O3–SBA-15-supported KF (KF/La2O3–SBA-15) was developed by a low-temperature strategy. The KF/La2O3–SBA-15 with ordered mesostructure and a high base strength (H?=27.0) was realized at 350 °C in still air, which breaks the traditional method of thermally induced decomposition of basic metal nitrate derived species KNO3 under higher temperatures (>600 °C). The resultant mesoporous basic materials were adopted for the production of 1-methoxy-2-propanol from propylene oxide and methanol. It showed excellent catalytic performance exhibiting 93 % conversion of propylene oxide and 93 % selectivity to 1-methoxy-2-propanol. This performance is better than that over the catalysts without mesoporous silica despite having a higher KF content.
Synthetic Methods and Reactions; 68. Nafion-H-Catalyzed Hydration and Methanolysis of Epoxides
Olah, George A.,Fung, Alexander P.,Meidar, David
, p. 280 - 282 (1981)
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13C-N.M.R.-SPECTRAL AND RELATED STUDIES ON THE DISTRIBUTION OF SUBSTITUENTS IN O-(2-HYDROXYPROPYL)CELLULOSE
Lee, Dae-Sil,Perlin, Arthur S.
, p. 1 - 20 (1982)
Information about the degree of substitution at individual oxygen atoms of O-(2-hydroxypropyl)cellulose, and the total molar substitution, was obtained from 13C-n.m.r. spectra of the intact polymer and of its hydrolyzate.On the basis of their 13-CH3 chemical-shifts, O-(2-hydroxypropyl) (HOPr) substituents occurring singly, or as terminal units of substituent chains, were radily distinguished from inner HOPr units of chains.Differentiation between monomeric HOPr units and longer chains located at O-2 of D-glucosyl residues was effected by the transformation of appropriatly substituted sugars in the hydrolyzate into 1,2-cyclic acetals incorporating a 2-O-(2-hydroxypropyl) group.Similarly, the pattern of substitution at O-6 of D-glucosyl residues was determined, through selective degradation, from the identity of HOPr derivatives of ethylene glycol, representing C-5 and C-6 of the residues.Overall, it was found that, although O-2 and O-6 are more readily substituted than O-3, the rate at which each, initially introduced, HOPr substituent is converted into a dimeric structure is not materially affected by its location.Also described are the synthesis and the n.m.r. spectra of several HOPr derivatives of D-glucose, and of simple alkanols that served as model compounds.
Ship-in-bottle preparation of multi-SO3H functionalized ionic liquid@MIL-100(Fe) for acid-catalyzed ring-opening of epoxides
Mortazavi, Saeideh-Sadat,Masteri-Farahani, Majid,Abbasi, Alireza
, (2021)
The fact that the homogeneous acid catalysts are usually separated difficulty than heterogeneous catalysts from the reaction media, the opportunity to combine the advantages of both homogeneous and heterogeneous catalytic systems by immobilizing ILs within the pores of a porous solid support host is an alternative method. In this research, a multi-SO3H functionalized ionic liquid derived from hexamethylenetetramine (HMTA) and 1,3-propane sultone was entrapped inside the pores of MIL-100(Fe) through the ship-in-bottle method and utilized for heterogeneous acid-catalyzed ring-opening of epoxides under solvent-free conditions. The physicochemical properties of prepared catalyst were fully elucidated by various methods. FT-IR spectroscopy and elemental analysis approved the successful incorporation of modified groups within the MIL-100(Fe) cavities. The concentration of acid sites was measured via the acid–base titration which exhibited the 0.9?mmol/g H+ in the catalyst structure. Also, thermogravimetric analysis (TGA) profile showed the loosing of modified groups at 300–600°C. Moreover, X-ray diffraction (XRD) analysis showed that the MIL-100(Fe) structure was retained after modification and nitrogen adsorption–desorption analysis (BET method) manifested the decrease in surface area caused by incorporation of ionic liquid. The fabricated catalyst exhibited high catalytic efficiency in methanolysis of styrene oxide (99% conversion in 3?h) under ambient conditions and used without a substantial drop in product yield in further rounds.
Methylammonium-FAU zeolite: Investigation of the basic sites in base catalyzed reactions and its performance
Martins, Leandro,Hoelderich, Wolfgang,Cardoso, Dilson
, p. 14 - 24 (2008)
The basicity of methylammonium-faujasite zeolites (FAU) was evaluated in the Knoevenagel and Claisen-Schmidt condensation reactions and in the alcoholysis of propylene oxide with methanol. The basic character of FAU zeolites (Y zeolite with Si/Al = 2.5 and X zeolite with Si/Al = 1.4) was systematically altered by incorporating cesium and methylammonium cations, which were located in charge compensation sites. In all three reactions, methylammonium-FAU zeolites showed higher specific activity in comparison to cesium-FAU, indicating that these catalysts encompass stronger basic sites. Characterization of the zeolites has shown that ion exchange of sodium by methylammonium cations reduces their micropore volume, however enhances the strength of their basic sites. TPD-CO2 experiments demonstrated that aluminum rich zeolites possess higher basicity due to higher number of sites. Additionally, XPS (O1s) measurements illustrated that when monomethylammonium cation is present in ion exchange sites, structural zeolite oxygen anions have a higher basic character in comparison to cesium-FAU. This unique result opens news perspectives for application of these highly basic and low-cost methylammonium molecular sieves in base-catalyzed reactions such as Knoevenagel, Claisen-Schmidt condensation and nucleophilic cleavage of propylene oxide with methanol.
An improved one-pot synthesis of dimethyl carbonate from propylene oxide, CO2 and methanol
Fan, Bin,Qu, Bo,Cai, Liang,Chen, Qingchuan,Wen, Yicun,Zhang, Rui
, p. 654 - 656,3 (2011)
The direct synthesis of dimethyl carbonate (DMC) and propylene glycol from propylene oxide, CO2 and methanol has been studied with potassium carbonate as catalyst. This is the first time that K2CO3 which is readily available has been used as a catalyst. It is quite simple and cheap to use. This route may be an effective way of producing DMC on the large-scale. DMC is used in polycarbonate synthesis, polyurethane synthesis, carbonylating reagents, alkylating reagents, polar solvents, octane boosters in gasoline, carbon-particle reducing agents for diesel engines It is a safe and environmentally benign alternative for phosgene in some reactions.
Kinetics of propylene epoxidation with hydrogen peroxide catalyzed by extruded titanium silicalite in methanol
Sulimov,Danov,Ovcharova,Ovcharov,Flid
, p. 466 - 473 (2016)
The kinetics of propylene oxidation into propylene oxide in the presence of extruded titanium silicalite was studied. Based on the experimental data, a kinetic model of the process was designed and the activation energies of the target and side reactions, the rate constants, and the adsorption equilibrium constants were determined. The adequacy of the proposed kinetic model was verified on a continuously-operated test bench laboratory unit.
Synthesis of cyclic carbonates and dimethyl carbonate using CO2 as a building block catalyzed by MOF-5/KI and MOF-5/KI/K2CO 3
Song, Jinliang,Zhang, Binbin,Jiang, Tao,Yang, Guanying,Han, Buxing
, p. 21 - 30 (2011)
The synthesis of cyclic carbonates or dimethyl carbonate (DMC) using CO2 as a building block is a very interesting topic. In this work, we found that the metalorganic framework-5 (MOF-5)/KI was an active and a selective catalytic system for the synthesis of cyclic carbonates from CO 2 and epoxides, and MOF-5/KI/K2CO3 was efficient for the preparation of DMC from CO2, propylene, and methanol by a sequential route. The impacts of temperature, pressure, and reaction time length on the reactions were investigated, and the mechanism of the reactions is proposed on the basis of the experimental results.
Nanotitania catalyzes the chemoselective hydration and alkoxylation of epoxides
Ballesteros–Soberanas, Jordi,Leyva–Pérez, Antonio,Martínez–Castelló, Aarón,Oliver–Meseguer, Judit,Tejeda–Serrano, María
, (2021/10/12)
Glycols and ethoxy– and propoxy–alcohols are fundamental chemicals in industry, with annual productions of millions of tons, still manufactured in many cases with corrosive and unrecoverable catalysts such as KOH, amines and BF3?OEt2. Here we show that commercially available, inexpensive, non–toxic, solid and recyclable nanotitania catalyzes the hydration and alkoxylation of epoxides, with water and primary and secondary alcohols but not with phenols, carboxylic acids and tertiary alcohols. In this way, the chemoselective synthesis of different glycols and 1,4–dioxanones, and the implementation of nanotitania for the production in–flow of glycols and alkoxylated alcohols, has been achieved. Mechanistic studies support the key role of vacancies in the nano–oxide catalyst.
