T:Toxic;
106-89-8Relevant articles and documents
Mechanism of olefin epoxidation in the presence of a titanium-containing zeolite
Danov,Krasnov,Sulimov,Ovcharova
, p. 1809 - 1812 (2013)
The effect of the nature of a solvent on the liquid-phase epoxidation of olefins with an aqueous solution of hydrogen peroxide over a titanium-containing zeolite is studied. Butanol-1, butanol-2, propanol-1, isopropanol, methanol, ethanol, water, acetone, methyl ethyl ketone, isobutanol, and tert-butanol are examined as solvents. A mechanism of olefin epoxidation with hydrogen peroxide in an alcohol medium over a titanium-containing zeolite is proposed. Epoxidation reactions involving hydrogen peroxide and different olefins are studied experimentally.
Efficient Catalytic System Involving Molybdenyl Acetylacetonate and Immobilized Tributylammonium Chloride for the Direct Synthesis of Cyclic Carbonates from Carbon Dioxide and Olefins
Siewniak, Agnieszka,Jasiak-Jaroń, Katarzyna,Kotyrba, ?ukasz,Baj, Stefan
, p. 1567 - 1573 (2017)
Abstract: An effective direct method for preparing of cyclic carbonates from CO2 and olefins in the presence of tert-butyl hydroperoxide as an oxidant was provided. The first stage, the epoxidation of olefins, was carried out using MoO2(acac)2 as a catalyst (1h, 100 °C), and the second stage, the cycloaddition of CO2 to the resulting epoxide, was proceeded in the presence of immobilized tributylmethylammonium chloride on a polystyrene cross-linked with divinylbenzene, and an aqueous solution of ZnBr2 (100 °C, 0.9?MPa of CO2, 4?h). The proposed method allowed to obtain cyclic carbonates with high yields (50–77%) under mild conditions. Moreover, the immobilized catalyst could be reused at least five times without significant loss of its catalytic activity.
Continuous flow upgrading of glycerol toward oxiranes and active pharmaceutical ingredients thereof
Morodo, Romain,Gérardy, Romaric,Petit, Guillaume,Monbaliu, Jean-Christophe M.
, p. 4422 - 4433 (2019)
A robust continuous flow procedure for the transformation of bio-based glycerol into high value-added oxiranes (epichlorohydrin and glycidol) is presented. The flow procedure features a central hydrochlorination/dechlorination sequence and provides economically and environmentally favorable conditions involving an organocatalyst and aqueous solutions of hydrochloric acid and sodium hydroxide. Pimelic acid (10 mol%) shows an exceptional catalytic activity (>99% conversion of glycerol, a high selectivity toward 1,3-dichloro-2-propanol and 81% cumulated yield toward intermediate chlorohydrins) for the hydrochlorination of glycerol (140 °C) with 36 wt% aqueous HCl. These conditions are validated on a sample of crude bio-based glycerol. The dechlorination step is effective (quantitative conversion based on glycerol) with concentrated aqueous sodium hydroxide (20 °C) and can be directly concatenated to the hydrochlorination step, hence providing a ca. 2:3 separable mixture of glycidol and epichlorohydrin (74% cumulated yield). An in-line membrane separation unit is included downstream, providing usable streams of epichlorohydrin (in MTBE, with an optional concentrator) and glycidol (in water). The scalability of the dechlorination step is then assessed in a commercial pilot-scale continuous flow reactor. Next, bio-based epichlorohydrin is further utilized for the continuous flow preparation of β-amino alcohol active pharmaceutical ingredients including propranolol (hypertension, WHO essential), naftopidil (prostatic hyperplasia) and alprenolol (angina pectoris) within a concatenable two-step procedure using a FDA class 3 solvent (DMSO). This work provides the first example of direct upgrading of bio-based glycerol into high value-added pharmaceuticals under continuous flow conditions.
Phase Transfer of the Organic Substrate in the Epoxidation Reaction of Allyl Chloride in Two-Phase Aqueous–Organic Systems
Panicheva,Meteleva,Ageikina,Panichev
, p. 884 - 888 (2018)
Abstract: The mechanism of synergism for mixtures of phase-transfer carriers QХ with tertiary amines and pyridine in the epoxidation reaction of allyl chloride has been established. It has been shown that tertiary amines (triethylamine, tributylamine, N,N-dimethylaniline, and N-methyldiethanolamine) and pyridine oxidizable in situ to N-oxides promote the transfer of the organic substrate (allyl chloride) to the interface (PB). It is assumed that the synergism of mixtures of phase-transfer carriers QХ with a tertiary amine oxide or pyridine oxide can also be due to the formation of a mixture of two catalysts, Q3[PW4O24] and WO(O2)2L (where L = a tertiary amine oxide or pyridine oxide). The WO(O2)2L complex will provide the stage of reoxidation of the complex Q3[PW4O24 ?х] in the organic phase and, hence, the possibility for the development of the process of epoxidation not only at the interface but also in the bulk of the organic phase. The maximum coefficient of synergistic effect (ks = 2) is observed for a mixture of cetylpyridinium bromide (90 mol %) and pyridine N-oxide (10 mol %).
Controlling the Morphology and Titanium Coordination States of TS-1 Zeolites by Crystal Growth Modifier
Chang, Xinyu,Chen, Ziyi,Hu, Dianwen,Jia, Mingjun,Li, Yingying,Song, Xiaojing,Yang, Xiaotong,Yu, Jihong,Zhang, Hao,Zhang, Peng,Zhang, Qiang,Zhang, Tianjun
, p. 13201 - 13210 (2020)
Developing an effective strategy to synthesize perfect titanosilicate TS-1 zeolite crystals with desirable morphologies, enriched isolated framework Ti species, and thus enhanced catalytic oxidation properties is a pervasive challenge in zeolite crystal engineering. We here used an amino acid l-carnitine as a crystal growth modifier and ethanol as a cosolvent to regulate the morphologies and the Ti coordination states of TS-1 zeolites. During the hydrothermal crystallization process, the introduced l-carnitine can not only tailor the anisotropic growth rates of zeolite crystals but also induce the formation of uniformly distributed framework Ti species through building a suitable chemical interaction with the Ti precursor species. Condition optimizations could afford the generation of perfect hexagonal plate TS-1 crystals and elongated platelet TS-1 crystals enriched in tetrahedral framework Ti sites (TiO4) or mononuclear octahedrally coordinated Ti species (TiO6). Both samples showed significant improvement in catalytic activity for the H2O2-mediated epoxidation of alkenes. In particular, the elongated platelet TS-1 enriched in "TiO6"species afforded the highest activity in 1-hexene epoxidation, with a turnover frequency (TOF) of up to 131 h-1, which is approximately twice as high as that of the conventional TS-1 zeolite (TOF: 65 h-1) and even higher than those of the literature-reported TiO6-containting TS-1 catalysts derived from the hydrothermal post-treatment of TS-1 zeolites. This work demonstrates that the morphologies and the titanium coordination states of TS-1 zeolites can be effectively tuned by directly introducing suitable crystal growth modifiers, thus providing new opportunities for developing highly efficient titanosilicate zeolite catalysts for important catalytic applications.
An Easy Way to Prepare Titanium Silicalite-1 (TS-1)
Gao, Huanxin,Suo, Jishuan,Li, Shuben
, p. 835 - 836 (1995)
Titanium silicalite-1 (TS-1) is easily synthesized using an aqueous solution of TiCl3 as the titanium source.
A safer and greener chlorohydrination of allyl chloride with H2O2 and HCl over hollow titanium silicate zeolite
Peng, Xinxin,Xia, Changjiu,Lin, Min,Shu, Xingtian,Zhu, Bin,Wang, Baorong,Zhang, Yao,Luo, Yibin,Mu, Xuhong
, p. 17 - 25 (2017)
Industrial production of dichloropropanols through chlorohydrination of allyl chloride suffers from a series of disadvantages such as use of hazardous Cl2, low atom economy, low dichloropropanol concentration and serious pollution. In this work, a safer and greener route for chlorohydrination of allyl chloride with H2O2 and HCl over hollow titanium silicate (HTS) at mild condition is developed. Unlike the traditional Cl2-based chlorohydrination, this novel method is initiated via synergistic effect of Lewis acidity (HTS) and Br?nsted acidity (HCl) to promote occurrence of oxidation, protonation and nucleophilic reaction of allyl chloride simultaneously and hence dichloropropanols are generated. Owing to a completely different reaction route, the formation of 1,2,3-trichloropropane by-product is depressed and the content of dichloropropanol exceeded 22?wt%, which increase by about 4 times compared with traditional Cl2-based chlorohydrination (the content of dichloropropanol is below 4?wt%). At the optimized conditions, both of the allyl chloride conversion and dichloropropanol selectivity could approach 99% simultaneously and the waste is minimized. What's more, the HTS was reusable. Concentrated HCl solution treatment was adopted to test HTS's stability. The characterization and catalytic evaluation results reveal that, although parts of the framework Ti species have transformed into non-framework Ti and then leached into the solution, HTS remains structural stable, and the allyl chloride conversion and dichloropropanol selectivity didn't decrease obviously during the treatment.
Converting wastes into added value products: From glycerol to glycerol carbonate, glycidol and epichlorohydrin using environmentally friendly synthetic routes
Dibenedetto, Angela,Angelini, Antonella,Aresta, Michele,Ethiraj, Jayashree,Fragale, Carlo,Nocito, Francesco
, p. 1308 - 1313 (2011)
Glycerol carbonate, synthesised via a non-phosgene route using glycerol and CO2 or urea in presence of a heterogeneous catalyst, was efficiently converted into a series of derivatives through the functionalization of the -OH moiety, using high yield, high selectivity synthetic routes not affecting the carbonate functionality. So, for example, glycerol carbonate was converted into epichlorohydrin, a product that has a large industrial application, under very mild conditions, using a two-step reaction with a 98% yield and 100% selectivity. The high yield and mild reaction conditions (very often close to the ambient conditions) make the environmentally friendly synthetic approach described in this work of potential applicative interest. All compounds prepared were fully characterized.
Kinetics of allyl chloride epoxidation with hydrogen peroxide catalyzed by extruded titanium silicalite
Sulimov,Danov,Ovcharova,Ovcharov,Flid
, p. 712 - 721 (2014)
A mechanism is suggested for the heterogeneous catalytic epoxidation of allyl chloride with hydrogen peroxide in methanol. The kinetics of allyl chloride oxidation into epichlorohydrin in the presence of extruded titanium silicalite has been investigated. A kinetic model of the process has been derived from experimental data, and the activation energies of the target and side reactions, the rate constants of the reactions, and the adsorption equilibrium constant have been determined. The allyl chloride epoxidation process has been tested using a bench-scale continuous apparatus, and the adequacy of the kinetic model has been estimated.
Synthesis of 1,3-dichloropropanol from glycerol using muriatic acid as chlorinating agent
Herliati,Yunus, Robiah,Rashid, Umer,Abidin, Zurina Zainal,Ahamad, Intan Salwani
, p. 2907 - 2912 (2014)
Today, one of the problems associated with biodiesel production is the availability of high amount of glycerol byproduct. Among the various possibilities, technology to convert glycerol to dichloropropanol has diverted our attention. Dichloropropanol an important raw material for epichlorohydrin production was successfully synthesized via hydrochlorination reaction of glycerol with aqueous hydrogen chloride to produce 1,3-dichloropropanol. Experimental study was carried out under temperatures ranged; 80 to 120 °C, reactant molar ratio; 1:16 to 1:32 and various carboxylic acid catalysts. The optimal reaction conditions were: temperature, 110 °C; reactant molar ratio glycerol to HCl, 1:24; catalyst, malonic acid; and time duration, 3 h.
