285-67-6Relevant articles and documents
Catalyst Systems Based on a Metal Halide and a Quaternary Ammonium Salt in the 1,2-Epoxycyclopentane Carboxylation Reaction
Taranenko, G. Yu.,Rybina,Srednev,Meshechkina,Tarasov
, p. 78 - 84 (2019)
Abstract: Results of a study of 1,2-epoxycyclopentane carboxylation to cyclopentene carbonate (CPC) in the presence of various catalyst systems have been described. It has been found that the reaction occurs most efficiently in the presence of cobalt (nickel) chloride (bromide) hydrate and a quaternary ammonium salt (TEAB, TBAB). It has been recommended that CPC should be synthesized under a CO2 pressure of no less than 3.5 MPa at a temperature of 140–150°С without any solvent or in the medium of a solvent, such as target CPC, DMF, or N-MP, at a 1,2-epoxycyclopentane weight fraction in the feed mixture of no less than 25%. These conditions provide the formation of CPC with a selectivity of 97–99% and almost complete epoxide conversion within 2–4 h. It has been shown that the developed catalyst system can be recycled.
Basic ionic liquid supported on mesoporous SBA-15: An efficient heterogeneous catalyst for epoxidation of olefins with H2O 2 as oxidant
Yuan, Chengyuan,Huang, Zhiwei,Chen, Jing
, p. 56 - 60 (2012)
Basic ionic liquid functionalized mesoporous silica SBA-15 was prepared and characterized by XRD, N2 adsorption-desorption, FT-IR and TEM. The catalyst demonstrated to be an efficient heterogeneous catalyst for olefin epoxidation using H2O2 as oxidant. The catalyst could be recycled at least five times without appreciable loss of catalytic activity.
Efficiency of phase-transfer catalysis in cyclopentene epoxidation with hydrogen peroxide
Meshechkina,Mel'Nik,Rybina,Srednev,Shevchuk
, p. 661 - 665 (2012)
The effect of the structure and amount of the phase-transfer catalyst (quaternary ammonium salts) and the solvent effect on cyclopentene oxidation with an aqueous hydrogen peroxide solution in the liquid-liquid two-phase system was studied. The phase-tran
Polyoxometalate-based hybrid mesostructured catalysts for green epoxidation of olefins
Karimi,Mahjoub,Harati
, p. 1 - 9 (2011)
Novel hybrid polyoxometalates (POM) of α-H3PW 12O40·nHMPA and α-H3PMo 12O40·nHMPA composed of α-H 3PW12O40 and H3PMo 12O40 heteropoly acides (HPAs) and hexamethylphosphoramide (HMPA) organic substrate has been synthesized and purified. SBA-15 mesoporous silica is synthesized, using P123 surfactant via hydrothermal method, and functionalized with aminopropyl functional groups via grafting method. The synthesized mesostructured supports are used for intercalation of the hybrid POMs. The parent Keggin HPAs are also immobilized within the supports to perform closer and more efficient investigation. After characterization, effect of functional groups on immobilization pattern and quality is taken into consideration. The mesostructured organic-inorganic hybrid materials are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic absorption, and FT-IR analysis. The newly designed hybrid catalysts are investigated for heterogeneous epoxidation of olefins. Effects of temperature, oxidant, and catalyst amount are studied and the reaction conditions are optimized. An interpretation of the differences in the catalytic activity of the precursors is put forward and their catalytic activity is compared with their HPA counterparts. Furthermore, effects of functionalization on catalyst activity, stability, and reusability are taken into consideration. Results reveal that the designed mesostructured POM based hybrid catalysts can selectively and efficiently epoxidize olefins in presence of hydrogen peroxide as oxidant. The catalysts are shown to be heterogeneous and reusable without significant loss of activity in the proceeding rounds.
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Kretchmer et al.
, p. 1251 (1973)
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A Na2WO4/H2WO4-based highly efficient biphasic catalyst towards alkene epoxidation, using dihydrogen peroxide as oxidant
Maheswari, Palanisamy Uma,De Hoog, Paul,Hage, Ronald,Gamez, Patrick,Reedijk, Jan
, p. 1759 - 1764 (2005)
The tungsten-containing biphasic catalytic system [Na2WO 4/H2WO4/PTR/chloroacetic acid] effectively epoxidizes alkenes with 50% H2O2 as terminal oxidant, under organic solvent-free conditions. The catalytic process is proposed to proceed via a dinuclear tungsten peroxo species with coordinated chloroacetic acid, as suggested by ESI-MS measurements. The catalytic system is suggested to involve tungsten-peroxo and/or peracetic acid type of epoxidation catalyzed by the tungsten(VI) in the presence of an organic acid and H2O 2. The reaction conditions employed for various alkenes for epoxidation are mild compared to the earlier studies and result in high product selectivity and conversion rate.
Rhenium-containing compound(PyHReO4): synthesis, characterization and catalytic application in olefin epoxidation and baeyer-villiger oxidation
Dong, Yingnan,Li, Yucai,Song, Shiwei,Wang, Gang,Wang, Han,Wang, Jian,Wang, Shuaijie,Zhang, Dong,Zhao, Yan
, (2021/12/24)
A novel compound based on catalytic functional metal rhenium, pyridinium perrhenate(PyHReO4) was synthesized and characterized. The pyridinium perrhenate was used as catalyst in two types of reactions. One is the epoxidation of cyclooctene, the other is the Baeyer-Villiger oxidation of cyclic ketones to lactones. The effects of catalyst, oxidant, solvent, reaction time and temperature were investigated, which confirmed the optimum reaction conditions of the catalyst system. Both types of catalytic reactions exhibit high yields and high selectivity. Graphical abstract: The synthesized novel compound based on catalytic functional metal rhenium, pyridinium perrhenate(PyHReO4) exhibit excellent catalytic activity. The system with PyHReO4 as a catalyst provided an effective, easy separation, mild and convenient method in two different types of reactions(One is the epoxidation of cyclooctene, the other is the Baeyer-Villiger oxidation of 2-adamantanone). [Figure not available: see fulltext.]
Aldehyde-catalyzed epoxidation of unactivated alkenes with aqueous hydrogen peroxide
Kokotos, Christoforos G.,Kokotou, Maroula G.,Lotter, Dominik,Sparr, Christof,Triandafillidi, Ierasia
, p. 10191 - 10196 (2021/08/12)
The organocatalytic epoxidation of unactivated alkenes using aqueous hydrogen peroxide provides various indispensable products and intermediates in a sustainable manner. While formyl functionalities typically undergo irreversible oxidations when activating an oxidant, an atropisomeric two-axis aldehyde capable of catalytic turnover was identified for high-yielding epoxidations of cyclic and acyclic alkenes. The relative configuration of the stereogenic axes of the catalyst and the resulting proximity of the aldehyde and backbone residues resulted in high catalytic efficiencies. Mechanistic studies support a non-radical alkene oxidation by an aldehyde-derived dioxirane intermediate generated from hydrogen peroxide through the Payne and Criegee intermediates.
