- Covalent heterogenization of a discrete Mn(II) Bis-Phen complex by a metal-template/metal-exchange method: An epoxidation catalyst with enhanced reactivity
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Considerable attention has been devoted to the immobilization of discrete epoxidation catalysts onto solid supports due to the possible benefits of site isolation such as increased catalyst stability, catalyst recycling, and product separation. A synthetic metal-template/metal-exchange method to imprint a covalently attached bis-1,10-phenanthroline coordination environment onto high-surface area, mesoporous SBA-15 silica is reported herein along with the epoxidation reactivity once reloaded with manganese. Comparisons of this imprinted material with material synthesized by random grafting of the ligand show that the template method creates more reproducible, solution-like bis-1,10-phenanthroline coordination at a variety of ligand loadings. Olefin epoxidation with peracetic acid shows the imprinted manganese catalysts have improved product selectivity for epoxides, greater substrate scope, more efficient use of oxidant, and higher reactivity than their homogeneous or grafted analogues independent of ligand loading. The randomly grafted manganese catalysts, however, show reactivity that varies with ligand loading while the homogeneous analogue degrades trisubstituted olefins and produces trans-epoxide products from cis-olefins. Efficient recycling behavior of the templated catalysts is also possible.
- Terry, Tracy J.,Daniel,Stack
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Read Online
- Simple iron catalyst for terminal alkene epoxidation
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(Matrix presented) A μ-oxo-iron(III) dimer, [((phen)2(H 2O)FeIII)2(μ-O)](ClO4) 4, is an efficient epoxidation catalyst for a wide range of alkenes, including terminal alkenes, using peracetic acid as the oxidant. Low catalyst loadings, in situ catalyst preparation from common reagents, fast reaction times (5 min at 0°C), and enhanced reaction performance at high substrate concentrations combine to create a temporally and synthetically efficient procedure for alkene epoxidation.
- Dubois, Geraud,Murphy, Andrew,Daniel,Stack
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Read Online
- METHOD FOR PRODUCING EPOXY COMPOUND
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The invention provides a method for producing an epoxy compound by hydrogen peroxide using an organic compound having a carbon-carbon double bond as a raw material, wherein a by-product is suppressed from being generated and the epoxy compound is produced in a high yield. In particular, the invention provides a method for producing an epoxy compound involving oxidizing a carbon-carbon double bond in an organic compound with hydrogen peroxide in the presence of a catalyst, wherein the catalyst comprises a tungsten compound; a phosphoric acid, a phosphonic acid or salts thereof; and an onium salt having an alkyl sulfate ion represented by formula (I) as an anion: wherein R1 is a linear or branched aliphatic hydrocarbon group having 1 to 18 carbons, which may be substituted with 1 to 3 phenyl groups.
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Paragraph 0089-0091
(2021/11/05)
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- SO2F2-Mediated Epoxidation of Olefins with Hydrogen Peroxide
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An inexpensive, mild, and highly efficient epoxidation protocol has been developed involving bubbling SO2F2 gas into a solution of olefin, 30% aqueous hydrogen peroxide, and 4 N aqueous potassium carbonate in 1,4-dioxane at room temperature for 1 h with the formation of the corresponding epoxides in good to excellent yields. The novel SO2F2/H2O2/K2CO3 epoxidizing system is suitable to a variety of olefinic substrates including electron-rich and electron-deficient ones.
- Ai, Chengmei,Zhu, Fuyuan,Wang, Yanmei,Yan, Zhaohua,Lin, Sen
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p. 11928 - 11934
(2019/10/02)
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- Safe, environment-friendly and controllable synthetic process of di-epoxide
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The invention relates to the field of synthesis of epoxide, and more specifically, relates to a safe, environment-friendly and controllable synthetic process of di-epoxide. The synthetic process of the di-epoxide at least comprises the following steps: mixing diolefin, carboxylic acids, basic salt and solvent, and cooling; dropwise adding a hydrogen peroxide solution for 1-12 h; standing for layering to obtain a lower layer organic phase-1, washing the organic phase-1 with a cleaning solution, and standing for layering to obtain a lower layer organic phase-2; purifying. The reaction system ofthe synthetic process is simple, environmentally friendly, safe and controllable, is low in production cost, and can meet the requirements of technical economy; the prepared di-epoxide is high in purity and yield and low in solvent content, chroma and halogen content, and is suitable for large-scale industrial production.
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Paragraph 0152-0168
(2019/10/01)
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- Regioselective Cleavage of Electron-Rich Double Bonds in Dienes to Carbonyl Compounds with [Fe(OTf)2(mix-BPBP)] and a Combination of H2O2 and NaIO4
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A method for the regioselective transformation of dienes to carbonyl compounds has been developed. Electron-rich olefins react selectively to yield valuable aldehydes and ketones. The method is based on the catalyst [Fe(OTf)2(mix-BPBP)] with an oxidant combination of H2O2 (1.0 equiv.) and NaIO4 (1.5 equiv.); it uses mild conditions and short reaction times, and it outperforms other olefin cleavage methodologies. The combination of an Fe-based catalyst, [Fe(OTf)2(mix-BPBP)], and the oxidants H2O2 and NaIO4 can discriminate between electronically different double bonds and oxidatively cleave the electron-rich bond in dienes to yield aldehydes and ketones in a regioselective manner. The reaction requires mild conditions (0-50 C) and short reaction times (70 min).
- Spannring, Peter,Yazerski, Vital A.,Chen, Jianming,Otte, Matthias,Weckhuysen, Bert M.,Bruijnincx, Pieter C. A.,Klein Gebbink, Robertus J. M.
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p. 3462 - 3466
(2015/08/06)
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- 2,2,2-Trifluoroacetophenone: An organocatalyst for an environmentally friendly epoxidation of alkenes
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A cheap, mild, fast, and environmentally friendly oxidation of olefins to the corresponding epoxides is reported using polyfluoroalkyl ketones as efficient organocatalysts. Namely, 2,2,2-trifluoroacetophenone was identified as an improved organocatalyst for the epoxidation of alkenes. Various olefins, mono-, di-, and trisubstituted, are epoxidized chemoselectively in high to quantitative yields utilizing 2-5 mol % catalyst loading and H2O 2 as the green oxidant.
- Limnios, Dimitris,Kokotos, Christoforos G.
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p. 4270 - 4276
(2014/06/09)
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- Liquid-phase synthesis of cyclic diene diepoxides using metal halides and hydrogen peroxide
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Optimal conditions were found for induced hydroxyhalogenation of cyclic dienes (tetrahydroindene, 4-vinylcyclohexene and 5-vinyl- and 5-cyclohexenylbicyclo[2.2.1]hept-2-enes) in the system [MHlg-HA or HHlg]-H 2O2 (or NaClO). Dehydrohalogenation of the chloro- and bromohydrins thus obtained with powdered potassium carbonate gave the corresponding diepoxy derivatives, and their hydrolysis led to mixtures of stereoisomeric tetrahydric alcohols. Pleiades Publishing, Ltd., 2012.
- Alimardanov, Kh. M.,Sadygov,Garibov,Abdullaeva, M. Ya.
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p. 1302 - 1308
(2013/02/21)
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- Designing the synthesis of catalytically active Ti-β by using various new templates in the presence of fluoride anion
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Crystallization of large-pore Ti-β by using a variety of diquaternary ammonium derivatives of dibromoalkane and amines such as triethylamine, 1,4-diazabicyclo[2,2,2]octane (DABCO), and quinuclidine as structure-directing agents (SDA) is described. The size of hydrophobic bridging alkyl-chain length of the template [R3N+-(CH2)x-N +R3](OH-)2 directs the final crystalline product: Ti-β, Ti-ZSM-12, Ti-nonasil or Ti-ZSM-5, as x gradually changes from 6 to 1, in the fluoride medium under hydrothermal conditions. A dense phase such as Ti-nonasil (clathrasil type) is crystallized as the size of hydrophobic bridging alkyl-chain length decreases. The use of F- anions as a mineralizer and Ti4+ as a heteroatom in the synthesis gel also influences the selectivity of final crystalline product. The phase purity and incorporation of Ti4+ into the lattice of β (BEA) and ZSM-12 frameworks are confirmed using XRD, UV-visible, FT-IR, 29Si NMR spectroscopes, elemental analysis (ICP), surface area measurements and catalytic test reactions. The morphology of Ti-β samples is dependent on the nature of the structure-directing agent as revealed by the scanning electron microscopic (SEM) observations. The catalytic activity in the epoxidation of 4-vinyl-1-cyclohexene is increased with the amount of tetrahedral Ti4+ atoms in the framework. The new templates can be effectively used for preparation of catalytically active Ti-β with the minimum number of framework defect sites.
- Sasidharan, Manickam,Bhaumik, Asim
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experimental part
p. 16282 - 16294
(2012/01/14)
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- Regioselective epoxidation of different types of double bonds over large-pore titanium silicate Ti-β
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Regioselective epoxidation of different types of double bonds located within the cyclic and acyclic parts of bulky olefins has been investigated using large-pore titanium silicate Ti-β in the presence of dilute aqueous H 2O2 as oxidant under mild liquid-phase conditions. Our experimental results revealed that side-chain vinylic double bonds are selectively epoxidized than those in the cyclohexene-ring. The epoxidation tendency of various bulky olefins with different positional and/or geometric isomers over Ti-β follows the order: terminal -CC- > ring -CC- ≈ bicyclic ring -CC- > allylic C - H bond. Unlike 4-vinyl-1-cyclohexene, epoxidation of an equimolar mixture of cyclohexene and 1-hexene under identical conditions using Ti-β exhibits completely different selectivity and product distributions. Steric factor and accessibility of reactants to active Ti-sites are responsible for the observed regioselectivity of bulky alkenes.
- Sasidharan, Manickam,Bhaumik, Asim
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experimental part
p. 60 - 67
(2010/12/18)
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- A broad substrate-scope method for fast, efficient and selective hydrogen peroxide-epoxidation
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The efficient epoxidation of a broad range of olefins using hydrogen peroxide (H2O2) as the oxidant has been accomplished by a manganese catalyst that exhibits an uncommon chemoselectivity.
- Garcia-Bosch, Isaac,Ribas, Xavi,Costas, Miquel
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supporting information; experimental part
p. 348 - 352
(2009/12/27)
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- A simple and effective catalytic system for epoxidation of aliphatic terminal alkenes with manganese(II) as the catalyst
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A simple catalytic system that uses commercially available manganese(II) Perchlorate as the catalyst and peracetic acid as the oxidant is found to be very effective in the epoxidation of aliphatic terminal alkenes with high product selectivity at ambient temperature. Many terminal alkenes are epoxidised efficiently on a gram scale in less than an hour to give excellent yields of isolated product (>90%) of epoxides in high purity. Kinetic studies with some C9-alkenes show that the catalytic system is more efficient in epoxidising terminal alkenes than internal alkenes, which is contrary to most commonly known epoxidation systems. The reaction rate for epoxidation decreases in the order: 1-nonene>cis-3-nonene> trans-3-nonene. ESI-MS and EPR spectroscopic studies suggest that the active form of the catalyst is a high-valent oligonuclear manganese species, which probably functions as the oxygen atomtransfer agent in the epoxidation reaction.
- Ho, Kam-Piu,Wong, Wing-Leung,Lam, Kin-Ming,Lai, Cheuk-Piu,Chan, Tak Hang,Wong, Kwok-Yin
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experimental part
p. 7988 - 7996
(2009/11/30)
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- Epoxidation of alkenes by hydrogen peroxide over 12-heteropolyacids of molybdenum and tungsten (H3PMo3W9O 40) combined with cetylpyridinium bromide
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In the epoxidation of 4-vinylcyclohex-1-ene with H2O2 in monophasic acetonitrile solution catalysed by Keggin-type 12-heteropolyacids, i.e., H3PMo12-nWnO 40 (n = 0-12), which are precursors of active peroxo complexes, and phase transfer catalysts Q+Br, the catalyst H3PMo 3W9O40 showed the highest activity, giving a conversion of 98% and a selectivity of 88%. By this method, a variety of water-insoluble unactivated alkenes, internal or terminal, open chain or cyclic and isolated, were epoxidised under mild conditions and after relatively short reaction times. The state of the H3PMo3W9O 40/CPB/H2O2/CH3CN system was studied using UV, IR, and 31P NMR spectroscopies with the [H 2O2]: [HPA] ratio = 50. Several peroxo species were observed by 31P NMR spectroscopy at a lower field than the original heteropolyacids. Their composition varied regularly with that of the starting catalyst. The P-containing peroxo species formed were deduced as [(PO 4){Mo4-xWxO20}]3- (x= 0-4), which are the true catalytically active species under the reaction conditions.
- Ding, Yong,Ma, Baochun,Gao, Qiang,Suo, Jishuan
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p. 499 - 503
(2007/10/03)
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- Aerobic epoxidation of alkenes catalysed by cobalt(II) 1,1,1,5,5,5-hexafluoroacetylacetonate or cobalt(II) benzoylacetonate
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The aerobic epoxidation of terminal or electron deficient alkenes with an aldehyde does not proceed with cobalt(II) acetylacetonate but goes to completion with the cobalt(II) benzoylacetonate and cobalt(II) 1,1,1,5,5,5-hexafluoroacetylacetonate complexes.
- Hunter,Turner,Rimmer
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p. 4461 - 4466
(2007/10/03)
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- Metal silicates by a molecular route as catalysts for epoxidation of alkenes with tert-butyl hydroperoxide
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Macroporous, site isolated metal silicates are synthesized by a molecular route; the molybdenum silicate is especially active for the selective epoxidation of alkenes with tert-butyl hydroperoxide.
- Juwiler, David,Blum, Jochanan,Neumann, Ronny
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p. 1123 - 1124
(2007/10/03)
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- Epoxidation of terminal or electron-deficient olefins with H2O2, catalysed by Mn-trimethyltriazacyclonane complexes in the presence of an oxalate buffer
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A catalytic amount of an oxalate/oxalic acid buffer strongly enhances the catalytic properties of Mn-tmtacn complexes for epoxidation reactions with H2O2. Especially terminal olefins are easily epoxidized. Yields for e.g. allyl acetate or 1-hexene reach up to 99 % and 65 % on olefin and peroxide basis respectively. The reaction is stereospecific; there are no products of solvolysis.
- De Vos, Dirk E.,Sels, Bert F.,Reynaers, Mattias,Subba Rao,Jacobs, Pierre A.
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p. 3221 - 3224
(2007/10/03)
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- Quaternary Ammonium Tetrakis(diperoxotungsto)phosphates(3-) as a New Class of Catalysts for Efficient Alkene Epoxidation with Hydrogen Peroxide
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The use of quaternary ammonium tetrakis(diperoxotungsto)phosphates(3-) in conjuction with hydrogen peroxide as the primary oxidant in an aqueous/organic biphase system provides an efficient, versatile, and synthetically valuable catalytic method for olefin epoxidation.By this method, a variety of water-insoluble unactivated alkenes, internal or terminal, open-chain or cyclic, isolated or carrying diversified functionalities, were epoxidized in high yields under mild conditions and after relatively short reaction times.
- Venturello, Carlo,D'Aloiso, Rino
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p. 1553 - 1557
(2007/10/02)
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- Selective catalyzed-rearrangement of terminal epoxides to methyl ketones
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Terminal epoxides of the type {A figure is presented} have been selectively converted into methyl ketones by various catalysts. Some lanthanide derivatives, MnI2, and Co2(CO)8 gave the best results. The rearrangement of internal epoxides into ketones is much slower, allowing specific transformation of terminal epoxides. The scope of the reaction and tentative mechanisms are discussed.
- Prandi,Namy,Menoret,Kagan
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p. 449 - 460
(2007/10/02)
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- EPOXIDATION OF OLEFINS BY HYDROGEN PEROXIDE IN THE PRESENCE OF TETRACHLOROACETONE
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1,1,3,3-Tetrachloroacetone, an inexpensive, commercially available material, has been shown to be effective in mediating the hydrogen peroxide oxidation of a variety of olefins to epoxides.The chloroacetone is readily recovered for re-use.
- Stark, Charles J.
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p. 2089 - 2092
(2007/10/02)
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