- Kinetics and mechanism of oxidation of dimethyl sulphoxide by mono- and di-substituted N,N-dichlorobenzenesulphonamides in aqueous acetic acid
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In an effort to introduce N,N-dichloroarylsulphonamides of different oxidising strengths, four mono- and five di-substituted N,N-dichlorobenzenesulphonamides are prepared, characterised and employed as oxidants for studying the kinetics of oxidation of dimethyl sulphoxide (DMSO) in 50% aqueous acetic acid. The reactions show first order kinetics in [oxidant], fractional to first order in [DMSO] and nearly zero order in [H +]. Increase in ionic strength of the medium slightly increases the rates, while decrease in dielectric constant of the medium decreases the rates. The results along with those of the oxidation of DMSO by N,N-dichlorobenzenesulphonamide and N,N-dichloro-4-methylbenzenesulphonamide have been analysed. Effective oxidising species of the oxidants employed in the present oxidations is Cl+ in different forms, released from the oxidants. Therefore the introduction of different substituent groups into the benzene ring of the oxidant is expected to affect the ability of the reagent to release Cl+ and hence its capacity to oxidise the substrate. Significant changes in the kinetic and thermodynamic data are observed in the present investigations with change of substituent in the benzene ring. The electron releasing groups such as CH3 inhibit the ease with which Cl+ is released from the oxidant, while electron-withdrawing groups such as Cl enhance this ability. The Hammett equation, log kobs = -3.19 + 1.05 σ, is found to be valid for oxidations by all the p-substituted N,N-dichlorobenzenesulphonamides. The substituent effect on the energy of activation, Ea and log A for the oxidations is also analysed. The enthalpies and free energies of activation correlate with an isokinetic temperature of 320 K.
- Gowda, B. Thimme,Jayalakshmi,Jyothi
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- Kinetics and mechanism of oxidation of dimethyl sulfoxide with benzoyl peroxide in superbasic media
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Oxidation of dimethyl sulfoxide with benzoyl peroxide in some dipolar aprotic solvents and superbasic media was studied. The kinetic parameters were correlated with the main physicochemical characteristics of solvents. The oxidation rate grows with increasing donor number and polarizability of the solvent. A two-step scheme of dimethyl sulfoxide oxidation with benzoyl peroxide in superbasic media was suggested, involving preliminary cleavage of the peroxide to perbenzoate with the base. In the reaction, sodium tert-butylate is preferable over sodium hydroxide.
- Lyavinets,Marushchak
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- Micellar effect on the reaction of picolinic acid catalyzed chromium(VI) oxidation of dimethyl sulfoxide in aqueous acidic media: A kinetic study
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The kinetics and mechanism of picolinic acid (PA) catalyzed oxidation of dimethyl sulfoxide (DMSO) to dimethyl sulfone by chromium(VI) in both aqueous H2SO4 and HClO4 media have been studied in the absence and presence of surfactants at different temperatures. Cr(VI)-PA complex formed in preequilibrium steps is the active oxidant that experiences the nucleophilic attack by DMSO to form a positively charged intermediate ternary complex. Within the proposed ternary complex, an oxygen transfer or a ligand coupling or both occurs to generate the product, dimethyl sulfone. Cr(VI) is ultimately converted to Cr(III)-PA complex. Under the experimental conditions, the process shows a first-order dependence on each of the reactants (i.e., [Cr(VI)]T, [PA]T, [DMSO]T, and [H+]). HCrO4- has been found kinetically active. The reaction is catalyzed by sodium dodecyl sulfate (SDS, a representative anionic surfactant) monotonically, while cetylpyridinium chloride (CPC, a representative cationic surfactant) retards the reaction continuously. The observed micellar effects have been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. A pseudo-phase ion exchange (PIE) model has been applied to explain the micellar effect. The Piszkiewicz cooperative model has been applied to determine the kinetic parameters, and it indicates the existence of catalytically productive submicellar aggregates. Because of this reactant-promoted micellization of the surfactant before or below the cmc value, the present systems do not show any discontinuity at the respective reported cmc values of the surfactants.
- Das,Mondal,Kar,Das
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- Synthesis of new polyfluorinated oxaziridines
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The article describes a synthesis of new per- and polyfluorinated oxaziridines along with some reactions of these materials.
- Petrov, Viacheslav,Marshall, Will
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- OXIDATION OF DIMETHYLSUPHOXIDE BY SODIUM N-BROMOBENZENESULPHONAMIDE: A KINETIC AND MECHANISTIC STUDY
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The kinetics of oxidation of dimethylsulphoxide (DMSO) by sodium N-bromobenzenesulphonamide or bromamine-B (BAB) has been studied in HClO4, HCl and NaOH media, at 35 deg C, with OsO4 as a catalyst in the latter medium.In acid medium, the rateshows a first order dependence on and second order in +>, but is independent of substrate concentration.Alkali retards the reaction (inverse first order) and rate is independent of oxidant concentration, but shows fractional order in and depends on 4>2.The solvent isotope effect was studied by using D2O.Activation parameters have also been determined.Mechanisms pro posed and the derived rate laws are consistent with the observed kinetics.
- Mahadevappa, D.S.,Ananda, S.,Murthy, A.S.A.,Rangappa, K.S.
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- Oxidation of dimethyl sulfoxide with hydrogen peroxide in the presence of potassium hydroxide
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Kinetic relationships in oxidation of DMSO to dimethyl sulfone with hydrogen peroxide in the presence of potassium hydroxide were studied. Kinetic parameters of the process were calculated. It was established that the reaction proceeded through the intermediate formation of potassium hydroperoxide.
- Choban,Yurchuk,Lyavinets
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- Polyoxometalate nanocone nanoreactors: Magnetic manipulation and enhanced catalytic performance
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Magnetic personality: Nanocone nanoreactors consisting of polyoxometalates functionalized with surfactant alkyl chains and magnetite nanocrystals (NCs) provide enhanced catalytic performance for the oxidation of sulfides to sulfones by a trap-release mechanism and advanced catalyst recovery under an external magnetic field. Copyright
- Nisar, Amjad,Lu, Yao,Zhuang, Jing,Wang, Xun
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- Effect of base nature on the oxidation of dimethyl sulfoxide with hydrogen peroxide in superbasic media
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Kinetic relationships of the dimethyl sulfoxide oxidation to dimethyl sulfone with hydrogen peroxide in the presence of an alkali (MOH) or sodium tert-butoxide were investigated. Kinetic parameters of the process were calculated. The process was found to proceed through the intermediate formation of the alkaline salts MeOOH. The effect of the base nature on the stage of salt formation and oxidation was revealed. Pleiades Publishing, Ltd., 2012.
- Choban,Yurchuk,Lyavinets
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- Oxygen-atom-transfer reactions of a palladium(II) peroxocarbonate complex
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Reactivity of a palladium(II) peroxocarbonate complex was investigated. It was found that a bis(N-heterocyclic carbene) palladium(II) peroxocarbonate acts as an oxygen-atom-transfer (OAT) reagent toward a phosphine and a sulfoxide. In these OAT reactions, the peroxocarbonate was converted to the corresponding palladium(II) carbonate. While the OAT reaction toward triphenylphosphine proceeded only sluggishly, addition of lithium chloride remarkably facilitated the reaction. It was proposed that the chloride ion induces the liberation of the peroxocarbonate moiety from the coordination sphere of palladium.
- Sase, Shohei,Hashimoto, Maki,Goto, Kei
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- Kinetics and Mechanism of Picolinic Acid Promoted Chromium(vl) Oxidation of Dimethyl Sulfoxide in the Presence and Absence of Surfactants
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In the picolinic acid (PA) promoted Crv! oxidation of dimethyl sulfoxide (DMSO), the Crv'-PA complex formed at the pre-equilibrium step undergoes nucleophilic attack by the S of DMSO to form a positively charged reactive intermediate which experiences an oxygen transfer or a ligand coupling to give the products; the anionic surfactant (SDS) accelerates the process while the cationic surfactant (CPC) retards the reaction.
- Das, Asim K.,Mondal, Sudhin K.,Kar, Dalia,Das, Mahua
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- Oxovanadium and dioxomolybdenum complexes: synthesis, crystal structure, spectroscopic characterization and applications as homogeneous catalysts in sulfoxidation
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New oxovanadium and dioxomolybdenum Schiff base complexes, [VO(L)(OCH3)] n and [MoO2(L)(CH3OH)], were synthesized by treating an ONO donor Schiff base (H2L) derived by condensation of 3-ethoxysalicylaldehyde and nicotinic hydrazide with oxo and dioxo acetylacetonate salts of vanadium and molybdenum (VO(acac)2 and MoO2(acac)2), respectively. The synthesized ligand and complexes were characterized by FTIR, multinuclear (1H, 13C) NMR, elemental and single crystal X-ray diffraction analysis. In both complexes, the geometry around the central metal ions was distorted octahedral as revealed by diffraction studies. Theoretical calculations of the synthesized compounds were carried out by DFT at B3LYP/Def2-TZVP level of theory, which showed good correlation with the experimental results. Moreover, the catalytic efficiency of both complexes was investigated by oxidizing aryl and alkyl sulfides in the presence of 30% H2O2 in ethanol.
- Kargar, Hadi,Kaka-Naeini, Azar,Fallah-Mehrjardi, Mehdi,Behjatmanesh-Ardakani, Reza,Amiri Rudbari, Hadi,Munawar, Khurram Shahzad
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p. 1563 - 1583
(2021/05/11)
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- Magneli-type tungsten oxide nanorods as catalysts for the selective oxidation of organic sulfides
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Selective oxidation of thioethers is an important reaction to obtain sulfoxides as synthetic intermediates for applications in the chemical industry, medicinal chemistry and biology or the destruction of warfare agents. The reduced Magneli-type tungsten oxide WO3?xpossesses a unique oxidase-like activity which facilitates the oxidation of thioethers to the corresponding sulfoxides. More than 90% of the model system methylphenylsulfide could be converted to the sulfoxide with a selectivity of 98% at room temperature within 30 minutes, whereas oxidation to the corresponding sulfone was on a time scale of days. The concentration of the catalyst had a significant impact on the reaction rate. Reasonable catalytic effects were also observed for the selective oxidation of various organic sulfides with different substituents. The WO3?xnanocatalysts could be recycled at least 5 times without decrease in activity. We propose a metal oxide-catalyzed route based on the clean oxidant hydrogen peroxide. Compared to other molecular or enzyme catalysts the WO3?xsystem is a more robust redox-nanocatalyst, which is not susceptible to decomposition or denaturation under standard conditions. The unique oxidase-like activity of WO3?xcan be used for a wide range of applications in synthetic, environmental or medicinal chemistry.
- D?ren, René,Hartmann, Jens,Leibauer, Benjamin,Panth?fer, Martin,Mondeshki, Mihail,Tremel, Wolfgang
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p. 14027 - 14037
(2021/10/19)
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- A sustainable approach towards solventless organic oxidations catalyzed by polymer immobilized Nb(V)-peroxido compounds with H2O2 as oxidant
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New heterogeneous catalysts comprising of peroxidoniobium(V) complexes immobilized on amino acid grafted cross-linked poly(styrene-divinylbenzene) resin has been developed. Results of FTIR, Raman, NMR, XPS, XRD, EDX, SEM, BET, TGA, and elemental analysis confirmed the successful anchoring of triperoxidoniobium(V), [Nb(O2)3]? species to the host polymer via the pendant amino acid groups. The supported catalysts exhibited excellent performance in epoxidation of styrene and a range of cyclic and terpenic compounds under environmentally acceptable solvent-free condition, with aqueous H2O2 as oxidant. The catalytic protocols provided excellent conversion to the desired epoxide (up to 100%) with selectivity > 99%, TON as high as 1000, and high H2O2 utilization efficiency (92–97%). Moreover, the catalysts efficiently facilitated chemoselective solvent-free oxidation of a variety of thioethers to sulfones at room temperature. Simple operational strategy, easy recyclability for multiple reaction cycles with the consistent activity-selectivity profile are the additional significant attributes of the developed catalytic processes.
- Ahmed, Kabirun,Gogoi, Sandhya Rani,Islam, Nashreen S.,Saikia, Gangutri,Sultana, Sazida Yasmin,Talukdar, Hiya
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- Inorganic-organic hybrid polyoxovanadates based on [V4O12]4-or [VO3]22-clusters: Controllable synthesis, crystal structures and catalytic properties in selective oxidation of sulfides
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By rationally controlling hydrothermal conditions, three new inorganic-organic hybrid polyoxovanadates (POVs) [Ni2(1-vIM)7H2O][V4O12]·H2O (1), [Cu2(1-vIM)8][V4O12]·H2O (2) and [Co(1-vIM)H2O][VO3]2 (3) (1-vIM = 1-vinylimidazole) have been synthesized and thoroughly characterized by single X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), infrared spectroscopy (FT-IR), and elemental analyses (EA). Interestingly, complexes 1 and 2 have similar structures including [V4O12]4- clusters; complex 3, however, was isolated as a structure by including the [VO3]22- cluster under a different synthetic condition compared with those of 1 and 2. Both complexes 1 and 2 display an interesting 3D supramolecular structure, and complex 3 shows a 2D two parallel networks supramolecular structure linked by a [Co2O2] unit due to the different coordination environments of the central metals. Three inorganic-organic hybrid POVs asheterogeneous catalysts are active in the selective oxidation of sulfides to produce sulfoxides or sulfones with high conversion and high selectivity (up to 99.5 for sulfoxides and 98.5% for sulfones respectively catalyzed by 1). Complex 1 is also used as catalyst in the oxidative CEES (2-chloroethyl ethyl sulfide, a sulfur mustard simulant) abatement with high activity and selectivity towardthe corresponding sulfoxide. Moreover, complex 1 can be reused at least three times in sulfoxidationreactions without losing its activity.
- Guo, Daigaojie,Han, Yinfeng,He, Guofang,Hu, Changwen,Huang, Xianqiang,Li, Jikun,Wang, Congcong,Wei, Chuanping,Zhang, Jianping
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p. 14148 - 14157
(2020/11/02)
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- A new approach to large scale production of dimethyl sulfone: A promising and strong recyclable solvent for ligand-free Cu-catalyzed C-C cross-coupling reactions
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Dimethyl sulfone (DMSN) was easily prepared through efficient oxidation of dimethyl sulfoxide (DMSO) and used as a strong and green solvent for organic reactions. A mixture of HNO3/NaOCl was used as an oxidizing agent for efficient oxidation of DMSO to DMSN. The effect of DMSN was evaluated for copper-catalyzed coupling reactions. It is worth noting that DMSN could play the role of a ligand for copper ions. A general survey was accomplished for various types of C-C cross-coupling reactions catalyzed by CuI in DMSN in the absence of any ligand. Moderate to good yields were achieved for Sonogashira, Heck, and Suzuki cross-coupling reactions. Finally, DMSN was recovered and reused for several consecutive runs without any loss of its activity.
- Cheng, Shen,Wei, Wei,Zhang, Xingyu,Yu, Hewei,Huang, Mingming,Kazemnejadi, Milad
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p. 2069 - 2076
(2020/04/07)
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- Photochemical oxidation of benzylic primary and secondary alcohols utilizing air as the oxidant
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A mild and green photochemical protocol for the oxidation of alcohols to aldehydes and ketones was developed. Utilizing thioxanthenone as the photocatalyst, molecular oxygen from air as the oxidant and cheap household lamps or sunlight as the light source, a variety of primary and secondary alcohols were converted into the corresponding aldehydes or ketones in low to excellent yields. The reaction mechanism was extensively studied.
- Nikitas, Nikolaos F.,Tzaras, Dimitrios Ioannis,Triandafillidi, Ierasia,Kokotos, Christoforos G.
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p. 471 - 477
(2020/02/13)
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- Cage Effect on Oxidation of Dimethyl Sulfoxide via Pd2L4 Prolate Spheroids
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Self-assembly of PdX2 (X? = NO3 ?, BF4 ?, and CF3SO3 ?) with 2,6-bis(4′-nicotinamidephenoxy)naphthalene (L) forms a series of [Pd2L4]X4 prolate spheroids. The O donors of two Me2SO molecules within the prolate spheroid cage are oriented toward the Pd(II) metal centers. In the presence of H2O2, the nestled Me2SO within the cage is efficiently oxidized to Me2SO2 at room temperature.
- Hwang, Seo Young,Kim, Dongwon,Lee, Haeri,Jung, Ok-Sang
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p. 513 - 517
(2020/03/23)
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- Effect of Organic Solvents on the Rate of Oxidation of Sulfoxides with Peroxy Acids
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Abstract: The reaction of sulfoxides with peroxy acids in various organic media was studied. The reaction mechanism involves the rapid formation of a sulfoxide-–peroxy acid intermediate which decomposes in the second stage to form carboxylic acid and the corresponding sulfone. The second stage is the rate-limiting step. The reaction medium significantly affects the rate of oxidation. The calculated activation parameters of the oxidation process indicate a compensation effect in the investigated reaction. Correlations between the main physicochemical parameters of solvents and the effective rate constants (k) of dimethyl sulfoxide oxidation with peroxy acids were found. Depending on the reaction conditions, the main factors affecting the k values are specific and nonspecific solvation of the reactants and structural factors.
- Dutka, V. S.,Dutka, Yu. V.,Midyana, G. G.,Pal’chikova, E. Ya.
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p. 329 - 334
(2020/04/27)
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- Synthesis method of sulfone compound
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The invention discloses a synthesis method of a sulfone compound. The synthesis method specifically comprises the following steps: taking a compound shown as formula (I) as a reaction raw material, Ru/C as a catalyst, NaIO4 as an oxidant and water as a solvent, reacting at room temperature, and after the reaction is finished, carrying out after-treatment on an obtained reaction solution to obtainthe sulfone compound shown as formula (II), wherein the use amount of Ru/C is 0.5-2% of the molar amount of the compound shown in the formula (I) in terms of the molar amount of Ru; the molar amount of NaIO4 is 50-150% of the molar amount of the compound represented by formula (I). Under normal temperature conditions, cheap ruthenium carbon is oxidized by sodium periodate to generate ruthenium tetroxide, so that a thioether compound is further oxidized to synthesize the sulfone compound, the yield is close to 100 %, the subsequent treatment is simple, and a pure product can be obtained withoutcomplex separation and purification. Therefore, the method is more efficient, faster, more environmentally friendly and milder.
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Paragraph 0025-0029
(2020/01/25)
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- Solid-state rearrangement of sandwich-type polyoxometalate-dopamine nanohybrid to the nanoflower Keggin polyoxometalate: synthesis, characterization, and catalytic efficiency
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Sponge-like inorganic-organic nanohybrid consisting of sandwich-type polyoxometalate of [P2W18Ce3(H2O)2O71]12? (P2W18Ce3) and dopamine (DA) was fabricated by a simple procedure. The DA/P2W18Ce3 sponge-like nanohybrid is turned into a nanoflower by calcination at 300 °C. The results showed a structure rearrangement of sandwich-type polyoxometalate to the Keggin-type polyoxometalate along with this morphology change. The nanomaterials were fully characterized by scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, texture analysis (BET), and X-ray powder diffraction (XPRD). The DA/P2W18Ce3 sponge-like nanohybrid and the Keggin nanoflower showed efficiency toward degradation of methylene blue (MB) and rhodamine B (RhB). Moreover, the catalytic activity of the Keggin nanoflower was examined in the oxidation of sulfides to sulfones with H2O2 as oxidant in water at room temperature. The catalyst was reused at least four times without loss of its catalytic activity.
- Pirdosti, Soleiman Fazeli,Khoshnavazi, Roushan,Naseri, Elham
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p. 723 - 736
(2020/04/28)
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- Preparation method of sulfone
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The invention discloses a preparation method for a sulfone. The method comprises the following steps: providing a reaction feeding material containing at least one thioether, at least one oxidant andoptionally at least one solvent; and enabling the reaction feeding material to enter a first catalyst bed layer and flow through the first catalyst bed layer to an n-th catalyst bed layer, wherein thecatalyst bed layers are filled with a catalyst containing molecular sieves, and when overall pressure drop of the catalyst bed layers is higher than initial overall pressure drop, dividing the feeding material in the first catalyst bed layer into a first material flow to an f-th material flow, enabling the first material flow to enter the first catalyst bed layer, and enabling the remaining material flow other than the first material flow to enter the catalyst bed layers located at downstream of the first catalyst bed layer. When the method provided by the invention is adopted to oxidize thethioether to prepare the sulfone, the tendency of increase of pressure drop of the catalyst bed layers in a long-time continuous reaction process can be effectively inhibited, the system energy consumption can be reduced, and the stable running time of a device can be prolonged.
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Paragraph 0154-0206
(2020/12/14)
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- Method for oxidizing thioether
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A method for oxidizing thioether comprises the following steps: providing a reaction feed comprising at least one thioether, at least one oxidizing agent and optionally at least one solvent; allowingthe reaction feed to enter a first catalyst bed layer and flow through the first catalyst bed layer to the nth catalyst bed layer, wherein the catalyst bed layer is filled with a catalyst containing molecular sieve, when the total pressure drop of the catalyst bed is higher than the initial total pressure drop, the feed to the first catalyst bed layer is divided into a first stream to the fth stream, the first stream enters the first catalyst bed layer, and the remaining stream except the first stream enters the catalyst bed layer on the downstream of the first catalyst bed layer. The method for oxidizing thioether can effectively inhibit the rising trend of the pressure drop of the catalyst bed in the long-time continuous reaction process, reduce the energy consumption of the system and prolong the stable operation time of the device.
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Paragraph 0156-0208
(2019/05/16)
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- Reactions between 5-Nitroso-1,3-diphenyltetrazolium salts and electron-rich arenes, amines, thiophenol, sulfoxides, and thioanisole
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A series of reactions between 5-nitroso-1,3-diphenyltetrazo-lium tetrafluoroborate and methoxybenzenes, amines, thiols, sulfoxides, and sulfides, most of which are generally accepted as being inert to nitroso groups, is reported here. The tetrazolium-activated nitroso functionality is capable of oxidizing the aforementioned substrates to give the corresponding oxidized products, and the nitroso tetrazolium itself is transformed into the corresponding amide or hydroxyamide, depending on the nature of the reaction partners. In the case of thioanisole, an addition product was obtained.
- Matsukawa, Yuta,Hirashita, Tsunehisa,Araki, Shuki
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supporting information
p. 540 - 544
(2019/04/05)
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- Oxidizing Ability of a Dioxygen-Activating Nonheme Iron(II)-Benzilate Complex Immobilized on Gold Nanoparticles
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An iron(II)-benzilate complex [(TPASH)FeII(benzilate)]ClO4@C8Au (2) (TPASH = 11-((6-((bis(pyridin-2-ylmethyl)amino)methyl)pyridin-2-yl)methoxy)undecane-1-thiol) immobilized on octanethiol stabilized gold nanoparticles (C8Au) of core diameter less than 5 nm has been prepared to evaluate its reactivity toward O2-dependent oxidations compared to a nonimmobilized complex [(TPA-O-Allyl)FeII(benzilate)]ClO4 (1a) (TPA-O-Allyl = N-((6-(allyloxymethyl)pyridin-2-yl)methyl)(pyridin-2-yl)-N-(pyridin-2-ylmethyl)methanamine). X-ray crystal structure of the nonimmobilized complex 1a reveals a six-coordinate iron(II) center in which the TPA-O-Allyl acts as a pentadentate ligand and the benzilate anion binds in monodentate fashion. Both the complexes (1a and 2) react with dioxygen under ambient conditions to form benzophenone as the sole product through decarboxylation of the coordinated benzilate. Interception studies reveal that a nucleophilic iron-oxygen intermediate is formed in the decarboxylation reaction. The oxidants from both the complexes are able to carry out oxo atom transfer reactions. The immobilized complex 2 not only performs faster decarboxylation but also exhibits enhanced reactivity in oxo atom transfer to sulfides. Importantly, the immobilized complex 2, unlike 1a, displays catalytic turnovers in sulfide oxidation. However, the complexes are not efficient to carry out cis-dihydroxylation of alkenes. Although the immobilized complex yields a slightly higher amount of cis-diol from 1-octene, restricted access of dioxygen and substrates at the coordinatively saturated metal centers of the complexes likely makes the resulting iron-oxygen species less active in oxygen atom transfer to alkenes. The results implicate that surface immobilized nonheme iron complexes containing accessible coordination sites would exhibit better reactivity in O2-dependent oxygenation reactions.
- Sheet, Debobrata,Bera, Abhijit,Jana, Rahul Dev,Paine, Tapan Kanti
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p. 4828 - 4841
(2019/04/25)
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- Water-soluble polymer anchored peroxotitanates as environmentally clean and recyclable catalysts for mild and selective oxidation of sulfides with H2O2 in water
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Anchoring of peroxotitanium (pTi) species to linear water-soluble acrylic acid based polymers, poly(sodium acrylate) (PA) and poly(sodium methacrylate) (PMA) led to the successful synthesis of a pair of new, water-tolerant and recyclable catalysts of the type [Ti2(O2)2O2(OH)2]4-—L (L = PA or PMA), highly effective in chemoselective sulfoxidation of organic sulfides with 30% H2O2 in aqueous medium at ambient temperature. The catalytic protocol is high yielding (TOF up to 11,280 h?1), operationally simple as well as environmentally clean and safe, being free from halide, or any other toxic auxiliaries. The catalysts are sufficiently stable to afford easy recyclability for at least 10 consecutive reaction cycles of sulfoxidation with consistent activity selectivity profile. Oxidation of dibenzothiophene (DBT) to respective high purity sulfoxide or sulfone could also be accomplished using the same catalysts by variation of reaction conditions.
- Ahmed, Kabirun,Saikia, Gangutri,Paul, Sivangi,Baruah, Satyajit Dey,Talukdar, Hiya,Sharma, Mitu,Islam, Nashreen S.
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- Molybdenum (VI)-functionalized UiO-66 provides an efficient heterogeneous nanocatalyst in oxidation reactions
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A novel heterogeneous nanocatalyst was established by supporting molybdenum (VI) on Zr6 nodes in the structure of the well-known UiO-66 metal–organic framework (MOF). The structure of the UiO-66 before and after Mo (VI) immobilization was confirmed with XRD, DR-FTIR and UV–vis spectroscopy, and the presence and amount of Mo (VI) was identified by X-ray photoelectron spectroscopy and inductively coupled plasma atomic emission spectroscopy. TEM imaging confirmed the absence of Mo clusters on the MOF surface, while SEM confirmed that the appearance of the MOF has not changed upon immobilizing the Mo (VI) catalyst. BET adsorption measurements were used to confirm the porosity of the catalyst. The catalytic activity of this heterogeneous catalyst was investigated in oxidation of sulfides with H2O2 in acetonitrile and oxidative desulfurization of dibenzothiophene. Easy work up, convenient and steady reuse and high activity and selectivity are prominent properties of this new hybrid material.
- Afzali, Niloufar,Kardanpour, Reihaneh,Zadehahmadi, Farnaz,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Mechler, Adam,Mohammadpoor-Baltork, Iraj,Bahadori, Mehrnaz
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- Manganese-Catalyzed Acceptorless Dehydrogenative Coupling of Alcohols with Sulfones: A Tool to Access Highly Substituted Vinyl Sulfones
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The development of first-row-transition-metal catalysts that can match with the reactivities of the noble metals is considered to be challenging yet very much a desirable goal in homogeneous catalysis. It has become even more fascinating to develop processes where these metals show a unique reactivity and selectivity than their higher congeners. Herein, we report on the catalytic activity of a pincer complex of the abundant earth metal manganese for an unprecedented acceptorless dehydrogenative coupling of alkyl sulfones with alcohols. Thus, highly functionalized vinyl sulfones were obtained in moderate to good yields. Both benzylic and aliphatic alcohols could be utilized, and several functional groups including bromides and iodides are tolerated under the reaction conditions. The reaction is environmentally benign, producing dihydrogen and water as byproducts. Preliminary mechanistic experiments involving kinetic, deuterium-labeling, and NMR experiments were performed.
- Barman, Milan K.,Maji, Biplab,Waiba, Satyadeep
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p. 973 - 982
(2021/08/24)
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- Alkylation of Diethylphosphonoacetic Aldehyde and Triethyl Phosphonoacetate with Ethyl α-Bromopropanoate
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The alkylation reactions of phosphonoacetic aldehyde and ethyl phosphonoacetate with ethyl α-bromopropanoate in DMSO in the presence of K2CO3 have been studied.
- Ismailov,Ibragimova,Allakhverdiyeva,Sadikhova,Mamedov,Mamedbeyli,Yusubov
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p. 1394 - 1397
(2019/08/21)
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- METHOD FOR PRODUCING SULFONE COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing a sulfone compound from a sulfoxide compound with high efficiency and in high yield. SOLUTION: A sulfoxide compound represented by general formula (1) is subjected to optical oxygen oxidation, in the presence of a secondary alcohol, a gas with an oxygen content of 25 vol.% or more, anthracene or a derivative thereof, at 40°C or more, to produce a sulfone compound represented by general formula (2) (where R1 and R2 independently represent a C1-6 organic group, S, R1 and R2 may form a ring). SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0038-0051
(2018/09/27)
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- Method for producing dimethyl sulfone from hydrogen sulfide
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The invention discloses a method for producing dimethyl sulfone from hydrogen sulfide. The method includes: (1) subjecting hydrogen sulfide and methyl alcohol to contacting to obtain a mixture containing dimethyl sulfide; optionally, (2) subjecting the mixture containing dimethyl sulfide to gas-liquid separation to obtain a gas-phase material flow and a liquid-phase material flow containing dimethyl sulfide; optionally, (3) cyclically feeding at least part of the gas-phase material flow to the step (1); (4) subjecting the mixture containing dimethyl sulfide or a liquid phase low in hydrogen sulfide content to contact oxidation reaction with an oxidizing agent and titanium silicate molecular sieves to obtain a mixture containing dimethyl sulfone, wherein a mole ratio of the oxidizing agentto dimethyl sulfide is larger than 2. According to the method, continuous production of dimethyl sulfone from hydrogen sulfide is realized, and high raw material conversion rate and dimethyl sulfone selectivity can be obtained even oxidation reaction is carried out under mild conditions.
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Paragraph 0137-0138; 0149-0262
(2018/12/05)
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- METHOD OF PRODUCING SULFONE COMPOUND
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PROBLEM TO BE SOLVED: To provide a method of producing a sulfone compound from a sulfide compound efficiently with a high yield. SOLUTION: A sulfone compound represented by general formula (2) is produced by optical oxygen oxidation of a sulfide compound represented by general formula (1) at at least 40°C in the presence of a secondary alcohol, a gas containing at least 25 vol.% of oxygen, and anthracene or a derivative thereof. (In the formulas, R1 and R2 are each independently a C1-6 organic group, or S, R1 and R2 may form a ring.) SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2019,JPOandINPIT
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Paragraph 0040; 0041; 0043; 0044
(2019/01/25)
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- Sandwich type polyoxometalates encapsulated into the mesoporous material: Synthesis, characterization and catalytic application in the selective oxidation of sulfides
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The A-type sandwich polyoxometalates of [(HOSnIVOH)3(PW9O34)2]12- (P2W18Sn3) and [(OCeIVO)3(PW9O34)2]12- (P2W18Ce3) were immobilized for the first time into the porous metal-organic framework MIL-101(Cr). FT-IR, powder X-ray diffraction, SEM-EDX, ICP analysis, N2 adsorption and thermogravimetric analysis collectively confirmed immobilization and good distribution of polyoxometalates into cages of MIL-101(Cr). The catalytic activities of the homogeneous P2W18Sn3 and P2W18Ce3 and the corresponding heterogeneous catalysts were examined in the oxidation of sulfides to sulfones with H2O2 as the oxidant at room temperature. The effects of different dosages of polyoxometalates, type of solvent, reaction time, amount of catalyst and oxidant in this catalytic system were investigated. The new P2W18Sn3@MIL-101 and P2W18Ce3@MIL-101 nanocomposites exhibited good recyclability and reusability in at least five consecutive reaction cycles without significant loss of activity or selectivity.
- Naseri, Elham,Khoshnavazi, Roushan
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p. 28249 - 28260
(2018/08/16)
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- Oxidation reactions catalysed by molybdenum(VI) complexes grafted on UiO-66 metal–organic framework as an elegant nanoreactor
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A heterogeneous catalyst was synthesized by immobilizing Mo(CO)3 in a UiO-66 metal–organic framework. The benzene ring of the organic linker in UiO-66 was modified via liquid-phase deposition of molybdenum hexacarbonyl, Mo(CO)6, as starting precursor to form the (arene)Mo(CO)3 species inside the framework. The structure of this catalyst was characterized using X-ray diffraction, and chemical integrity was confirmed using Fourier transform infrared and diffuse reflectance UV–visible spectroscopic methods. The metal content was analysed with inductively coupled plasma. Field emission scanning electron microscopy was used to measure particle size and N2 adsorption measurements to characterize the specific surface area. This catalytic system was efficiently applied for epoxidation of alkenes and oxidation of sulfides. The Mo-containing metal–organic framework was reused several times without any appreciable loss of its efficiency.
- Afzali, Niloufar,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Mechler, Adam,Mohammadpoor-Baltork, Iraj,Kardanpour, Reihaneh,Zadehahmadi, Farnaz
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- A hydrogen sulfide production by the method of the dimethyl sulfoxide (by machine translation)
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The invention discloses a method of hydrogen sulfide production dimethyl sulfoxide, including: (1) the hydrogen sulfide with methanol, containing the dimethyl sulfide mixture; (2) the mixture of the gas-liquid separation, to obtain the vapor stream and a liquid stream containing dimethyl sulfide, optionally a gas phase stream circulation into the step (1) in; (3) under the conditions of the oxidation reaction, the liquid phase stream and the oxidizing agent and the titanium-silicon is exposed to molecular sieves, containing the mixture of dimethyl sulfoxide; optionally, (4) containing dimethyl sulfoxide is separated from the mixture, to obtain the dimethyl sulfide; optionally, (5) the step (4) of the separated dimethyl sulfide circulation into the step (3) in. The method of continuous production of hydrogen sulfide as a raw material to dimethyl sulfoxide, can obtain higher of dimethyl sulfide conversion, is especially suitable for large-scale production of the occasions. (by machine translation)
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Paragraph 0183-0191; 0206-0213; 0218
(2018/12/02)
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- A novel synthesis of aryl methyl sulfones and β-hydroxysulfones from sodium sulfinates and di-tert-butyl peroxide in H2O medium
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A novel and convenient synthetic route for aryl methyl sulfones and β-hydroxysulfones was developed via the radical reaction between sodium sulfinates and di-tert-butyl peroxide (DTBP). Without any catalysts and additives, the synthetic process could be smoothly carried out to afford the target products in good to excellent yields in H2O medium, demonstrating its promising application. In the present system, H2O could act not only as a green solvent but also as a reactant.
- Lai, Junyi,Yuan, Gaoqing
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supporting information
p. 524 - 527
(2018/01/10)
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- Synthesis and characterization of PMoV/Fe3O4/g-C3N4 from melamine: An industrial green nanocatalyst for deep oxidative desulfurization
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A facile approach to the preparation of a novel magnetically separable H5PMo10V2O40/Fe3O4/g-C3N4 (PMoV/Fe3O4/g-C3N4) nanocomposite by chemical impregnation is demonstrated. The prepared nanocomposite was characterized and its acidity was measured by potentiometric titration. PMoV/Fe3O4/g-C3N4 showed high catalytic activity in the selective oxidative desulfurization of sulfides to their corresponding sulfoxides or sulfones. The catalytic oxidation of a dibenzothiophene (DBT)-containing model oil and that of real oil were also studied under optimized conditions. In addition, the effects of various nitrogen compounds, as well as the use of one- and two-ring aromatic hydrocarbons as co-solvents, on the catalytic removal of sulfur from DBT were investigated. The catalyst was easily separated and could be recovered from the reaction mixture by using an external magnetic field. Additionally, the remaining reactants could be separated from the products by simple decantation if an appropriate solvent was chosen for the extraction. The advantages of this nanocatalyst are its high catalytic activity and reusability; it can be used at least four times without considerable loss of activity.
- Rafiee, Ezzat,Khodayari, Maryam
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p. 458 - 468
(2017/04/04)
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- Generation of VBr? VBi? VO?? defect clusters for 1O2 production for molecular oxygen activation in photocatalysis
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Defect engineering on a semiconductor surface can provide coordinatively unsaturated sites for molecular oxygen activation in photocatalysis. In this work, we demonstrated that the vacancy type was key to modulate the molecular oxygen activation process on BiOBr nanosheets. By regulating the reaction time, an oxygen vacancy (VO??), a double atom defect cluster (VBi? VO??) and triple atom clusters (VBi? VO?? VBi? and VBr? VBi? VO??) were accordingly generated on the surface, subsurface and bulk of BiOBr. More importantly, the newly-discovered VBr? VBi? VO?? defect cluster was highly related to the singlet oxygen (1O2) production ability of BiOBr. Meanwhile, the excellent photocatalytic selective oxidation reactions were successfully realized over BiOBr with the VBr? VBi? VO?? defect cluster. In addition, time-dependent defect cluster generation and the associated molecular oxygen activation were discussed.
- Ding, Jie,Dai, Zan,Tian, Fan,Zhou, Bo,Zhao, Bin,Zhao, Huiping,Chen, Zhiquan,Liu, Yunling,Chen, Rong
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supporting information
p. 23453 - 23459
(2017/11/30)
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- An environmentally benign and selective electrochemical oxidation of sulfides and thiols in a continuous-flow microreactor
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A practical and environmentally benign electrochemical oxidation of thioethers and thiols in a commercially-available continuous-flow microreactor is presented. Water is used as the source of oxygen to enable the oxidation process. The oxidation reaction utilizes the same reagents in all scenarios and the selectivity is solely governed by the applied potential. The procedure exhibits a broad scope and good functional group compatibility providing access to various sulfoxides (15 examples), sulfones (15 examples) and disulfides (6 examples). The use of continuous flow allows the optimal reaction parameters (e.g. residence time, applied voltage) to be rapidly assessed, to avoid mass- and heat-transfer limitations and to scale the electrochemistry.
- Laudadio, Gabriele,Straathof, Natan J. W.,Lanting, Menno D.,Knoops, Benny,Hessel, Volker,No?l, Timothy
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supporting information
p. 4061 - 4066
(2017/09/07)
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- A method of oxidation-dimethyl sulfoxide
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The invention provides a method for oxidizing dimethyl sulfoxide. The method for oxidizing the dimethyl sulfoxide comprises the step that under the oxidization reaction condition, a liquid mixture makes contact with at least one titanium silicalite molecular sieve as a catalyst, the liquid mixture contains the dimethyl sulfoxide and at least one kind of peroxide, the method further comprises the step that at least one kind of acid is added into the liquid mixture, and the additive amount of the acid is determined by the fact that the pH value of the liquid mixture ranges from 0.5 to 5.5. Compared with the fact that the liquid mixture containing the dimethyl sulfoxide and the peroxide and the titanium silicalite molecular sieve are directly subjected to a contact reaction, by means of the method for oxidizing the dimethyl sulfoxide, the selectivity to the dimethyl sulfoxide can be obviously improved, and meanwhile the higher dimethyl sulfoxide conversion rate and the higher oxidizing agent effective utilization rate can also be achieved. In addition, under the condition that the rest of conditions is the same, by means of the method for oxidizing the dimethyl sulfoxide, the basically same dimethyl sulfoxide conversion rate, the higher oxidizing agent effective utilization rate and the higher selectivity to the dimethyl sulfoxide can be achieved even the reaction is performed at a lower temperature. Furthermore, the method for oxidizing the dimethyl sulfoxide is easy to implement.
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Paragraph 0049; 0050
(2017/10/14)
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- A process for preparing dimethyl sulfone method
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The invention discloses a dimethyl sulfone preparation method. The dimethyl sulfone preparation method comprises causing a liquid mixture to be in contact with at least one titanium silicalite molecular sieve in a reaction zone in a catalytic distillation reactor with at least one reaction zone, so as to obtain material flow containing dimethyl sulfone, wherein the liquid mixture contains dimethyl sulfoxide and at least one oxidizing agent. The method can achieve high dimethyl sulfoxide conversion rate, dimethyl sulfone selectivity and effective utilization rate of the oxidizing agent. Besides, the method can make full use of reaction latent heat and even enables an oxidation product to be separated while the oxidation product reacts with raw material dimethyl sulfoxide, so that the follow-up separation cost is reduced, and energy saving and emission reduction are achieved.
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Paragraph 0090-0092; 0094; 0096; 0098-0101; 0103; 0105
(2017/10/13)
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- A Simple Metal Free Oxidation of Sulfide Compounds
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Abstract: This work reports simple, efficient, selective protocol for the oxidation of sulfide compounds. Various sulfides were selectively and completely converted into their corresponding sulfoxides and sulfones using H2O2as an oxidant in presence of catalytic amount of caprylic acid. The reaction proceeds at room temperature to give sulfoxide and by increasing the reaction temperature to 50 °C, this system provides selective formation of sulfone with high conversion and excellent yields. Green, convenient, easy work-up, chemoselectivity, broad substrate scope and regeneration of catalyst are the important highlights of this protocol. Graphical Abstract: [Figure not available: see fulltext.] Using H2O2as an oxidant in presence of catalytic amount of caprylic acid various sulfides were selectively and completely converted into their corresponding sulfoxides and sulfones.
- Wagh, Ravindra B.,Nagarkar, Jayashree M.
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p. 181 - 187
(2017/02/18)
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- A process for preparing dimethyl sulfone method (by machine translation)
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The invention provides a process for preparing dimethyl sulfone method, the method comprises the oxidation under the reaction conditions, will be a liquid mixture to contact with the catalyst, the liquid mixture containing dimethyl sulfide and at least one oxidizing agent, wherein said catalyst is modified titanium silicon molecular sieve, or the catalyst is titanium-silicon molecular sieve and modified titanium-silicon molecular sieve, the molecular sieve is modified titanium Ti-Si molecular sieve and at least one acid contact is obtained. With the direct use of titanium-silicon molecular sieve as a catalyst, the method of the invention by use of the modified titanium-silicon molecular sieve can significantly improve the dimethyl sulfone selectively, at the same time also can improve the dimethyl sulfide conversion and oxidizing agent effective utilization. (by machine translation)
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Paragraph 0055; 0058
(2017/06/09)
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- Method for simultaneous production of dimethyl sulfone and acetone
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The invention discloses a method for simultaneous production of dimethyl sulfone and acetone. The method comprises the following steps that in the presence of oxygen, dimethyl sulfide and isopropanol are contacted with a titanium silicon molecular sieve, so that a mixture containing dimethyl sulfone and acetone is obtained. By adopting the method, the higher conversion rate of dimethyl sulfide and higher selectivity of methyl sulfone can be obtained, furthermore, byproducts, namely acetone can be produced simultaneously. According to the invention, raw materials used in the method are environment-friendly and produced environmental pollutants are less, thereby being more conducive to environmental protection. Solvents cannot be used in the method, and various raw materials can be further directly used, without being prepared into a solution, so that the effective processing capacity of a device can be effectively improved. The method disclosed by the invention is simple and convenient in technological process, easy to operate and suitable for large-scale implementation.
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Paragraph 0066; 0067; 0068; 0069; 0070; 0071; 0071-0157
(2017/08/29)
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- A method of preparing plants the sulphone (by machine translation)
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The invention discloses a method of preparing plants the sulphone, the method comprises the oxidation under the reaction conditions, the at least one sulfide and at least one oxidizing agent with the titanium-silicon is exposed to molecular sieves, the oxidizing agent is selected from peroxides, includes the sulphone mixture obtained, the [...] molecular sieve is modified titanium silicon molecular sieve, dinucleotide [...] molecular sieve is modified titanium-silicon molecular sieve and not modified titanium-silicon molecular sieve, the modified titanium-silicon molecular sieve experience modified processing, the not modified titanium-silicon molecular sieve has not undergoing the modified processing, the modified treatment may include as the raw material of the titanium silicon molecular sieve and contains nitric acid and at least one peroxide of the modify the contact. The method of the invention can effectively improve titanium-silicon molecular sieve catalytic performance, prolong the service life of the one-way titanium-silicon molecular sieve, reduce the titanium-silicon molecular sieve regeneration frequency. (by machine translation)
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Paragraph 0080; 0081; 0082; 0083; 0084; 0085; 0086-0185
(2017/10/22)
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- Method for selectively compounding aryl methyl sulphone and belta-hydroxy sulphone derivative
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The invention discloses a method for selectively compounding an aryl methyl sulphone and belta-hydroxy sulphone derivative. The method has the advantages that sulfinic acid sodium salt and di-tert-butyl peroxide serve as raw materials, water serves as green reaction solvent, additives and catalysts are not needed, and the aryl methyl sulphone and belta-hydroxy sulphone derivative is obtained through control of reaction temperature selectivity. The method has the advantages of mild reaction condition, simplicity in operation, low cost, environment friendliness, high product selectivity, high yield and the like, and has practical application value.
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Paragraph 0067; 0068; 0069
(2017/08/29)
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- On the incompatibility of lithium-O2 battery technology with CO2
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When solubilized in a hexacarboxamide cryptand anion receptor, the peroxide dianion reacts rapidly with CO2 in polar aprotic organic media to produce hydroperoxycarbonate (HOOCO2-) and peroxydicarbonate (-O2COOCO2-). Peroxydicarbonate is subject to thermal fragmentation into two equivalents of the highly reactive carbonate radical anion, which promotes hydrogen atom abstraction reactions responsible for the oxidative degradation of organic solvents. The activation and conversion of the peroxide dianion by CO2 is general. Exposure of solid lithium peroxide (Li2O2) to CO2 in polar aprotic organic media results in aggressive oxidation. These findings indicate that CO2 must not be introduced in conditions relevant to typical lithium-O2 cell configurations, as production of HOOCO2- and -O2COOCO2- during lithium-O2 cell cycling will lead to cell degradation via oxidation of organic electrolytes and other vulnerable cell components.
- Zhang, Shiyu,Nava, Matthew J.,Chow, Gary K.,Lopez, Nazario,Wu, Gang,Britt, David R.,Nocera, Daniel G.,Cummins, Christopher C.
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p. 6117 - 6122
(2017/08/29)
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- Initiation in Photoredox C-H Functionalization Reactions. Is Dimsyl Anion a Key Ingredient?
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Previous studies have reported the arylation of unactivated arenes with ArX, base (KOtBu or NaOtBu), and an organic additive at high temperatures. Recently, we showed that this reaction proceeds in the absence of additives at rt but employs UV-vis light. However, details of mechanisms that can use a photoinduced base-promoted homolytic aromatic substitution reaction (photo-BHAS) have remained elusive until now. This work examines different mechanistic routes of the essential electron-transfer step (ET) of this reaction in order to identify a possible path for the formation of 1-adamantyl radicals from 1-haloadamantanes (initiation step). On the basis of photochemical and photophysical experiments and computational studies, we propose an unprecedented initiation step that could also be applied to other ET reactions performed in DMSO. For the first time, it is reported that dimsyl anion, formed from a strong base and DMSO (solvent), is responsible for inducing the initiation by a photo-BHAS process on alkyl halides.
- Budén, María E.,Bardagí, Javier I.,Puiatti, Marcelo,Rossi, Roberto A.
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p. 8325 - 8333
(2017/08/23)
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- An eco-friendly oxidation of sulfide compounds
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An improved green route has been developed for the oxidation of sulfide compounds. Albendazole is converted to ricobendazole or albendazole sulfone using H 2O2 as an oxidant and H 2O as the solvent. High yields of the corresponding products were obtained by carrying out the reaction at room temperature. This synthetic method is environmentally clean and safe, operationally simple for the oxidation of other benzimidazole anthelmintics and various sulfide compounds. [Figure not available: see fulltext.]
- Wagh, Ravindra B,Gund, Sitaram H,Nagarkar, Jayashree M
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p. 1321 - 1325
(2016/08/19)
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- A dimethyl sulfide oxidation method
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The invention discloses a method for oxidizing dimethyl sulfide, which comprises the step of contacting dimethyl sulfide with an oxidizing agent under oxidation reaction conditions and is characterized in that the oxidizing agent is gas containing ozone. The method disclosed by the invention is free from any inhibitor or initiator in feed gas and has high selectivity and higher effective ozone utilization rate; particularly, the effective ozone utilization rate is greatly increased in the presence of a titanium-containing catalyst; furthermore, the method disclosed by the invention is simple in process and easy for control and is beneficial to industrial production and application; in addition, compared with the traditional method, the problems of being complex in traditional production process, corrosive in equipment, harmful for discharging and the like are overcome.
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Paragraph 0039; 0040
(2017/01/05)
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- A dimethyl sulfoxide, dimethyl sulfone method of preparation
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The invention discloses a method for preparing dimethyl sulfone from dimethyl sulfoxide. The method comprises the following step: contacting dimethyl sulfoxide and an oxidant under the oxidizing reaction conditions. The method is characterized in that the oxidant is ozone-containing gas. According to the method, the selectivity of dimethyl sulfone is high, and especially the effective utilization rate of ozone is greatly improved in the presence of a titanium-containing catalyst.
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Paragraph 0046; 0047; 0048; 0049
(2016/10/07)
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- Aerobic alcohol oxidation and oxygen atom transfer reactions catalyzed by a nonheme iron(II)-α-keto acid complex
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α-Ketoglutarate-dependent enzymes catalyze many important biological oxidation/oxygenation reactions. Iron(iv)-oxo intermediates have been established as key oxidants in these oxidation reactions. While most reported model iron(ii)-α-keto acid complexes exhibit stoichiometric reactivity, selective oxidation of substrates with dioxygen catalyzed by biomimetic iron(ii)-α-keto acid complexes remains unexplored. In this direction, we have investigated the ability of an iron(ii) complex [(TpPh,Me)FeII(BF)] (1) (TpPh,Me = hydrotris(3-phenyl-5-methylpyrazolyl)borate and BF = monoanionic benzoylformate) to catalyze the aerobic oxidation of organic substrates. An iron-oxo oxidant, intercepted in the reaction of 1 with O2, selectively oxidizes sulfides to sulfoxides, alkenes to epoxides, and alcohols to the corresponding carbonyl compounds. The oxidant from 1 is able to hydroxylate the benzylic carbon of phenylacetic acid to afford mandelic acid with the incorporation of one oxygen atom from O2 into the product. The iron(ii)-benzoylformate complex oxidatively converts phenoxyacetic acids to the corresponding phenols, thereby mimicking the function of iron(ii)-α-ketoglutarate-dependent 2,4-dichlorophenoxyacetate dioxygenase (TfdA). Furthermore, complex 1 exhibits catalytic aerobic oxidation of alcohols and oxygen atom transfer reactions with multiple turnovers.
- Sheet, Debobrata,Paine, Tapan Kanti
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p. 5322 - 5331
(2016/08/02)
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- Dimethyl sulfone preparation method
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The invention discloses a dimethyl sulfone preparation method. The method includes the steps that under the oxidation reaction condition, a liquid mixture makes contact with a titanium silicalite molecular sieve serving as the catalyst to obtain a mixture containing dimethyl sulfone, and the liquid mixture contains dimethyl sulfoxide and at least one peroxide, wherein the titanium silicalite molecular sieve is contained in tubes of a tubular reactor to form a catalyst bed layer. The method further includes the step that in the contact process, cooling media are conveyed into spaces between the tubes, and the cooling media and the tubes conduct heat exchange. According to the method, in the process that dimethyl sulfoxide is oxidized to prepare dimethyl sulfone, reaction heat released in the reaction process is transferred in time, and during long-time continuous operation, the dimethyl sulfoxide conversion rate, dimethyl sulfone selectivity and the oxidant effective utilization rate can be higher. Meanwhile, activity stability of the catalyst is good, and the service life is longer.
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Paragraph 0070; 0071; 0072; 0073; 0075; 0076; 0077-0170
(2017/06/02)
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- Production process of dimethyl sulfone
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The invention belongs to the technical field of chemical engineering, and particularly discloses a production process of dimethyl sulfone. The production process comprises the following steps that 1, an oxidation reaction is carried out, wherein dimethyl sulfoxide, an oxidizing agent and a catalyst are added into a reaction device, the reaction temperature is controlled, and dimethyl sulfone is generated through stirring reaction, wherein the catalyst is 2,6-naphthalic acid; 2, a solid catalyst is separated; 3, a dimethyl sulfone crystal is generated through crystallization; 4, solid-liquid separation is performed to obtain the dimethyl sulfone crystal; 5, drying is carried out. Due to the fact that the 2,6-naphthalic acid is adopted as the catalyst for preparing the dimethyl sulfone from dimethyl sulfoxide through oxidization, the oxidization reaction speed is greatly increased, and the high-purity dimethyl sulfone product with the purity of 99% or above can be obtained only by separating the solid catalyst, generating and separating the dimethyl sulfone crystal and then carrying out drying treatment in the follow-up treating process. By the adoption of the novel catalyst, production energy consumption of dimethyl sulfone can be lowered, the produciton period is shortened, production efficiency is improved, and economic benefits are increased.
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Paragraph 0025-0093
(2017/08/23)
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- By means of a micro channel reactor method of preparing sulfoxide or sulfone
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The invention discloses a method for preparing sulfoxide or sulfone by using a micro-channel reactor. The invention provides a method for preparing sulfoxide or sulfone. The method comprises the following steps: respectively feeding a homogeneous solution prepared from thioether 1 and a solvent, and an oxidant into the micro-channel reactor, and contacting the homogeneous solution with the oxidant in a micro-channel for oxidation reaction so as to obtain sulfoxide or sulfone, wherein the oxidation reaction time is 1-300 seconds. The method disclosed by the invention is very short in reaction time, precise in reaction condition control, high in security, applicable to rapid preparation of kilogram-scale products and capable of realizing continuous production; the sulfoxide and sulfone are high in selectivity, high in yield, good in purity and applicable to on-scale industrial production.
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Paragraph 0080-0084
(2017/04/11)
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- The reduced flavin-dependent monooxygenase SfnG converts dimethylsulfone to methanesulfinate
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The biochemical pathway through which sulfur may be assimilated from dimethylsulfide (DMS) is proposed to proceed via oxidation of DMS to dimethylsulfoxide (DMSO) and subsequent conversion of DMSO to dimethylsulfone (DMSO2). Analogous chemical oxidation processes involving biogenic DMS in the atmosphere result in the deposition of DMSO2 into the terrestrial environment. Elucidating the enzymatic pathways that involve DMSO2 contribute to our understanding of the global sulfur cycle. Dimethylsulfone monooxygenase SfnG and flavin mononucleotide (FMN) reductase MsuE from the genome of the aerobic soil bacterium Pseudomonas fluorescens Pf0-1 were produced in Escherichia coli, purified, and biochemically characterized. The enzyme MsuE functions as a reduced nicotinamide adenine dinucleotide (NADH)-dependent FMN reductase with apparent steady state kinetic parameters of Km = 69 μM and kcat/Km = 9 min?1 μM ?1 using NADH as the variable substrate, and Km = 8 μM and kcat/Km = 105 min?1 μM ?1 using FMN as the variable substrate. The enzyme SfnG functions as a flavoprotein monooxygenase and converts DMSO2 to methanesulfinate in the presence of FMN, NADH, and MsuE, as evidenced by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The results suggest that methanesulfinate is a biochemical intermediate in sulfur assimilation.
- Wicht, Denyce K.
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p. 159 - 166
(2016/07/22)
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- Preparation method of dimethyl sulfoxide
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The invention discloses a preparation method of dimethyl sulfoxide. The preparation method comprises that under oxidation reaction conditions, a liquid mixture contacts with a titanium silicalite molecular sieve as a catalyst so that a dimethyl sulfoxide mixture is obtained, wherein the liquid mixture contains dimethyl sulfide and at least one peroxide, row tubes of a tubular reactor are filled with the titanium silicalite molecular sieve so that a catalyst bed layer is formed, and in contact, a cooling medium is fed into a space between the row tubes and is used for heat change of the row tubes. In preparation of dimethyl sulfone through dimethyl sulfide oxidation, the reaction heat released by the reaction process is removed timely. In long-term continuous operation, a dimethyl sulfide conversion rate, dimethyl sulfone selectivity and an oxidizing agent effective utilization rate are improved, catalyst activity and stability are good and a long service life is obtained.
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Paragraph 0055; 0056; 0080; 0081
(2016/10/27)
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- Direct Tryptophols Synthesis from 2-Vinylanilines and Alkynes via C - C Triple Bond Cleavage and Dioxygen Activation
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An unexpected metal-free C - C triple bond cleavage, dioxygen activation, and reassembly into tryptophol derivatives has been developed. This chemistry provides a novel, simple, and efficient approach to highly valuable tryptophol derivatives from simple substrates under mild conditions. The mechanistic studies may promote the discovery of new methodologies through C-C bond cleavage and dioxygen activation.
- Shen, Tao,Zhang, Yiqun,Liang, Yu-Feng,Jiao, Ning
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supporting information
p. 13147 - 13150
(2016/10/24)
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- Radical Beckmann Rearrangement and Its Application in the Formal Total Synthesis of Antimalarial Natural Product Isocryptolepine via C-H Activation
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The Beckmann rearrangement of ketoximes, mediated by ammonium persulfate-dimethyl sulfoxide as a reagent, has been achieved under neutral conditions. Based on the radical trapping and 18O-labeling experiments, the transformation follows a mechanism involving a radical pathway. The scope and generality of the developed protocol has been demonstrated by 19 examples. The developed protocol and Pd-catalyzed intramolecular double C-H activation were used as key steps in the formal total synthesis of antimalarial natural product isocryptolepine.
- Mahajan, Pankaj S.,Humne, Vivek T.,Tanpure, Subhash D.,Mhaske, Santosh B.
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supporting information
p. 3450 - 3453
(2016/07/26)
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- Iron(II) catalysis in oxidation of hydrocarbons with ozone in acetonitrile
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Oxidation of alcohols, ethers, and sulfoxides by ozone in acetonitrile is catalyzed by submillimolar concentrations of Fe(CH3CN)62+. The catalyst provides both rate acceleration and greater selectivity toward the less oxidized products. For example, Fe(CH3CN)62+-catalyzed oxidation of benzyl alcohol yields benzaldehyde almost exclusively (>95%), whereas the uncatalyzed reaction generates a 1:1 mixture of benzaldehyde and benzoic acid. Similarly, aliphatic alcohols are oxidized to aldehydes/ketones, cyclobutanol to cyclobutanone, and diethyl ether to a 1:1 mixture of ethanol and acetaldehyde. The kinetics of oxidation of alcohols and diethyl ether are first-order in [Fe(CH3CN)62+] and [O3] and independent of [substrate] at concentrations greater than ~5 mM. In this regime, the rate constant for all of the alcohols is approximately the same, kcat = (8 ± 1) × 104 M-1 s-1, and that for (C2H5)2O is (5 ± 0.5) × 104 M-1 s-1. In the absence of substrate, Fe(CH3CN)62+ reacts with O3 with kFe = (9.3 ± 0.3) × 104 M-1 s-1. The similarity between the rate constants kFe and kcat strongly argues for Fe(CH3CN)62+/O3 reaction as rate-determining in catalytic oxidation. The active oxidant produced in Fe(CH3CN)62+/O3 reaction is suggested to be an Fe(IV) species in analogy with a related intermediate in aqueous solutions. This assignment is supported by the similarity in kinetic isotope effects and relative reactivities of the two species toward substrates.
- Bataineh, Hajem,Pestovsky, Oleg,Bakac, Andreja
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p. 1629 - 1637
(2015/03/14)
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