67-71-0Relevant articles and documents
Kinetics and mechanism of oxidation of dimethyl sulphoxide by mono- and di-substituted N,N-dichlorobenzenesulphonamides in aqueous acetic acid
Gowda, B. Thimme,Jayalakshmi,Jyothi
, p. 787 - 794 (2003)
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.
Micellar effect on the reaction of picolinic acid catalyzed chromium(VI) oxidation of dimethyl sulfoxide in aqueous acidic media: A kinetic study
Das,Mondal,Kar,Das
, p. 173 - 181 (2001)
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.
OXIDATION OF DIMETHYLSUPHOXIDE BY SODIUM N-BROMOBENZENESULPHONAMIDE: A KINETIC AND MECHANISTIC STUDY
Mahadevappa, D.S.,Ananda, S.,Murthy, A.S.A.,Rangappa, K.S.
, p. 1673 - 1682 (1984)
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.
Polyoxometalate nanocone nanoreactors: Magnetic manipulation and enhanced catalytic performance
Nisar, Amjad,Lu, Yao,Zhuang, Jing,Wang, Xun
, p. 3187 - 3192 (2011)
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
Oxygen-atom-transfer reactions of a palladium(II) peroxocarbonate complex
Sase, Shohei,Hashimoto, Maki,Goto, Kei
, p. 157 - 159 (2015)
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.
Oxovanadium and dioxomolybdenum complexes: synthesis, crystal structure, spectroscopic characterization and applications as homogeneous catalysts in sulfoxidation
Kargar, Hadi,Kaka-Naeini, Azar,Fallah-Mehrjardi, Mehdi,Behjatmanesh-Ardakani, Reza,Amiri Rudbari, Hadi,Munawar, Khurram Shahzad
, p. 1563 - 1583 (2021/05/11)
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.
A sustainable approach towards solventless organic oxidations catalyzed by polymer immobilized Nb(V)-peroxido compounds with H2O2 as oxidant
Ahmed, Kabirun,Gogoi, Sandhya Rani,Islam, Nashreen S.,Saikia, Gangutri,Sultana, Sazida Yasmin,Talukdar, Hiya
, (2021/11/16)
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.
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
Cheng, Shen,Wei, Wei,Zhang, Xingyu,Yu, Hewei,Huang, Mingming,Kazemnejadi, Milad
, p. 2069 - 2076 (2020/04/07)
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.