- Cathodic oxidation of sulfoxides to sulfones using a tungstate/pertungstate redox mediator
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A new cathodic oxidation system for the oxidation of sulfoxides was developed. The system involves the cathodic reduction of dioxygen to hydrogen peroxide which oxidizes tungstate to pertungstate in the solution, and sulfoxides arc oxidized to the corresponding sulfones with the resulting tungstate/ pertungstate redox mediator in high cfficncy and selectivity.
- Li, Wei,Nonaka, Tsutomu
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- Nucleophile-mediated oxa-Michael addition reactions of divinyl sulfone - a thiol-free option for step-growth polymerisations
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Triphenylphosphine and 4-dimethylaminopyridine promote the oxa-Michael addition reaction of alcohols and divinyl sulfone. Under solvent-free conditions, the reaction is particularly fast and allows for the preparation of polymers.
- Strasser, Simone,Slugovc, Christian
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- Locus-specific microemulsion catalysts for sulfur mustard (HD) chemical warfare agent decontamination
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The rates of catalytic oxidative decontamination of the chemical warfare agent (CWA) sulfur mustard (HD, bis(2-chlororethyl) sulfide) and a range (chloroethyl) sulfide simulants of variable lipophilicity have been examined using a hydrogen peroxide-based microemulsion system. SANS (small-angle neutron scattering), SAXS (small-angle X-ray scattering), PGSE-NMR (pulsed-gradient spin-echo NMR), fluorescence quenching, and electrospray mass spectroscopy (ESI-MS) were implemented to examine the distribution of HD, its simulants, and their oxidation/hydrolysis products in a model oil-in-water microemulsion. These measurements not only present a means of interpreting decontamination rates but also a rationale for the design of oxidation catalysts for these toxic materials. Here we show that by localizing manganese-Schiff base catalysts at the oil droplet-water interface or within the droplet core, a range of (chloroethyl) sulfides, including HD, spanning some 7 orders of octanol-water partition coefficient (Kow), may be oxidized with equal efficacy using dilute (5 wt. % of aqueous phase) hydrogen peroxide as a noncorrosive, environmentally benign oxidant (e.g., t1/2 (HD) ～ 18 s, (2-chloroethyl phenyl sulfide, C6H5SCH2CH 2Cl) ～ 15 s, (thiodiglycol, S(CH2CH 2OH)2) ～ 19 s {20°C}). Our observations demonstrate that by programming catalyst lipophilicity to colocalize catalyst and substrate, the inherent compartmentalization of the microemulsion can be exploited to achieve enhanced rates of reaction or to exert control over product selectivity. A combination of SANS, ESI-MS and fluorescence quenching measurements indicate that the enhanced catalytic activity is due to the locus of the catalyst and not a result of partial hydrolysis of the substrate.
- Fallis, Ian A.,Griffiths, Peter C.,Cosgrove, Terence,Dreiss, Cecile A.,Govan, Norman,Heenan, Richard K.,Holden, Ian,Jenkins, Robert L.,Mitchell, Stephen J.,Notman, Stuart,Platts, Jamie A.,Riches, James,Tatchell, Thomas
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scheme or table
p. 9746 - 9755
(2011/03/20)
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- Synthesis of Sulfoxides by the Hydrogen Peroxide Induced Oxidation of Sulfides Catalyzed by Iron Tetrakis(pentafluorophenyl)porphyrin: Scope and Chemoselectivity
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The oxidation of sulfides with H2O2 catalyzed by iron tetrakis(pentafluorophenyl)porphyrin in EtOH is an efficient and chemoselective process. With a catalyst concentration 0.03-0.09% of that of the substrate, sulfoxides are obtained with yields generally around 90-95% of isolated product. With vinyl and allyl sulfides, no epoxidation is observed. With a catalyst concentration between 0.09% and 0.25% of that of the substrate, sulfones are obtained in almost quantitative yield and with the same high chemoselectivity observed in the synthesis of sulfoxides.
- Baciocchi, Enrico,Gerini, Maria Francesca,Lapi, Andrea
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p. 3586 - 3589
(2007/10/03)
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- THE CHEMISTRY OF 1,1'-THIOBIS(2-CHLOROETHANE) (SULPHUR MUSTARD) PART I: SOME SIMPLE DERIVATIVES
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Some derivatives of 1,1'-thiobis(2-chloroethane) (sulphur mustard) have been synthesized for use as reference compounds in a wide range of studies embracing analysis, metabolism, environmental degradation and decontamination.Compounds include products formed by hydrolysis, substitution and elimination reactions and their oxidised sulphoxide and sulphone analogues.A comprehensive series of methylthio, methylsulphinyl and methylsulphonyl derivatives has been synthesised in support of metabolic studies. Key words: Thiobis(2-chloroethane) and derivatives; analysis; metabolism; environmental degradation; decontamination
- Black, R. M.,Brewster, K.,Harrison, J. M.,Stansfield, N.
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- A FACILE OXIDATIVE LACTONIZATION OF 1,ω-DIOLS WITH SODIUM BROMITE
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A practically useful method for the oxidation of 1,ω-diols to lactones is described.The scope and limitations are also presented.
- Kageyama, Toshifumi,Kawahara, Shuji,Kitamura, Kohji,Ueno, Yoshio,Okawara, Makoto
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p. 1097 - 1100
(2007/10/02)
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