- Visible-light-induced sulfoxidation of alkanes in the presence of titania
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The first catalytic photosulfoxidation of alkanes is accomplished in the presence of titanium dioxide and visible light (λ≥400 nm) under an atmosphere of SO2/O2. For n-heptane and cyclohexane the reaction is performed in the neat liquid, for adamantane in glacial acetic acid. Charge-transfer (CT) complexation of sulfur dioxide by the titania surface generates a CT band at 400-420 nm responsible for the visible-light activity of otherwise only UV light absorbing titania. The primary charges generated upon optical electron transfer produce alkyl radicals by dissociative electron transfer from the alkane and by hydrogen abstraction by OH radicals produced from oxygen reduction. Once formed, the alkyl radicals initiate a radical chain reaction as known from the classical UV-induced sulfoxidation in the absence of a catalyst. The reaction exhibits features characteristic for product inhibition by strong adsorption. Accordingly, the initial photocatalytic activity is fully restored after washing the catalyst with methanol. Time-resolved photovoltage measurements indicate that photocatalyst deactivation is connected with a change from n-type to p-type titanium dioxide. Small amounts of water and radical scavengers inhibit product formation. The reaction proceeds with high chemoselectivity because only traces of expected by-products like sulfates, ketones, and alcohols are formed. Thus, in addition to its basic role in visible-light-induced charge generation, the surface of titania enables also a chemoselective C-S bond formation.
- Parrino, Francesco,Ramakrishnan, Ayyappan,Damm, Cornelia,Kisch, Horst
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p. 713 - 720
(2013/01/14)
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- Synthesis of sulfonyl chlorides and sulfonic acids in SDS micelles
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H2O2/POCl3 is found to be a reactive reagent system that can be used in sodium dodecyl sulfate (SDS) micellar solution in aqueous media for the direct oxidative chlorination of thiol and di-sulfide derivatives to give the desired sulfonyl chlorides. The oxidation of thiols and disulfides to sulfonic acids with this system is also reported. In most cases, these reactions are highly selective, simple, and clean, affording products in excellent yields and high purity. Georg Thieme Verlag Stuttgart · New York.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Abbasi, Jamshid
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experimental part
p. 316 - 322
(2012/03/26)
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- Semiconductor-photocatalyzed sulfoxidation of alkanes
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(Equation Presented) The C-H activation of alkanes with visible light is possible with a semiconductor as the photocatalyst. Upon irradiation, a mixture of titanium dioxide, sulfur dioxide, and oxygen can be used to convert alkanes into the corresponding sulfonic acids (see scheme).
- Parrino, Francesco,Ramakrishnan, Ayyappan,Kisch, Horst
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experimental part
p. 7107 - 7109
(2009/04/07)
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- General, fast, and high yield oxidation of thiols and disulfides to sulfonic and sulfinic acids using HOF·CH3CN
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Thiols and disulfides are oxidized to the corresponding sulfonic and sulfinic acids using HOF·CH3CN. This oxidation is suitable for a variety of thiols and disulfides and proceeds under mild conditions, in short reaction times and with high yields.
- Shefer, Neta,Carmeli, Mira,Rozen, Shlomo
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p. 8178 - 8181
(2008/03/14)
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- PROCESS FOR PREPARING ORGANIC SULFUR ACIDS OR SALTS THEREOF
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A process for producing organic sulfur acid or a salt thereof of the present invention allows an organic substrate to react with a sulfur oxide in the presence of a metallic compound catalyst and in the absence of N-hydroxy and N-oxo cyclic imide compounds and thereby yields a corresponding organic sulfur acid or a salt thereof. Such organic substrates include, for example, (a) homocyclic or heterocyclic compounds having a methylene group, (b) compounds having a methine carbon atom, (c) compounds having a methyl group or methylene group at the adjacent position to an unsaturated bond, (d) non-aromatic heterocyclic compounds having a carbon-hydrogen bond at the adjacent position to a hetero atom, and (e) straight-chain alkanes. The sulfur oxide includes, for example, sulfur dioxide. This production process can efficiently produce an organic sulfur acid or a salt thereof under mild conditions.
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- Process for preparing organic sulfur acids or salts thereof
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A process for producing organic sulfur acid or a salt thereof of the present invention allows an organic substrate to react with a sulfur oxide in the presence of a metallic compound catalyst and in the absence of N-hydroxy and N-oxo cyclic imide compounds and thereby yields a corresponding organic sulfur acid or a salt thereof. Such organic substrates include, for example, (a) homocyclic or heterocyclic compounds having a methylene group, (b) compounds having a methine carbon atom, (c) compounds having a methyl group or methylene group at the adjacent position to an unsaturated bond, (d) non-aromatic heterocyclic compounds having a carbon-hydrogen bond at the adjacent position to a hetero atom, and (e) straight-chain alkanes. The sulfur oxide includes, for example, sulfur dioxide. This production process can efficiently produce an organic sulfur acid or a salt thereof under mild conditions.
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- Induced decomposition of acetylcyclohexylsulfonyl peroxide
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The kinetics of thermal decomposition of acetylcyclohexylsulfonyl peroxide is studied in a n-decane solution in an oxygen atmosphere (303-333 K) and under anaerobic conditions (313-333 K); the reaction products are also studied in a cyclohexane solution under oxygen-free conditions (323 K).In the absence of oxygen, the reaction is found to proceed via a chain-radical mechanism.Some kinetic parameters of the process are determined. - Key words: acetylcyclohexylsulfonyl peroxide, induced decomposition.
- Zaripov, R. N.,Safiullin, R. L.,Yaubasarova, E. I.,Muslukhov, R. R.,Komissarov, V. D.
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p. 1011 - 1013
(2007/10/02)
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- Mercury-Photosensitized Sulfination, Hydrosulfination, and Carbonylation of Hydrocarbons: Alkane and Alkene Conversion to Sulfonic Acids, Ketones, and Aldehydes
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Mercury-photosensitized sulfination of alkanes, RH, with SO2 forms sulfinic acids (RSOOH) and sulfinate esters (RSOOR) in high conversion and yield; oxidation of the mixture produces RSO2OH in high yield.Mercury-photosensitized hydrosulfination of alkenes with H2 and SO2 gives RSO2OH after oxidative workup.Mercury-photosensitized carbonylation of alkanes with CO gives RCHO and R2CO.
- Ferguson, Richard R.,Crabtree, Robert H.
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p. 5503 - 5510
(2007/10/02)
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