- 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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- Intermediates in the Peroxy Acid Oxidation of Phenyl Phenylmethanethiosulfinate
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The m-chloroperoxybenzoic acid (MCPBA) oxidation of phenyl phenylmethanethiosulfinate (9) in CDCl3 has been studied.Low-temperature 1H NMR and 13C NMR spectra show that phenyl phenylmethanethiosulfonate (7), phenylmethanesulfonic acid (26), and phenylmethanesulfinic acid (27) are formed during the early stages of oxidation.Although 7 may be formed via direct attack of MCPBA at the sulfinyl sulfur atom of 9, the presence of 7, 26, and 27 is also explicable in terms of formation and rearrangement of metastable α-disulfoxide (13) and sulfenyl sulfinate (14) intermediates.
- Freeman, Fillmore,Angeletakis, Christos N.
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- Selective oxidation reactions of diaryl- and dialkyldisulfides to sulfonic acids by CH3ReO3/hydrogen peroxide
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Diaryl- and dialkyl disulfides were oxidized in acetonitrile at 20 °C by CH3ReO3/H2O2 oxidant system to yield selectively the corresponding sulfonic acids in short reaction times and in high yields.
- Ballistreri, Francesco P.,Tomaselli, Gaetano A.,Toscano, Rosa M.
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- Formation of Elusive vic-Disulfoxides and OS-Sulfenyl Sulfinates during the m-Chloroperoxybenzoic Acid (MCPBA) Oxidation of Alkyl Aryl Disulfides and Their Regioisomeric Sulfinothioic Acid S-Esters
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The initial step in the 1 equiv m-chloroperoxybenzonic acid (MCPBA) oxidation of 2,2-dimethylpropyl phenyl disulfide (10) and phenyl phenylmethyl disulfide (14) occurs predominantly at the sulfur atom bonded to the alkyl group to give S-phenyl 2,2-dimethylpropanesulfinothioate (5) and S-phenyl phenylmethanesulfinothioate (6), respectively.The 2 equiv MCPBA oxidation of disulfide 10 gives S-phenyl 2,2-dimethylpropanesulfonothioate (23) as the major product.The 1 equiv MCPBA oxidation of thiosulfinates 5 and 6 and S-2,2-dimethylpropyl benzenesulfinothioate (9) ultimately gives thiosulfonate 23, S-phenyl phenylmethanesulfonothioate (17), and thiosulfonate 23, respectively, as the major products.Thus, peroxidation of regioisomeric S-alkyl and S-aryl sulfinothioates 5 and 9 occurs predominantly at the sunfenyl sulfur atom to give diastereomeric vic-disulfoxides (α-disulfoxides) which may undergo cycloelimination to sulfines and sulfenic acids, dissociate to sulfinyl radicals, and rearrange intramoleculary to OS-sulfenyl silfinates and/or to sulfonothioic acid S-esters.OS-Sulfenyl sulfinates may isomerize to sulfonothioic acid S-esters or dissociate to sulfinyl radicals and/or to thiyl and sulfonyl radicals.The sulfinyl radicals may combine to form vic-disulfoxides and/or OS-sulfenyl sulfinates while the thiyl and sulfonyl radicals may lead to sulfonothioic acid S-esters.
- Freeman, Fillmore,Angeletakis, Christos N.
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- The mechanistic dissection of the plunge in enzymatic activity upon transition from water to anhydrous solvents
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Subtilisin Carlsberg dissolved in aqueous solution is several orders of magnitude more active than the enzyme suspended in anhydrous acetonitrile. In order to ascertain why, we employed crystalline subtilisin lightly cross-linked with glutaraldehyde as a catalyst in both aqueous and organic media. The structure of this crystalline enzyme in acetonitrile had been previously found to be virtually identical to that in water, thus ruling out solvent induced conformational changes as the cause of the enzymatic activity drop. Titration of the competent active centers of subtilisin revealed that k(cat)/K(M) is solely responsible for this activity plunge. Quantitative mechanistic analysis of the 7-order-of-magnitude difference in (cat)/K(M) values between subtilisin dissolved in water and cross-linked subtilisin crystals suspended in anhydrous acetonitrile allowed accounting for at least 5.6 orders of magnitude. This drastic decline is due to (i) a marked shift in the activity vs pH profile of the cross-linked crystalline enzyme compared to its soluble counterpart; (ii) different (far less favorable in acetonitrile than in water) energetics of substrate desolvation; and (iii) very low thermodynamic activity of water in anhydrous acetonitrile resulting in a much more rigid and thus less active enzyme.
- Schmitke, Jennifer L.,Wescott, Charles R.,Klibanov, Alexander M.
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- Selective and mild oxidation of thiols to sulfonic acids by hydrogen peroxide catalyzed by methyltrioxorhenium
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Aromatic and aliphatic thiols are oxidized in acetonitrile at 20 °C by hydrogen peroxide in the presence of methyltrioxorhenium as the catalyst to yield the corresponding sulfonic acids in high isolated yields (85-94%).
- Ballistreri, Francesco P.,Tomaselli, Gaetano A.,Toscano, Rosa M.
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- Formation of the bisulfite anion (HSO3 -, m/z 81) upon collision-induced dissociation of anions derived from organic sulfonic acids
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In the negative-ion collision-induced dissociation mass spectra of most organic sulfonates, the base peak is observed at m/z 80 for the sulfur trioxide radical anion (SO3 -·). In contrast, the product-ion spectra of a few sulfonates, such as cysteic acid, aminomethanesulfonate, and 2-phenylethanesulfonate, show the base peak at m/z 81 for the bisulfite anion (HSO3 - ). An investigation with an extensive variety of sulfonates revealed that the presence of a hydrogen atom at the β-position relative to the sulfur atom is a prerequisite for the formation of the bisulfite anion. The formation of HSO3 - is highly favored when the atom at the β-position is nitrogen, or the leaving neutral species is a highly conjugated molecule such as styrene or acrylic acid. Deuterium-exchange experiments with aminomethanesulfonate demonstrated that the hydrogen for HSO3 - formation is transferred from the β-position. The presence of a peak at m/z 80 in the spectrum of 2-sulfoacetic acid, in contrast to a peak at m/z 81 in that of 3-sulfopropanoic acid, corroborated the proposed hydrogen transfer mechanism. For diacidic compounds, such as 4-sulfobutanoic acid and cysteic acid, the m/z 81 ion can be formed by an alternative mechanism, in which the negative charge of the carboxylate moiety attacks the α-carbon relative to the sulfur atom. Experiments conducted with deuterium-exchanged and deuterium-labeled analogs of sulfocarboxylic acids demonstrated that the formation of the bisulfite anion resulted either from a hydrogen transfer from the β-carbon, or from a direct attack by the carboxylate moiety on the α-carbon. Copyright
- Jariwala, Freneil B.,Wood, Ryan E.,Nishshanka, Upul,Attygalle, Athula B.
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- Effects of methoxy substituents on the glutathione peroxidase-like activity of cyclic seleninate esters
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Cyclic seleninate esters function as mimetics of the antioxidant enzyme glutathione peroxidase and catalyze the reduction of hydrogen peroxide with a stoichiometric thiol. While a single electron-donating methoxy substituent para to the selenium atom enhances the catalytic activity, m-methoxy groups have little effect and o-methoxy substituents suppress activity. The effects of multiple methoxy groups are not cumulative. This behavior can be rationalized by opposing mesomeric and steric effects. Oxidation of the product disulfide via its thiolsulfinate was also observed.
- Press, David J.,McNeil, Nicole M. R.,Hambrook, Miranda,Back, Thomas G.
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p. 9394 - 9401
(2014/12/11)
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- Synthesis of (2-alkylthiothiazolin-5-yl)methyl dodecanoates via tandem radical reaction
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A series of (2-alkylthiothiazolin-5-yl)methyl dodecanoates was synthesized from various alkyl N-allylcarbamodithioates and dilauroyl peroxide via a tandem radical hydrogen-abstraction-cyclization-substitution/combination reaction with a 5-exo-trig radical cyclization as a key step. The current route is the first, convenient, and efficient synthesis of (2-alkylthiothiazolin-5-yl)methanol derivatives. The Royal Society of Chemistry.
- Kakaei, Saeed,Xu, Jiaxi
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p. 5481 - 5490
(2013/08/28)
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- SULPHONYLAMINO DERIVATIVES FOR THE TREATMENT OF ALZHEIMER'S DISEASE
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A compound of formula (I), wherein R1 is alkyl, alkenyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, heteroaryl, heteropolycyclyl or polycyclyl, any of which is optionally substituted with alkyl, heteroaryl, aryl or -O-aryl; R2 is alkyl, alkenyl or aryl, any of which is optionally substituted with hydroxy, halogen, aryl, heteroaryl, cycloalkyl, cycloalkenyl, -C(O)NH-aryl, heterocycloalkyl, heterocycloalkenyl, heteropolycyclyl or polycyclyl; R3 is hydrogen or aryl; R4 is alkyl, alkenyl, alkoxy, alkylthio or aryl, any of which is optionally substituted with hydroxy, aryl, heteroaryl, cycloalkyl, cycloalkenyl, thioalkyl, heterocycloalkyl, heterocycloalkenyl, heteropolycyclyl or polycyclyl; R5 is hydrogen or an alkyl or alkenyl group optionally substituted with hydroxy, aryl, -C(O)O- alkyl or -C(O)NH- alkyl; or R4-C-R5 taken together form cycloalkyl, cycloalkenyl or polycyclyl, any of which is optionally substituted with alkyl or hydroxyalkyl; R6 is hydrogen, alkyl, -alkyl-aryl or -alkyl-heteroaryl; or a pharmaceutically-acceptable salt thereof.
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- Competing sulfonylation and phosphonylation following rearrangement of an O-sulfonyl-N-phosphinoylhydroxylamine with tert-butylamine: Demonstration of a phosphonamidic-sulfonic anhydride intermediate and 18O-labelling evidence on how it may be formed
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Reaction of R(Ph)P(O)NHOSO2Bn (R = PhMeCH) with Bu tNH2 in CH2Cl2 gives a mixture of RP(O)(NHPh)NHBut and ButNHSO2Bn, the proportion of the sulfonamide increasing steadily (14.6% to 32.9%) as the concentration of amine is reduced (8.0 to 0.2 mol dm-3). Apparently the phenyl and sulfonate groups in the substrate become transposed, giving a phosphonamidic-sulfonic anhydride RP(O)(NHPh)OSO2Bn which then reacts at the phosphorus or sulfur atom to give the final products; an authentic sample of the anhydride gives similar mixtures of products. Substrate labelled with 18O in the sulfonyl position (57 mol% one 18O atom) gives sulfonamide containing most but not all of the label (43.7 mol% one 18O atom with 2.0 mol dm-3 amine). This implies partial equilibration of the three sulfonate oxygen atoms during rearrangement, or after the anhydride intermediate has been formed.
- Harger, Martin J.P.
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p. 3390 - 3395
(2007/10/03)
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- Direct synthesis of thioethers from sulfonyl chlorides and activated alcohols
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An efficient, safe one-pot synthesis of thioethers from aromatic sulfonyl chlorides and activated alcohols has been developed under non-aqueous conditions.
- Martin, Michael T,Thomas, Alford M,York, Douglas G
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p. 2145 - 2147
(2007/10/03)
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- The reaction of mercaptans with dimethyldioxirane. A facile synthesis of alkanesulfinic acids
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Dimethyldioxirae oxidizes aliphatic thiols to sulfinic acids in very good yield. Benzylic and aromatic thiols give a variety of other oxidation products using DMD.
- Gu,Harpp
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- Tetrakis(pyridine)silver(II) Peroxodisulfate, S2O8, a Reagent for the Oxidative Transformations
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Tetrakis(pyridine)silver(II) peroxodisulfate oxidizes aromatic aldehydes to carboxylic acids, benzylic alcohols to carbonyl compounds, aromatic thiols, and allylaryl thioethers to arylsulfonic acids and benzylic carbon-hydrogen bonds to carbonyl groups. α-Hydroxycarboxylic acids and phenylacetic acids are decarboxylated to produce carbonyl compounds.Dibenzyl ether and its sulfur analogue are converted to their corresponding ester and the thioester, respectively.
- Firouzabadi, Habib,Salehi, Peyman,Mohammadpour-Baltork, Iraj
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p. 2878 - 2880
(2007/10/02)
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- MECHANISTIC VARIATION IN ALKANESULFONYL CHLORIDE HYDROLYSIS AND RELATED REACTIONS
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Kinetic and product ratio studies are consistent with the following mechanisms for the hydrolysis of methanesulfonyl chloride: (a) in acidic medium (pH 1-6) via a direct substitution on sulfur (SN2-S), (b) in mildly basic medium (pH 8-10) by way of sulfene (CH2=SO2) formation followed by trapping with water, and (c) in strongly basic solution (pH >10) via sulfene with trapping by the hydroxide ion.The reactions of primary and secondary alkanesulfonyl chlorides are qualitatively similar.
- King, J. F.,Lam, J. Y. L.,Skonieczny, S.
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p. 177 - 180
(2007/10/02)
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- Studies on the Hydrolysis of Aromatic Sulfochlorides
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The hydrolysis of aromatic sulfochlorides can be described by a second-order law.Due to the strenght of the base the constants of velocity are between 10E-6 (H2O) or 10E3 (OH-) l/Mols respectively.The reaction of benzensulfochlorides proceeds according to an addition-elimination mechanism, whereas benzylic sulfochlorides, reacting with a strong base, proceed to an elimination-addition mechanism.
- Beck, H.,Doerffel, K.
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