- Primary sulfonamide as a coupling partner: Copper(I)-catalyzed regioselective cross-coupling of 2-nitro benzenesulfonamides with thiol through the cleavage of Ar–SO2NH2 bonds
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In this article, we have presented a novel and efficient method for the direct synthesis of unsymmetrical sulfides through the copper(I)-catalyzed cross-coupling of 2-nitro benzenesulfonamides with thiols in the presence of catalytic amount of CuI in DMF as solvent at 100 °C. In addition, the products were obtained in high to excellent yields. More importantly, the novel system showed the primary 2-nitro benzenesulfonamides as a new coupling partner and regioselectively promoted C–S bond-forming transformations through the cleavage of Ar–SO2NH2 bonds.
- Chen, Junmin,Zhang, Kuo,Zhao, Yongli,Pu, Shouzhi
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p. 1316 - 1323
(2018/04/05)
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- Syntheses of, and structural studies on, benzo-fused 1,2,4-thiadiazines
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The syntheses of nine benzo-fused-1,2,4-thiadizines are reported. The use of microwave synthesis has been shown to afford high yields and short reaction times in several key reaction steps. The molecular geometries of these heterocycles are discussed and
- Clark, Ewan R.,Hayward, John J.,Leontowicz, Bryce J.,Eisler, Dana J.,Rawson, Jeremy M.
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p. 1755 - 1762
(2014/03/21)
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- Fused-Ring Thiadiazines: Preparation and Crystallographic Characterization of 3-Phenyl Derivative of Benzo-, Pyridio[2,3-e]-, Pyrazino[2,3-e]-, and Tetrafluorobenzo-[1,2,4]thiadiazines
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Four bicyclic 4H-[1,2,4]thiadiazines 1a-d were prepared in 74-88% yields in two steps from the corresponding amidines 2. Three of them, 1a, 1b, and 1d, were obtained by thermal elimination of propene from the intermediate S-propylsulfilimines 12. The pyrazino derivative 1c was formed upon thermolysis of sulfoxide 14c obtained from 2c. The Ei mechanism was investigated using DFT methods. The elimination in the sulfilimine appears to be more favorable by about 2 kcal/mol than in the analogous sulfoxide. Crystal and molecular structures of three out of the four thiadiazines were established by single-crystal X-ray analysis. All thiadiazines were found as the 4H tautomers with the heterocyclic ring puckered along the S(1)...N(4) line. The benzo derivative 1a forms a unidimensional N(4)-H...N(2) chain, the pyrazino derivative 1c forms dimeric pairs with two synergistic hydrogen bonds, and the crystal structure of 1d is characterized by strong C6F 4...C6H5 quadrupolar interactions.
- Zienkiewicz, Jozef,Kaszynski, Piotr,Young Jr., Victor G.
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p. 2551 - 2561
(2007/10/03)
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- Relative Nucleophilicities of Aryldisulphide and Thiolate Ions in Dimethylacetamide Estimated from their Reaction Rates with Alkyl Halides
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The relative rates of nucleophilic substitution (SN2) of alkyl halides by aromatic thiolates ArS- and aryldisulphide ions ArS2- have been studied in dimethylacetamide by UV-visible spectrophotometry for Ar = 4-nitrophenyl (1), 2-nitrophenyl (2), and 8-quinolyl (3).Rate constants are relative to the rate constants for benzenethiolate ions (4), studied as reference.With Ar = (1), the reaction rate for disulphide ions is ten times higher than that for monosulphide ions stabilized by the elevated delocalization of their charge.With Ar = (2) and (3), the reactivity of disulphide ions is higher than that of the corresponding thiolates.Our study is consistent with the uncomplicated introduction of a disulphide bond into various substrates from aryldisulphide ions stabilized in aprotic dipolar media.
- Benaichouche, Meriem,Bosser, Gerard,Paris, Jacky,Plichon, Vincent
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p. 1421 - 1424
(2007/10/02)
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- 149. Notizen zur Synthese von 2-Aminophenylsulfonen
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Syntheses of the alkyl, cycloalkyl and aryl 2-aminophenyl sulfones 10 were achieved by oxidation of the corresponding 2-nitrophenyl sulfides 7 to the 2-nitrophenyl sulfones 9 followed by ethanolic Bechamp-reduction.The sulfides 7 in turn were obtained by either reactions of 2-nitro-thiophenol (8) with the appropriate alkyl and cycloalkyl halides or of 2-chloro-nitrobenzene (5) with the relevant thiols.Condensation of 2-nitrobenzenesulfinic acid (3) with bromoacetic acid in aqueous alkaline solution led - presumably via 2-nitrophenylsulfonylacetic acid (4) - to methyl2-nitrophenyl sulfone (1), reduction of which gave 2-aminophenyl methyl sulfone (2).Treatment of 2-aminothiophenol (11) with t-butyl alcohol in aqueous sulfuric acid gave 2-aminophenyl t-butyl sulfide (12), which was acetylated to o-t-butylthio-acetanilide (13).Oxidation of the latter to o-t-butylsulfonyl-acetanilide (14) followed by hydrolysis led to 2-aminophenyl t-butyl sulfone (15).
- Courtin, Alfred,Tobel, Hans-Rudolf von,Auerbach, Guenther
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p. 1412 - 1419
(2007/10/02)
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