54815-65-5

Upstream product

• 100-68-5 methyl-phenyl-thioether 
• 882-33-7 diphenyldisulfane 
• 24380-78-7 S-phenyl-N-methyl-sulfenamide 
• 23837-25-4 N-(phenylthio)-N-(normal-butyl)amine 

Relevant academic research and scientific papers

Electrochemical Formation and Activation of Hydrogen Peroxide from Water on Fluorinated Tin Oxide for Baeyer-Villiger Oxidation Reactions

The two-electron oxidation of water (2e-WOR) has been studied in the past as a possible method for the alternative preparation of hydrogen peroxide. Often, fluorinated tin oxide (FTO) is used as an anode and FTO itself was found also to be active for 2e-WOR. Because one use of H2O2is as an oxygen donor for Baeyer-Villiger oxidation of ketones catalyzed by tin compounds and materials, presently we were interested in studying the use of in situ formed H2O2for these reactions. First, the formation of H2O2was verified in an acetonitrile/water solvent in a 2e-WOR reaction, which is more efficient than a comparable reaction in water in terms of the H2O2concentration attained and faradaic efficiency at comparable potentials, that is, ～3 V vs SHE. Second, initial studies on oxygenation of reactive substrates such as sulfides showed normalized reaction rates (NRRs) for two-electron oxidation reactions that were about 3 times higher than the NRR for H2O2formation, indicating the formation of an active oxygen-donating or oxidizing species on the electrode surface prior to the formation and release of H2O2into solution. Third, the Baeyer-Villiger oxygenation of 2-adamantanone at 2.1 V versus SHE in acetonitrile/water showed both the formation of the expected lactone product and hydroxylation at both tertiary and secondary C-H bonds. Hydroxylation is most easily explained by the presence of hydroxyl radical species as supported by the formation of a spin adduct and its identification by electron paramagnetic resonance. However, the potential used, 2.1 V versus SHE, is an underpotential for the formation of a solvated hydroxyl radical in solution, thereby leading to the conclusion that surface-bound hydroxyl species, OH*, are those that are reactive for the apparent one-electron water oxygenation reaction. Fourth, it was shown that although H2O2can be thermally activated on FTO as a catalyst to a minor degree, electrochemical activation is by far more significant, leading to the use of FTO as an electrochemical catalyst for activation of H2O2for the Baeyer-Villiger oxygenation and also alkene epoxidation.

Kinetic support for the generation of a phenylsulfenium ion intermediate

In the reaction of N-methylbenzenesulfenamide (1) with thioanisole (4) in the presence of trifluoroacetic acid (TFA), the initial rate υ0 of total appearance of 2- and 4-(methylthio)phenyl phenyl sulfides (5) is first and zero order with respect to the initial concentrations of 1 and 4, respectively: υ0=kobs[1]0. The pseudo-first order rate constant kobs is evaluated as 5.2×10-4 sec-1 with varying concentrations of 4 (0.72 to 5.0 M) in a mixture of 4 and CH2Cl2 in the presence of TFA at 10 °C. This data supports the notion that a phenylsulfenium ion intermediate 3 interacting with both the counter ion and the unshared electron-pair of amine is generated by heterolytic N-S scission of the protonated sulfenamide 2, leading to the observed formation of 5.

Novel efficient aromatic arylthiolation by disulfide radical cations generated by oxidation of diaryl disulfides

The disulfide radical cation was generated by oxidation of diphenyl disulfide using H2SO4 in CF3CO2H or SbCl5 in CH2Cl2, and allowed to react with benzene, toluene, ethylbenzene, chlorobenzene, anisole and alkyl phenyl sulfides to give efficiently para-substituted diphenyl sulfides along with a small amount of the ortho-isomers. The intermediacy of the radical cation in this aromatic phenylthiolation is consistent with the evidence derived from a Hammett plot with ρ = -7.0 (using SbCl5 in CH2Cl2), from effects of oxidants, counter-anions and solvents and from electronic absorptions (540 and 650 nm). Using di-4-anisyl, di-4-tolyl and di-4-chlorophenyl disulfides instead of diphenyl disulfide, the aromatic arylthiolation similarly occurs via radical cations from their disulfides.

Novel Generation of Arylsulfenium Ion Intermediates and Efficient Aromatic Arylthiolation by the Intermediates

Reactions of hydrazoic acid and alkyl azides with alkyl aryl sulfide in trifluoroacetic acid containing trifluoromethanesulfonic acid or H2SO4 proceeded through an S-arylaminosulfonium ion and a protonated S-arylsulfenamide, giving efficiently 4-alkylthiophenyl aryl sulfide via an arylsulfenium ion interacting with both the counter-anion and the unshared electron pair of the amine.The use of the S-arylsulfenamide instead of the azides also afforded the above product by aromatic arylthiolation in a good yield via the sulfenium ion along with its ortho-isomer, diaryl disulfide and diaryl sulfide.The formation of the sulfenium ion was demonstrated by the effect of the counter-anion, the amine, the aryl substituent of the sulfenamide and the solvent nucleophilicity.We ruled out the possibility that the arylthiolation occurs via an arylthiyl radical and an aminium radical from the sulfenamide and by direct reaction of the protonated sulfenamide with alkyl aryl sulfides.

Novel Generation of Phenylsulfenium Ion and Aromatic Phenylthiolation. Reactions of Hydrazoic Acid, Alkyl Azides and Hydroxylamine Derivatives with Alkyl Phenyl Sulfides in the Presence of Both Trifluoromethanesulfonic Acid and Trifluoroacetic Acid

Reactions of hydrazoic acid and alkyl azides with alkyl phenyl sulfides in the presence of both trifluoromethanesulfonic acid and trifluoroacetic acid gave 4-alkylthiophenyl phenyl sulfides in high yields via a phenylsulfenium ion.