33240-29-8

Upstream product

• 113306-30-2 (2R,3R)-3-(2-Chloro-5-nitro-phenyl)-2-(toluene-4-sulfonyl)-oxaziridine 
• 3705-95-1 4,4'-dichlorothiobenzophenone 
• 90-98-2 4,4'-Dichlorobenzophenone 
• 106864-84-0 methyl bis(4-chlorophenyl)methanesulfinate 
• 132102-73-9 4,4'-dichlorodiphenylmethyl (phenylsulfonyl)methyl sulfoxide 

Downstream Products

• 124401-74-7 N,N-Diisopropyl-1,1-bis(p-chlorophenyl)methanesulfinamide 
• 90-98-2 4,4'-Dichlorobenzophenone 

Relevant academic research and scientific papers

Kinetics and Mechanism of the Methyltrioxorhenium-Catalyzed Sulfoxidation of Thioketones and Sulfines

Kinetic studies have been carried out on the oxidation of thiobenzophenones and thiocamphor by hydrogen peroxide and on the second step in the sequence, oxidation of the resulting sulfines (Ar2C= S=O). The first reaction follows the pattern now common to methyltrioxorhenium/H2O2 reactions, in that the rate constant for the reaction between the peroxorhenium intermediate and the thioketone follows a Hammett correlation such that electron-releasing substrates react more rapidly. The reaction constant is p = -1.12. However, the plot of log(kX/kH) for the sulfines against 2σ, determined over the range -1.6 2 under these conditions rather than undergoing disproportionation to SO2 and S. Also, SO was trapped with a 1,3-diene as a thiophene-1-oxide.

Methoxide-Catalyzed Decomposition of Diarylmethyl (Arylsulfonyl)methyl Sulfoxides: A Sulfine-Forming Elimination on the (E1cB)rev/(E1cB)irrev Borderline

In 7:3 CH3OH-DMSO (v/v) in the presence of methoxide ion, diarylmethyl (arylsulfonyl)methyl sulfoxides (Ar2CHS(O)CH2SO2Ar') 4, undergo elimination remarkably easily to afford the diarylsulfine and the aryl methyl sulfone (eq 4).Comparison of the rate of cleavage of 4 (kelim) and the rate of disappearance of the 1H NMR signal (kCHSO) for the Ar2CHS(O) proton in CD3OD-DMSO shows that the mechanism for the elimination is on the (E1cB)rev/(E1cB)irrev borderline, (kCHSO/kelim) ranging from 1.2 to 5.2, depending on the nature of the Ar and Ar'groups in 4.Slight changes in structure can shift the mechanism from (E1cB)rev to (E1cB)irrev as a result of their effect on the partitioning of the α-sulfinyl carbanion intermediate (Ar2CS(O)CH2SO2Ar') 5, between cleavage to diarylsulfine plus ArSO2CH2- (step kii, eq 8) and protonation to regenerate 4 (step k-i).Structural changes that make Ar'SO2CH2 a better leaving group increase kii/k-i and shift the mechanism toward (E1cb)irrev as does also an increase in the percentage of DMSO in the solvent.Structural changes in Ar that enhance the stability of 5 decrease kii/k-i and shift the mechanism toward (E1cb)rev.It is also shown that for 4 in general kii appears larger than would be expected for a leaving group of the basicity of Ar'SO2CH2-.Repulsion between the dipoles of the S(O) and SO2 groups in 5 is thought to be responsible.

Osidation of Thiones to Sulphines (Thione S-Oxides) with N-Sulphonyloxaziridines: Synthetic and Mechanistic Aspects

The kinetics of the two-step oxidation of diarylthiones by N-sulphonyloxaziridines to sulphines and then to ketones have been investigated and the results compared with those for reactions with perbenzoic acid.The synthetic utility of the oxaziridine and peracid oxidations has been compared for a few aliphatic thiones

Elimination Reactions of Alkanesulfinyl Derivatives: Mechanism and Reactivity in Base-Induced Sulfine Formation from Methyl Diarylmethanesulfinates

Upon treatment in methanol at room temperature with methoxide ion methyl diarylmethanesulfinates, ArAr'CHS(O)OCH3 (1), and methyl 9-fluorenesulfinate (2) undergo elimination readily to afford the corresponding sulfines (3 and 4) in quantitative yield.Studies in CD3O-/CD3OD show that, surprisingly, elimination of 1 to give 3 is significantly faster than nucleophilic substitution by methoxide ion at the sulfinyl group (exchange of CH3O by CD3O).Even more unexpected, the kinetic isotope effect for elimination of 2-9-d (kH/kD=6.1) and absence of detectable H/D exchange of the methine proton of 1 in CD3OD prior to sulfine formation extablish that, even though the leaving group is MeO-, the elimination takes place by either an irreversible ElcB or an E2 mechanism, rather than the reversible ElcB mechanism found (ref 4 and 7) for the analogous sulfene-forming elimination of arylmethanesulfonate esters with oxyanion leaving groups of comparable pKa.Reaction of amines with 2 in methanol also gives sulfine 4, and the amine-induced elimination, which has a large Broensted β, also proceeds by either an (ElcB)irrev or an ElcB-like E2 mechanism.Why sulfine-forming eliminations of 1 and 2 favor an (ElcB)irrev or E2 mechanism whereas sulfene-forming eliminations of arylmethanesulfonates with even better leaving groups proceed by an (ElcB)rev mechanism is considered and a possible explanation presented.

Photochemical Oxidation of Thioketones: Steric and Electronic Aspects

Oxidation of diaryl, aryl alkyl, and dialkyl thioketones by singlet oxygen generated via self-sensitization and other independent methods yielded the corresponding ketone and sulfine in varying amounts.A zwitterionic/diradical intermediate arising out of the primary interaction of singlet oxygen with the thiocarbonyl chromophore is believed to be the common intermediate for the ketone and sulfine.While closure of the zwitterion/diradical to give 1,2,3-dioxathietane would lead to the ketone, competing oxygen elimination is believed to lead to the sulfine.This partitioning is governed by steric and electronic factors operating on the zwitterionic/diradical intermediate.

Mechanistic Investigations into the Photochemical Oxidation of Thioketones

Singlet-oxygen reaction with dialkyl, aryl alkyl, and diaryl thioketones is found to give the corresponding sulphines and ketones in proportions depending on the nature of the thioketone.

CARBONYL SULFIDES AS POSSIBLE INTERMEDIATES IN THE PHOTOLYSIS OF OXATHIIRANES

Diphenyl oxathiirane, formed by irradiation of thiobenzophenone S-oxide at 77 K, is photochemically converted into a blue, thermally unstable compound which decomposes at ca 100-110 K (λmax 550 nm, (ε ca 11,000).Lack of change in magnetic susceptibility during the light induced conversion of sulfine to ketone via the oxathiirane and the subsequent blue intermediate implies the absence of triplet and biradical singlet transients.The unknown carbonyl sulfide functionality, R2C=O=S, thereby emerges as a strong candidate for producing the visible absorption.Comparison of the wave function for CH2=S=O and CH2=O=S arising from MNDO limited CI geometry optimizations leads to the conclusion that the carbonyl sulfide structure is best described as a zwitterion rather than as a singlet biradical.The failure to observe cycloaddition products between the blue species and several dipolarophiles is rationlized in terms of a labile carbonyl sulfide intermediate capable of facile sulfur extrusion from a long, weak O-S bond.Finally, the electronic absorption spectra of a series of para-substituted benzaldehyde O-sulfide model system have been calculated with CNDO/S-CI and correlated with the λmax's of the corresponding series of diaryl blue substrates.The sum of the available experimental and theoretical data is consistent with the existence of closed shell carbonyl sulfides as observable, though labile, intermediates from the photolysis of oxathinanes.