1016-82-6

A solvent-free, rapid, and highly selective oxidation of sulfides, selenides, and tellurides (chalcogenides) to the corresponding monoxides (sulfoxides, selenoxides, and telluroxides) or the corresponding dioxides (sulfones, selenones, and tellurones) has been developed using aqueous sodium hypochlorite on solid supports by exposure to microwave. Chemoselectivity and quantitative yields have been attained in most cases.

The kinetics of picolinic acid (PA)-catalysed Cr(VI) oxidation of organic sulphur compounds have been studied with several alkyl aryl sulphides and diphenyl sulphides in acetic acid-water mixtures.The PA-catalysed oxidation follows third-order kinetics, f

The oxidation of 4-substituted phenyl phenyl sulfides was carried out with several oxo(salen)manganese( V) complexes in MeCN/H2O9 : 1. The kinetic data show that the reaction is first-order each in the oxidant and sulfide. Electron-attracting s

Suzuki-Miyaura coupling of haloarenes is the most widely used protocol for the synthesis of biphenyls. Organosulfur compounds are promising electrophiles since they are abundant in nature and versatile in organic synthesis. We report here the desulfinylative Suzuki-Miyaura coupling of aryl sulfoxides with phenylboronic acids using bench-stable nickel/5-(2,4,6-triisopropylphenyl)imidazolylidene[1,5-a]pyridines as the catalyst. The ligands are readily prepared from common commercial chemicals. The method is applicable to both symmetric and unsymmetric aryl sulfoxides, and a range of biphenyls bearing various functional groups were obtained in up to 94% yield. (Figure presented.).

Sodium sulfinate reacts electrophilically with aromatics in trifluoromethanesulfonic acid to give the corresponding aryl sulfoxides and sulfonium salts.

Abstract: A vanadium Schiff base complex on nano silica was prepared by reaction of nano silica NH2-functionalized, 2,4-dihydroxy benzaldehyde and VO(acac)2. The VSBC@NS was used as an efficient and reusable heterogeneous catalyst fo

Sulfides are readily oxidized to sulfoxides by a solution of pyridine, water, and trichloroisocyanuric acid in acetonitrile and methylene chloride.

TeO2-H2O2 system was found to be an efficient selective reagent for the oxidation of sulfides to sulfoxides in the presence of other common functional groups.Over-oxidation of sulfoxides to sulfones was not observed.

The oxidation of diaryl sulfides and aryl alkyl sulfides to the corresponding sulfoxides and sulfones under electrochemical conditions is reported. Sulfoxides are selectively obtained in good yield under a constant current of 5 mA for 10 h in DMF, while sulfones are formed as the major product under a constant current of 10 or 20 mA for 10 h in MeOH. The oxygen of both the sulfoxide and sulfone function is derived from water.

A NiCl2/2,2′-bipyridine-catalyzed cross-coupling of thiophenols with arylboronic acids has been developed for the synthesis of symmetric and unsymmetric diarylsulfides at room temperature and in air. This methodology is reliable and offers a mild and easy to operate process for the synthesis of arylthioethers, which are essential compounds with applications in the pharmaceutical and agricultural industries. This method avoids the use of expensive transition metals, such as Pd, Ir or Rh, sophisticated ligands and elevated temperatures. It also has a wide substrate scope (55 examples) and provides products in good to excellent yields (72-93%).

The development of eco-friendly and switchable catalytic systems for the conversion of a sole raw-material into distinct high-value products is a particularly attractive concept and a daunting synthetic challenge. In the present work, the first example of efficient and selective oxidation of sulfides to sulfones and sulfoxides using molecular oxygen under clean conditions was established.

The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted. The sulfoxides and sulfones could be obtained by simply switching the reaction media, i.e., bis(2-butoxyethyl)ether (BBE) or poly(ethylene glycol)dimethyl ether (PEGDME). The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents. This strategy represents an economic and eco-friendly method that could find potential applications.

A facile and efficient visible-light-driven method has been developed to construct sulfoxides via oxidative coupling of aryldiazo sulfones with thiols using the O2 in air as the oxidant. This reaction could be performed at room temperature under catalyst- and additive-free conditions. The present methodology offers a mild and environmentally benign approach to obtain a library of sulfoxides in good yields with favorable functional group tolerance.

The invention belongs to the field of organic synthetic chemistry, particularly relates to a preparation method of an asymmetric sulfoxide compound, and particularly discloses a method for synthesizing the asymmetric sulfoxide compound based on visible light catalysis. A compound shown in the formula I and a compound shown in the formula II are added to a reactor, a mixture of an organic solvent and water is added as a reaction solvent, the reactor is connected to air, under the irradiation of visible light, a reaction at a room temperature is performed for 16-40 hours; and after a detection reaction of a TLC thin layer chromatography plate is completed, pure water is added, then the extraction is performed, extract liquid is combined and dried, the extract liquid is concentrated and purified to obtain a compound shown in the formula III, and the compound is the asymmetric sulfoxide compound. The reaction conditions are mild, energy is clean, a strong oxidant is not needed, the safetyof the reaction is improved, the pollution caused by using a metal reagent is avoided, and the reaction cost is saved.

A highly chemoselective, efficient and nano-Pd catalyzed protocol for the rapid construction of sulfoxides and sulfones via the oxidation of symmetrical and unsymmetrical sulfides using H2O2 as an oxidant has been developed, respectively. The ready availability of starting materials, easy recovery and reutilization of the catalyst, wide substrate scope, and high yields make this protocol an attractive alternative. The process also involves the metal-free and microwave-promoted synthesis of symmetrical diarylsulfides, and FeCl3-mediated preparation of symmetrical diaryldisulfides through the reaction of arenediazonium tetrafluoroborates with Na2S·9H2O as a sulfur source. In addition, unsymmetrical sulfides were generated via the K2CO3-mediated reaction of arenediazonium tetrafluoroborates with symmetrical disulfides.

Two benzyne-enabled desulfurization reactions have been demonstrated which convert diaryl sulfoxides and heteroaryl sulfoxides to biaryls and desulfurized heteroarenes, respectively. The reaction accessing biaryls tolerates a variety of functional groups, such as halides, pseudohalides, and carbonyls. Mechanistic studies reveal that both reactions proceed via a common assembly process but divergent disassemblies of the generated tetraaryl(heteroaryl) sulfuranes.

A transition-metal-free arylation of sulfenate anions generated from β-sulfinyl esters with diaryliodonium salts was developed. In this process, a new C-S bond is formed under mild reaction conditions providing a wide range of S,S-diaryl and S-alkyl S-aryl sulfoxides.

Herein we reported an efficient palladium-catalyzed enantioselective arylation of both alkyl and aryl sulfenate anions to deliver various chiral sulfoxides in good yields (up to 98%) with excellent enantioselectivities (up to 99% ee) by the use of our developed chiral O,P-ligands (PC-Phos). PC-Phos are easily prepared in short steps from inexpensive commercially available starting materials. The single-crystal structure of the PC4/PdCl2 showed that a rarely observed 11-membered ring was formed via the O,P-coordination with the palladium(II) center. The salient features of this method include general substrate scope, ease of scale-up, applicable to the late-stage modification of bioactive compounds, and the synthesis of a marketed medicine Sulindac.

The invention discloses a method for selective synthesis of an aryl sulfoxide compound (III) and an aryl thioether compound (IV). According to the invention, in a reactive solvent, an aryl high iodinesalt is adopted as the reaction raw material, aryl/alkyl thiosulfate is taken as the vulcanizing reagent, under the catalysis of visible light and a photosensitive reagent, and under the action of lewis acid and alkali, when the reaction atmosphere is nitrogen, the thioether compound (IV) can be generated, and when the reaction atmosphere is air, the sulfoxide compound (III) can be generated. Thesynthesis method provided by the invention has the advantages of easily available and cheap raw materials, simple reaction operation, mild and environment-friendly reaction conditions, high yield, and excellent functional group tolerance. The invention also discloses the new aryl sulfoxide compound (III) and aryl thioether compound (IV), also successfully realizes later modification of drugs andsugar, and realizes the formal synthesis of some drugs, and provides an efficient method for selective construction of thioether and sulfoxide compounds.

Sulfoxides and sulfides are two important functional groups in organic molecules, containing different valence states of sulfur. Both sulfoxidation and sulfenylation with common sulfurating reagents were successfully tuned via a facile variation of the atmosphere under photocatalyzed conditions. The sulfoxidation and sulfenylation transformations involved tandem electron-/energy-transfer and single-electron-transfer processes, respectively. Late-stage sulfoxidation for pharmaceuticals and sugar derivatives was established to be highly compatible. Divergent formal syntheses of sulfoxide/sulfide-containing marketed pharmaceuticals were switchably implemented. Gram-scale operations further demonstrated the practicability of the protocol.

A palladium-catalyzed arylation of aryl sulfenate anions generated from aryl 2-(trimethylsilyl)ethyl sulfoxides and CsF has been developed. This protocol is effective for the synthesis of diaryl sulfoxides and heteroaryl aryl sulfoxides under mild conditions employing aryl bromides. Various functional groups, including those with acidic protons, are well tolerated.

A novel approach to produce diaryl sulfoxides from aryl benzyl sulfoxides is reported. Optimization of the reaction conditions was performed using high-throughput experimentation techniques. The [Pd(dba)2]/NiXantPhos catalyst system successfully promotes a triple relay process involving sulfoxide α-arylation, C-S bond cleavage, and C-S bond formation. The byproduct benzophenone is formed by an additional palladium-catalyzed process. It is noteworthy that palladium-catalyzed benzylative C-S bond cleavage of sulfoxides is unprecedented. A wide range of aryl benzyl sulfoxides, as well as alkyl benzyl sulfoxides with various (hetero)aryl bromides were employed in the triple relay process in good to excellent yields (85-99 %). Moreover, aryl methyl sulfoxides, dibenzyl sulfoxides, and dimethylsulfoxide could be utilized to generate diaryl sulfoxides involving multiple catalytic cycles by a single catalyst. Three for one: The [Pd(dba)2]/NiXantPhos (dba=dibenzylideneacetone) catalyst system successfully promotes a triple relay process involving sulfoxide α-arylation, C-S bond cleavage, and C-S bond formation to give diaryl sulfoxides (see picture). Aryl benzyl sulfoxides, as well as alkyl benzyl sulfoxides reacted with various (hetero)aryl bromides. Copyright

The previously established aluminium-chloride-(AlCl3)-catalysed electrophilic aromatic substitution (EAS) of benzene (PhH) with thionyl chloride (SOCl2) has been extended to toluene (PhCH3), chlorobenzene (PhCl), and phenol (PhOH). -CH3 was found to be mainly a para-director with a minor ortho-directing effect on the EAS reactions giving diaryl sulfoxides (Ar2SO). -Cl was found to be exclusively a para-director for formation of Ar2SO. All the -CH3, -Cl, and -OH groups were shown to be exclusive para-directors for formation of diaryl sulfides (Ar2S) from the EAS reactions. Although the reactions of PhH and PhCH3 with SOCl2 in the presence of AlCl 3 gave the major Ar2SO and minor Ar2S at ambient temperature, the phenol (PhOH) reaction was shown to give only the reduced sulfide (p-HOC6H4)2S with no sulfoxide (p-HOC6H4)2SO formed. The mixed diaryl sulfoxides ArSOAr′ (Ar, Ar′=C6H5, p-CH 3C6H4; C6H5, o-CH 3C6H4; and C6H5, p-ClC6H4) were produced in the AlCl3-catalysed reactions of SOCl2 with molar 1:1 PhH-PhX mixtures (X=CH3 and Cl). Efforts to enhance the yield of S-aryl arenesulfonothioates ArSO 2SAr (Ar=Ph, p-CH3C6H4, and p-ClC6H4) from the AlCl3-catalysed EAS reactions of SOCl2 were made, showing that decreasing the molar ratios of ArH/SOCl2 or lowering the temperature resulted in an increase in the product yield. A detailed mechanism has been proposed to account for the formation of ArSO2SAr. The Lewis-acid-MCl3-(M=Al and Fe)-catalysed EAS reactions of PhH with selenyl chloride (SeOCl2) were demonstrated to give the reduced diphenyl selenide (Ph2Se) and diphenyl diselenide (PhSeSePh) via novel auto-redox processes in selenium of the key EAS intermediates.

The oxygenation of aryl methyl sulfides and diaryl sulfides by peroxomonophosphoric acid in acetonitrile-water mixture follows an overall second-order kinetics, first-order in each reactant. The study of the influence of [H+] on the oxidation of phenyl methyl and diphenyl sulfides reveals that H2PO5- and HPO52- are the oxidising species in the oxidation process. In substituted phenyl methyl sulfides and diphenyl sulfides, the rate of oxygenation is accelerated by electron-donating substituents and retarded by electron-withdrawing groups, indicating the nucleophilic displacement by the sulfide sulfur on the peroxide oxygen. The negative ρ value obtained in the correlation analysis of rate constants with σ constants also shows the formation of a more positively charged sulfur species in the rate-limiting step. Studies with different alkyl phenyl sulfides (C6H5SR; R=Me, Et, Pri or But) indicate that the rate is retarded by bulky R groups. Similar kinetic results are also obtained in the peroxomonophosphoric acid oxidation of sodium phenylmercaptoacetate. On the basis of the kinetic studies, a common mechanism has been proposed.

Kinetic measurements of the oxidation of divalent organic sulfur compounds by N-chlorosuccinimide in acetonitrile-water mixture at constant [H+] show that the reaction is first order in both the oxidant and the organic sulfur compound. While th

The kinetics of oxidation of a few 4-substituted diphenyl sulphides with six oxo(salen)manganese(V) complexes has been studied in acetonitrile spectrophotometrically at 25°C. The reaction is second order overall, first order each in the complex and the su

The mechanism of Cr(VI) oxidation of organic sulfur compounds has been investigated by studying the rates of oxidation of 17 alkyl aryl sulfides and 6 diphenyl sulfides respectively in 50percent (v/v) aqueous acetic acid and 75:25 acetic acid-water (v/v)

N-Unsubstituted sulfoximines and N-mono-tosylsulfonediimines were found to react readily with tert-butyl nitrite to give the corresponding sulfoxides and N-tosylsulfilimines in high yields with no racemization.

The kinetics of oxidation of diphenyl sulphides by phenyliodoso diacetate have been investigated in 60percent acetonitrile - 40percent water (v/v) mixture.The reaction is second order, first order each in sulphide and phenyliodoso diacetate.Electron-relea

Reduction of sulfimides and sulfoximides with p-toluenesulfonyl nitrite, a new nitrosating agent, gave nearly quantitatively the corresponding deimination products, sulfides and sulfoxides, respectively.In the reaction of dialkyl and aryl alkyl sulfoximides with t-butyl thionitrate, N-t-butylthiosulfoximides were obtained besides the usual deimination products, although diaryl sulfoximides were readily deiminated to the corresponding sulfoxides in good yields in the same treatment. t-Butyl thionitrsate was also found to deiminate diphenyl sulfimide to give diphenyl sulfide in good yield.Sulfoximides reacted sluggishly with t-butyl thionitrite, however, eventually affording a small amount of sulfoxides.