Selective Oxidation Of Sulfides Research Articles

Catalyst-free approach for solvent-dependent selective oxidation of organic sulfides with oxone

Selective oxidation of sulfides was successfully performed by employing oxone (2KHSO5·KHSO4·K2SO4) as oxidant without utilization of any catalyst/additive under mild reaction conditions. Notably, the reaction can be controlled by the chosen solvent. When ethanol was used as the solvent, sulfoxides were obtained in excellent yield; the reaction almost exclusively gave the sulfone in water. Furthermore, this protocol worked well for various sulfides to the corresponding sulfoxides in ethanol or sulfones in water.

Iron-catalyzed selective oxidation of sulfides to sulfoxides with the polyethylene glycol/O2system

Readily available iron compounds were found to be active catalysts for the selective oxidation of sulfide to sulfoxide with molecular oxygen as the oxidant in polyethylene glycol (PEG). As an indispensable component, PEG had a great promotive effect on the reaction. Notably, high conversion (>99%) along with excellent chemo-selectivity of up to 94% could be attained by using Fe(acac)2 as the catalyst at 100 °C. This methodology was proved to be applicable for the transformation of various aromatic and aliphatic sulfides into the corresponding sulfoxides with high selectivity. PEG is considered to play a crucial role in stablizing the Fe(IV)-oxo species formed in situ which is supposed to be responsible for the sulfide oxidation.

Gold nanocluster-catalyzed selective oxidation of sulfide to sulfoxide

Thiolate-protected gold nanoclusters are explored for catalytic application in the selective oxidation of sulfide to sulfoxide by PhIO. The TiO(2)-supported Au(25)(SR)(18) nanocluster catalysts give rise to high catalytic activity (e.g.∼97% conv. of Ph-S-CH(3) and ∼92% selectivity for Ph-S(=O)-CH(3) sulfoxide) and show excellent recyclability in the sulfoxidation process.

Selective Oxidation of Sulfides to Sulfoxides with Cetyltrimethylammonium Periodate

Selective Oxidation of Sulfides to Sulfoxides with Cetyltrimethylammonium Periodate

Metal-free oxidation of sulfides by carbon nitride with visible light illumination at room temperature

Mesoporous graphitic carbon nitride (mpg-C3N4) has been developed as a non-metal, heterogeneous photocatalyst for the selective oxidation of sulfides to sulfoxides with O2 at room temperature. Especially, the combination of mpg-C3N4 and aldehydes was a highly active system under visible-light irradiation. For example, mpg-C3N4/isobutyraldehyde catalytic oxidation of methyl phenyl sulfide afforded 97% conversion with 98% selectivity for the methyl phenyl sulfoxide in 4 h. Moreover, the mpg-C3N4 can be easily recovered by filtration and then reused at least four times without losing activity. By exploring the electron spin resonance and some comparative experiments, a catalytic mechanism of this oxidation was provided. Finally, the system also works well in the oxidation of a number of sulfides, including sulfides bearing various groups, and phenyl disulfide. The use of a metal-free heterogeneous catalyst and visible light energy, along with the mild reaction conditions makes this oxidation reaction an environmentally benign and energy-saving chemical process.

ChemInform Abstract: Efficient and Highly Selective Aqueous Oxidation of Sulfides to Sulfoxides at Room Temperature Catalyzed by Supported Iron Oxide Nanoparticles on SBA‐15.

AbstractThe catalyst is found to be an efficient, easily recoverable agent for the selective oxidation of sulfides to sulfoxides in water.

Polyvinylpolypyrrolidone-supported hydrogen peroxide (PVP-H2O2), silica sulfuric acid and catalytic amounts of ammonium bromide as green, mild and metal-free oxidizing media for the efficient oxidation of alcohols and sulfides

Polyvinylpolypyrrolidone-supported hydrogen peroxide (PVP-H2O2), silica sulfuric acid (SiO2OSO3H) and catalytic amounts of ammonium bromide (NH4Br) are introduced as green media for the in situ generation of bromoniume ion (Br+), which was applied for the selective oxidation of sulfides and alcohols into sulfoxides and carbonyl compounds, respectively. The oxidation reactions were carried out heterogeneously in acetonitrile, as solvent, at room temperature (oxidation of sulfides) and/or 60 °C (oxidation of alcohols).

Synthesis, characterization and application of nano-sized Co 2CrO 4 spinel catalyst for selective oxidation of sulfides to sulfoxides

The nano-sized Co 2CrO 4 spinel was produced for the first time by thermal decomposition of Cr–Co gel prepared by sol–gel method. It was shown that well-crystallized spinel structure is formed after calcination at 450 °C. The usual characterizations were performed and the results showed the particle size of the prepared spinel is 9 nm. Moreover, the prepared nano-sized Co 2CrO 4 spinel was applied in a simple, efficient and recyclable method for selective oxidation of sulfides to their corresponding sulfoxides with aqueous hydrogen peroxide in tert-butanol.

Selective oxidation of sulfides and oxidative bromination of organic substrates catalyzed by polymer anchored Cu(II) complex

A new polymer-anchored Cu(II) complex has been synthesized and characterized. The catalytic performance of the complex has been tested for the oxidation of sulfides and in oxidative bromination reaction with hydrogen peroxide as the oxidant. Sulfides have been selectively oxidized to the corresponding sulfoxides in excellent yields and in the presence of KBr as the bromine source, organic substrates have been selectively converted to mono bromo substituted compounds using polymer-anchored Cu(II) catalyst. This catalyst showed excellent catalytic activity, high selectivity, and recyclability. The polymer-anchored Cu(II) catalyst could be easily recovered by filtration and reused more than five times without appreciable loss of its initial activity.

Doped Keggin heteropolyacids as catalysts in sulfide oxidation

In this research, we report the preparation of doped PMo Keggin heteropolyacids where Mo is partially replaced by V, Bi, and Bi–V. These catalysts were characterized by means of ICP-AES analysis, 31P-NMR, UV–visible spectra, FT-IR spectra, thermal analysis, and textural properties. In addition, the activities of the synthesized catalysts were evaluated in the selective oxidation of sulfides to sulfoxides/sulfones. The incorporation of V, Bi and Bi–V into the structure of H3PMo12O40 increases the catalytic activity. The two most active catalysts, those with V and V–Bi were supported on aminopropyl-functionalized silica (SiO2NH2) and they were found to be and efficient heterogeneous catalysts for the selective oxidation of diphenylsulfide to the corresponding sulfoxide/sulfone.

Peroxotungstates immobilized on multilayer ionic liquid brushes-modified silica as an efficient and reusable catalyst for selective oxidation of sulfides with H 2O 2

Peroxotungstates held in a series of different supported ionic liquid brush catalysts were synthesized and characterized. Their catalytic performance towards the selective oxidation of sulfides with aqueous hydrogen peroxide was investigated under mild conditions. We found that the catalytic activities of the different catalysts depend on the number of supported ionic liquid layers and N-end-capped alkyl group on the imidazole ring. The highest yield of methyl phenyl sulfoxide was obtained using the BisILs-C 8H 17-W2 catalyst under optimum conditions. The sulfides were selectively oxidized to sulfoxides in high yields with trace sulfones detected by GC upon using 1.1 equivalents of H 2O 2. At 2.5 equivalents of H 2O 2 the sulfones were found to be the main products. It is noteworthy that the catalyst resulted in high chemoselectivity towards sulfur groups with unsaturated double bonds even though excess hydrogen peroxide was used in addition to exhibiting high catalytic activity. There was no apparent loss of catalytic efficiency until the 8th cycle.

ChemInform Abstract: TMSCl‐Promoted Selective Oxidation of Sulfides to Sulfoxides with Hydrogen Peroxide.

AbstractTmsCl as an additive promotes the chemoselective mono‐oxidation in high yields.

Alumina-supported monoperphosphoric acid for selective oxidation of sulfides to sulfoxides

Selective oxidation of aromatic and aliphatic sulfides to the corresponding sulfoxide was achieved by using POCl3/H2O2 and (alumina-supported phosphorus oxychloride)/H2O2. A versatile procedure for the oxidation of sulfides to sulfoxides without any over-oxidation to sulfones has been reported. It is noteworthy that the reaction is clean and tolerates oxidatively sensitive functional groups and the sulfur atom is selectively oxidized.

SBA-15-Pr–SO3H as nanoreactor catalyzed oxidation of sulfides into sulfoxides

The selective oxidation of sulfides to sulfoxides was achieved in excellent yields at 40 °C with SBA-15-Pr–SO3H as a recyclable nanoreactor active catalyst and H2O2 as the terminal oxidant. The H2O2–SBA-15-Pr–SO3H system can chemoselectively oxidize alkyl and aryl sulfides in the presence of oxidatively sensitive functional groups such as CC, –CN, and –OH.

TMSCl-promoted selective oxidation of sulfides to sulfoxides with hydrogen peroxide

Selective oxidation of sulfides to sulfoxides is achieved using H 2O 2 and TMSCl as the promotor. Aromatic and aliphatic sulfides are oxidized to sulfoxides in excellent yields and in short reaction times. Different functional groups including ketone, alkene, ester, and alcohol are tolerated.

Oxidation of Sulfides with a Silica‐Supported Peracid in Supercritical Carbon Dioxide under Flow Conditions: Tuning Chemoselectivity with Pressure

AbstractSupercritical carbon dioxide is a convenient medium for performing the selective oxidation of sulfides 1 to either sulfoxides 2 or sulfones 3 with [2‐percarboxyethyl]‐functionalized silica (4) under flow conditions. The chemoselectivity of the reaction, which results from the different diffusion rates of sulfide and sulfoxide over the reagent bed, can be controlled by adjusting the pressure and the hydration of the silica surface as both the solvating power of the mobile phase and the surface activity of the stationary phase determine the migration rates of sulfide 1 and sulfoxide 2 over the supported peroxide. The results elucidate the impact of surface phenomena on the course of chemical reactions carried out under flow conditions.

Aqueous sodium hypochlorite mediated chemoselective oxidation of chalcogenides to monoxides and dioxides by microwave exposure

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.

Mn(salophen)Cl] supported on modified polystyrene as a selective heterogeneous catalyst for oxidation of sulfides under ultrasonic irradiation

The use of ultrasonic irradiation for the selective synthesis of sulfone in the oxidation of sulfides with NaIO4 catalyzed by Mn(Salophen) supported on chloromethylated polystyrene-bound imidazole, [Mn(Salophene)-PSI], is reported. This heterogeneous catalyst efficiently catalyzed selective oxidation of sulfides to sulfones under ultrasonic irradiation and no sulfoxide was detected in the reaction mixture.

A highly efficient, green, rapid, and chemoselective oxidation of sulfides using hydrogen peroxide and boric acid as the catalyst under solvent-free conditions

Abstract We report boric acid as a highly efficient and eco-friendly catalyst for the selective oxidation of sulfides to sulfoxides or sulfones, in excellent yields under solvent-free conditions, using 30% hydrogen peroxide as an oxidant. Various sulfides possessing functional groups such as alcohol, ester, and aldehyde are successfully and selectively oxidized without affecting sensitive functionalities.

ChemInform Abstract: Guanidinium Nitrate/Silica Sulfuric Acid/Ammonium Bromide as an Effective, Viable and Metal‐Free Catalytic Media for the Selective Oxidation of Sulfides to the Sulfoxides.

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