Oxidation of aromatic sulfides with molecular oxygen: Controllable synthesis of sulfoxides or sulfones

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.     

Oxidation of aromatic sulfides with molecular oxygen: Controllable synthesis of sulfoxides or sulfones

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 mild protocol for the deoxygenation of α-hydrogen-containing sulfoxides to the corresponding sulfides

A mild method for the deoxygenation of α-hydrogen-containing sulfoxides to sulfides is reported. This synthetically useful and operationally simple protocol derives mechanistically from the Swern oxidation methodology.     

2,6-Dicarboxypyridinium chlorochromate: an efficient and selective reagent for the oxidation of thiols to disulfides and sulfides to sulfoxides

2,6-Dicarboxypyridinium chlorochromate (2,6-DCPCC) was found to be an efficient reagent for the conversion of thiols to disulfides and sulfides to sulfoxides under neutral and anhydrous conditions in good to excellent yields. Selective oxidation of thiols in the presence of sulfides at room temperature is also observed with this reagent.     

Safe oxidation of sulfides into sulfoxides using SIBX

SIBX is a stabilized (i.e., nonexplosive) formulation of the λ⁵-iodane 2-iodoxybenzoic acid IBX that can be used as a suspension in various organic solvents to oxidize safely sulfides into sulfoxides. Most yields are comparable to those obtained using IBX or other iodanes such as PhIO and PhIO₂. An asymmetric version of this SIBX-mediated sulfoxidation was performed in high chemical yield and moderate enantioselectivity by simple addition of an external chiral source.     

A novel rapid sulfoxidation of sulfides with cyclohexylidenebishydroperoxide

Cyclohexylidenebishydroperoxide was successfully used as the oxygen source for the oxidation of sulfides to sulfoxides for the first time. The sulfoxides were obtained in good to high yields without any detectable over-oxidation to sulfones under normal conditions.     

Selective oxidation of sulfides to sulfoxides and sulfones using 30% aqueous hydrogen peroxide and silica-vanadia catalyst

A green, efficient and selective approach for the oxidation of sulfides to sulfoxides and sulfones with stoichiometric amount of 30% aq. H₂O₂ is reported. The reaction is performed in methanol with silica-vanadia as heterogeneous and reusable catalyst.     

The first application of titanocenes in the asymmetric oxidation of sulfides

Investigations were carried out on the oxidation of sulfides to sulfoxides catalyzed by the commercial Cp₂Ti(X)₂ (X=Cl, OTf)/t-butyl hydroperoxide (TBHP). The asymmetric version of prochiral sulfides oxidation was achieved using Cp₂TiCl₂, as transition metal catalyst, in the presence of (+)-(R)-BINOL, as chiral ligand and activated 4 Å molecular sieves (m.s.).     

1-(2’-烷硫基乙氧基)甲基尿嘧啶及其氧化物的合成

采用 3 0 %H2 O2 /DEAD的试剂组合 ,用于将硫醚及亚砜的衍生物氧化成砜类物质的反应 ,合成了1 ( 2 烷硫基乙氧基 )甲基尿嘧啶及其氧化物 ,产物结构经元素分析、1HNMR和IR进行表征 ,并研究了其抗癌活性     

Selective and efficient oxidation of sulfides to sulfoxides with N-bromosuccinimide in the presence of β-cyclodextrin in water

A simple and highly selective oxidation of sulfides to sulfoxides with N-bromosuccinimide (NBS) catalyzed by β-cyclodextrin in water has been developed. A series of sulfides were oxidized selectively at room temperature in excellent yields. This reaction proceeds without over-oxidation to sulfones under mild conditions using water as a solvent and has many advantages over the existing methodologies.     

Metal-free imination of sulfoxides and sulfides

Using a nitrogen transfer agent obtained in situ by mixing of NsNH₂ and PhI(OAc)₂, various N-nosyl sulfoximines and N-nosyl sulfilimines have been prepared under metal-free conditions starting from the corresponding sulfoxides and sulfides, respectively.     

A Selective Solid State Oxidation of Sulfides and Thiols with Benzyltriphenylphosphonium Peroxymonosulfate

Benzyltriphenylphosphonium peroxymonosulfate 1 could be used for oxidation of sulfides 2 and thiols 4 to their corresponding sulfoxides 3 and disulfides 5 under solid-phase conditions.     

A comparison of hydrogen bonding solvent effects on the singlet oxygen reactions of allyl and vinyl sulfides, sulfoxides, and sulfones

The singlet oxygen (¹Δ_g) photooxidations of 2-methyl-3-phenylthio-2-butene (1a), 1-[(4-nitrophenyl)thio]-2,3-dimethyl-2-butene (2c), 2-methyl-3-phenylsulfinyl-2-butene (3), 2-methyl-3-phenylsulfonyl-2-butene (6), and 1-[(4-nitrophenyl)sulfonyl]-2,3-dimethyl-2-butene (7c) were conducted in the following deuterated solvents: acetonitrile, benzene, chloroform, methanol, or methanol/water mixture. In each case the ene allylic hydroperoxide products and/or the [2+2] cycloaddition products were quantified and inspected for possible hydrogen bonding induced differences in product selectivity and regiochemistry. After comparison to literature values for related substrates, the results indicate that only photooxidations of vinyl sulfides are susceptible to hydrogen bonding solvent effects.     

Tetracyanoethylene oxide not only oxidizes sulfides to sulfoxides but also reduces sulfoxides to sulfides

It was found that tetracyanoethylene oxide not only oxidizes sulfides to sulfoxides but also reduces sulfoxides to sulfides with generation of two molecules of carbonyl cyanide. The reaction thus also functions as a new method for generation of carbonyl cyanide.     

Selective and efficient oxidation of sulfides to sulfoxides using ammonium cerium (IV) nitrate in the presence of a catalytic amount of KBr or NaBr

A wide range of aliphatic or aromatic sulfides are selectively oxidized to the corresponding sulfoxides using ammonium cerium (IV) nitrate (CAN) and a catalytic amount of KBr or NaBr in the presence of wet SiO₂ in CH₂Cl₂ under heterogeneous conditions in moderate to high yields. Correspondence: Mohammad Ali Zolfigol, Faculty of Chemistry, Bu-Ali Sina University, P.O. Box 6517838683, Hamadan, Iran; Kamal Amani, Department of Chemistry, Faculty of Science, University of Kurdistan, P.O. Box 6617715175, Sanandaj, Iran.     

4-Methoxy-3′-alkylsulfinyl-3,4′-diquinolinyl Sulfides--Synthesis and the Reaction with Sodium Methoxide #

Reaction of 4-methoxy-3'-alkylthio-3,4'-diquinolinyl sulfides 1a-d with a nitrating mixture led to the title sulfoxides 2a-d , but the same treatment of isopropylthio derivative 1e resulted in S-dealkylation and oxidation with formation of 3,3'-diquinolinyl disulfide 3 . 3'-Alkylsulfinyl group promotes nucleophilic methoxy-desulfidation of 4'-quinolinyl sulfur bond in sulfoxides 2 , as compared to that in sulfides 1 , in which case it leads to 3-quinolinyl sulfoxides 6 and 3-quinolinethiolate 4-A .     

Selective oxidations of sulfides to sulfoxides using immobilised cerium alkyl phosphonate

A range of sulfides can be selectively oxidised to the corresponding sulfoxides in good yields using catalytic quantities of immobilised cerium alkyl phosphonate and either sodium bromate or tert-butyl hydroperoxide as oxidants.     

Tetrabutylammonium phosphomolybdate on fluorapatite: an efficient solid catalyst for solvent-free selective oxidation of sulfides

A new synthetic method of sulfoxides and sulfones using solvent-free oxidations of sulfides with urea–hydrogen peroxide complex (urea–H₂O₂) and tetrabutylammonium phosphomolybdate catalyst on fluorapatite ((Bu₄N)₃[PMo₁₂O₄₀]/FAp). In the solid-phase system the oxidations of aromatic and alkyl sulfides proceeded at 4–25 °C and the corresponding sulfoxides or sulfones were selectively obtained in good yields by controlling the amount of urea–H₂O₂.     

Silica Sulfuric Acid Catalysis the Oxidation of Organic Compounds with Sodium Bromate

Abstract

The oxidation of organic compounds by sodium bromate/silica sulfuric acid under solvent‐free conditions and in CH₂Cl₂ have been studied at room temperature.