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.     

Activation of superoxide by boron trifluoride: chemoselective and efficient oxidation of sulfides to sulfoxides via tetrafluorodiboronperoxide

Activation of superoxide with boron trifluoride in dry acetonitrile can facilitate highly chemoselective and efficient oxidation of sulfides to corresponding sulfoxides at ice-water bath in excellent yields without any interference in the presence of ketone, olefin, ether, and hydroxyl functionalities. This new method also offers further advantages of a short reaction time, no overoxidation to sulfones, and none of complex catalysts and toxic metallic compounds used. A tetrafluorodiboronperoxide intermediate formed in situ from this new process is proposed.     

Mn(III)-catalyzed oxidation of sulfides to sulfoxides with hydrogen peroxide

Sulfides were selectively oxidized to the corresponding sulfoxides in good yields with hydrogen peroxide using a manganese(III) Schiff-base complex as a catalyst in glacial acetic acid as solvent under mild conditions.     

A general and selective zinc-catalyzed oxidation of sulfides to sulfoxides

A general zinc-catalyzed oxidation of sulfides to sulfoxides has been developed. All the reactions proceeded at room temperature. Hydrogen peroxide was used as a green oxidant. Twenty-one examples of sulfoxides were prepared in moderate to excellent yields.     

A highly efficient reusable homogeneous copper catalyst for the selective aerobic oxygenation sulfides to sulfoxides

Readily available copper showed efficient activity and great selectivity for the homogeneous catalysis of oxidation of sulfides to sulfoxides using molecular oxygen as the oxidant. The reaction proceeds under mild conditions in the presence of a catalytic amount of TEMPO. Importantly, the catalysts could be conveniently recovered and reused. And this methodology was proved to be applicable for the transformation of various aromatic and aliphatic sulfides into the corresponding sulfoxides with high conversion and high selectivity.     

Selective synthesis of sulfoxides and sulfones by tantalum(V) catalyzed oxidation of sulfides with 30% hydrogen peroxide

The reaction of sulfides with 30% hydrogen peroxide catalyzed by tantalum(V) chloride in acetonitrile, i-propanol, or t-butanol selectively provided the corresponding sulfoxides in high yields. On the other hand, the reaction of sulfides with 30% hydrogen peroxide-catalyzed by tantalum(V) chloride or tantalum(V) ethoxide in methanol effectively gave the sulfones.     

Poly(4-vinylpyridinium tribromide) as metal-free, green and recoverable oxidizing polymer for the chemoselective oxidation of sulfides into sulfoxides

Poly(4-vinylpyridinium tribromide) was prepared from poly(4-vinylpyridin) and used for the selective oxidation of a variety of sulfides to the corresponding sulfoxides.The oxidation reaction was carried out heterogeneously in acetone/water,as green solvent, at room temperature.     

Selective oxidation of sulfides to sulfoxides using a silica immobilised vanadyl alkyl phosphonate catalyst

A range of sulfides can be selectively oxidised to the corresponding sulfoxides in good yields using catalytic quantities of immobilised vanadyl, cobalt or nickel alkyl phosphonates and the reoxidant sodium bromate or vanadyl alkyl phosphonate with tert-butyl hydroperoxide or aqueous hydrogen peroxide as oxidants.     

Copper catalyzed oxidation of sulfides to sulfoxides with aqueous hydrogen peroxide

Copper(II) complex 1 catalyzes the oxidation of sulfides to sulfoxides with 30% H₂O₂ in high yields. Addition of a catalytic amount of TEMPO to the reaction mixture enhances the conversion and selectivity. Complex 1 can be recycled without loss of activity.     

Selective and mild oxidation of sulfides to sulfoxides by H_2O_2 using DBUH-Br_3 as catalyst

<正>DBUH-Br_3 catalyzed selective conversion of sulfides to sulfoxides in the presence of H_2O_2 as oxidizing agent is described.The reaction was performed selectively at room temperature and relatively short reaction times.     

A novel catalytic system poly(1-vinyl-3-dodecylimidazolium tribromide)/TBN for the oxidation of sulfides to sulfoxides with air as oxidant

A novel and recoverable polymeric ionic liquid, poly(1-vinyl-3-dodecylimidazolium tribromide) (Poly[VDIM]Br₃), was successfully prepared and fully characterized. And a highly efficient metal-free catalytic system Poly[VDIM]Br₃/tert-butyl nitrite was developed for the oxidation of sulfides. With air as oxidant, we have successfully achieved 19 kinds of sulfides selectively and efficiently oxidized to corresponding sulfoxides using this catalytic system at room temperature.     

Thiourea dioxide (TUD): a robust organocatalyst for oxidation of sulfides to sulfoxides with TBHP under mild reaction conditions

Thiourea dioxide (TUD) has been reported for the first time as a highly efficient and selective organocatalyst for the oxidation of sulfides to sulfoxides in high to excellent yields by using tert-butylhydroperoxide as oxidant under mild reaction conditions.     

Fe3O4 as a magnetically reusable Fenton nanocatalyst for the oxidation of thiols to sulfonic acid and sulfides to sulfoxides and sulfones

In this study, the oxidation of thiols to sulfonic acids and sulfides to sulfoxides and sulfones was carried out in the presence of Fe₃O₄/H₂O₂ as an efficient heterogeneous Fenton system. The products were obtained in good to excellent yields and short reaction times. Further results showed that the heterogeneous catalyst could be recovered easily using an external magnetic field and reused several times without any loss of its catalytic activity.     

Selective hydrogen peroxide oxidation of sulfides to sulfoxides or sulfones with MWW-type titanosilicate zeolite catalyst under organic solvent-free conditions

Selective oxidation of sulfides to sulfoxides and sulfones with hydrogen peroxide under organic solvent-free conditions was demonstrated by the MWW-type titanosilicate zeolite catalyst. Sulfides were oxidized smoothly to give sulfoxides with good selectivities at ambient temperature using 1.0–1.2 equiv of hydrogen peroxide with the MWW-type titanosilicate zeolite catalyst. Especially, the Ti-MWW with an interlayer-expanded structure (Ti-IEZ-MWW) catalyst showed high activity with good chemoselectivity for the oxidation of various sulfides. The catalyst is recyclable for at least five cycles, and the only byproduct is water. Sulfides were directly oxidized to give sulfones in high yields by 2.5 equiv of hydrogen peroxide with the MWW-type titanosilicate zeolite catalyst under organic solvent-free conditions.     

中孔MCM-41锚合Zr（IV）-salen催化剂制备及用于硫化物氧化制亚砜和Knoevenagel缩合反应

通过NH2-MCM-41与水杨醛反应得到席夫碱配体,然后加入八水氧氯化锆形成络合物,制得Zr(IV)-salen-MCM-41催化剂。采用X射线衍射、N2吸附-脱附、热重、红外光谱、电感耦合等离子体发射光谱和能量散射谱等分析手段对催化剂结构进行了表征。在含有该催化剂的体系中进行了硫化物选择氧化为亚砜以及醛与丙二腈和氰乙酸乙酯的Knoveonagel缩合反应,并考察了催化剂的循环使用性能。     

An efficient solvent free catalytic oxidation of sulfides to sulfoxides with hydrogen peroxide catalyzed by a binaphthyl-bridged Schiff base titanium complex

A titanium binaphthyl-bridged Schiff base complex proved to be an efficient catalyst for the hydrogen peroxide oxidation of aromatic and aliphatic sulfides to the corresponding sulfoxides in satisfactory yields under solvent-free conditions.     

Rhodium(II)-catalyzed addition of 2-diazo(fluoroalkyl)acetoacetates to sulfides: a simple synthesis of stable sulfonium ylides

2-Diazo(fluoroalkyl)acetoacetates 1 reacted readily with many sulfides under mild reaction conditions in the presence of catalytic Rh₂(OAc)₄ affording to the corresponding sulfonium ylides. While thianthrene gave trans-thianthrenium 5,10-di(fluoroalkylacetoethoxycarbonyl)methylides (7a and 7b) under the same reaction condition, the structure of 7btrans-thianthrenium 5,10-di(bromodifluoroacetoethoxy-carbonyl)methylides was fully confirmed by spectral methods and X-ray single crystal diffraction analysis. All the ylide products obtained are fairly stable due to the strong electron-withdrawing properties of the fluorine atom.     

Ferric nitrate in the presence of catalytic amounts of KBr or NaBr: an efficient and homoselective catalytic media for the selective oxidation of sulfides to sulfoxides

Abstract  A mild, efficient, and highly selective oxidation method of sulfides to sulfoxides using Fe(NO₃)₃·9H₂O and catalytic amounts of KBr or NaBr in the presence of wet SiO₂ (50% w/w) has been developed. A variety of aliphatic and aromatic sulfides were selectively oxidized at room temperature in good to excellent yields. Graphical abstract