In situ generated hypoiodous acid in an efficient and heterogeneous catalytic system for the homo-oxidative coupling of thiols

Supported hydrogen peroxide on polyvinylpolypyrrolidone (PVPH2O2), silica sulfuric acid (SiO2-OSO3H) and catalytic amounts of potassium iodide (KI) has been developed as a heterogeneous medium for the rapid oxidative coupling of thiols into symmetrical homodisulfides. This oxidizing system proceeds under extremely mild conditions and gives no other oxidized side products

Metal-free catalytic oxidation of sulfides to sulfoxides with ammonium nitrate, ammonium hydrogen sulfate and ammonium bromide as catalyst

A general and metal-free catalytic oxidation of aliphatic and aromatic sulfides to their corresponding sulfoxides via combination of ammonium nitrate (NH4NO3), supported ammonium hydrogen sulfate on silica gel (NH4HSO4-SiO2) and a catalytic amount of ammonium bromide (NH4Br) in the presence of wet SiO2 (50%, w/w) has been investigated. The reactions were carried out heterogeneously and selectively in short reaction times in CH2Cl2 at room temperature. This protocol is mild and efficient compared to other reported methods