Dinitrogen tetroxide supported on polyvinylpyrrolidone (PVP–N2O4): a new nitrosating and coupling agent for thiols and a selective oxidant for sulfides and disulfides

Gaseous N2O4 was immobilized on polyvinylpyrrolidone to give a stable polymeric reagent. Thiols were converted to S-nitrosothiols (thionitrites) using this new nitrosating agent in n-hexane or CHCl3 at 10°C. With this reagent, thiols were also converted into their corresponding disulfides. Selective oxidation of sulfides to sulfoxides and disulfides to thiosulfonates can also be achieved by this reagent at room temperature. By using an excess of the reagent, the selective one-pot synthesis of thiosulfonates from thiols at room temperature was also performed.