Metal-free oxidative coupling of thiols to disulfides using guanidinium nitrate or nitro urea in the presence of silica sulfuric acid

Abstract

Efficient combination of nitro urea or guanidinium nitrate and silica sulfuric acid (SiO2OSO3H) as a new oxidizing system is able to oxidize a variety of aliphatic or aromatic thiols to the corresponding disulfides. The process reported here is operationally simple, environmentally benign and reactions have been mildly and heterogeneously performed in dichloromethane at room temperature. © Indian Academy of Sciences.