Metal- and Solvent-Free Synthesis of Phosphinothioates, Phosphonothioates, Phosphorothioates, and Related Selenium Derivatives: An Efficient Green Protocol

Methodologies for the effective fabrication of phosphinothioates, phosphonothioates, and phosphorothioates have always been of great interest due to their widespread application in many research fields. We present here a solvent-free reaction system for the synthesis of above compounds without any catalysts or additives, directly using disulfides with diarylphosphine oxides, dialkylphosphites, and phosphinates as substrates. Most of the target compounds were obtained in nearly quantitative yields by heating at 50 °C for 5-10 min or stirring at room temperature for 3 h. The products were efficiently separated via a water extraction operation, simultaneously recovering the by-product thiols. This mild and practical coupling protocol was also employed to prepare phosphinoselenoates from the corresponding diselenides with good yields.