A robust methodology for the synthesis of phosphorothioates, phosphinothioates and phosphonothioates

Abstract

A robust methodology for the synthesis of phosphorothioates, phosphinothioates and phosphonothioates, including those bearing low molecular weight S‐alkyl side‐chains, is presented. Application of the “caesium effect” in conjunction with the disulfide 3,3’‐dithiobis(propionitrile), which acts as a shelf‐stable sulfur source, avoids recourse to malodorous alkanethiols and toxic P−Cl precursors. A diverse range of sulfur‐containing organophosphorus targets, including phosphorus‐based heterocycles, may be prepared in consistently high yields. This chemistry also provides ready access to the corresponding DBU salts which are potential substrates for Pd‐catalysed coupling reactions.