The nucleophilicity of M(SPh) $_{3}$ (M=P,As) and PhAs(SPh) $_{2}$ towards carboxylic acid anhydrides

Abstract

The reaction of P(SPh) $_{3}$ , As(SPh) $_{3}$ , and Ph-As(SPh) $_{2}$ with carboxylic acid anhydrides gives not only the thiol esters RCOSPh, but also the easily identified triphenyl phosphorotrithioate O=P(SPh) $_{3}$ , diphenyl disulfide PhSSPh, and the anion RCOO $^{-}$ in various proportions depending on the reaction conditions (in solution or neat at 120°C; in the absence and in the presence of an anhydride activator). The probable origin of the additional products is discussed.