Diaryl disulfides are effective catalysts to reduce arenesulfonic acids with triphenylphosphine to the corresponding arenethiols in good yields, while alkanesulfonic acids are transferred into the corresponding alkyl aryl sulfides. Arenesulfonic acids bearing electron-donating substituents can be reduced more readily than those having electron- withdrawing substituents, while diaryl disulfides bearing electron-withdrawing substituents ...
