of vinyl sulfides and unsaturated nitriles via quaternary phosphonium salts have been established. The reaction of isopropylidenetriphenylphosphorane with S-ethyl thiobenzoate or substituted S-ethyl thiobenzoates afforded vinyl sulfides and triphenylphosphine oxide in good yields. Further, it was found that the reaction of α-benzoylalkylphosphonium salts with sodium ethylmercaptide or potassium cyanide