ELECTROINITIATED OXYGENATION OF ALKENYL SULFIDES AND ALKYNES IN THE PRESENCE OF THIOPHENOL

Electrolysis of alkenyl sulfides in the presence of thiophenol with bu bbling of molecular oxygen gave the corresponding alpha-(phenylthio) c arbonyl compounds with the consumption of a catalytic amount of electr icity. An electroinitiated radical chain mechanism has been proposed. The reaction also took place without electrochemical initiation, but m uch (5-50 times) longer reaction time was required for the completion of the reaction. The potential utility of the present reaction in orga nic synthesis is demonstrated by the net 1,2-transposition of a phenyl thio group and a carbonyl group. The electroinitiated oxygenation of k etene dithioacetals also proceeded smoothly to give the corresponding alpha-(phenylthio) thiol esters. It was also found that the electroini tiated oxygenation of alkynes in the presence of thiophenol gave alpha -(phenylthio) carbonyl compounds. A mechanism involving the initial fo rmation of alkenyl sulfides has been proposed.