Electro-initiated oxygenation of alkenylsilanes in the presence of thiophenol.

Electrolysis of alkenylsilanes in the presence of thiophenol with bubbling of molecular oxygen gave the corresponding α-phenylthio carbonyl compounds with the consumption of a catalytic amount of electricity. An electro-initiated radical chain mechanism is proposed. The reaction also took place without electrochemical initiation, but much longer reaction time was required for the completion of the reaction. Since various types of alkenylsilanes are prepared by the alkylation of 1-bromo-1-(trimethylsilyl)ethene, 1-bromo-1-(trimethylsilyl)ethene can be utilized as a synthon of phenylthioacetyl anion. The oxygenation of 1-phenylthio-1-(trimethylsilyl)alkenes in the presence of thiophenol gave α-phenylthio thiolesters indicating that the carbon-silicon bond was cleaved exclusively without affecting the carbon-sulfur bond.