Michael additions to 3(2H)-thiophenone 1,1-dioxide

Article abstract of DOI:10.1016/0040-4039(95)02088-8

The addition of thiols and amines to 3(2H)thiophenone 1,1-dioxide takes place with extrusion of sulfur dioxide, furnishing in high yields the corresponding vinyl sulfides and enamines. Addition of dithiols afforded the corresponding thioacetals. The rates of the Michael addition and the extrusion reaction are strongly influenced by the solvent employed. In ethanol, sulfur dioxide extrusion took place even at room temperature.