The first electricity-promoted, catalyst-free cascade thia-Michael addition and thioacetalization of cyclic enones with thiols are described. The electro-organic protocol was found to be suitable for both alkyl and aryl thiols, which reacted with a variety of cyclic enones to afford the corresponding tris-sulfane in good to excellent yields. Based on control experiments, it was found that this cascade reaction is chemoselective, involving first thia-Michael addition followed by thioacetalization process.
Key words
thioacetalization - electrochemistry - thia-Michael addition - regioselectivity - metal-free reactions