A novel stereoselective preparation of various vinyl sulfide derivatives using beta-alkylthioalkenylselenonium salts

The treatment of alkynylselenonium salt and various thiophenol derivatives with a catalytic amount of triethylamine gave beta-arylthioalkenylselenonium salts in good yields. The alkenylselenonium salts thus prepared reacted with nucleophiles such as acetylides, thiolates, and alkoxides to produce (Z)-beta-arylthio-alpha-functionalized ethenes in high yields. The vinylselenonium salts bearing a hydroxy group on a beta-side chain caused intramolecular cyclization upon treatment with sodium hydride to produce medium-membered heterocyclic compounds containing sulfur and oxygen atoms. The reactions giving (Z)-beta-arylthio-alpha-functionalized ethenes would proceed via the formation of selenurane intermediates followed by the ligand coupling reaction.