Some reactions of phenylsulphine and phenylsulphene

Abstract

Phenylsulphine has been prepared in solution from triethylamine and phenylmethanesulphinyl chloride. It slowly decomposes at room temperature to give stilbene, trans-4,5-diphenyl-1,2,3-trithiolan 1,1-dioxide, and a 5,6-diphenyl-1,2,3,4-tetrathian dioxide. Phenylsulphine does not react with aldehydes, phenyl isocyanate, benzoyl chloride, or 1,3-dipolar systems. With enamines, electrophilic attack at sulphur to give a dipolar intermediate is followed by proton transfer to form a benzylsulphinyl enamine. Phenylsulphene with enamines gives either thietans or benzylsulphonyl enamines; with the ynamine PhC⋮C·NEt₂ it gives a thieten S,S-dioxide. With the ylid Ph₃P:CH·CO₂Et, phenylsulphine and phenylsulphene give the stable ylids Ph₃P:C(SO·CH₂Ph)·CO₂Et and Ph₃P:C(SO₂·CH₂Ph)·CO₂Et, respectively.