Preparation and reactivity of unsymmetrical di- and trisulfides

Abstract

Triphenylmethanesulfenyl chloride TrSCl (6) and triphenylmethanethiosulfenyl chloride TrSSCl (7) react with various thiols RSH to give the corresponding unsymmetrical polysulfides TrSSR 9 and TrSSSR 10, respectively. Compounds 9 and 10 were obtained in excellent yield and identified by ¹H- and ¹³C-NMR as well as by elemental analysis. p-Methoxybenzyl trityl trisulfide 10c was characterized by X-ray crystallography. Preliminary experiments showed an interesting reactivity of trisulfides TrSSSR 10 with electrophiles to give polysulfides RS_XR; the use of elemental iodine results in the formation of the corresponding hexasulfides RS₆R, 15 in high yield and with higher than 90% selectivity.

Keywords:

• Trityl
• Thiol
• Disulfides
• Trisulfides
• Sulfenyl chloride
• Thiosulfenyl chloride; Polysulfides
• Sulfur transfer reagent

Acknowledgements

We thank the Natural Sciences and Engineering Research Council (NSERC) of Canada and the American University of Sharjah (AUS) for financial support of this work.