Sulfenyl chlorides from thiols

These sulfides are prepared from other sulfur protective groups by reaction with the sulfenyl chloride. The Npys group can also be introduced directly by treatment of the thiol with NpysCl. ... 

In contrast to the free acids, sulfenate esters, amides and halides are more stable. Disulfides (52) can be obtained from thiols by mild oxidation (see p. 57), and sulfenyl chlorides () can in turn be prepared from disulfides (52) by treatment with chlorine (Scheme 30). Sulfenyl chlorides (51) react with alcohols to give esters, e.g. the methyl sulfenate (53) which on alkaline hydrolysis yields the sulfenic acid (45) (Scheme 30). 

Formation of Unsymmetrical Disulfides. This facile protocol (eq O proceeds through sulfenyl thiocarbonate intermediates obtained in very good yields from equimolar amounts of thiols and alkoxycarbonylsulfenyl chlorides (of which methoxycarbonylsulfenyl chloride is widely used) at low temperature (generally 0-10 °C), in solvents such as methanol, chloroform, dichloromethane, and dioxane. An oxygen-free atmosphere of nitrogen is recommended. ... 

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