Sulfides / Thiols
Sulfides or thioethers are a class of organic compounds that contain C-S-C linkage while thiols are sulfur analogues of alcohols. Many thiols have strong odours resembling that of garlic or rotten eggs. Sulfides are typically prepared by alkylation of thiols. Alternatively, they can be synthesized by the addition of a thiol to an alkene (thiol-ene reaction). Sulfides can be easily oxidized to sulfoxides, which can themselves be further oxidized to sulfones. They are readily alkylated to give stable sulfonium salts. Sulfides bind to metals to form thioether complexes or they can undergo reductive dealkylation in the presence of certain metals. Thiols can be prepared from alkyl halides via an S-alkylation of thiourea or sodium hydrosulfide. Thiolates are more potent nucleophiles than the corresponding alkoxides. As the functional group of the cysteine, it plays a very important role in biology, many cofactors feature thiols. Many commercial drugs also contain thiol group.
