Organosulfonyl

Organosulfonyl refers to compounds that feature the sulfonyl functional group, SO2, bonded to organic substituents. The sulfonyl group consists of a sulfur atom in oxidation state +6 double-bonded to two oxygens and singly bonded to two substituents. When at least one substituent is carbon, the species are considered organosulfonyl. This class encompasses sulfonyl chlorides, sulfonyl fluorides, sulfones (R-SO2-R'), sulfonamides, and sulfonate esters.

Common examples and subtypes include sulfonyl chlorides, such as R-SO2-Cl, exemplified by tosyl chloride (p-toluenesulfonyl chloride), mesyl chloride (methanesulfonyl chloride), and nosyl chloride (2-nitrobenzenesulfonyl chloride). These reagents are widely used to activate alcohols and amines, forming sulfonate esters (tosylates, mesylates) or sulfonamides, and they are typically prepared by chlorinating corresponding sulfonic acids. Sulfonyl fluorides, R-SO2-F, are another important class, notable for stability toward hydrolysis and their use in sulfur(VI) fluoride exchange (SuFEx) click chemistry. Sulfonyl groups bonded to two carbon substituents (R-SO2-R’) define sulfones, which are valuable in pharmaceuticals, agrochemicals, and polymers.

Applications and reactions: organosulfonyl chlorides are versatile sulfonylating agents for converting alcohols into good leaving groups and for installing sulfonamide or sulfonate functionalities. Sulfonamides (R-SO2-NR2) are a major class of pharmaceuticals and agrochemicals. Sulfonate esters serve as protecting groups for alcohols in synthesis and can be removed under specific conditions. Safety considerations include corrosivity of sulfonyl chlorides and potential hydrolysis to sulfonic acids.

See also: sulfonyl group, sulfonyl chloride, sulfonamide, tosyl, mesyl, nosyl.