Chlorosulfonylated

Chlorosulfonylated is a term used in organic and materials chemistry to describe a molecule that contains a chlorosulfonyl group, –SO2Cl, introduced by a chlorosulfonylation reaction. The chlorosulfonyl group is a reactive sulfonyl chloride substituent that can serve as a versatile handle for further derivatization.

Traditionally, chlorosulfonylation refers to the introduction of –SO2Cl onto an aromatic system or an alkene, typically using chlorosulfonyl chloride (ClSO2Cl) or sulfuryl chloride-derived reagents under acidic or Lewis-acid activation. In arenes, this affords aryl chlorosulfonyl derivatives (ArSO2Cl). The exact conditions depend on substrate electronics and desired regiochemistry.

Applications and transformations: The chlorosulfonyl group is a good leaving-like site for subsequent reactions. Nucleophiles such as amines, alcohols, or thiols can replace the chloride or the sulfonyl moiety, yielding sulfonamides, sulfonate esters, or related linkages. The –SO2Cl group can also be converted into other functional groups, such as sulfonic acids or sulfones, enabling polymer cross-linking or post-polymerization modification. Chlorosulfonylated substrates are widely used in the synthesis of sulfonamide drugs, dyes, agrochemicals, and functional polymers.

Safety: Chlorosulfonyl chloride is highly reactive, lachrymatory, and corrosive, and it releases hydrogen chloride and sulfurous acids upon contact with moisture. Reactions require proper ventilation, protective equipment, and careful handling of moisture-free reagents.

See also: Chlorosulfonyl chloride, Sulfonyl chloride, Sulfonylation.