Used as a key reagent in organic synthesis, particularly in the protection and deprotection of amines during peptide synthesis. It selectively reacts with primary amines to form stable sulfonamides, which can later be cleaved under specific conditions, allowing stepwise construction of complex molecules. Its utility extends to the synthesis of pharmaceuticals and bioactive compounds where controlled amine reactivity is essential. Also employed in chemical biology for protein labeling and modification due to its selective electrophilic behavior toward nucleophilic amino acid residues.