Butane-1-sulfonyl fluoride is primarily used in organic synthesis as a versatile reagent for introducing sulfonyl fluoride groups into molecules. It is particularly valuable in click chemistry and chemical biology for labeling proteins and other biomolecules due to its high reactivity and selectivity. The compound is also employed in the development of covalent inhibitors, where it forms stable bonds with target proteins, enabling the study of enzyme mechanisms and drug discovery. Additionally, it serves as a building block in the synthesis of pharmaceuticals and agrochemicals, contributing to the creation of compounds with enhanced biological activity and stability. Its use in polymer chemistry for modifying materials to achieve specific properties is another notable application.