Pent-4-yne-1-sulfonyl chloride is primarily used in organic synthesis as a versatile building block for creating more complex molecules. Its sulfonyl chloride group is highly reactive, making it useful for forming sulfonamides, sulfonate esters, and other sulfonyl derivatives. These compounds are often employed in pharmaceuticals, agrochemicals, and materials science. The alkyne functionality in the molecule allows for further modifications through click chemistry, such as copper-catalyzed azide-alkyne cycloaddition (CuAAC), enabling the creation of triazole-linked structures. This makes it valuable in drug discovery and bioconjugation applications, where precise molecular assembly is required. Additionally, its unique structure can be leveraged in polymer chemistry to design functionalized polymers with specific properties.