Sodium 4-pentynoate is primarily used in organic synthesis, particularly in click chemistry applications. It serves as a key reagent in the copper-catalyzed azide-alkyne cycloaddition (CuAAC), enabling the efficient formation of 1,2,3-triazole linkages and the creation of complex molecules with high precision. This compound is often employed in the synthesis of pharmaceuticals, where its terminal alkyne functional group allows for selective coupling reactions. Additionally, it finds utility in material science for modifying surfaces or polymers, enhancing their properties through functionalization. Its water solubility further facilitates its use in aqueous reaction environments.