5-Ethynylpicolinaldehyde is primarily utilized in organic synthesis as a versatile building block for the creation of complex molecules. Its aldehyde and ethynyl functional groups make it a valuable intermediate in the development of pharmaceuticals, particularly in the synthesis of biologically active compounds. It is often employed in click chemistry reactions, such as the copper-catalyzed azide-alkyne cycloaddition (CuAAC), to form triazole derivatives, which are significant in drug discovery and material science. Additionally, it serves as a precursor in the preparation of ligands for catalysis and in the construction of molecular frameworks for advanced materials.