Used in solid-phase peptide synthesis as a chiral building block for incorporating propargyl-modified amino acids into peptide chains. The Fmoc protection group allows for mild deprotection under basic conditions, making it compatible with standard Fmoc-strategy protocols. The alkyne side chain serves as a reactive handle for click chemistry, particularly copper-catalyzed azide-alkyne cycloaddition (CuAAC), enabling peptide conjugation with labels, polymers, or biomolecules. Commonly applied in the development of peptide-based drugs, bioconjugates, and functional biomaterials.