Used in peptide synthesis as a protected amino acid derivative, particularly in solid-phase synthesis. The fluorenylmethyloxycarbonyl (Fmoc) group provides excellent protection for the amine functionality, allowing selective deprotection under mild basic conditions without affecting other sensitive groups. Its polyether chain enhances solubility in aqueous and polar organic solvents, improving reaction efficiency. Commonly employed in the preparation of bioconjugates, PEGylated peptides, and functionalized biomolecules for pharmaceutical and diagnostic applications.