Used in peptide synthesis as a protected amino acid building block, particularly in solid-phase synthesis. The Fmoc group provides temporary N-terminal protection that is easily removed under mild basic conditions, allowing stepwise assembly of peptides. The tert-butoxycarbonyl (Boc) group offers orthogonal protection for a secondary amine, enabling selective deprotection and coupling in complex peptide sequences. Its solubility in common organic solvents and stability during repeated synthesis cycles make it suitable for automated peptide synthesizers. Frequently employed in the preparation of long or branched peptides, including those used in pharmaceutical research and development.