Used in peptide synthesis as a protected amino acid building block, particularly in the preparation of complex bioactive peptides. The Boc (tert-butoxycarbonyl) group protects the amine functionality, allowing selective reaction at the carboxylic acid end, which is useful in solid-phase and solution-phase peptide coupling. Commonly employed in pharmaceutical research for developing protease inhibitors and other therapeutic peptides where a hydrophobic phenyl-substituted phenylalanine moiety is required. Its structure helps modulate peptide stability, lipophilicity, and receptor binding properties.