(S)-2-((tert-Butoxycarbonyl)amino)-5-phenylpentanoic acid is primarily used in the field of peptide synthesis. It serves as a protected amino acid derivative, where the tert-butoxycarbonyl (Boc) group safeguards the amino functionality during the peptide chain assembly process. This compound is particularly valuable in solid-phase peptide synthesis (SPPS), enabling the stepwise construction of peptides with high precision. The Boc protection can be selectively removed under acidic conditions, allowing for further elongation of the peptide chain without affecting other functional groups. Additionally, its phenylpentanoic acid moiety contributes to the structural diversity of synthesized peptides, making it useful in the development of bioactive peptides, peptidomimetics, and pharmaceutical agents. Its application extends to research in drug discovery, where it aids in the creation of compounds with potential therapeutic effects.