(S)-Boc-2-cyano-β-Homophe-OH is a non-natural, protected amino acid derivative. Its structure features a (S)-configuration, a Boc (tert-butoxycarbonyl) protecting group on the amine, a cyano group at the alpha-carbon, and a homophenylalanine (β-Homophe) side chain terminated with a carboxylic acid. This combination of functional groups makes it a specialized chiral building block. This compound is primarily used in the research and development of peptide-based drugs and peptidomimetics. The cyano group can serve as a versatile synthetic handle for further chemical transformations, such as conversion into tetrazoles (bioisosteres for carboxylic acids) or other heterocycles, which are crucial for modulating the pharmacokinetic and pharmacodynamic properties of therapeutic peptides. The homophenylalanine side chain contributes to lipophilicity and potential receptor binding interactions. As a protected and functionalized amino acid, it is a valuable intermediate in medicinal chemistry for creating novel peptide structures with enhanced metabolic stability, bioavailability, and target specificity. Its applications are centered in the field of drug discovery, particularly for designing protease inhibitors, receptor agonists/antagonists, and other bioactive peptide analogues.