Fmoc-(R)-3-Amino-4-(1-naphthyl)-butyric acid is primarily used in peptide synthesis as a building block. It is particularly valuable in solid-phase peptide synthesis (SPPS) due to its Fmoc protecting group, which can be easily removed under mild basic conditions. The naphthyl group in its structure provides steric bulk and enhances the hydrophobicity of the peptide, making it useful in designing peptides with specific structural and functional properties. This compound is often employed in the development of bioactive peptides, enzyme inhibitors, and peptidomimetics, where the incorporation of aromatic groups is crucial for binding interactions. Additionally, it is utilized in research focused on studying peptide-protein interactions and in the synthesis of peptide-based drugs. Its unique structure allows for the creation of peptides with tailored properties for applications in medicinal chemistry and biochemistry.