Fmoc-d-3,4,5-trifluorophenylalanine is primarily used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). Its Fmoc (9-fluorenylmethoxycarbonyl) protecting group allows for selective deprotection, enabling the stepwise construction of peptides. The incorporation of trifluorophenylalanine enhances the peptide's stability and can influence its binding affinity, making it valuable in the development of peptide-based drugs and bioactive molecules. Additionally, the presence of fluorine atoms can improve the peptide's metabolic stability and membrane permeability, which is crucial for pharmaceutical applications. This compound is also utilized in research to study peptide-protein interactions and to design peptides with specific structural or functional properties.