Used in solid-phase peptide synthesis to introduce a fluorinated tyrosine residue into peptide chains. The Fmoc group allows for mild, base-labile protection during stepwise synthesis, making it compatible with standard Fmoc strategies. The fluorine atom enhances metabolic stability and can improve binding selectivity in bioactive peptides. Commonly applied in the development of peptide-based pharmaceuticals, enzyme inhibitors, and probes for NMR or PET imaging due to the presence of fluorine-19 or potential labeling with fluorine-18.