Used in peptide synthesis as a chiral building block for introducing phenylalanine derivatives with a vinyl-functionalized side chain. The vinyl group allows for post-synthetic modifications via cross-coupling reactions or polymerization, making it valuable in the development of functional biomaterials, bioconjugates, or stimuli-responsive peptides. The Fmoc protection enables solid-phase synthesis, while the (R)-configuration provides stereochemical control in designing specific peptide conformations.