Used as a key intermediate in peptide synthesis, particularly in the preparation of structurally complex peptides and peptidomimetics. The presence of the 2-cyanophenyl group provides steric and electronic features that influence conformation during coupling steps. The Fmoc group allows for mild, base-labile protection of the amine, making it compatible with solid-phase synthesis. Commonly employed in the development of pharmaceuticals and bioactive molecules where stereochemistry and side-chain functionality are critical. Its chiral (S)-configuration ensures enantioselective incorporation into peptide chains, maintaining desired biological activity.