Used primarily in peptide synthesis as a protected chiral building block. The Fmoc group enables reversible amine protection under mild basic conditions, making it ideal for solid-phase peptide synthesis. The bromine atom at the 4-position allows for further functionalization, such as nucleophilic substitution to introduce side chains or cyclization precursors. Its stereochemistry supports the construction of stereodefined peptides and peptidomimetics, often used in pharmaceutical research and development of bioactive molecules.