(S)-4-Fluorophenylglycine is primarily used in the pharmaceutical industry as a chiral building block for the synthesis of various active pharmaceutical ingredients (APIs). Its stereochemistry makes it valuable in the production of enantiomerically pure compounds, which are crucial for developing drugs with specific biological activities. It is often employed in the synthesis of beta-lactam antibiotics, such as penicillins and cephalosporins, where the fluorine substituent can enhance the drug's potency and metabolic stability. Additionally, it serves as a key intermediate in the preparation of peptide-based therapeutics and other biologically active molecules, contributing to improved drug efficacy and reduced side effects.