Used as a chiral building block in the synthesis of pharmaceuticals, particularly in the development of protease inhibitors and other biologically active compounds. Its rigid pyrrolidine structure with a trifluoromethyl group enhances metabolic stability and binding selectivity, making it valuable in drug design. Commonly employed in asymmetric synthesis to introduce stereochemical control. Also utilized in the preparation of intermediates for antiviral and anticancer agents. The hydrochloride salt form improves solubility and handling in aqueous reaction systems.