Used as a chiral building block in the synthesis of pharmaceuticals, particularly in the development of central nervous system agents and alkaloid-based drugs. Its rigid tetrahydroisoquinoline structure provides stereochemical control in asymmetric synthesis, making it valuable in creating enantiomerically pure compounds. Commonly employed in medicinal chemistry for designing inhibitors and receptor ligands, especially for neurological targets. Also utilized in the preparation of peptidomimetics and bioactive molecules where conformational restriction enhances stability and selectivity.