Used in peptide synthesis as a protected amino acid building block, particularly in the development of opioid receptor ligands. The Boc group provides temporary protection for the amine function, allowing selective coupling at the carboxylic acid end. Tic (tetrahydroisoquinoline carboxylic acid) is a constrained amino acid that imparts conformational rigidity, enhancing receptor selectivity and metabolic stability in bioactive peptides. Commonly employed in research related to central nervous system agents and pain management drug discovery.