Used in peptide synthesis as a protected building block, particularly for introducing cysteinol residues with orthogonal protection. The Boc group protects the amine, while the benzyl group protects the thiol, allowing selective deprotection in multi-step syntheses. Commonly employed in the preparation of complex peptides and proteins where controlled disulfide bond formation is required. Also utilized in medicinal chemistry for the development of cysteinol-containing drug candidates and enzyme inhibitors. Its stability under various reaction conditions makes it suitable for solid-phase and solution-phase peptide coupling strategies.