Widely used in peptide synthesis and bioconjugation, this compound enables efficient and selective coupling of D-proline to primary amines under mild conditions. Its N-hydroxysuccinimide (NHS) ester group reacts readily with amino groups in proteins, peptides, or other amine-containing molecules, making it valuable for labeling, crosslinking, and modifying biomolecules. The tert-butoxycarbonyl (Boc) protecting group ensures the amine remains blocked during reactions, preventing unwanted side reactions and improving coupling specificity. It is particularly useful in solid-phase peptide synthesis and the preparation of peptide libraries where stereochemical control is important. Due to the D-proline moiety, it can be employed to introduce conformational constraints or enhance metabolic stability in peptide-based drug design.