Used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS), where it serves as a protected form of D-histidine. The Fmoc group ensures selective deprotection during the synthesis process, while the Trt (trityl) group protects the imidazole side chain of D-histidine, preventing unwanted side reactions. This compound is essential for constructing peptides with D-histidine residues, which are crucial in many biologically active peptides and proteins. Its application is widespread in pharmaceutical research, drug development, and the study of protein-protein interactions.