Fmoc-OSu is widely used in peptide synthesis as a protecting group for amino acids. It is particularly effective in solid-phase peptide synthesis (SPPS), where it helps to temporarily shield the amino group during the formation of peptide bonds. This allows for selective deprotection and elongation of the peptide chain. Its high reactivity and stability under various conditions make it a preferred choice in the synthesis of complex peptides and proteins. Additionally, Fmoc-OSu is utilized in the preparation of peptide libraries and in combinatorial chemistry for drug discovery and development. Its application ensures precise control over peptide assembly, enhancing the efficiency and accuracy of synthetic processes.