HATU is widely used in peptide synthesis as a coupling reagent to facilitate the formation of amide bonds between amino acids. It is particularly effective in both solution-phase and solid-phase synthesis due to its high reactivity and low racemization. HATU activates carboxylic acids quickly, allowing efficient coupling even with sterically hindered or unreactive amines. It is commonly used in the preparation of complex peptides and small molecule pharmaceuticals where high yields and purity are critical. Additionally, HATU is employed in the synthesis of amide-containing drugs and bioconjugates in medicinal chemistry and research settings.