TBTU, or 2-(1H-7-Azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate, is a highly efficient coupling reagent widely used in peptide synthesis. Known for its rapid activation and low racemization, TBTU ensures precise and reliable peptide bond formation, making it a cornerstone in solid-phase peptide synthesis (SPPS) and solution-phase peptide synthesis.