Development of a Triazinyluronium-Based Dehydrative Condensing Reagent with No Heteroatomic Bonds

A triazinyluronium-based dehydrative condensing reagent, 2-(4,6-dimethoxy-1,3,5-triazin-2-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (DMT-TU), has been developed. Unlike commonly used guanidinium- and uronium-based reagents, DMT-TU does not contain high-energy N-N and N-O bonds, reducing its explosivity, as suggested by differential scanning calorimetry. Using DMT-TU in the presence of ⁱPr₂EtN at room temperature, carboxylic acids and amines were effectively converted to their corresponding amides. Additionally, peptide bond formation with DMT-TU exhibited suppressed racemization ratios.