An effective alternative to HATU on an industrial scale. An aminium-based coupling reagent, analogous to HBTU, which in comparative studies was found to give greater stability and is less allergenic than other coupling reagents, superior results to TBTU in the synthesis of difficult peptides, in hindered couplings, and cyclizations.1,2,3,4,5 But nonetheless it should be handled cautiously. HCTU showed reduced rates of racemization compared to BOP.6
1. Lett. Pept.Sci. 2002, 9, 119.
2. Lett. Pept. Sci. 2002, 9, 125.
3. J. Org. Chem. 2002, 67, 856.
4. J. Pept Sci. 2008,14, 97.
5. Pept. Sci. 2006, 84, 340.
6. Racemization studies on a novel Cl-HOBt-based coupling reagents, presented at the European Peptide Symposium, 2002.