Amide bond formation is the cornerstone of peptide synthesis, yet selecting the right conditions remains a challenge. This collection explores the mechanisms, efficiency, and safety profiles of peptide coupling reagents—from standard activators to advanced systems—to help you minimize racemization and optimize difficult couplings.
OxymaPure / DIC System
The modern gold standard for Fmoc-SPPS. Offers superior suppression of racemization and higher coupling efficiency compared to HOBt, with a significantly better safety profile.
HOBt & HOAt Additives
Covers the classic benzotriazole mechanism and anchimeric assistance (HOAt). Includes critical safety protocols regarding explosive classification and proper desensitization.
HATU & HBTU Coupling
Explains aminium vs uronium structure, active ester formation (OBt vs OAt), and the 7-aza effect behind HATU performance. Links mechanism directly to coupling efficiency, racemization control, and bench limitations.
PyBOP Peptide Coupling
Covers the phosphonium activation mechanism, OBt active ester pathway, and why PyBOP tolerates reagent excess without N-terminal capping. Includes selection logic across PyBOP, PyAOP, and PyClock.