HOAt
HOAt (1-Hydroxy-7-azabenzotriazole; CAS 39968-33-7) is a peptide coupling reagent frequently employed in peptide synthesis for the activation of carboxylic groups. Structurally, HOAt serves as an activating additive that forms reactive intermediates facilitating amide bond formation while mitigating side reactions such as racemization. As reported in experimental peptide coupling studies, combining HOAt with diisopropylcarbodiimide (DIC) promotes coupling reactions with improved retention of stereochemical integrity relative to traditional coupling systems utilizing other benzotriazole derivatives. HOAt is thus commonly used both in segment coupling and stepwise solid-phase peptide assembly methodologies aimed at synthesizing peptides requiring minimal epimerization.
Reference:
Carpino L A, El-Faham A. The diisopropylcarbodiimide/1-hydroxy-7-azabenzotriazole system: segment coupling and stepwise peptide assembly[J]. Tetrahedron, 1999, 55(22): 6813-6830.
- 1. Anjali Dixit, Brian M Paegel, et al. "Solid - phase DNA - encoded library synthesis: a master builder's instructions." Nat Protoc. 2025 May 22 PMID: 40404924
- 2. Kacy L Black, Ian K Webb, et al. "Development of Electrostatic-to-Covalent Gas Phase Cross-linkers for Protein Structure Measurements by Mass Spectrometry." J Am Soc Mass Spectrom. 2025 Mar 5;36(3):483-494. PMID: 39936477
| Physical Appearance | A solid |
| Storage | Desiccate at -20°C |
| M.Wt | 136.11 |
| Cas No. | 39968-33-7 |
| Formula | C5H4N4O |
| Solubility | ≥3.62 mg/mL in H2O with ultrasonic; ≥6.81 mg/mL in DMSO; ≥9.29 mg/mL in EtOH with ultrasonic |
| Chemical Name | 3-hydroxytriazolo[4,5-b]pyridine |
| SDF | Download SDF |
| Canonical SMILES | C1=CC2=C(N=C1)N(N=N2)O |
| Shipping Condition | Small Molecules with Blue Ice, Modified Nucleotides with Dry Ice. |
| General tips | We do not recommend long-term storage for the solution, please use it up soon. |
Quality Control & MSDS
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Chemical structure
