TCO-NHS Ester (axial) (CCT-1509)


TCO-NHS Ester is an amine-reactive building block used for modification of amine-containing molecule in organic media. TCO-NHS ester is supplied as a single axial (minor, rel-(1S-2S-5E-pS), ref 1 and 4) diastereomer. Specially formulated crystalline provides easy handling and extended shelf life.

Axial TCO derivatives demonstrate much higher reactivity in the inverse electron demand cycloaddition reaction compared to equatorial TCO derivatives. Up to 10-fold increase in reactivity was reported (ref 4) compared to equatorial TCO derivatives. At the same time, the axial TCO derivatives undergo cis-trans deactivation at faster rate compared to equatorial TCO derivatives (ref 4).


Unit Size25 mg, 100 mg, 1000 mg
Molecular weight267.28
Chemical compositionC13H17NO5
SolubilityDMSO, DMF, DCM, THF, Chloroform
Purity>95% (HPLC)
AppearanceWhite to slightly grey crystalline
Storage Conditions-20°C. Desiccate
Shipping ConditionsAmbient temperature

Selected References

  1. Royzen, M., et al. (2008). A Photochemical Synthesis of Functionalized trans-Cyclooctenes Driven by Metal Complexation. J. AM. CHEM. SOC., 130: 3760-1. [PubMed]
  2. Blackman, M.L., et al. (2008). Tetrazine ligation: fast bioconjugation based on inverse-electron-demand Diels-Alder reactivity. J. AM. CHEM. SOC., 130: 13518-9. [PubMed]
  3. Rahim, M.K., et al. (2015). Enhancing Reactivity for Bioorthogonal Pretargeting by Unmasking Antibody-Conjugated trans-Cyclooctenes. Bioconjugate Chem., 26: 352-60. [PubMed]
  4. Rossin, R., et al. (2013). Highly Reactive trans-Cyclooctene Tags with Improved Stability for Diels−Alder Chemistry in Living Systems. Bioconjugate Chem., 24: 1210-7. [PubMed]

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