Backbone Modification using H-Phosphonates


Applicable Products

2005 dT-H Phosphonate, TEA Salt
2006 dG-H Phosphonate, TEA Salt
2007 dA-H Phosphonate, TEA Salt
2035 dC-H Phosphonate, DBU Salt

Please note that the liquid reagents used in H-phosphonate synthesis are unfortunately not available from Link Technologies.

Physical & Dilution Data

Dilution volumes (in ml) are for 0.1M solutions in dry acetonitrile/pyridine (1:1). Adjust accordingly for other concentrations. For µmol pack sizes, products should be diluted as 100µmol/ml to achieve 0.1M, regardless of molecular weight.


Mol. Formula

Mol. Wt.

Unit Wt.




2005 C37H48N3O9P 707.79 304.20 3.52 7.04 14.09
2006 C41H53N6O9P 804.89 329.21 3.11 6.21 12.42
2007 C44H51N6O8P 822.90 313.21 3.04 6.08 12.15
2035 C43H51N4O9P 849.93 289.18 2.94 5.88 11.77


All monomers must be dissolved in acetonitrile/ pyridine (1:1).

Coupling & Capping1

Normal deblock is used, however activation is carried out with 1-adamantane carbonyl chloride dissolved in acetonitrile/pyridine (95:5). Capping is carried out with the TEA salt of isopropyl phosphite.


There are two oxidation steps and they need only be carried out at the end of the synthesis. The first is accomplished using 0.1M iodine in pyridine/ N-methylimidazole/water/THF (5:1:5:89), and the second with 0.1M iodine in triethylamine/water/ THF (5:5:90).


Standard oligonucleotide deprotection conditions can be applied when deprotecting an oligo synthesised using these products.

Storage & Stability

Refrigerate monomers. Stability in solution is approximately 1 week.


  1. Novel activating and capping reagents for improved hydrogenphosphonate DNA synthesis, A. Andrus, J.W. Efcavitch, L.T. McBride and B. Giusti, Tetrahedron Lett., 29, 861-864, 1988.


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