Iterative Synthesis of Nucleoside Oligophosphates with Phosphoramidites


  • We are grateful to Prof. J. Siegel and Prof. J. Robinson for continuous support, and the NMR facilities at UZH (O. Zerbe). This work was supported by the Fonds der Chemischen Industrie (FCI, Liebig Stipend to H.J.J.) and the Swiss National Science Foundation (SNF, Ambizione Grant PZ00P2_136816 to H.J.J.).


P-Amidites can be used in iterative couplings to selectively give mixed PIII–PV anhydrides. These intermediates can be oxidized followed by a rapid removal of the two terminal fluorenylmethyl groups. An iterative synthesis (coupling, oxidation, deprotection) of nucleoside oligophosphates can be carried out in solution and on a solid support. The coupling rates and yields are high, the procedures convenient (non-dry reagents and solvents, ambient conditions, unprotected nucleotides), and the purification is very simple. The method works with all canonical nucleosides and holds promise for significant simplification of the usually cumbersome process of P-anhydride bond construction.