J. Baraniak et al., NEW APPROACH TO THE SOLID-PHASE SYNTHESIS OF N3'-]P5' PHOSPHORAMIDATEOLIGONUCLEOTIDES, Nucleosides & nucleotides, 17(8), 1998, pp. 1347-1353
LCA-CPG-nucleoside 5'-O-(O-beta-cyanoethyl-H-phosphonates) react with
3'-amino-2',3'-dideoxynucleoside in the presence of iodine giving in a
high yield N3'-->P5' phosphoramidate oligonucleotides.