[Functionalization of oligonucleotides containing internucleotide phosphoamide bonds]

A new method for functionalization of oligonucleotides by addition of aminoalkyl derivatives to the intermolecular phosphorus atom of the oligonucleotide N3'-P5' phosphoramidate bond in the presence of triphenylphosphine, 4-dimethylaminopyridine, and 2,2'-dipyridyl disulfide was suggested. The reaction proceeded with both low-molecular alkylamines (1,6-diaminohexane or N,N-dimethyl-1,3-diaminopropane) and a ligand in minor groove containing a aminoalkyl group.