Synthesis and properties of oligonucleotides containing 4'-selenoribonucleosides

We report herein the synthesis and properties of oligonucleotides (ONs) containing 4'-selenoribonucleosides. 4'-Selenouridine derivative 1, prepared via the stereoselective seleno-Pummerer reaction, was converted into 4'-selenouridine 9 and -cytidine 10 phosphoramidites. The resulting 4'-selenouridine unit was stable under a standard phosphoramidite protocol including oxidation step and was able to be introduced in ONs (5'--3', and 5'--3'). This is the first example of ONs synthesis containing 4'-selenoribonucleosides.