Synthesis and characterization of various 5'-dye-labeled ribonucleosides.

Hitherto unknown chromophoric nucleosides are reported. This novel set of visibly coloured dye-labeled 5'-nucleosides, including 1,2,4,5-tetrazine, dicyanomethylene-4H-pyran, benzophenoxazinone, 9,10-anthraquinone and azobenzene chromophores, were prepared mainly under Cu-catalyzed azide-alkyne cycloaddition (CuAAC). The design criteria are outlined.