Abstract
Monoconjugated and multiply conjugated oligonucleotides were efficiently synthesized by starting from monothiohexyl- or tetra-thiohexyl-oligonucleotides and treatment with acrylamide derivatives (carbohydrates, ferrocene, biotin, fluorescent dyes, deoxycholic acid). The thiol Michaeltype additions (TMTAs) occurred during the deprotection and release of the oligonucleotides from the solid support, so no additional time for conjugation was needed. Sequential combination either of Copper-catalyzed Azide-Alkyne Cycloaddition (CuAAC) on solid support and then TMTA or of TMTA followed by CuAAC in solution allowed the synthesis of several oligonucleotides decorated with two different biomolecules.