Easy introduction of maleimides at different positions of oligonucleotide chains for conjugation purposes

Abstract

[2,5-Dimethylfuran]-protected maleimides were placed at both internal positions and the 3′-end of oligonucleotides making use of solid-phase synthesis procedures. A new phosphoramidite derivative and a new solid support incorporating the protected maleimide moiety were prepared for this purpose. In all cases maleimide deprotection (retro-Diels-Alder reaction) followed by reaction with thiol-containing compounds afforded the target conjugate. © 2012 The Royal Society of Chemistry.