The synthesis and evaluation of a range of piperazino‐derivatized diastereomeric O2′,C3′‐linked bicyclic nucleotides are described. A new and optimized protocol is presented for the synthesis of the bicyclic scaffold on which the piperazino moiety is appended. At low salt concentration, the C2″‐S‐configured piperazino‐modified oligonucleotides display significantly enhanced hybridization affinity toward complementary DNA and RNA targets relative to the unmodified oligonucleotide control, whereas no melting transition is observed for hybrids formed with the C2″‐R‐configured piperazino‐modified oligonucleotides. Upon derivatization of the piperazino moiety with a 1‐pyrenebutanoyl group, all modified oligonucleotides display strong DNA binding and profound DNA hybridization selectivity.
Raunkjær, M., Haselmann, K., & Wengel, J. (2005). Oligodeoxynucleotides containing diastereomeric O2',C3'-linked bicyclic nucleotide units for functionalization of the major groove of nucleic acid duplexes: A summery and novel derivatives. Journal of Carbohydrate Chemistry, 24(4-6), 475-502. https://doi.org/10.1081/CAR-200067044