Stereoselective Synthesis of (5′S)-5′-C-(5-Bromo-2-penten-1-yl)-2′-deoxyribofuranosyl Thymine, a New Convertible Nucleoside

Pd0-Catalyzed Methyl Transfer on Nucleosides and Oligonucleotides, Envisaged as a PET Tracer

“…Finally, even a slight increase of the proportion of H 2 O was not appropriate at all (entry 10). After the achievement of the procedure optimization on the monomeric substrates, the last step was to test our best conditions on the dinucleotide 4 synthesized as a 70/30 mixture of diastereomers according to the standard phosphoramidite method from the 5'C-substituted nucleoside from 1b [19,20].…”

Oligonucleotide Labelling Using a Fluorogenic “Click” Reaction with a Hemicarboxonium Salt

“…The ODN2 and ODN4 derivatives were obtained by automated synthesis according to the standard phosphoramidite technology [20]. The primary alkylamine function of ODN2 was generated by displacement of the bromine of the convertible nucleoside during the ammonia treatment for the cleavage and protective groups removal of the oligonucleotide [21,22].…”

DNA Three Way Junction Core Decorated with Amino Acids-Like Residues-Synthesis and Characterization

“…It has been shown that such modifications including alkyl [31], allyl, hydroxypropyl or aminomethyl [32], within oligonucleotides induced significant loss in thermal stability of duplexes built with DNA counterparts. Only aminopropyl-aminopentenyl substituent [11] exhibited a slight improvement in the thermal stability that could be attributed to a favorable interaction of the protonated amino group with the opposite phosphate group. Here, we observed that the propargyl group destabilized the duplex formed with S 1 , S 2 and S 3 in comparison with unmodified duplex by 1 or 2 • C, and that was in accordance with the effect observed for alkyl or allyl substituted thymidine (Table 1).…”

“…5′-C-alkyl modifications could be introduced at any position within the ODN and are mostly investigated to enhance nucleic acids analogs stability against nucleases [10]. As the carbon in position 5′ is chiral, we focused our efforts towards the synthesis of the (5′S)-5′-C-modified epimer as we showed that this configuration allowed the pendent functionality to lie across the minor groove without altering significantly the Watson and Crick base pairing in duplexes [11]. Moreover, diverging from the concept of using rigid DNA duplex grooves as scaffold where chemical reactions could take place, 3WJ can be applied as a three-dimensional structure that is recognized to be flexible [12,13] and yet stable enough to accommodate modifications.…”