We report the synthesis of (2-(N-acetylsulfamoyl)ethyl)carbamate (NAC)-linked thymidine dinucleotide via the sulfo-click reaction and its incorporation into DNA oligonucleotides. Thermal denaturation…

We report the synthesis of (2-(N-acetylsulfamoyl)ethyl)carbamate (NAC)-linked thymidine dinucleotide via the sulfo-click reaction and its incorporation into DNA oligonucleotides. Thermal denaturation ...

By applying the Liebeskind–Srogl cross-coupling reaction to pyrimidine nucleosides, a Pd(0)-catalyzed, Cu(I)-mediated process that effectively couples thioesters and boronic acids to form ketones, we previously described an efficient and easy access to 5′-C-acyl nucleosides. By reduction of the 5′-carbonyl group into a secondary alcohol, we report herein the synthesis of new 5′-C-aryl-5′-O-dimethoxytrityl-3′-O-phosphoramidite building blocks ready to be incorporated into oligonucleotides by automated synthesis. We describe the preparation of two sets of (R)- and (S)-diastereoisomers of 5′-C-phenylthymidine (PhT) and 5′-C-pyrenylthymidine (PyT), their conversion to phosphoramidites and incorporation into oligodeoxynucleotides (ODN). We also discuss the challenges faced by the synthesis of PyT-modified ODN, which required to modify the automated cycle to prevent backbone degradation in subsequent steps. The affinity and specificity of several 5′-C-aryl modified-ODN toward their complementary sequence were studied by UV-melting experiments. While thermal melting analysis failed to differentiate between matched and mismatched pairs, fluorescence measurements demonstrated that pyrenyl-modified ODN can effectively distinguish correct from incorrect base pairs. This highlights their potential use in the detection of genetic mutations through structural changes in DNA duplexes.

Antisense oligonucleotides (ASOs) can modulate gene expression at the mRNA level, providing the ability to tackle conventionally undruggable targets and usher in an era of personalized medicine. A key...

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