Résumé
DAST and Deoxofluor are usually used for nucleophilic fluorination of nucleosides via SN1 or SN2 mechanism. DAST and Deoxo-fluor could enhance anomerization of N-substituted thymidine and 2′-deoxyuridine in dichloromethane into the more stable and favored α-anomers due to in-situ liberation of HF. This is strongly supported by computational calculations based on the density functional theory, that were performed to rationalize energy stability and electronic properties of both anomers in order to provide further insights into the proposed mechanism.