A facile synthesis of 2-azidoadenosine derivatives from guanosine as photoaffinity probes

Purine Nucleosides with a Reactive (β‐Iodovinyl)sulfone or a (β‐Keto)sulfone Group at the C8 Position and Their Polymerase‐Catalyzed Incorporation into DNA

“…Use of polar solvents to improve solubility of 1 a (entry 3) or adding weak bases to avoid cleavage (entry 4) were ineffective. We found, however, that iodosulfonylation [41] of 1 b with molecular I 2 and sodium p-toluenesulfinate (TsNa) in the presence of NaOAc (CH 3 under mild desilylation conditions [42] (NH 4 F/MeOH/60 °C) led to the formation of the 8-(β-aminovinyl)sulfone 6 a (50%) as a single Z isomer instead of 4 a. The Z stereochemistry of 6 a was tentatively assigned based on the 1 H NMR spectra in agreement with the literature precedents [36,38,43,44] and can be explained by stabilizing intramolecular H-bonding between amine and the sulfone group.…”

“…Modified nucleosides received great attention because of their potential to function as anticancer and antiviral therapeutics. [1,2] Nucleosides with modified purine bases bearing reactive groups such as azide, [3,4] alkene, [5,6] alkyne, [6] aldehyde [7] or radical precursors [8][9][10] have been explored for imaging cellular DNA, bioconjugation with DNA-bound proteins, DNA damage repair, and applications in the fluorescent bioanalysis [2,11] of DNA and RNA. The 5' triphosphate or 3' phosphoroamidite of these probes were incorporated into oligonucleotides (ON) by DNA/ RNA polymerases [6,12,13] or solid-phase synthesis.…”

Azido/Tetrazole Tautomerism in 2‐Azidoadenine β‐D‐Pentofuranonucleoside Derivatives

“…Syntheses of 2-azidoadenosine (6) [7] and 2-azido-2Ј-deoxyadenosine (7), [6] starting from a 2-amino-6-chloropurine riboside derivative or 2Ј-deoxyguanosine by treatment with trimethylsilyl azide in the presence of isoamyl or butyl nitrite, respectively, have been reported previously. For our purposes, we chose to synthesize the 2-azidoadenine nucleoside derivatives from their 2-chloro counterparts (Scheme 1).…”

“…However, the 1 H and 13 C NMR spectra in each case show the presence of two compounds, implying the existence of tautomeric forms of the 2-azidoadenine nucleoside derivatives. It is noteworthy that the existence of such tautomeric forms has also been mentioned in the cases of the previously reported compounds 6 [7] and 7. [6] Indeed, azido-substituted π-deficient nitrogen heterocycles with an azido group attached to a carbon atom adjacent to an annular nitrogen atom may spontaneously cyclize to give a fused tetrazole ring, or at least an equilibrium mixture of both forms.…”

Inhibition of Siderophore Biosynthesis by 2-Triazole Substituted Analogues of 5′-O-[N-(Salicyl)sulfamoyl]adenosine: Antibacterial Nucleosides Effective against Mycobacterium tuberculosis

“…21 Methanolysis of 7 followed by acetonide protection furnished 9 , which was sulfamoylated to provide 10 22. Copper catalyzed coupling of 2-iodoadenosine derivative 8 23 with sodium azide provided an alternate route to compound 9 24…”