Efficient N-arylation and N-alkenylation of the five DNA/RNA nucleobases.
A general approach to N-arylation and N-alkenylation of all five DNA/RNA nucleobases at the nitrogen atom normally attached to the sugar moiety in DNA or RNA has been developed. Various protected or masked nucleobases engaged readily in the copper-mediated Chan-Lam-Evans-modified Ullmann condensation with a range of different boronic acids at room temperature and were subsequently converted to the corresponding deprotected or unmasked adducts. Different N(3)-protecting groups were examined in the case of thymine, where the benzoyl group afforded the highest yields. A 4-alkylthio-substituted pyrimidin-2(1H)-one served as both a cytosine and a uracil precursor and was N-arylated and N-alkenylated in high yields. Adenine was efficiently and selectively N-arylated and N-alkenylated at the N(9) position by employing a bis-Boc-protected adenine derivative, while a bis-Boc-protected 2-amino-6-chloropurine served as guanine precursor and could also be selectively N(9)-arylated and N(9)-alkenylated.
Jacobsen
Mikkel F
MF
Center for Catalysis and Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, University of Aarhus, Langelandsgade 140, 8000 Aarhus C, Denmark.
Knudsen
Martin M
MM
Gothelf
Kurt V
KV
D004247:DNA / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D012313:RNA / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
D012313:RNA; D004247:DNA