Nucleotide C3‘,4‘-Radical Cations and the Effect of a 2‘-Oxygen Substituent. The DNA/RNA Paradox

Chemistry of β-(Acyloxy)alkyl and β-(Phosphatoxy)alkyl Radicals and Related Species: Radical and Radical Ionic Migrations and Fragmentations of Carbon−Oxygen Bonds

“…138 The greatly diminished reactivity of RNA, as compared to DNA, with the Fe‚bleomycin complex 117,139 inspired Crich and Mo to investigate the reactivity of 337. 140 the methoxy group does not significantly affect the initial equilibrium (337/338 h 339/340) the methoxy group is seen to substantially reduce the rate constant (k frag ) for cleavage of the adduct 339 to the radical cation 341 with respect to that seen in the DNA model (340f342) through inductive destabilization of the polar transition state.…”

Acid‐Catalysed or Radical‐Promoted Allylic Substitution of 2‐Methylene‐2,3‐dihydrobenzofuran‐3‐ols with Thiol Derivatives: a Novel and Expedient Synthesis of 2‐(Thiomethyl)benzofurans

“…Direct fragmentation of II to give 3 and the hydroxyl radical HO · appears unlikely in view of the high instability of the latter species 6. Alternatively, intermediate II can undergo ionic fragmentation with elimination of HO – and formation of a radical cation species III 7,8. Deprotonation of the latter by HO – can then afford the stabilized radical species IV .…”

Reactivity of Nucleic Acid Radicals

“…106 The decrease in reactivity of 57 compared to the comparable DNA radical is modest compared to a related model study containing phosphate triesters (instead of phosphate diesters that are present in DNA and RNA) that was carried out in aqueous alcohol solvent (as opposed to H 2 O). 175 The modest difference in the rate constants for phosphate elimination from 57 compared to its DNA counterpart ( 44 , Scheme 24 ) was attributed to solvation of the radical cation by the aqueous solvent, such that the proximal 2′-hydroxyl group in RNA had a small effect on the intermediate’s stability. 174 …”