Selective Generation and Reactivity of 5-Adenosinyl and 2-Adenosinyl Radicals
| Autor: | Chryssostomos Chatgilialoglu, Maria Duca, Bernd Giese, Maurizio Guerra, Carla Ferreri, Harald Strittmatter, Marcella Ioele, Quinto G. Mulazzani |
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| Rok vydání: | 2004 |
| Předmět: |
Radical-nucleophilic aromatic substitution
Adenosine Radical substitution Free Radicals Molecular Structure Chemistry Radical Organic Chemistry Electrons General Chemistry Photochemistry Radical cyclization Catalysis Radiation Effects Kinetics Radical ion Cobalt-mediated radical polymerization Radical clock Radical disproportionation |
| Zdroj: | info:cnr-pdr/source/autori:Chryssostomos Chatgilialoglu, Maria Duca, Carla Ferreri,Maurizio Guerra, Marcella Ioele, Quinto G. Mulazzani, Harald Strittmatter, and Bernd Giese/titolo:Selective Generation and Reactivity of 5-Adenosinyl and 2-Adenosinyl Radicals/doi:/rivista:/anno:2004/pagina_da:1249/pagina_a:1255/intervallo_pagine:1249–1255/volume:10 |
| Popis: | The reaction of hydrated electrons (e(-)(aq) with 8-bromoadenosine 7 has been investigated by radiolytic methods coupled with product studies. Pulse radiolysis revealed that one-electron reductive cleavage of the C-Br bond gives the C8 radical 8 followed by a fast radical translocation to the sugar moiety. The reaction is partitioned between C5' and C2' positions in a 60:40 ratio leading to 5'-adenosinyl radical 9 and 2'-adenosinyl radical 11. This radical translocation from C8 to different sites of the sugar moiety has also been addressed computationally by means of DFT B3LYP calculations. In addition, ketone 21 was prepared and photolyzed providing an independent generation of C2' radical 11. Both C5' and C2' radicals undergo unimolecular reactions. Radical 9 attacks adenine with a rate constant of 1.0 x 10(4) s(-1) and gives the aromatic aminyl radical 10, whereas C2' radical 11 liberates adenine with a rate constant of 1.1 x 10(5) s(-1). |
| Databáze: | OpenAIRE |
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