Alternative mechanisms of electrophilic substitution in azole series
- Autores: Belen’kii L.1, Chuvylkin N.1
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Afiliações:
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences
- Edição: Volume 65, Nº 6 (2016)
- Páginas: 1441-1447
- Seção: Reviews
- URL: https://journals.rcsi.science/1066-5285/article/view/238372
- DOI: https://doi.org/10.1007/s11172-016-1471-3
- ID: 238372
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Resumo
Data on three mechanisms of aromatic electrophilic substitution in azole series have been presented. First of them is similar to an ordinary addition–elimination mechanism including the formation of a cationic σ-complex (Wheland intermediate). The second mechanism is realized according to the elimination–addition scheme and includes a protonation or a formation of a complex on the “pyridine” N atom, proton abstraction from the C atom adjacent to the above N atom, and addition of a cationoid reagent to the ylide (carbene) formed. The third mechanism proposed by the present authors can be realized for azoles having three and two N atoms of the pyridine type. It does not require the preliminary N-protonation or complex formation and occurs due to a strong electron withdrawing effect of several “pyridine” atoms, resulting in the CH-deprotonation followed by the interaction of the carbanion formed with a cation under mild conditions.
Sobre autores
L. Belen’kii
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences
Autor responsável pela correspondência
Email: libel31@mail.ru
Rússia, 47 Leninsky prosp., Moscow, 119991
N. Chuvylkin
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences
Email: libel31@mail.ru
Rússia, 47 Leninsky prosp., Moscow, 119991