1,2-Disubstituted Benzimidazoles by the Iron Catalyzed Cross-Dehydrogenative Coupling of Isomeric o-Phenylenediamine Substrates
| العنوان: | 1,2-Disubstituted Benzimidazoles by the Iron Catalyzed Cross-Dehydrogenative Coupling of Isomeric o-Phenylenediamine Substrates |
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| المؤلفون: | Tam Tran, Brad S. Pierce, Frank W. Foss, P. Thapa, Philip M. Palacios |
| المصدر: | The Journal of Organic Chemistry. 85:1991-2009 |
| بيانات النشر: | American Chemical Society (ACS), 2020. |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | Benzimidazole, 010405 organic chemistry, Organic Chemistry, Intermolecular force, Aromatization, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, law.invention, Catalysis, chemistry.chemical_compound, chemistry, law, o-Phenylenediamine, Reagent, Oxidative coupling of methane, Electron paramagnetic resonance |
| الوصف: | Benzimidazoles are common in nature, medicines, and materials. Numerous strategies for preparing 2-arylbenzimidazoles exist. In this work, 1,2-disubstituted benzimidazoles were prepared from various mono- and disubstituted ortho-phenylenediamines (OPD) by iron-catalyzed oxidative coupling. Specifically, O2 and FeCl3·6H2O catalyzed the cross-dehydrogenative coupling and aromatization of diarylmethyl and dialkyl benzimidazole precursors. N,N'-Disubstituted-OPD substrates were significantly more reactive than their N,N-disubstituted isomers, which appears to be relative to their propensity for complexation and charge transfer with Fe3+. The reaction also converted N-monosubstituted OPD substrates to 2-substituted benzimidazoles; however, electron-poor substrates produce 1,2-disubstituted benzimidazoles by intermolecular imino-transfer. Kinetic, reagent, and spectroscopic (UV-vis and EPR) studies suggest a mechanism involving metal-substrate complexation, charge transfer, and aerobic turnover, involving high-valent Fe(IV) intermediates. Overall, comparative strategies for the relatively sustainable and efficient synthesis of 1,2-disubstituted benzimidazoles are demonstrated. |
| تدمد: | 1520-6904 0022-3263 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::c981abdf4ad5c8302a6c3b0b9fab48f4 https://doi.org/10.1021/acs.joc.9b02714 |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi...........c981abdf4ad5c8302a6c3b0b9fab48f4 |
| قاعدة البيانات: | OpenAIRE |
Find this issue from the American Chemical Society | تدمد: | 15206904 00223263 |
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