Light‐Induced Mechanistic Divergence in Gold(I) Catalysis: Revisiting the Reactivity of Diazonium Salts
| Autor: | Maximilian F. S. J. Menger, Matthias Rudolph, Frank Rominger, René Döpp, Martin N. Ackermann, A. Stephen K. Hashmi, Folkert de Vries, Johannes E. M. N. Klein, Svenja Taschinski |
|---|---|
| Přispěvatelé: | Molecular Inorganic Chemistry, Theoretical Chemistry, Faculty of Science and Engineering |
| Rok vydání: | 2019 |
| Předmět: |
vinyl gold intermediate
mechanistic divergence homogeneous gold catalysis Alkyne 010402 general chemistry Photochemistry 01 natural sciences Redox ARYLATIVE CYCLIZATION ALKYNE Catalysis PHOTOSENSITIZER-FREE Oxidation state OXIDATIVE ADDITION Reactivity (chemistry) Research Articles chemistry.chemical_classification photochemistry 010405 organic chemistry Photoredox catalysis PHOTOREDOX CATALYSIS ORGANOGOLD COMPOUNDS General Chemistry General Medicine ARYLDIAZONIUM SALTS Oxidative addition 0104 chemical sciences diazo compound BOND FORMATION chemistry DUAL GOLD Electrophile COMPLEXES Research Article |
| Zdroj: | Angewandte Chemie-International Edition, 58(7), 16988-16993. WILEY-V C H VERLAG GMBH Angewandte Chemie (International Ed. in English) |
| ISSN: | 1521-3757 0044-8249 1433-7851 |
| DOI: | 10.1002/ange.201908268 |
| Popis: | In a systematic study of the Au‐catalyzed reaction of o‐alkynylphenols with aryldiazonium salts, we find that essentially the same reaction conditions lead to a change in mechanism when a light source is applied. If the reaction is carried out at room temperature using a AuI catalyst, the diazonium salt undergoes electrophilic deauration of a vinyl AuI intermediate and provides access to substituted azobenzofurans. If the reaction mixture is irradiated with blue LED light, C−C bond formation due to N2‐extrusion from the diazonium salt is realized selectively, using the same starting materials without the need for an additional photo(redox) catalyst under aerobic conditions. We report a series of experiments demonstrating that the same vinyl AuI intermediate is capable of producing the observed products under photolytic and thermal conditions. The finding that a vinyl AuI complex can directly, without the need for an additional photo(redox) catalyst, result in C−C bond formation under photolytic conditions is contrary to the proposed mechanistic pathways suggested in the literature till date and highlights that the role of oxidation state changes in photoredox catalysis involving Au is thus far only poorly understood and may hold surprises for the future. Computational results indicate that photochemical activation can occur directly from a donor–acceptor complex formed between the vinyl AuI intermediate and the diazonium salt. The Au‐catalyzed reaction of o‐alkynylphenols with aryldiazonium salts undergoes a change in mechanism when a light source is applied. If the reaction is carried out at room temperature using a AuI catalyst, the diazonium salt undergoes electrophilic deauration of a vinyl AuI intermediate generating substituted azobenzofurans. If the reaction mixture is irradiated with blue LED light, C−C bond formation due to N2‐extrusion from the diazonium salt is observed. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
| Nepřihlášeným uživatelům se plný text nezobrazuje | K zobrazení výsledku je třeba se přihlásit. |