Oxidative Coupling of 4‐Hydroxycoumarins with Quinoxalin‐2(1 H )‐ones Induced by Visible Light under Aerobic Conditions
| Autor: | Loris Laze, Paula Romero, Irene Bosque, Jose C. Gonzalez‐Gomez |
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| Přispěvatelé: | Universidad de Alicante. Departamento de Química Orgánica, Universidad de Alicante. Instituto Universitario de Síntesis Orgánica, Nuevos Materiales y Catalizadores (MATCAT) |
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | European Journal of Organic Chemistry. 26 |
| ISSN: | 1099-0690 1434-193X |
| DOI: | 10.1002/ejoc.202201484 |
| Popis: | Direct and selective C(sp2)-H/C(sp2)-H cross-dehydrogenative coupling has become a promising strategy to increase molecular complexity with a high atom economy. This study describes an efficient and straightforward protocol for the regioselective C3-H/C3-H cross-coupling of 4-hydroxycoumarin derivatives with quinoxalin-2(1H)-ones, including late-stage modification of natural drugs, promoted by visible light under aerobic conditions at room temperature. With this approach, a wide range of hybrid drug-like molecules were prepared, using air as the terminal oxidant. Remarkably, the C4 OH group at the coumarin ring is essential for the reaction and has been used as a handle for diverse functionalizations of the final products. Moreover, sunlight can promote the reaction under very mild and sustainable conditions, even on a gram scale. Qualitative and semi-quantitative tools were used to demonstrate the greenness advance of this methodology over previously reported ones. Several experiments were conducted to propose a plausible mechanism for this transformation. This work was financially supported by the Spanish Ministerio de Ciencia e Innovación (grant no. CTQ2017-88171-P), Generalitat Valenciana (SEJIGENT/2021/005, granted to I. B.), and the University of Alicante (GRE20-03-A granted to I. B.). |
| Databáze: | OpenAIRE |
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