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An organophotocatalytic late-stage N–CH(3) oxidation of trialkylamines to N-formamides with O(2) in continuous flow
We report an organophotocatalytic, N–CH(3)-selective oxidation of trialkylamines in continuous flow. Based on the 9,10-dicyanoanthracene (DCA) core, a new catalyst (DCAS) was designed with solubilizing groups for flow processing. This allowed O(2) to be harnessed as a sustainable oxidant for late-st...
Autores principales: | , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society of Chemistry
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8849051/ https://www.ncbi.nlm.nih.gov/pubmed/35308839 http://dx.doi.org/10.1039/d1sc05840a |
Sumario: | We report an organophotocatalytic, N–CH(3)-selective oxidation of trialkylamines in continuous flow. Based on the 9,10-dicyanoanthracene (DCA) core, a new catalyst (DCAS) was designed with solubilizing groups for flow processing. This allowed O(2) to be harnessed as a sustainable oxidant for late-stage photocatalytic N–CH(3) oxidations of complex natural products and active pharmaceutical ingredients bearing functional groups not tolerated by previous methods. The organophotocatalytic gas–liquid flow process affords cleaner reactions than in batch mode, in short residence times of 13.5 min and productivities of up to 0.65 g per day. Spectroscopic and computational mechanistic studies showed that catalyst derivatization not only enhanced solubility of the new catalyst compared to poorly-soluble DCA, but profoundly diverted the photocatalytic mechanism from singlet electron transfer (SET) reductive quenching with amines toward energy transfer (E(n)T) with O(2). |
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