Visible‐Light‐Triggered Quantitative Oxidation of 9,10‐Dihydroanthracene to Anthraquinone by O 2 under Mild Conditions

Autor: Mengke Chen, Yachun Liu, Anqun Su, Feng Mao, Chao Zhang, Bo Yang, Wenwei Hu, Zaihui Fu, Dulin Yin, Dabo Jiang
Rok vydání: 2020
Předmět:
Zdroj: ChemSusChem. 13:1785-1792
ISSN: 1864-564X
1864-5631
DOI: 10.1002/cssc.201903549
Popis: The development of mild and efficient processes for the selective oxygenation of organic compounds by molecular oxygen (O2 ) is key for the synthesis of oxygenates. This paper discloses an atom-efficient synthesis protocol for the photo-oxygenation of 9,10-dihydroanthracene (DHA) by O2 to anthraquinone (AQ), which could achieve quantitative AQ yield (100 %) without any extra catalysts or additives under ambient temperature and pressure. A yield of 86.4 % AQ was obtained even in an air atmosphere. Furthermore, this protocol showed good compatibility for the photo-oxidation of several other compounds with similar structures to DHA. From a series of control experiments, free-radical quenching, and electron paramagnetic resonance spin-trapping results, the photo-oxygenation of DHA was probably initiated by its photoexcited state DHA*, and the latter could activate O2 to a superoxide anion radical (O2 .- ) through the transfer of its electron. Subsequently, this photo-oxidation was gradually dominated by the oxygenated product AQ as an active photocatalyst obtained from the oxidation of DHA by O2 .- , and was accelerated with the rapid accumulation of AQ. The present photo-oxidation protocol is a good example of selective oxygenation based on the photoexcited substrate self-activated O2 , which complies well with green chemistry ideals.
Databáze: OpenAIRE
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