2-Bromoanthraquinone as a highly efficient photocatalyst for the oxidation of sec-aromatic alcohols: experimental and DFT study. Issue 61 (7th October 2020)

• Record Type: Journal Article
• Authors: Liao, Shengfu; Liu, Jianguo; Yan, Long; Liu, Qiying; Chen, Guanghui; Ma, Longlong
• Is Part Of: RSC advances. Volume 10:Issue 61(2020)
• Page Start: 37014
• Page End: 37022
• Publication Date: 2020-10-07
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0ra06414a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Anthraquinones are recognized as high efficiency photocatalysts which can perform various redox reactions in aqueous or organic phases. Abstract : Anthraquinones are recognized as high efficiency photocatalysts which can perform various redox reactions in aqueous or organic phases. We have experimentally proven that 2-BrAQ can undergo hydrogen transfer with an alpha-aromatic alcohol under light conditions, thereby efficiently oxidizing the aromatic alcohol to the corresponding product. The yield of 1-phenethanol to acetophenone can reach more than 96%. In subsequent catalyst screening experiments, it was found that the electronegativity of the substituent at the 2 position of the anthraquinone ring and the acidity of the solvent affect the photocatalytic activity of anthraquinones. After using various aromatic alcohol substrates, 2-BrAQ showed good conversion and selectivity for most aromatic alcohols, but showed C–C bond cleavage and low selectivity with non-α-position aromatic alcohols. In order to explore the mechanism of the redox reaction of 2-BrAQ in acetonitrile solution, the corresponding free radical reaction pathway was proposed and verified by density functional theory (DFT). Focusing on calculations for 2-BrAQ during the reaction and the first-step hydrogen transfer reaction between the 2-BrAQ triplet molecule and the 1-phenylethanol molecule, we recognized the changes that occurred during the reaction and thus have a deeper understanding of the redox reaction of anthraquinone compounds in organic systems.