Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

IF 2.2 4区化学 Q2 CHEMISTRY, ORGANIC

Beilstein Journal of Organic Chemistry Pub Date : 2024-07-24 DOI:10.3762/bjoc.20.153

Hiwot M. Tiruye, Solon Economopoulos, Kåre B. Jørgensen

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Abstract

The electrochemical oxidation of polycyclic aromatic phenols (PAPs) has been developed in a microfluidic cell to synthesize polycyclic aromatic quinones (PAQs). Methanol was used as nucleophile to trap the phenoxonium cation formed in the oxidation as an acetal, that later were hydrolysed to the quinone. Formation of hydrogen gas as the cathode reaction caused challenges in the flow cell and were overcome by recycling the reaction mixture through the cell at increased flow rate several times. The specific quinones formed were guided by the position of an initial hydroxy group on the polycyclic aromatic hydrocarbon. An available para-position in the PAPs gave p-quinones, while hydroxy groups in the 2- or 3-position led to o-quinones. The substrates were analysed by cyclic voltammetry for estitmation of the HOMO/LUMO energies to shed more light on this transformation. The easy separation of the supporting electrolyte from the product will allow recycling and makes this a green transformation.

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Beilstein J. Org. Chem. 2024, 20, 1746–1757. doi:10.3762/bjoc.20.153

查看原文本刊更多论文

利用连续流电化学氧化法合成多环芳香族醌类化合物：多环芳香族苯酚（PAPs）的阳极甲氧基化反应

摘要在微流控芯片中开发了多环芳香族酚（PAPs）的电化学氧化，以合成多环芳香族醌（PAQs）。甲醇被用作亲核剂，将氧化过程中形成的苯氧阳离子捕获为缩醛，随后水解为醌。在阴极反应过程中形成的氢气给流动池带来了挑战，但通过多次提高流速使反应混合物在流动池中循环流动，克服了这一挑战。形成的特定醌类化合物取决于多环芳烃上初始羟基的位置。多环芳烃中的对位可产生对醌，而 2 或 3 位的羟基可产生邻醌。我们通过循环伏安法分析了底物的 HOMO/LUMO 能量，以进一步了解这种转化。支持电解质与产物的分离非常容易，因此可以循环利用，是一种绿色转化。Chem.2024, 20, 1746–1757. doi:10.3762/bjoc.20.153

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来源期刊

Beilstein Journal of Organic Chemistry 化学-有机化学

CiteScore

4.90

自引率

3.70%

发文量

167

审稿时长

1.4 months

期刊介绍： The Beilstein Journal of Organic Chemistry is an international, peer-reviewed, Open Access journal. It provides a unique platform for rapid publication without any charges (free for author and reader) – Platinum Open Access. The content is freely accessible 365 days a year to any user worldwide. Articles are available online immediately upon publication and are publicly archived in all major repositories. In addition, it provides a platform for publishing thematic issues (theme-based collections of articles) on topical issues in organic chemistry. The journal publishes high quality research and reviews in all areas of organic chemistry, including organic synthesis, organic reactions, natural product chemistry, structural investigations, supramolecular chemistry and chemical biology.