Site-Selective Electrochemical C-H Carboxylation of Arenes with CO2

Angew Chem Int Ed Engl. 2023 Jan 16;62(3):e202214710. doi: 10.1002/anie.202214710. Epub 2022 Dec 7.

Abstract

Herein, a direct, metal-free, and site-selective electrochemical C-H carboxylation of arenes by reductive activation using CO2 as the economic and abundant carboxylic source was reported. The electrocarboxylation was carried out in an operationally simple manner with high chemo- and regioselectivity, setting the stage for the challenging site-selective C-H carboxylation of unactivated (hetero)arenes. The robust nature of the electrochemical strategy was reflected by a broad scope of substrates with excellent atom economy and unique selectivity. Notably, the direct and selective C-H carboxylation of various challenging arenes worked well in this approach, including electron-deficient naphthalenes, pyridines, simple phenyl derivatives, and substituted quinolines. The method benefits from being externally catalyst-free, metal-free and base-free, which makes it extremely attractive for potential applications.

Keywords: CO2 Valorization; Carbon Dioxide; C−H Carboxylation; Electroreduction; Selectivity.