1,3,5-Triazine-Mediated Electrochemical Carboxylation of Aryl Thianthrenium Salts with CO₂

A 1,3,5-triazine-mediated aryl anion-involved electrochemical carboxylation of aryl thianthrenium salts with CO₂ is developed, which provides a useful method for the rapid synthesis of aryl carboxylic acids. Mechanistic investigations and density functional theory calculations indicated that the 1,3,5-triazine radical anion is the key intermediate for reducing aryl radicals to aryl anions.