Electrochemical Di-functionalization: Oxidative Amination and Oxygenation of 4-Hydroxy-α-Benzopyrones under Ring Contraction

Abstract

We report a catalyst-free, singlet oxygen-mediated electrochemical rearrangement and di-functionalization protocol for the green synthesis of biorelevant 2-hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxamides from 4-hydroxy-α-benzopyrones. The transformation is carried out using lithium perchlorate as a cost-effective and eco-friendly electrolyte in a 1,4-dioxane:water solvent system at ambient temperature. The proposed mechanism is well supported by systematic control experiments. This one-pot strategy features a broad substrate scope, mild reaction conditions, and delivers good to excellent yields without the need for external catalysts. Key advantages of this method include operational simplicity, environmental sustainability, and high energy efficiency, making it a valuable addition to the toolbox of green synthetic methodologies.