Rapid Alternating Polarity-Enabled Electrochemical Decarboxylative Borylation of Aryl Carboxylic Acids

Abstract

Aromatic carboxylic acids are attractive feedstocks owing to their stability, commercial abundance, and widespread presence in pharmaceuticals and functional molecules. However, their direct decarboxylation under mild conditions has remained a longstanding challenge because of the slow fragmentation of aroyloxyl radicals and the prevalence of competing pathways. Herein, we report an electrochemical decarboxylative borylation of aryl carboxylic acids enabled by rapid alternating polarity (rAP) using reticulated vitreous carbon (RVC) electrodes. The protocol operates at ambient temperature without transition metals or external oxidants, delivering aryl boronic acid esters directly from abundant aromatic acid feedstocks. In addition to its synthetic utility, the method exhibits markedly lower energy intensity than previously reported photochemical decarboxylation platforms, highlighting its potential as a scalable and sustainable strategy for the direct conversion of abundant aromatic acid feedstocks into valuable organoboron building blocks.