Mechanistic Aspects of Copper-Catalyzed Decarboxylative Coupling Reactions of (Hetero)Aryl Carboxylic Acids

Copper-catalyzed oxidative decarboxylative coupling reactions of benzoic acids have emerged as attractive routes to access functionalized arenes. Unfortunately, substrate scope limitations and forcing reaction conditions have prevented the widespread implementation of these methodologies. A mechanistic understanding of these systems could enable the development of more robust reactions, yet few studies have targeted the mechanistic elucidation of these complex systems. This article reviews the copper-catalyzed decarboxylation reactions of hetero(aromatic) acids, including protodecarboxylations, redox-neutral decarboxylative couplings, and oxidative decarboxylative coupling reactions. We emphasize the mechanistic insights learned from each system to build a framework for understanding copper-catalyzed decarboxylative coupling reactions.