Palladium-catalyzed direct carboxylation of aryl bromides with carbon dioxide

A novel protocol for the direct carbon dioxide insertion (CO₂) into aryl halides in a catalytic manner is presented herein. Unlike other carboxylation methods using CO₂, there is no need for the synthesis of the corresponding organometallic intermediates. Additionally, and in contrast to the well-established carbonylation processes, our protocol does not use highly toxic CO for the preparation of benzoic acids. Furthermore, this method is distinguished by its mild conditions, allowing the tolerance of a wide range of functional groups and substitution patterns. The crucial step of the process involves a challenging catalytic CO₂ insertion into Pd-C bonds.