A practical route to 2-iodoanilines via the transition-metal-free and base-free decarboxylative iodination of anthranilic acids under oxygen

Abstract

A simple and practical procedure for synthesizing 2-iodoanilines has been developed. A series of highly regioselective 2-iodoanilines was obtained in satisfactory to good yields (of up to 90%) by carrying out the decarboxylative iodination of readily available anthranilic acids with inexpensive KI and I₂ as halogen donors under transition-metal-free and base-free conditions. Oxygen was shown to be necessary for the transformation. This practical decarboxylative iodination route was operationally scalable and shown to exhibit high functional-group tolerance. Control experiments suggested that a radical pathway was involved in the transformation.