Bismuth(III)-catalyzed three-component selenation of imidazo[1,2-a]pyridines or related arenes with selenium and arylboronic acids.

Unsymmetrical diaryl selenides bearing heteroaromatic moieties have attracted increasing attention because of their notable biological activities. In this paper, a novel bismuth-catalyzed three-component reaction is reported for the synthesis of 3-selanylimidazopyridines from imidazopyridines, arylboronic acids, and elemental selenium. The reaction proceeded under aerobic conditions at 100 °C using BiI3 (10 mol %) as the catalyst, affording the desired products in moderate to good yields. The application of this method to other electron-rich arenes was also explored. This transformation represents the first example of a three-component reaction catalyzed by a bismuth reagent. The use of BiI3, a non-hygroscopic and low-toxicity catalyst, offers an alternative to traditional transition-metal-catalyzed systems.