Iodine Mediated Annulation of Triethylamine, Aldehydes and 2‐Aminopyridines for the Synthesis of 3‐Formyl‐Imidazo[1,2‐a]pyridine Derivatives

With triethylamine as a synthon, an alternative method for the synthesis of 3‐formyl imidazo[1,2‐a]pyridines has been accomplished from aldehydes, and 2‐aminopyridines. The reaction proceeded via iodine‐catalyzed C−N bond cleavage of triethylamine, generation of α , β ‐unsaturated aldehyde in situ, and oxidative cyclization with air as the oxygen source. This protocol may facilitate the synthesis of imidazo[1,2‐a]pyridine derivatives and provide a reference for the usage of triethylamine as a synthon.