Synthesis of Disubstituted Imidazo[4,5-<i>b</i>]pyridin-2-ones

Regioselective palladium-catalyzed amination of 2-chloro-3-iodopyridine followed by a subsequent palladium-catalyzed amination leads to 2,3-diaminopyridines. Treatment with triphosgene affords highly functionalized unsymmetrical imidazo[4,5-<i>b</i>]pyridin-2-ones in just three synthetic steps. A two-step synthesis of pseudosymmetrically disubstituted imidazo[4,5-<i>b</i>]pyridin-2-ones, 1,4-disubstituted pyrido[2,3-<i>b</i>]pyrazinediones, and 1,3-disubstituted thiadiazolo[3,4-<i>b</i>]pyridin-2-ones is also described.