1,3-Diaryl-7-chloroimidazo[4,5-b]pyridinium Salts As Precursors for the Preparation of Decorated NHCs and M/NHCs

1,3-Diaryl-7-chloroimidazo[4,5-b]pyridinium salts were readily prepared via chlorination of their 7-hydroxy precursors with POCl3. Their utility as platforms for the synthesis of various decorated imidazo[4,5-b]pyridinium salts via nucleophilic substitution of the chlorine atom was demonstrated in the reaction with thiols. The obtained chloro- and sulfanyl-substituted compounds were employed as N-heterocyclic carbene (NHC) precursors for the preparation of novel M/NHC (M = Pd, Cu) complexes via C2–H bond metallation.