Use of Imidazo[1,2‐a]pyridine as a Carbonyl Surrogate in a Mannich‐Like, Catalyst Free, One‐Pot Reaction

Derivatization of imidazo[1,2‐ a ]pyridine scaffolds have gained considerable attention due to the biological significance of therapeutics based on the imidazopyridine core. By utilizing a catalyst‐free, “Mannich type” reaction, we developed a simple and efficient protocol to aminomethylate the C‐3 position of imidazo[1,2‐ a ]pyridine through a multicomponent, decarboxylation reaction involving imidazo[1,2‐ a ]pyridine, a secondary amine, and glyoxylic acid. The developed protocol requires mild reaction conditions and furnishes diverse imidazo[1,2‐ a ]pyridine analogues from commercially available starting materials. Additionally, the current protocol improves prior methods, which were limited by the amine substrate scope. Taken together, this current methodology permits rapid diversification of imidazo[1,2‐ a ]pyridines to enhance combinatorial efficiency in the drug discovery processes.