Nitrogen Position Matters: Synthetic Strategies, Functional Behavior and Dual Roles in Medicine and Materials in the Imidazopyridine Family

Imidazopyridines are a versatile class of nitrogen-fused heterocycles bridging medicinal chemistry and materials science. Their π-conjugated framework allows broad structural tuning, yielding diverse biological and photophysical properties. The best-known isomers, imidazo[1,2-a]pyridine and imidazo[1,5-a]pyridine, have been widely studied as pharmacophores and luminescent materials, respectively. The less explored imidazo[4,5-b] and imidazo[4,5-c]pyridines are now emerging as alternative scaffolds with distinctive electronic and functional behavior. This review summarizes synthetic strategies, electronic features, and key applications—from kinase inhibition and antiviral activity to fluorescence imaging, down-conversion, Organic Light Emitting Diode (OLED)/Light-emitting Electrochemical Cell (LEC) and hybrid optoelectronic systems—outlining how imidazopyridines can evolve from molecular frameworks into multifunctional platforms for bioimaging and advanced optoelectronic technologies.