Visible-Light-Promoted Dearomatization for The Construction of Imidazole Scaffolds

Abstract

Dearomatization is a powerful strategy for constructing complex carbocycles and heterocycles, though it typically relies on harsh conditions due to aromatic stability. Herein, a visible-light-driven photocatalytic dearomatization strategy for electron-poor imidazo[1,2-a]pyridines is reported, addressing a key limitation of current methods, which predominantly target electron-rich aromatic systems. Using α-keto acids as acyl radical precursors, this mild method enables the efficient synthesis of structurally diverse and functionalized imidazole derivatives, a privileged scaffold in pharmaceuticals and advanced materials. Some of the synthesized imidazoles display noteworthy photophysical properties. Some of the synthesized imidazoles show dual fluorescence from deep violet to greenish-cyan, highlighting potential as innovative fluorescent probes. This work expands the scope of dearomatization and provides a valuable tool for accessing new chemical space in drug discovery and materials science.