Visible‐Light‐Catalyzed Formal [3+2] Annulation‐Aromatization of Amidines with Isoquinolinium N‐Ylides: Access to Imidazo[2,1‐a]isoquinolines

Abstract A visible‐light‐catalyzed formal [3+2] annulation‐aromatization reaction for the synthesis of various substituted imidazo[2,1‐ a ]isoquinolines from amidines with stabilized isoquinolinium N ‐ylides in the presence of bases is developed. The procedure reported here involves a direct C−H activation and the formation of C−C/C−N bonds in one‐pot. The reaction mechanism is probed by radical‐trapping experiment, fluorescence quenching, and light on/off experiments. The late‐stage modification experiments provide the potential applications in the field of organic and medicinal chemistry for chemists.