Transition metal-free regioselective synthesis of 2-arylquinolines, benzo[h]quinolines, and pyrido[2,3-c]carbazoles and estimation of their photophysical properties

Abstract

A transition metal-free, iodine-catalyzed approach has been devised for the regioselective synthesis of diversely substituted 2-arylquinolines, benzo[h]quinolines, and pyrido[2,3-c]carbazole derivatives using β-chlorovinyl aldehydes as templates. The strategy has been found to be amenable to gram-scale synthesis, and its scope has been demonstrated with a library of 53 compounds with yields up to 95%. Operational simplicity, wide substrate scope, readily available starting materials, high efficiency, short reaction times, excellent yields, and metal-free conditions are the significant advantages offered by this strategy. The photophysical properties of all quinoline derivatives were also investigated, and excellent photophysical results were obtained with quantum yields (Φ_F) up to 36%.