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

A transition metal-free, iodine-catalyzed approach has been devised for the regioselective synthesis of diversely substituted 2-arylquinolines, benzo[]quinolines, and pyrido[2,3-]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 () up to 36%.