Solvent-free synthesis of 2,4-diaryl substituted quinoline derivatives via a three-component one-pot procedure

In this paper, a solvent-free and efficient method for the synthesis of 2,4-diaryl substituted quinoline derivatives via a three-component one-pot procedure has been reported. Utilizing arylamines, aromatic aldehydes and aryl ethylenes as readily available starting materials, the imine intermediates were generated by arylamines and aromatic aldehydes which then reacted with aryl ethylenes via a 4+2 cycloaddition catalyzed by Lewis acid FeCl₃, providing 2,4-diaryl substituted quinoline derivatives. The reaction was a concise and interesting model, possessing high atomic economy, giving twelve 2,4-diaryl substituted quinoline compounds were synthesized at a yield of 82%−92%, which provided the basis for green preparation of quinoline compounds and activity screening. All products were characterized by ¹H NMR, ¹³C NMR and HRMS.