Preparation of 2-arylquinolines from β-arylpropionitriles with aryllithiums and NIS through iminyl radical-mediated cyclization

Abstract

Treatment of β-arylpropionitriles with aryllithiums, followed by the reaction with water and then with NIS under irradiation with a tungsten lamp gave 2-arylquinolines in good to moderate yields. The present reaction proceeds through the formation of N-iodoimines from imines with NIS, the generation of imino-nitrogen-centered radicals, and their cyclization onto the aromatic rings of the imines to form 2-aryl-3,4-dihydroquinolines. Finally, the oxidation of 2-aryl-3,4-dihydroquinolines with NIS proceeds smoothly to generate 2-arylquinolines.