Regioselective Cross-Coupling Reactions of Benzoylquinolines: C–N, C–C and C–P Bond Formation

Regioselective cross-coupling reactions were performed using benzoylquinolines and cobalt(II) salts as catalysts, as well as manganese(III) acetate as an oxidant. Products of C–C (with 2-phenylpyridine), C–N (with morpholine) and C–P (with diphenylphosphine oxide) coupling were obtained and characterized using X-ray diffraction analysis, cyclic voltammetry, 1H NMR, 13C NMR spectroscopy, and ESI–MS. The electrochemical studies of benzoylquinolines and their products revealed the reaction pathways and factors affecting product yields. The cobalt catalyst directs the reaction to the ortho position of the phenyl ring in benzoylquinoline when coupled with morpholine or 2-phenylpyridine. Diphenylphosphine oxide, on the other hand, is active at the position 5 of the quinoline ring.