Regioselective functionalization of quinolin-4(1H)-ones via sequential palladium-catalyzed reactions

A practical and general synthesis of 1,3,6-trisubstituted quinolin-4(1H)-ones starting from 1-alkyl-6-bromo-3-iodoquinolin-4(1H)-one is described, based on regioselective sequential palladium-catalyzed cross-coupling reactions, namely Suzuki–Miyaura, Sonogashira and aminocarbonylation reactions, under microwave irradiation. Good substrate generality, ease of execution and practicability make this method exploitable for the generation of libraries of chemically diverse 4-quinolones.