Cross-coupling of 2-methylquinolines and in-situ activated isoquinolines: Construction of 1,2-disubstituted isoquinolinones

In this study, a method was developed to form C(sp3)–C(sp2) bonds via copper catalyst-promoted cross coupling of 2-methylquinoline and in-situ-activated 3-haloisoquinoline under mild conditions. The multi-component tandem reaction was used to construct new C–N, C=O and C–C bonds in one pot via sequential functionalization of the N1, C3 and C1 positions of 3-haloisoquinoline. This method can be used to efficiently access 1,2-disubstituted isoquinolinones by the three-component reaction of 3-halogen isoquinoline, alkyl halide, and 2-methylquinoline.