Nickel-Catalyzed Annulation of o-Haloarylamidines with Aryl Acetylenes: Synthesis of Isoquinolone and 1-Aminoisoquinoline Derivatives

An efficient method for the synthesis of substituted 1(2H)-isoquinolone derivatives via nickel-catalyzed annulation of substituted 2-halobenzamidines with aryl alkynes in the presence of water is described. Benzo[4,5]imidazo[2,1-a]isoquinolines were formed as the dominated products when dry dimethyl sulfoxide was used as the solvent. Furthermore, when benzyl substituted amidines were used as the substrates, debenzylation reaction occured to provide various 1-aminoisoquinoline products.