A variety of 4-(1-alkenyl)-3-arylisoquinolines have been prepared in moderate to excellent yields by the Pd (II)-catalyzed cyclization of 2-(1-alkynyl) arylaldimines in the presence of various alkenes. The introduction of an o-methoxy group on the arylaldimine promotes the Pd-catalyzed cyclization and stabilizes the resulting Pd (II) intermediate, improving the yields of the isoquinoline products. Ketone-containing isoquinolines 36 and 49-51 have also ...