Synthesis of isoquinolines by palladium-catalyzed cyclization, followed by a Heck reaction

A variety of 4-(1-alkenyl)-3-arylisoquinolines have been prepared by the Pd(II)-catalyzed cyclization of 2-(1-alkynyl)benzaldimines, followed by alkenylation (Heck reaction) in good to excellent yields. The introduction of an ortho-methoxy group on the benzaldimine promotes the Pd-catalyzed cyclization and stabilizes the resulting Pd(II) intermediate improving the yields of the desired isoquinoline products.