Palladium-catalyzed cascade reactions of benzyl halides with N,N-diallyl-p-toluenesulfonamide

Reaction of N,N-diallyl-p-toluenesulfonamide 1 with benzyl halides 2 in the presence of a palladium catalyst afforded a series of novel dihydropyrroles 3 in moderate yields. A palladium-catalyzed self-cyclization reaction of the diene 1 may take place to give a cyclic dihydropyrrole 4 during the reaction. It is proposed that the cyclic products 4 are formed via a palladium-catalyzed cascade cyclization-coupling process. Reaction of phenyl iodide 5 with 1 in the same condition afforded normal Heck vinylation products 6