Pd/C-Catalyzed Dehydrogenative [3 + 2] Cycloaddition for the Synthesis of Dihydropyrrolo[2,1-a]isoquinolines

A Pd/C-catalyzed dehydrogenative [3 + 2] cycloaddition/oxidative aromatization cascade process for the synthesis of dihydropyrrolo[2,1-a] isoquinolines has been developed. Pd/C was employed as a reusable catalyst, enabling good yields of the desired products without the requirement for additional oxidants. Remarkably, after five cycles, the palladium catalyst preserved its catalytic efficiency. Moreover, this approach offers a succinct total synthesis of lamellarin G trimethyl ether.