Iron Catalyzed [3+2] Cycloaddition of Tetrahydroisoquinoline: Synthesis of Dihydropyrrolo[2,1-a]isoquinolines

We have developed an iron(III) chloride hexahydrate catalyzed formal [3+2] cycloaddition of tetrahydroisoquinolines with amide group-bearing Morita-Baylis-Hillman (MBH) carbonates. A range of highly functionalized dihydropyrrolo[2,1-a]isoquinolines could be prepared through SN2'/oxidation/electrocyclization/aromatization cascade (32-62% yield).