Stereoselective Synthesis of Indoline, Tetrahydroquinoline, and Tetrahydrobenzazepine Derivatives from o-Bromophenyl N-tert-Butylsulfinyl Aldimines

The diastereoselective addition of an allylic indium intermediate to chiral o-bromophenyl sulfinyl imine 4 proceeded with good levels of diastereoselectivity. The resulting homoallylic amine derivatives were transformed into lactams 7 and 12, which upon copper-mediated intramolecular N-arylation led to the formation of benzo-fused 1-azabicyclo[j.k.0]alkanes 8 and 13. Benzo-fused 2-allyl-substituted heterocycles 14 could also be prepared by means of a palladium-catalyzed N-arylation of the corresponding free amines. The synthesis of the alkaloid (-)-angustureine was easily accomplished from (S)-2-allyltetrahydroquinoline (14b).