Enantioselective Assembly of Tricyclic Tetrahydroquinoline Derivatives

A three-step synthetic route towards enantioenriched tricyclic tetrahydroquinoline derivatives has been investigated. The first step involved the assembly of 4-amino-tetrahydroquinoline core through the asymmetric three-component Povarov reaction of benzyl (E)-prop-1-en-1-ylcarbamate and p-anisidine with aliphatic aldehydes of various length bearing protected hydroxyl group. The alcohol was then deprotected and employed in an intramolecular reaction with a secondary amine of tetrahydroquinoline moiety producing desired tricyclic scaffolds.