Domino Formation of Enamines - Intramolecular Cyclizations to 1-Aminotetralins from γ-Arylallene Aldehydes and Amines

1,5-/1,6-Allenals conjugated to an aromatic ring undergo a cyclization, in the presence of an amine, that leads to tricyclic compounds including the 1-aminotetralin scaffold. This domino process combines the in situ formation of the enamine and the cyclization affording the tricyclic 1-aminotetralins in very high diastereoselectivities.