Total Synthesis of Iheyamine A via the Cyanide-Catalyzed Imino-Stetter Reaction.

The total synthesis of iheyamine A from readily available ethyl 2-aminocinnamate and 5-methoxyindole-2-carboxaldehyde is described. The cyanide-catalyzed imino-Stetter reaction of an aldimine derived from ethyl 2-aminocinnamate and 5-methoxyindole-2-carboxaldehyde provided the desired unsymmetrical 2,2'-bisindole-3-acetic acid derivative. The subsequent introduction of an amino group at the C-3' position, followed by the formation of the azepine ring, completed the total synthesis of iheyamine A.