title: Synthesis of the Azepinobisindole Alkaloid Iheyamine A Enabled by a Cross-Mannich Reaction.
abstract: The total synthesis of the azepinobisindole alkaloid iheyamine A is described. The successful strategy hinged on an intermolecular cross-Mannich reaction between 5-methoxy-3-acetoxyindole and a protected tryptamine to access an unsymmetrical 2,2'-bisindole, which was subsequently converted into iheyamine A via a deep-blue 3-indolone intermediate. VT1H NMR infers that iheyamine A exists as a mixture of tautomers that undergo intermediate chemical exchange on the NMR time scale. The intermolecular cross-Mannich reaction described herein is a viable alternative to metal-catalyzed cross-coupling strategies commonly employed to access 2,2'-bisindoles.
authors.affiliation: School of Chemical Sciences, University of Auckland , 23 Symonds Street, Auckland 1000, New Zealand.
authors.forename: Ashley C
authors.initials: AC
authors.lastname: Lindsay
authors.affiliation: School of Chemical Sciences, University of Auckland , 23 Symonds Street, Auckland 1000, New Zealand.
authors.forename: Ivanhoe K H
authors.initials: IKH
authors.lastname: Leung
authors.affiliation: School of Chemical Sciences, University of Auckland , 23 Symonds Street, Auckland 1000, New Zealand.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Sperry