title: Intramolecular hetero Diels-Alder (Povarov) approach to the synthesis of the alkaloids luotonin A and camptothecin.
abstract: [reaction: see text] Pyrrolo[3,4-b]quinolines can be formed through the coupling of anilines with N-propargylic substituted heterocyclic aldehydes in the presence of mild Lewis acid catalysts (Ln(OTf)3). The coupling proceeds through sequential imine formation and a formal intramolecular aza-Diels-Alder (Povarov) reaction. This approach was applied in a total synthesis of luotonin A and a formal synthesis of camptothecin.
authors.affiliation: Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada.
authors.forename: Heather
authors.initials: H
authors.lastname: Twin
authors.forename: Robert A
authors.initials: RA
authors.lastname: Batey