title: New polycyclic diamine scaffolds from dimerization of 3-alkyl-1,4-dihydropyridines in acidic medium.
abstract: [reaction: see text] 3-Alkyl-1,4-dihydropyridines dimerize in acidic medium, at low temperature, to give polycyclic imminium salts derivatives that were reduced to afford new polycyclic diamine scaffolds. The reaction can be extended to enantiopure series starting from R-(+)- or S-(-)-1-phenylethylamine. Long exposure of the polycyclic imminium salt intermediates to air moisture at 20 degrees C resulted in formation of new amide derivatives. This is probably due to the addition of water followed by an intramolecular oxido-reduction process.
authors.affiliation: Institut de Chimie des Substances Naturelles, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Jakubowicz
authors.forename: Yung-Sing
authors.initials: YS
authors.lastname: Wong
authors.forename: Angèle
authors.initials: A
authors.lastname: Chiaroni
authors.forename: Michel
authors.initials: M
authors.lastname: Bénéchie
authors.forename: Christian
authors.initials: C
authors.lastname: Marazano