title: Stereoselective Synthesis of Chiral Polycyclic Indolic Architectures through Pd(0) -Catalyzed Tandem Deprotection/Cyclization of Tetrahydro-β-carbolines on Allenes.
abstract: Enantioenriched N-allyl tetrahydro-β-carbolines were prepared by chiral phosphoric acid-catalyzed Pictet-Spengler reactions. The compounds undergo Pd(0) -catalyzed cyclizations through a tandem deprotection/cyclization process. The regioselectivity of the attack is controlled by the chain length and by the substitution pattern of the allene function. Products resulting from 5-exo- or 6-exo-attack were obtained with diastereoisomeric ratio up to 95:5. Azepinopyrrido[3,4-b]indoles were obtained by 7-endo-cyclizations.
authors.affiliation: Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette (France).
authors.forename: Valérian
authors.initials: V
authors.lastname: Gobé
authors.affiliation: Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette (France). xavier.guinchard@cnrs.fr.
authors.forename: Xavier
authors.initials: X
authors.lastname: Guinchard
keywords: alkaloids; allenes; enantioselectivity; nitrogen heterocycles; palladium