title: Synergistic Effect of the TiCl4/p-TsOH Promoter System on the Aza-Prins Cyclization.
abstract: A novel aza-Prins cyclization promoted by a synergistic combination between a Lewis acid and a Brønsted acid to efficiently afford piperidines is described. Contrary to what has been previously reported in the literature, the generality of the reaction employing N-alkyl, N-aryl, and nonprotected homoallylamines has been demonstrated. The reaction is highly diastereoselective depending on the homoallylic amine used, N-PMP homoallyl amine leading preferentially to the trans diastereomer, and free homoallylamine affording the deprotected piperidine as single cis diastereomer.
authors.affiliation: Université de Rennes 1, UMR CNRS 6226 , Institut des Sciences Chimiques de Rennes, Equipe PNSCM, UFR des Sciences Biologiques et Pharmaceutiques, 2 avenue du Prof Léon Bernard, Rennes F-35043 Cedex, France.
authors.forename: Vianney
authors.initials: V
authors.lastname: Durel
authors.affiliation: Université de Rennes 1, UMR CNRS 6226 , Institut des Sciences Chimiques de Rennes, Equipe PNSCM, UFR des Sciences Biologiques et Pharmaceutiques, 2 avenue du Prof Léon Bernard, Rennes F-35043 Cedex, France.
authors.forename: Claudia
authors.initials: C
authors.lastname: Lalli
authors.affiliation: Université de Rennes 1, UMR CNRS 6226 , Institut des Sciences Chimiques de Rennes, Equipe PNSCM, UFR des Sciences Biologiques et Pharmaceutiques, 2 avenue du Prof Léon Bernard, Rennes F-35043 Cedex, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Roisnel
authors.affiliation: Université de Rennes 1, UMR CNRS 6226 , Institut des Sciences Chimiques de Rennes, Equipe PNSCM, UFR des Sciences Biologiques et Pharmaceutiques, 2 avenue du Prof Léon Bernard, Rennes F-35043 Cedex, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: van de Weghe