title: Chiral Memory in Silylium Ions.
abstract: The configurational stability of the chiral silicon center in Lewis base-stabilized silyliums has been studied. Complete retention of configuration at silicon is observed at low temperature in silylium ions stabilized by lone-pair interactions. In contrast, loss of chiral memory is observed with systems involving π-interactions. Epimerization of the silicon center was observed by simply allowing equilibration of the diastereomeric silyliums at RT or by adding a catalytic amount of a chelating solvent. Conditions for the transfer of axial chirality to Si-centered chirality were shown to rely on the strength of the Lewis base-silylium ion interaction.
authors.affiliation: Institute of Molecular Sciences, UMR-CNRS 5255, University of Bordeaux 351, Cours de la libération 33405 Talence cedex (France).
authors.forename: P
authors.initials: P
authors.lastname: Ducos
authors.affiliation: Institute of Molecular Sciences, UMR-CNRS 5255, University of Bordeaux 351, Cours de la libération 33405 Talence cedex (France).
authors.forename: V
authors.initials: V
authors.lastname: Liautard
authors.affiliation: Institute of Molecular Sciences, UMR-CNRS 5255, University of Bordeaux 351, Cours de la libération 33405 Talence cedex (France). f.robert@ism.u-bordeaux1.fr.
authors.forename: F
authors.initials: F
authors.lastname: Robert
authors.affiliation: Institute of Molecular Sciences, UMR-CNRS 5255, University of Bordeaux 351, Cours de la libération 33405 Talence cedex (France). y.landais@ism.u-bordeaux1.fr.
authors.forename: Y
authors.initials: Y
authors.lastname: Landais
keywords: H transfer; cations; chirality; silylium ions; stereochemistry