Chiral Memory in Silylium Ions |
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Authors: | P Ducos Dr? V Liautard Dr? F Robert Prof?Dr? Y Landais |
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Institution: | Institute of Molecular Sciences, UMR‐CNRS 5255, University of Bordeaux 351, Cours de la libération 33405 Talence cedex (France) |
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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. |
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Keywords: | cations chirality H transfer silylium ions stereochemistry |
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