Desymmetrization of cyclohexa-2,5-dienes through a diastereoselective protonation-hydroamination cascade.
[reaction: see text] Intramolecular hydroamination of cyclohexa-2,5-dienes led with high selectivity to the corresponding bicyclic allylic amines. This study demonstrates that the reaction does not proceed through a direct hydroamination of one of the diastereotopic olefins but more likely involves a diastereoselective protonation of a pentadienyl anion, followed by addition of a lithium amide across the double bond of the resulting 1,3-diene, and is concluded by a highly regioselective protonation of the final allylic anion.
Lebeuf
Raphaël
R
University Bordeaux-1, Laboratoire de Chimie Organique et Organométallique, 351, Cours de la Libération, 33405 Talence Cedex, France.
Robert
Frédéric
F
Schenk
Kurt
K
Landais
Yannick
Y