Desymmetrization of cyclohexa-2,5-dienes through a diastereoselective protonation-hydroamination cascade

Org Lett. 2006 Oct 12;8(21):4755-8. doi: 10.1021/ol0618353.

Abstract

[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.