A Diastereoselective Cascade Annulation Approach to Bridged Polycyclic Heterocycles Involving an Unexpected
Ali Nikbakht1, Ahmadreza Ebrahimi Valdani1, Hossein Zahedian Tejeneki1
1Peptide Chemistry Research Center, K. N. Toosi University of Technology, P.O. Box 15875-4416, Tehran 19697-64499, Iran.
Abstract:
A diastereoselective cascade annulation between allenoates and in-situ generated isoquinoline N-oxides generating sp3-rich bridged polycyclic heterocycles is disclosed. The reaction proceeds through an unprecedented non-rearomatized rearrangement and allows access to a broad range of bridged heterocycles in 38-93% yields with excellent functional group tolerance and high diastereoselectivity. Density functional theory calculations provided key insights into the possible reaction pathway and the stereoselectivity of this procedure.
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