Hidden Heptacyclic Chiral N-Acyl Iminium Ions: A New Entry to Enantioenriched Polycyclic Azepanes and Azocanes by Superacid-Promoted Intramolecular Pictet-Spengler Reaction

Chemistry. 2022 May 2;28(25):e202200432. doi: 10.1002/chem.202200432. Epub 2022 Mar 28.

Abstract

Enantioenriched complex fused-tricyclic azepanes or bridged-polycyclic azocanes were constructed via a two-step sequence involving an enantioselective organocascade followed by superacid activation of the domino adduct. The activated oxa-bridged azepane acts as a key hidden heptacyclic chiral N-acyl iminium ion triggering a chemo- and diastereoselective intramolecular mono- or di-arylation.

Keywords: N-acyliminium ion; azepane; azocane; organocatalysis; superacid.

MeSH terms

  • Ions
  • Stereoisomerism*

Substances

  • Ions