A New Synthesis for Imidazolo‐ and Pyrrolophanes by [3+2]Cycloaddition with Azaallenyl Radical Cations

Abstract

Imidazolophanes 3 bridged by short chains (n  5, 6) are readily accessible by [3 + 2] cycloadditions of imines with 2, formed from the bicyclic azirines 1 under electron-transfer conditions. Other heterocyclophanes can also be prepared by this method. DCN  naphthalene dicarbonitrile.