Expanded‐Ring and Backbone‐Functionalised N‐Heterocyclic Carbenes

Abstract

Abstract An unsaturated seven‐membered amidinium salt 7 decomposes in the presence of metal salts under basic conditions. However, 7 readily forms a Diels–Alder cycloadduct with CpH from which the Rh I complexes may be prepared. Thus, structurally elaborate, sterically crowded carbene ligand complexes bearing peripheral unsaturated functionality are available in a short versatile synthesis.