A New Arene Synthesis—Or: How Inert Is the Cyclopentadienyl Ligand?^†

A nice Cp recipe: The reaction of 1 with benzonitrile is a novel arene synthesis developed by Xi, Takahashi, and co-workers. Formally it is the breakdown of a cyclopentadienyl ligand into a C₂ fragment and a C₃ fragment which are then incorporated into a benzene and pyridine derivative, respectively. This synthetic variant has possible interesting applications in the preparation of oligoarenes.