Electrochemical Synthesis of Polycyclic N‑Heteroaromatics through Cascade Radical Cyclization of Diynes

An electrochemical cyclization reaction
of easily available urea-tethered
diynes has been developed for the synthesis of nitrogen-doped polycyclic
aromatic hydrocarbons (PAHs). The employment of ferrocene as a mild
and selective redox catalyst allows access to a variety of electron-rich
PAHs including helicene-like structures without overoxidation. The
electrosynthetic method involves an unprecedented amidyl radical cascade
cyclization process to form three rings in a single operation.