A Potassium Base‐Promoted Intramolecular Enolate–Olefin Metathesis

Polycyclic aromatic hydrocarbons (PAHs) are important structures known for their unique properties. Herein, we present a transition‐metal‐free method for synthesizing hydroxy‐substituted PAHs using base‐promoted intramolecular enolate‐olefin‐metathesis chemistry. 2‐Acyl‐2′‐alkenylbiaryl substrates were subjected to [2 + 2]‐/retro‐[2 + 2]‐cycloaddition sequences to afford functionalized PAH derivatives, including enantiomerically enriched [7]helicenes. Density functional theory (DFT) calculations predicted that ionic and radical intermediates are involved in a stepwise process. Various biaryl substrates, including heteroatom‐containing compounds, were successfully converted into the desired PAHs. The developed method also enabled the synthesis of π‐extended arenols, thereby offering a sustainable and efficient alternative to transition‐metal‐catalyzed processes.