Friedel-Crafts Reaction of Arenes by Oxidatively Generated Metal Carbene: Divergent Synthesis of Polycyclic Aromatic Hydrocarbons via Controllable Cyclization of Ynones.

The Friedel-Crafts reaction of arenes by oxidatively generated α-oxo copper carbenes is disclosed for the first time, in which easily available ynones are transformed in one pot into polycyclic aromatic hydrocarbons through sequential oxidative copper catalysis and base-promoted cyclization, which is complementary to the traditional generation of copper carbenes from diazo compounds. Importantly, the replacement of traditional diazo substrates with ynones allows a safe and convenient procedure for the generation of copper carbenes. In addition, when the same ynones are employed as starting materials, benzoylbenzo[a]azulen-10(9aH)-ones bearing synthetically challenging quaternary carbons can be exclusively formed under gold catalysis.