Palladium‐Catalyzed Cyclization of a Pyryne Precursor to Higher Pyrenylenes

The palladium catalyzed cyclotrimerization of ortho-silylaryl triflates as aryne precursors is meanwhile an established method to synthesize polycyclic aromatic hydrocarbons (PAHs) with triphenylene cores. During the palladium-catalyzed reaction a pyrene o-silylaryl triflate moiety in K-region higher homologues central eight- and ten-membered rings (the pyrenylenes) were found, besides expected trimer protocol was developed isolate all members this series. This unprecedented new class PAHs fully investigated by means, including X-ray diffraction single-crystals, UV/Vis fluorescence spectroscopy theoretical calculations. Supported density-functional theory (DFT) calculations, mechanism cyclooligomers proposed.