Attempted Synthesis of Bowl-Shaped Polycyclic Aromatic Hydrocarbons via Oxidative Electrocyclization. Products from the Dications of Dibenzo [g, p] chrysene, Tetrabenzo[5.5]fulvalene, and Diphenylmethylidenefluorene

Dications of Fluorenylidenes: Conformational and Electronic Effects on the Paratropicity/Antiaromaticity of Fluorenyl Cations with Cyclic Substituents

“…Olefin precursors 1 − 3 were prepared according to literature methods. − Olefin 4 was synthesized via Peterson olefination of 10,10-dimethylanthrone with fluorene. Olefin 5 was prepared from reaction of 2,3,6,7-dibenzocycloheptane-1-thione with diazofluorene, after the method of Schönberg et al Dications were formed via oxidation with a 30-fold excess of SbF 5 in SO 2 ClF at −78 or −90 °C …”

Dications of Fluorenylidenes. Electronic Effects on the Paratropicity/Antiaromaticity of Diphenylmethyl-Substituted Fluorenyl Cations

“…The progress of the oxidation was followed by 1 H and 13 C NMR spectroscopy at temperatures from −78 to −30 °C. For 4a , Y = H, the oxidation was so rapid that the 1 H NMR spectrum showed only a cyclized product, with no evidence of 4a 2+ . Oxidation of 4b − e with SbF 5 /SO 2 ClF resulted in formation of dications ( 4b 2+ − e 2+ ) whose 1 H NMR shifts at −50 °C are shown in Table along with the spectra of the neutral precursors .…”

Tailoring Diindenochrysene through Intramolecular Multi‐Assemblies by C−F Bond Activation on Aluminum Oxide

“…For example, 1 may react with electrophiles at the periphery as a conventional PAHs to give a product of S E Ar; alternatively, it also reacts in fullerene‐like (olefin) fashion with both nucleophiles and electrophiles through addition to the central double bond . Although 1 appears as an easy target molecule, there are only two currently published approaches allowing for its synthesis (Figure ) . The first has been reported by Scott and co‐workers, in which the flash vacuum pyrolysis approach was employed.…”

“…[1,17] Although 1 appearsasaneasy target molecule, there are only two currently publisheda pproaches allowing for its synthesis (Figure 1). [18][19][20][21][22] The first has been reported by Scott and coworkers, in which the flash vacuum pyrolysis approach was employed.A notherk nown pathway is based on intramolecular Pd-catalyzed aryl-arylc oupling. Both methods have some severel imitations, including low overall yields and moderate yields at the last step.…”