Synthesis and Structure of a Propeller-Shaped Polycyclic Aromatic Hydrocarbon Containing Seven-Membered Rings

The synthesis and structure of a <i>C</i>₃-symmetric propeller-shaped polycyclic aromatic hydrocarbon that bears three seven-membered rings is reported. The synthesis was accomplished in three steps from benzo­[<i>c</i>]­naphtho­[2,1-<i>p</i>]­chrysene, including a Pd-catalyzed intramolecular C–H arylation for the formation of the seven-membered rings. The combination of the helicities (<i>P</i>/<i>M</i>) of the three seven-membered-ring moieties and three [4]­helicene moieties affords 24 possible conformers, and two relatively stable conformations were observed by ¹H NMR spectroscopy

Synthesis and Structure of a Propeller-Shaped Polycyclic Aromatic Hydrocarbon Containing Seven-Membered Rings

The synthesis and structure of a <i>C</i>₃-symmetric propeller-shaped polycyclic aromatic hydrocarbon that bears three seven-membered rings is reported. The synthesis was accomplished in three steps from benzo­[<i>c</i>]­naphtho­[2,1-<i>p</i>]­chrysene, including a Pd-catalyzed intramolecular C–H arylation for the formation of the seven-membered rings. The combination of the helicities (<i>P</i>/<i>M</i>) of the three seven-membered-ring moieties and three [4]­helicene moieties affords 24 possible conformers, and two relatively stable conformations were observed by ¹H NMR spectroscopy