Polycyclic Aromatic Triptycenes: Oxygen Substitution Cyclization Strategies

The cyclization and planarization of polycyclic aromatic hydrocarbons with concomitant oxygen substitution was achieved through acid catalyzed transetherification and oxygen-radical reactions. The triptycene scaffold enforces proximity of the alcohol and arene reacting partners and confers significant rigidity to the resulting π-system, expanding the tool set of iptycenes for materials applications.Natural Sciences and Engineering Research Council of CanadaNational Institutes of Health (U.S.) (NIH BRP grant R01 AG026240-01A1)Natural Sciences and Engineering Research Council of Canada (NSERC) (Postdoctoral Fellowship)United States. Air Force Office of Scientific Research (FA9550-10-1- 0395

Practical synthesis and reactivity of [3]dendralene

(Chemical Equation Presented) Aconvenient and high-yielding three-step synthesis of the simplest branched triene, [3]dendralene, has been devised. The synthesis is robust and operationally simple, requiring no chromatography and involving no protecting groups or specialized equipment, allowing the synthesis of the volatile hydrocarbon in pure, solvent free form on a multigram scale. The stability, dimerization when stored neat, and Diels-Alder reactivity of [3]dendralene - including double cycloaddition sequences and catalytic enantioselective variant - are reported. © 2009 American Chemical Society