| Geodesic (bowl-shaped) polyarenes represent essential pieces in the realm of aromatic compounds, bridging the gap between planar polycyclic aromatic hydrocarbons (PAHs) and fullerenes. Their chemistry and properties are very intriguing and often atypical. The following is an account that describes new chemistry and ring annulations of corannulene, the smallest curved fullerene fragment.; Cycloaddition reactions of corannulene (Chapter 2) revealed an intriguing outcome in the addition of dihalocarbenes, i.e., fullerene-type products. However, other species (different carbenes, nitrenes, benzynes, dienophiles, 1,3-dipole, 1,3-diradicals, etc.) add predominantly at the perimeter double bond of corannulene or simply fail to react.; Chapter 3 describes the interactions of certain carbocations with corannulene that lead to products derived from electrophilic attack at an interior carbon atom of corannulene. This process may be the first example of such electrophilic attack in the realm of PAHs. A detailed mechanistic picture with factors that dictate substitution vs. addition is presented.; Chapter 4 presents synthetic efforts to extend the corannulene framework using six-membered ring annulations around the perimeter double bond. Further elaboration of the resulting compounds into tryptycene and helicene-type structures is also discussed.; A new methodology to synthesize indenoPAHs, that uses as the key step Flash Vacuum Pyrolysis (FVP), is described in Chapter 5. This two-step synthetic route allowed us to access new bowl shaped polyarenes (e.g., indenocorannulene, diindenocorannulenes, etc.) and to uncover examples of phenyl migrations in aryl diradicals.; Chapter 6 presents a study related to a new mechanistic link between alternant and non-alternant polyarenes at high temperatures: phenyl migration in dehydroPAHs.; Chapter 7 presents a new synthetic route towards benzo[ghi]fluoranthene-type polyarenes, a method that uses as the key step a cascade cyclization of dichlorostilbenes under FVP conditions. Applications of this method to the synthesis of new geodesic polyarenes is described.; Chapter 8 presents a new FVP “masked acetylene”: isopropenyl group. Synthetic applications toward fullerene fragments as well as possible further developments are described. |
