Corannulenes indenocorannulenes

In contrast to the FVP synthesis of indenocorannulene (98) from phenyl-corannulene, the fluoro-substituted analogue 29 (X=F) turns out to be very efficient [126] (Scheme 28). Catalytic cyclization is initiated by reaction of a silyl cation with an aryl fluoride to generate a phenyl cation and, subsequently, Friedel-Crafts reaction to an intramolecular aryl coupling, flowed by deprotonation, to give 98, The enabling feature of this reaction is the exchange of carbon-fluorine for sihcon-fluoiine bond enthalpies. 

The PAHs indenocorannulene (39), dibenzo[a,g]corannulene (40), and diben-zo[o,g]cyclopenta[h,I]corannulene (41) are three examples of extended corannulenes, which contain a central corannulene system fused to five- and six-membered rings. The reduction of these systems [119, 120] focused on the following issues. First, what is the aromaticity of these curved PAHs anions, will they behave like large polycyclic systems, or have aimulenic character Secondly, what is the possibility of aggregation and dimerization in these systems The third subject of interest was the effect of different alkali metals on the reduction process. 

Densely substituted fluoranthenes and indenocorannulenes were synthesized by RhCl(PPh3)3-catalyzed [2-t-2-1-2] cycloaddition of peri-dialkynyl naphthalenes and corannulenes with alkynes and norbornadiene (Scheme 4.29) [36], A highly curved buckybowl containing a corannulene fragment could also be synthesized via RhCl(PPh3)3-catalyzed [2 - - 2 - - 2] cycloaddition (Scheme 4.30) [37],... 

The corannulenes are the simplest examples of compounds with a curved surface. They include fluoranthenes that are important synthetic intermediates in the construction of corannulenes and their derivatives. Indenofluoranthenes have a curvature of a higher order due to the inclusion of two 5-membered rings. Methods for the synthesis of fluoranthenes from naphthalene and indenocorannulenes from corannulenes offer approaches to the formation of high-order spherical and tubular structures. 

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