Synthesis of hexabenzotriphenylene and other strained polycyclic aromatic hydrocarbons by palladium-catalyzed cyclotrimerization of arynes

[GRAPHICS] To evaluate the potential of the recently developed palladium-catalyzed tri merization of arynes for the synthesis of strained polycyclic hydrocarbons, the trimerizations of 1,2-didehydronaphthalene (1) and 9,10-didehydrophena nthrene (2), generated from the corresponding o-trimethylsilylaryl triflate s 5 and 11, respectively, were studied. The synthesis of tribenzo[a,g,o]tri phenylene (6), tribenzo[a,g,m]triphenylene (7), and hexabenzo[a,c,g,i,m,o]t riphenylene (12) is described.