Synthesis of Dibenzo[h,rst]pentaphenes and Dibenzo­[fg,qr]­pentacenes by the Chemoselective C–O Arylation of Dimethoxy­anthraquinones

A convenient method for the syntheses of dibenzo­[h,rst]­pentaphenes and dibenzo­[fg,qr]­pentacenes via the ruthenium-catalyzed chemoselective C–O arylation of 1,4- and 1,5-dimethoxy­anthra­quinones is described. Dimethoxy­anthraquinones reacted selectively with arylboronates at the ortho C–O bonds to give diarylation products. An efficient two-step procedure consisting of a Corey–Chaykofsky reaction and subsequent dehydrative aromatization afforded derivatives of dibenzo­[h,rst]­pentaphenes and dibenzo­[fg,qr]­pentacenes. Hole-transporting characteristics were observed for a device with a bottom-contact configuration that was fabricated from one of these polycyclic aromatic hydrocarbons.