Synthesis of heterosubstituted hexaarylbenzenes via asymmetric carbonylative couplings of benzyl halides.

[structure: see text]. Asymmetric carbonylative couplings of benzyl halides have been shown to give heterosubstituted 1,3-diarylacetones in moderate to high yields. These asymmetric ketones were converted via Knoevenagel condensations to tetraarylcyclopentadienones, and further conversion via dehydro-Diels-Alder cycloadditions gave highly heterofunctionalized hexaarylbenzenes with uniquely functionalized aryl groups at the para positions of the central benzene. This method allows control of the substituents on each of four unique pendent aryl group positions, giving rise to substitution patterns not available using symmetrical 1,3-diarylacetones.