Sequential Oxidative Transformation of Tetraarylethylenes to 9,10-Diarylphenanthrenes and Dibenzo[g,p]chrysenes using DDQ as an Oxidant

Tetraarylethylenes can be sequentially transformed into 9,10-diarylphenanthrenes and dibenzo[g,p]chrysenes using 1 and 2 equiv of DDQ, respectively, in CH(2)Cl(2) containing methanesulfonic acid, in excellent yields. Efficient access to substituted dibenzochrysenes from tetraarylethylenes establishes the versatility of this procedure over the existing multistep syntheses of dibenzochrysenes. Moreover, the ready regeneration of DDQ from easily recovered reduced DDQ-H(2) continues to advance the use of DDQ/H(+) for the oxidative C-C bond forming reactions.