3,6-Disubstituted carbazole building blocks are coupled via copper-catalyzed Ullmann reactions to afford trimeric and heptameric carbazoles with excellent solubilites in organic solvents. Alternatively, oligomeric carbazoles with phenylene spacers, that are more stable towards oxidation, can be obtained via palladium-catalyzed Suzuki coupling reactions. (C) 2003 Elsevier Science Ltd. All rights reserved.
Construction of Nitrogen-containing Polycyclic Aromatic Compounds by Intramolecular Oxidative C-H/C-H Coupling of Bis(9<i>H</i>-carbazol-9-yl)benzenes and Their Properties
Treatment of 1,3- and 1,4-bis(3,6-di-tert-butyl-9H-carbazol-9-yl)benzenes with an oxidizing system of Pd(II)/Ag(I) has been found to induce double intramolecular C-H/C-H coupling to give the corres...