CuCl-Catalyzed Ullmann-Type C-N Cross-Coupling Reaction of Carbazoles and 2-Bromopyridine Derivatives.

A CuCl-catalyzed Ullmann-type C-N cross-coupling reaction of carbazoles and 2-bromopyridine derivatives has been developed for the synthesis of N-heteroarylcarbazole derivatives employing 1-methyl-imidazole and t-BuOLi as ligand and base, respectively, both of which are found to significantly promote the reaction. Low cost and low loading of both catalyst and ligand, together with high reaction yields, render this practical reaction to be suitable for large-scale preparations and could be useful in material science.