Copper-catalyzed C-C coupling and cyclization: Synthesis of benzo[4,5]imidazo[1,2-a]pyridines and benzo[4,5]imidazo[2,1-a]isoquinolines

2-(2-Bromovinyl)benzimidazoles are coupled and cyclized with 1,3-diketones in DMF in the presence of a catalytic amount of copper(I) iodide and a base to afford the corresponding benzo[4,5]imidazo[1,2-a]pyridines in moderate yields. 2-(2-Bromoaryl)benzimidazoles also react with 1,3-diketones under similar reaction conditions to give benzo[4,5]imidazo[2,1-a]isoquinolines in similar yields.