Synthesis of Fused Imidazole Rings by Sequential van Leusen/C—H Bond Activation.

A concise route to access fused imidazole rings employing the van Leusen three-component reaction followed by a Pd/Cu catalyzed intramolecular C-arylation is reported. The reaction was found to be general and the products were formed in moderate to excellent yields using the two-step reaction sequence.