Copper(I)-Catalyzed Intramolecular Direct C-Arylation of Azoles with Aryl Bromides

A concise route to access 5H-imidazo[2,1-a]isoindole heterofused compounds by copper(I)-catalyzed intramolecular coupling of non-activated aryl bromides with azoles is reported. With CuI as catalyst, 1,10-phenanthroline as ligand, and K3PO4 as base, the reactions of 1-(2-bromobenzyl)-1H-imidazoles in DMF/o-xylene (1:1, V:V) at 145°C afford the corresponding substituted 5H-imidazo[2,1-a]isoindoles in high yields via intramolecular C-arylation.