Synthesis of imidazoles through the copper-catalyzed cross-cycloaddition between two different isocyanides.

The copper-catalyzed reaction between two different isocyanides produces the corresponding heteroaromatization products, imidazoles, in good yields. The reaction proceeds most probably through the activation of the sp3 C-H bond in the isocyanides by a copper catalyst, followed by a [3 + 2] cycloaddition between the cuprioisocyanide intermediates and arylisocyanides.