Domino synthesis of fused hexacyclic imidazoquinolinoacridinones catalyzed by CuI/l-proline

A three-component reaction of 2-halogenated aromatic aldehydes, 1H-benzo[d]imidazol-5-amine and cyclohexane-1,3-diones is described, and gives imidazoquinolinoacridinone derivatives in good yields catalyzed by CuI/ l -proline. This Domino reaction constructs a fused hexacyclic skeleton in one-pot containing two new rings, six new bonds and an Ullmann-type C–N bond coupling reaction.