A copper-catalyzed Ritter-type cascade via iminoketene for the synthesis of quinazolin-4(3H)-ones and diazocines.

We have developed a copper-catalyzed Ritter-type reaction/cyclization cascade of anthranilic acids and nitriles, affording the quinazolin-4(3H)-ones. The cascade proceeds through a Ritter-type reaction capturing the iminoketene intermediates by nitriles. Furthermore, we found a novel Ritter-type reaction/condensation/intramolecular anti-Markovnikov hydroamination cascade, providing access to functionalized diazocines in one-pot.