Copper-Catalyzed Dihydroquinolinone Synthesis from Isocyanides and O-Benzoyl Hydroxylamines.

A copper-catalyzed protocol has been realized for the rapid assembly of dihydroquinolinones from readily accessible isocyanides and O-benzoyl hydroxylamines. The reactions (10 mol % of CuOAc, 10 mol % of dppe, 3 equiv of PhONa, 30 °C) deliver various structurally interesting dihydroquinolinones in moderate to good yields (up to 76%). The reactions may proceed in a cascade manner involving isocyanide insertion into the N-O bond, Mumm-type rearrangement, and intramolecular nucleophilic substitution.