Copper-Catalyzed Benzylic C−H Oxygenation under an Oxygen Atmosphere via <i>N</i>-H Imines as an Intramolecular Directing Group

Copper-catalyzed benzylic C−H oxygenation under an oxygen atmosphere was developed starting from carbonitriles and Grignard reagents via N-H imine intermediates. The present process is characterized by the following two-step sequence in a one-pot manner: (1) addition of Grignard reagents to carbonitriles to form N-H imines and (2) benzylic C−H oxygenation (CO bond formation) triggered by 1,5-hydrogen atom transfer with transient iminyl copper species.