Copper-Catalyzed Imino C–N Bond Formation with Aryl Boronic Acids under Aerobic Conditions

A copper-catalyzed, ligand- and base-free C–N cross-coupling reaction of iminochromenes with arylboronic acids in a nontoxic ethanol solvent at room temperature under air is developed. The product yields are found to be good to moderate. The conservation of the sensitive imine functional group implies the mildness of this protocol