A transition-metal-free synthesis of arylcarboxyamides from aryl diazonium salts and isocyanides.

A transition-metal-free carboxyamidation process, using aryl diazonium tetrafluoroborates and isocyanides under mild conditions, has been developed. This novel conversion was initiated by a base and solvent induced aryl radical, followed by radical addition to isocyanide and single electron transfer (SET) oxidation, affording the corresponding arylcarboxyamide upon hydration of the nitrilium intermediate.