Ceric ammonium nitrate (CAN) enabled concerted nitration/ureation of carbodiimides to synthesize o-nitroaryl ureas

Abstract

A simple and facile strategy to construct o-nitroaryl urea employing carbodiimides and ceric ammonium nitrate (CAN) has been developed. This protocol achieves the installation of two functional groups in one step with high functional group compatibility. Control experiments show that the reaction mechanism involves an intriguingly concerted nitration/ureation process enabled by CAN, and is distinctive from conventional electrophilic nitrification. The oxygen atom of urea probably originates from the nitrate ions provided by CAN. The late-stage derivatization and gram-scale synthesis reveal the promising utility of this methodology.