Ir-Catalyzed C–H Amidation Using Carbamoyl Azides for the Syntheses of Unsymmetrical Ureas

An iridium-catalyzed C–H amidation for the syntheses of unsymmetrical urea was developed using carbamoyl azides (R(R′)N–C(O)-N3) as the nitrogen source. A combination of iridium and silver gave an active catalyst for C–N bond formation. A variety of urea derivatives were synthesized using carbamoyl azides with only dinitrogen byproducts. Finally, the use of the transient directing group strategy with carbamoyl azides extended the substrate scope of the catalytic C–H amidation to yield aldehyde-containing unsymmetrical ureas.