Photochemically-Mediated, Nickel-Catalyzed Synthesis of N-(Hetero)aryl Sulfamate Esters

A general method is described for the coupling of (hetero)aryl bromides with O -alkyl sulfamate esters. The protocol relies on catalytic amounts of nickel and photoexcitable iridium complexes and proceeds under visible light irradiation at ambient temperature. This technology engages a broad range of simple and complex O -alkyl sulfamate ester substrates under mild conditions. Furthermore, it is possible to avoid undesirable N -alkylation, which was found to plague palladium-based protocols for N -arylation of O -alkyl sulfamate esters. These investigations represent the first use of sulfamate esters as nucleophiles in transition metal-catalyzed C-N coupling processes.