Chemoselective carbene insertion into the N−H bonds of NH(3)·H(2)O

The conversion of inexpensive aqueous ammonia (NH(3)·H(2)O) into value-added primary amines by N−H insertion persists as a longstanding challenge in chemistry because of the tendency of Lewis basic ammonia (NH(3)) to bind and inhibit metal catalysts. Herein, we report a chemoselective carbene N−H insertion of NH(3)·H(2)O using a Tp(Br3)Ag-catalyzed two-phase system. Coordination by a homoscorpionate Tp(Br3) ligand renders silver compatible with NH(3) and H(2)O and enables the generation of electrophilic silver carbene. Water promotes subsequent [1,2]-proton shift to generate N−H insertion products with high chemoselectivity. The result of the reaction is the coupling of an inorganic nitrogen source with either diazo compounds or N-triftosylhydrazones to produce useful primary amines. Further investigations elucidate the reaction mechanism and the origin of chemoselectivity.