A novel intermediate in allylic amination catalyzed by iron salts

Our initial probe of the aminations catalyzed by iron salts excluded the intermediacy of free ArNO, suggesting that a coordinated organonitrogen species could be the active aminating agent. To elucidate the mechanism of these latter reactions we report herein (a) the isolation and first structural elucidation of a metal complex of a C-nitroso dimer (1), and (b) evidence that this novel compound is the key aminating agent in allylic aminations catalyzed by iron salts. We have established with 1 the first structurally verified metal complex of a C-nitroso dimer and its unprecedented reactivity and selectivity for the allylic N-functionalization of olefins. Its involvement as the aminating agent in FeX2,3-catalyzed allylic amination also has been strongly implicated.