Synthesis of aniline from dinitrogen and benzene mediated by magnesium oxide supported sodium hydride

The activation and valorization of inert molecules (e.g., dinitrogen (N2), alkanes, and alkenes) for the synthesis of nitrogen-containing organic compounds have long been a highly sought-after goal in chemistry. However, it remains a formidable challenge, stemming from the inherent chemical inertness of the robust N ≡ N and C-H bonds, as well as the competitive adsorption and activation of reactants. Consequently, examples of direct C-N bond formation using N2 and alkanes/alkenes as feedstocks remain exceptionally scarce. Herein, we report that sodium hydride supported on magnesium oxide (NaH/MgO) possesses unique multiple reactive sites, which enable the conversion of N2 and unactivated arenes and facilitate C-N bond formation. The synergistic interplay between sodium, magnesium, and hydride species at the NaH/MgO interface plays a pivotal role in the reduction of N2 to NHx species. These reactive NHx intermediates then deprotonate the aryl C-H bond, attack the alkali-interacted aryl ring, and drive the formation of sodium anilide on the surface. Subsequent protonation of sodium anilide yields aniline with high selectivity (>90%). This work demonstrates the feasibility of transforming N2 and simple arenes into key nitrogen-containing organic compounds via a solid surface-mediated process, thereby opening ample room for developing heterogeneous catalysts for the transformation of N2 and organic substrates. Making useful nitrogen compounds directly from nitrogen gas and simple aromatic molecules has been a major chemical challenge. A sodium hydride magnesium oxide surface enables direct carbon–nitrogen bond formation and selectively produces aniline.