Tandem Switch‐Triggered On‐Demand Synthesis of Aromatic Amines in High Yields

Abstract Tandem catalysis stands as a beacon of chemical sustainability. Although bifunctional catalysts have achieved wide success in two‐step tandem reactions, achieving multi‐step catalysis with three or more distinct and potentially incompatible catalytic sites and components remains an ambitious challenge. Here, we present a “tandem switch” strategy that transforms these incompatibilities into functional advantages, enabling on‐demand production of primary, secondary, and tertiary aromatic amines, all with yields exceeding 96 %. A kinetic switch, enabled by phosphotungstic acid functionalization of the Ni−Ni(Al)O heterojunction catalyst, modulates the Ni−Ni and Ni−O boundary microenvironment to simultaneously accelerate the rate‐determining steps in nitrobenzene hydrogenation, N‐alkylation, and aza‐Michael addition. Meanwhile, a thermodynamic switch, controlled by the competitive adsorption of ethanol, hydrogen, and acrylonitrile, stepwise minimizes Gibbs free energy to ensure a seamless reaction cascade. Hence, by toggling these tandem switches on or off, we achieve selective regulation of nitrobenzene conversion pathways into the production of targeted aromatic amine. Techno‐economic analysis shows the developed process significantly reduces material and energy consumption for sustainable amine production.