Switching acidity on manganese oxide catalyst with acetylacetones for selectivity-tunable amines oxidation.

The design of metal oxide catalysts predominantly focuses on the composition or geometry engineering to enable optimized reactivity on the surface. Despite the numerous reports investigating the surface chemisorption of organic molecules on metal oxides, insights into how adsorption of organic modifiers can be exploited to optimize the catalytic properties of metal oxides are lacking. Herein, we describe the use of enolic acetylacetones to modify the surface Lewis acid properties of manganese oxide catalysts. The acetylacetone modification is stable under the reaction conditions and strongly influences the redox-acid cooperative catalysis of manganese oxides. This enables a rational control of the oxidation selectivity of structurally diverse arylmethyl amines to become switchable from nitriles to imines.