Establishing a Molecular Mechanism for the Beckmann Rearrangement of Oximes over Microporous Molecular Sieves

At least two possible pathways were found for the Beckmann rearrangement of acetophenone oxime to acetanilide over zeolite catalysts. In the first step, the N atom of the oxime is protonated over the Brønsted acid sites of an aluminum siliceous zeolite (see picture), but not over the silanol groups of a pure siliceous zeolite.