Direct cyclohexanone oxime synthesis via oxidation-oximization of cyclohexane with ammonium acetate.

An unexpected cascade reaction for oxidation-oximization of cyclohexane with ammonium acetate was developed for the first time to access cyclohexanone oxime with 50.7% selectivity (13.6% conversion). Tetrahedral Ti sites in Ni-containing hollow titanium silicalite can serve as bifunctional catalytic centers in the reaction. This methodology not only provides a direct approach to prepare cyclohexanone oxime, but also simplifies process chemistry. Various available nitrogen sources, such as ammonium salt and even ammonia can be used as starting materials.