Studies in surface science and catalysis vol:84 issue:Part A-C pages:1411-1418
Adipic acid is produced in high yield by oxidation of cyclohexene with H2O2 on manganese diimine catalysts (cis-Manganese bis-2,2'-Bipyridyl complexes in faujasite type zeolites, cis-[Mn(bpy)2](2+)-NaX and NaY). This catalytic system allows to reach turn-over numbers of 760. The synthesis of cis-[Mn(bpy)2](2+)-NaFAU proceeds through ion exchange, followed by dehydration and melting the ligand on the dehydrated metal-loaded zeolite. In the last step the temperature and the metal to ligand stoichiometry needs to be carefully controlled. In the described reaction, alkene epoxidation competes with the allylic oxidation and, to a minor extent, with hydration of the double bond. The reaction is faster with (H)Na-Y zeolite, due to the higher Bronsted acid-strength that permits a faster acid-catalysed opening of the epoxide.
ZEOLITES AND RELATED MICROPOROUS MATERIALS: STATE OF THE ART 1994