Alumina-Catalyzed Epoxidation with Hydrogen Peroxide: Recycling Experiments and Activity of Sol-Gel Alumina

✍ Scribed by Renato G. Cesquini; Juliana M. de S. e Silva; Camile B. Woitiski; Dalmo Mandelli; Roberto Rinaldi; Ulf Schuchardt

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 61 KB
• Volume: 344
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/1615-4169(200209)344:8<911::aid-adsc911>3.0.co;2-t

✦ Synopsis

Commercial alumina looses some activity after the first epoxidation reaction of (S)-limonene with hydrogen peroxide, but maintains a good activity and a very high selectivity in the subsequent three reactions. After this its activity is strongly reduced, probably due to structural modifications. Aluminas obtained by sol-gel methods are normally less active than the commercial alumina. However, the use of monomeric aluminum sec-butoxide and of oxalic acid to form stable alumina mesophases allows a very active alumina to be obtained, which catalyses the epoxidation of the less reactive cyclohexene with hydrogen peroxide in 98% yield. Close to 50% of the active oxygen is used up in the formation of molecular oxygen.