Modified Wacker TBHP oxidation of 1-dodecene

• Published in: Applied catalysis. A, General General, 2008-02, Vol.335 (2), p.137-144
• Main Authors: Escola, J.M., Botas, J.A., Aguado, J., Serrano, D.P., Vargas, C., Bravo, M.
• Format: Article
• Language: English
• Subjects: 2-Dodecanone; Acetonitrile; Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Palladium chloride; tert-Butylhydroperoxide; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Wacker oxidation
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2007.11.005

A higher 1-olefin (1-dodecene) was oxidized to 2-dodecanone and other ketones in a modified Wacker system featured by omitting the use of copper chloride and employing tert-butyl hydroperoxide (TBHP) as oxidant. Acetonitrile was the chosen solvent due to its higher selectivity towards 2-dodecanone. At 40 °C, ∼90% conversion with 61% selectivity towards 2-dodecanone was attained after 3 h of reaction. ▪ A higher 1-olefin (1-dodecene) was oxidized to 2-dodecanone and other ketones in a modified Wacker system featured by omitting the use of copper chloride and employing tert-butylhydroperoxide (TBHP) as oxidant. Acetonitrile was the solvent of choice due to its higher selectivity towards 2-dodecanone, the reaction occurring mostly in the interface. A maximum in conversion and selectivity was measured for a ratio [CH 3CN]/[1-dodecene] = 10. The temperature abatement enhances the 2-dodecanone selectivity (61% at 40 °C) because of the lower extent of the competing isomerization reactions. An optimum in 2-dodecanone selectivity was found for a [TBHP]/[1-dodecene] ratio = 7. The use of H 2O 2 as oxidant led towards slower oxidation rates than TBHP. Other palladium salts (PdSO 4 and Pd(CH 3COO) 2) and several R–CN solvents (propionitrile, benzonitrile, isobutyronitrile) yielded lower performances than palladium chloride and acetonitrile, respectively. On the contrary, β-cyclodextrin, a phase transfer catalyst, improved the selectivity towards 2-dodecanone.