Selective oxidation of alkenes using graphite-supported gold-palladium catalysts
RIS ID
104880
Abstract
Oxidation is an important route for the activation of chemical feedstocks for the synthesis of chemical intermediates. Alkene epoxidation by the electrophilic addition of oxygen to a carbon-carbon double bond is a major challenge in oxidation catalysis. In particular it is important to use molecular oxygen as the oxidant to avoid the formation of reagent by-products. We report the oxidation with air using graphite-supported gold-palladium catalysts of two alkenes, cis-cyclooctene, which gives mainly the epoxide, and crotyl alcohol (trans-but-2-en-1-ol). With cyclooctene, the reaction requires catalytic amounts of t-butyl hydroperoxide. The Au-Pd ratio has a major effect on the conversion with very low activities being associated with Au:Pd ratios of ca. 4 : 1 and 1 : 4 by weight. The selectivity to the epoxide is not affected by the Au : Pd ratio. With crotyl alcohol, t-butyl hydroperoxide was not required for activity. In the absence of Pd, crotonaldehyde was formed, but the introduction of Pd leads to an isomerisation pathway to 3-buten-1-ol being favoured over epoxidation and crotonaldehyde was a minor product.
Publication Details
Bawaked, S., He, Q., Dummer, N. F., Carley, A. F., Knight, D. W., Bethell, D., Kiely, C. J. & Hutchings, G. J. (2011). Selective oxidation of alkenes using graphite-supported gold-palladium catalysts. Catalysis Science and Technology, 1 (5), 747-759.