Alkane oxygenation catalysed by gold complexes

Gold(III) and gold(I) complexes, NaAuCl4 and ClAuPPh3, efficiently catalyse the oxidation of alkanes by H2O2 in acetonitrile solution at 75 degreesC. Turnover numbers (TONs) attain 520 after 144 h. Alkyl hydroperoxides are th e main products, whereas ketones (aldehydes) and alcohols are formed in sma ller concentrations. It is suggested on the basis of the bond selectivity s tudy that at least one of the pathways in Au-catalysed alkane hydroperoxida tion does not involve the participation of free hydroxyl radicals. Possibly , the oxidation begins from the alkane hydrogen atom abstraction by a gold oxo species. The oxidation of cyclooctane by air at room temperature cataly sed by NaAuCl4 in the presence of Zn/CH3COOH as a reducing agent and methyl viologen as an electron-transfer agent gave cyclooctanol (TON = 10). (C) 20 01 Published by Elsevier Science Ltd.