Oxides of group 5-7 metals are convenient and efficient catalysts for the single-pot carboxylation of gaseous (methane, ethane, propane) and liquid alkanes to carboxylic acids, as well as for the aqueous peroxidative hydroxylation/oxygenation of liquid alkanes to alcohols and ketones. The reactions occur under mild conditions, and the carboxylations proceed with unprecedented remarkably high turnover numbers. The diagonal metals commonly provide the most active oxide catalysts in the order V > Re > Mo. (C) 2007 Elsevier Inc. All rights reserved.