Oxidation of aliphatic terminal alkenes having more than 30 carbon atoms to carboxylic acids is presented. Such long carboxylic acids are useful as waxes, lubricants, plasticizers, etc. The oxidation was conducted under solvent-free conditions or with small amounts of diluents (heptane, methylcyclohexane, and tert-butylbenzene). Hydrogen peroxide was used as the oxidant, and tungstic acid was used as the catalyst. Halogen-free quaternary ammonium salts were used as phase-transfer catalysts, and the importance of the elimination of halide ions is discussed. Purification of the crude oxidized product and tungsten removal are also presented. The products have a maximum acid number of 75 mg of KOH/g, a saponification number of 100 mg of KOH/g, and tungsten content below 400 ppm.

The aerobic oxidative cleavage of a-methylstyrene and other benzylic olefins catalyzed by N-hydroxyphthalimide (NHPI) under solvent-free conditions is described. The reaction was remarkably accelerated by the addition of azo-initiator (2,2 0 -azobis(2-methylpropionitryl)) or transition metal salts (Mn, Cu, Co) in combination with NHPI. Alkylammonium salts and acetophenone were successfully applied to increase the solubility of the polar NHPI catalyst in non-polar substrates. The effects of the catalyst and reaction parameters on the conversion of the substrate and the selectivity for ketones were investigated. New insights into the oxidation mechanism and NHPI-ammonium salt interaction are presented.

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