摘要：

Self-metathesis of unsaturated fatty acid esters provides a convenient route to unsaturated diesters which can be used as intermediate for the production of polymers and other useful chemical products such as civetone. Cross-metathesis reactions with lower alkenes result in medium-chain fatty acid esters which are highly-demanded raw materials for the industrial production of surfactants. Cross-metathesis with ethene ( ethenolysis ) gives compounds with terminal double bonds, having a broad range of applications. The metathesis of fats and oils proceeds intra- as well as intermolecularly. Ethenolysis of unsaturated fatty oils or triglycerides allows the transformation of long-chain fatty acid triglycerides into fatty oils of lower molecular weight. In recent years, new catalyst systems have proven useful for the metathesis of unsaturated esters. Especially modified heterogeneous rhenium-based catalysts have attracted much attention. Other catalyst systems have also appeared to be of interest for these substrates, notably molybdenum-based catalysts. Certain CO-photoreduced cyclopropane-treated supported MoO 3 catalysts give interesting results as a possible alternative to the promoted rhenium oxide catalysts, especially when supported on silica.

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