Metathesis in oleochemistry

Abstract

Metathesis is an attractive reaction for the conversion of oleochemical feedstocks into useful chemical products. Thus, metathesis of unsaturated fatty acid esters (the oleochemical raw materials) provides a convenient route to unsaturated diesters which can be used as intermediates for the production of polymers and specialty chemicals. Cross-metathesis with olefins is a means to change the chain length of fatty acids and derivatives; cross-metathesis with ethene (ethenolysis) gives compounds with terminal double bonds, having a broad range of applications. Ethenolysis of fatty oils or triglycerides allows the transformation of long-chain fatty acid triglycerides into fatty oils of lower molecular weight. Several highly selective catalyst systems - homogeneous as well as heterogeneous - have proven to be successful for the metathesis of unsaturated esters. Especially modified heterogeneous rhenium- and molybdenum-based catalysts have attracted much attention. Considering catalyst activation and regeneration procedures, rhenium-based catalysts are to be preferred.