The synthesis of silicon oleochemicals by hydrosilylation of unsaturated fatty acid derivatives

The hydrosilylation of fatty acid esters with terminal or internal double bonds catalysed by H2 PtCl6 is described. The reaction was carried out with good yields at ambient pressure under mild conditions. Methyl undec-10-enoate was reacted with chloro- or alkoxyhydrosilanes giving moderate to good yields (41—77%) and even its reaction with alkylhydrosilanes produced low yields (below 20%). Under optimised conditions the hydrosilylation of methyl linoleate gave only with reactive chlorohydrosilanes acceptable yields, between 25 to 83%, of regioisomers. The hydrosilylation of methyl α-linolenate with dimethylchlorosilane gave a mixture of regioisomeric 1:1- and 2:1-hydrosilylation adducts in a total yield of 40%. The hydrosilylation of ethyl oleate did not proceed at all under our conditions. In the case of methyl undec-10-enoate a biphasic solvent system permitted the simple separation and reuse of the homogeneous catalyst.