HETEROGENEOUS METATHESIS OF UNSATURATED ESTERS USING A RHENIUM-BASED CATALYST

Article abstract of DOI:10.1016/0022-328X(83)87019-3

The heterogeneous metathesis of unsaturated esters was carried out at room temperature, using the catalyst system Re2O7/Al2O3 with an organometallic compound as cocatalyst.The influence of several parameters on the activity of the catalyst was studied with methyl oleate (methyl-Z-9-octadecenoate) as substrate.The use of a nonpolar solvent and a cocatalyst of general formula SnR4, in which R is a linear alkyl group, provided optimal reaction conditions.The activity of a deactivated catalyst could be completely restored by recalcination in oxygen, followed by addition of a further amount of cocatalyst.The reactivities of various unsaturated esters as a function of their molecular structure was studied; these esters undergo metathesis when the double bond and the carboxylic group are separated by at least one methylene group.In general, α,β-unsaturated esters show a reasonable activity for cometathesis with simple alkenes, such as E-3-hexene.