Abstract:With the self-metathesis of 1-octene to 7-tetradecene catalyzed by Grubbs 1 st generation [benzylidene-bis(tricyclohexylphosphine)dichlororuthenium, (1)] precursor at low concentrations (0.02 mol %) as basis, the effects of the solubility of the substrate in ionic liquids, the solvent polarity, as well as the influence of various impurities stemming from the preparation of ionic liquids have been investigated. The solubility of the substrate in the ionic liquid has little effect on the conversion, and the reaction is not mass-transfer limited. While a higher polarity of an organic solvent increases the rate, it is independent of the polarity excerted by the cation of an ionic liquid. Of paramount importance for reproducible results is the purity of ionic liquids. An extensive study shows that catalyst deactivation by impurities increases in the order of water < halide < 1-methylimidazole. In the presence of water or 1-methylimidazole impurities, the Grubbs-Hoveyda precursor (3) is superior to both the 1 st (1) and 2 nd (2) generation Grubbs complexes. Under impurity-free conditions or in the presence of chloride, the performance of 2 is equivalent to that of 3.

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The self-metathesis of 1-octene to form 7-tetradecene catalyzed by ruthenium carbene complexes at low concentrations (0.02 mol %) was investigated in ionic liquids as reaction media and as additives. The study showed that the ionic liquid has a significant effect on the selectivity of the metathesis of 1-octene, with conversion to product of greater than 95% being obtained and selectivities of over 98% being realized. The outcomes of the reactions compared well with those performed under solventless conditions, showing improved conversions and selectivities.

The hydroformylation of Vinyl acetate to form 2acetoxypropanal (an important intermediate in the synthesis of the enVironmentally friendly solVent ethyl lactate) catalyzed by Rh(CO) 2 (acac) using phosphite or phosphine ligands was inVestigated in ionic liquids as reaction media (neat and as blends) or as additiVes to organic solVents. The ionic liquid had a significant effect on the selectiVity of the hydroformylation of Vinyl acetate, with Very high TOFs being realized and selectiVities of oVer 99% being obtained for the desired branched product at >95% selectiVity for aldehyde products in reactions up to 0.3 mol scale. This effect could be obtained for relatiVely low Volumes of the ionic liquid in an organic solVent, and combinations of benefits were obserVed by blending ionic liquids. It was also shown that the ionic liquid/catalyst could be recycled without loss of actiVity.