Synthesis Of Dinuclear Ruthenium-Carbene Catalyst And Research On Olefin Isomerization Reaction In Ionic Liquids

Olefin Metathesis was found in 1950s, it has become an important synthetic method for carbon-carbon bond. The olefin metathesis field has been improved dramatically from 1990s since the discovery of novel ruthenium-carbene catalysts. Today, many scientists are trying to prepare catalyst that is more stable, more active and more compatible to functional groups by modification of the ligands. In this paper a ligand 2,2'-diisopropoxy-3,3'-di(prop-1-enyl)biphenyl was synthesized from biphenyl-2,2'-diol and then a novel dinuclear ruthenium-carbene catalyst was obtained by ligand exchange with Grubbs II. Catalystic study show that the catatyst perfomed well in RCM reactions to many substrates.Olefin isomerization reaction using organometallic complexes have been reported in many papers. However, the application of olefin isomerization reaction was limited since the organometallic complex catalysts they used are expensive, unstable, not compatible to many functional groups. In this paper, RuCl3 was used as catalyst in ionic liquids to isomerize allybenzene type compounds to their stable isomers. We found the conversion of those reaction are good if substrates have a electron rich group. Compared to other catalysts, RuCl3 is cheaper,more stable to air and moisture. In this system, the catalyst can be recycled eight times with slightly decrease in activity, so this is an economic and environmental beneficial method.