Alkylidene complexes of ruthenium containing n-heterocyclic carbene ligands; use as highly active, selective catalysts for olefin metathesis

Abstract

The invention relates to a complex of ruthenium of the structural formula I, where Xand Xare identical or different and are each an anionic ligand,Rand Rare identical or different and can also contain a ring, and Rand Rare each hydrogen or/and a hydrocarbon group,the ligand Lis an N-heterocyclic carbene and the ligand Lis an uncharged electron donor, in particular an N-heterocyclic carbene or an amine, imine, phosphine, phosphate, stibine, arsine, carbonyl compound, carboxyl compound, nitrile, alcohol, ether, thiol or thioether,where R, R, Rand Rare hydrogen or/and hydrocarbon groups. The invention further relates to a process for preparing acyclic olefins having two or more carbon atoms or/and cyclic olefins having four or more carbon atoms from acyclic olefins having two or more carbon atoms or/and from cyclic olefins having four or more carbon atoms by an olefin metathesis reaction in the presence of at least one catalyst, wherein a complex is used as catalyst and R, R, Rand Rare hydrogen or/and hydrocarbon groups.