Catalysis of olefin metathesis

Ruthenium complexes B are stable in the presence of alcohols, amines, or water, even at 60 °C. Olefin metathesis can be realized even in water as solvent, either using ruthenium carbene complexes with water-soluble phosphine ligands [815], or in emulsions. These complexes are also stable in air [584]. No olefination of aldehydes, ketones, or derivatives of carboxylic acids has been observed [582]. During catalysis of olefin metathesis replacement of one phosphine ligand by an olefin can occur [598,809]. 

Cr=C species (metathesis active sites) should be transfonned into Cr-C species (polymerization active sites) in a mysterious way, as illustrated in Scheme 7. Such mysterious phenomenon of interconversion between catalysis of olefin metathesis and olefin polymerization with other types of catalysts has been previously reported [97, 98] and needs further investigation in the future. 

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