ACTIVE-SITES OF METATHESIS CATALYSTS - ANSWERS AND QUESTIONS

Recent literature on the origin of the active sites of heterogenous metathesis catalysts is reviewed, with special attention to the types of species on the surface of the support that are converted from active site precursors to active sites by interaction with the reactants. Different types of precursor species, with the transition metal in different oxidation states, may coexist on the surface of heterogenous metathesis catalysts. Also covered in this review are the contribution of homogenous catalysis to the elucidation of the reaction mechanism, the links between homogenous and heterogenous catalysis to the elucidation of the reaction mechanism, the links between homogenous and heterogenous catalysis and the synthetical and technical aspects of alkene metathesis.