Method for preparation of ruthenium-based metathesis catalysts with chelating alkylidene ligands

Method for the preparation of a ruthenium-based carbene catalyst with a chelating alkylidene ligand comprising the reaction of a ruthenium (II)-alkylidene complex with an olefin derivative according to the equation:

• wherein
• L is a neutral ligand, preferably a saturated or unsaturated N-heterocyclic carbene ligand (“NEC” ligand),
• X1 and X2 are, independently from each other, inorganic or organic anionic ligands, such as halide anions, pseudohalide anions, hydroxides, acetates, trifluoracetates or carboxylates,
• Y1 and Y2 are, independently -form from each other, hydrogen, C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, C1-C6-alkylthio, aryl, arylthio, C1-C6-alkylsulfonyl or C1-C6-alkylsulfinyl, or Y1 and Y2 are taken together to form a ring of the indenylidene type according to the formula
• wherein in said formula R3 is hydrogen, a substituted or unsubstituted aryl group or a substituted or unsubstituted phenyl group,
• Py is an N-heterocyclic two-electron donor ligand,
• R0 and R1 are, independently from each other, hydrogen, C1-C10-alkyl, C2-C10-alkenyl, C2-C10-alkynyl, a phenyl or an aryl group (which optionally can be substituted),
• a, b, c and d are, independently from each other, hydrogen, (C1-C10-alkyl, C2-C10-alkenyl, C2-C10-alkynyl, a phenyl or aryl group, or an electron withdrawing group (“EWG”), with the provision that each of a, b, c or d can form a ring with each other,
• Z is a heterodonor atom such as oxygen (O), sulphur (S), nitrogen (N) or a group comprising a heterodonor atom such as sulfinyl (>S═O),
• R2 is a substituted or unsubstituted hydrocarbon group, such as alkyl, alkenyl, alkynyl, aryl, alkylamino, alkylthio, a substituted or unsubstituted keto group such as —C(Ra)2—CO—C(Rb)3, a substituted or unsubstituted ester group such as —C(Ra)2—CO—O(Rc) (wherein in said groups le is hydrogen or C1-C10-alkyl, Rb is hydrogen, C1-C10-alkyl, C1-C10-fluoroalkyl, C1-C10-alkylamino, C1-C10-alkyl ammonium or C2-C10-alkenyl and Rc is C1-C10-alkyl, C1-C10-fluoroalkyl, C1-C10-alkyl ammonium or C2-C10-alkenyl) and wherein R2 and/or Z may form a ring with d.