Method of preparing ruthenium and osmium carbene complexes

A method of preparing a compound of formula ##STR42## the method comprising reacting a compound of the formula (XX.sup.1 ML.sub.n L.sup.1.sub.m).sub.p with a cyclopropene of the formula ##STR43## in the presence of a solvent wherein:

• M is Os or Ru;
• R.sup.2 and R.sup.3 are independently selected from the group consisting of hydrogen, and a substituent group selected from the group consisting of C.sub.1 -C.sub.18 alkyl, C.sub.2 -C.sub.18 alkenyl, C.sub.2 -C.sub.18 alkynyl, C.sub.2 -C.sub.18 alkoxycarbonyl, aryl, C.sub.1 -C.sub.18 carboxylate, C.sub.1 -C.sub.18 alkenyloxy, C.sub.2 -C.sub.18 alkynyloxy, C.sub.1 -C.sub.18 alkoxy, aryloxy, C.sub.1 -C.sub.18 alkylthio, C.sub.1 -C.sub.18 alkylsulfonyl and C.sub.1 -C.sub.18 alkylsulfinyl;
• each substituent group optionally substituted with C.sub.1 -C.sub.5 alkyl, halogen, C.sub.1 -C.sub.5 alkoxy or with a phenyl group optionally substituted with halogen, C.sub.1 -C.sub.5 alkyl or C.sub.1 -C.sub.5 alkoxy;
• X and X.sup.1 are independently selected from the group consisting of any anionic ligand;
• L and L.sup.1 are independently selected from the group consisting of any neutral electron donor;
• n and m are independently 0-4, provided n+m=2, 3 or 4;
• p is an integer equal to or greater than 1;
• and
• any 2 or 3 of X, X.sup.1, L, and L.sup.1 are optionally bonded together to form a chelating multidentate ligand.