| abstract |
Ruthenium and osmium carbene compounds which are stable in the presence of a variety of functional groups and which can be used to catalyze olefin metathesis reactions are discussed. Methods for synthesizing these carbene compounds are also disclosed. Specifically, the present invention relates to carbene compounds of formula (I) wherein: M is Os or Ru; R and R1 are independently selected from hydrogen; C¿2?-C20 alkenyl, C2-C20 alkynyl, C1-C20 alkyl, aryl, C1-C20 carboxylate, C2-C20 alkoxy, C2-C20 alkenyloxy, C2-C20 alkynyloxy, aryloxy, C2-C20 alkoxycarbonyl, C1-C20 alkylthio, C1-C20 alkylsulfonyl or C1-C20 alkylsulfinyl; each optionally substituted with C1-C5 alkyl, halogen, C1-C5 alkoxy or with a phenyl group optionally substituted with halogen, C1-C5 alkyl or C1-C5 alkoxy; X and X?1¿ are independently selected from any anionic ligand; and L and L1 are each trialkyl phosphine ligands where at least one of the alkyl groups on the phosphine is a secondary alkyl or a cycloalkyl. In a preferred embodiment, all of the alkyl groups of the trialkyl phosphine are either a secondary alkyl or a cycloalkyl. In a more preferred embodiment, the alkyl groups are either isopropyl, isobutyl, sec-butyl, neopentyl, neophenyl, cyclopentyl or cyclohexyl. |