Ruthenium polymerisation catalysts

A method of catalysing a metathesis reaction comprising:

• providing a reactant having at least one olefin and/or alkyne functional group;
• providing a trans ruthenium complex according to general formula II, or a cis ruthenium complex according to formula I:
• wherein for each occurrence the groups X are the same or different and are anionic ligands or are fused to form a bidentate ligand;
• the groups R1 and R2 are the same or different and are selected from the group consisting of hydrogen, C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C2-C20 alkoxycarbonyl, aryl, C1-C20 carboxylate, C1-C20 alkoxy, C2-C20 alkenyloxy, C2-C20 alkynyloxy, aryloxy, C1-C20 alkylthio, C1-C20 alkylsulfonyl, and C1-C20 alkylsulfinyl;
• and when not hydrogen are optionally substituted;
• or
• the groups R1 and R2 are fused together to form a ring that may be substituted or unsubstituted, saturated or unsaturated and may be fused to a further ring;
• and
• the group Z is selected from the group consisting of:
• wherein the groups R3, R4 and R5 are each independently for each occurrence selected from the group consisting of substituted or unsubstituted primary, secondary or tertiary alkyl, that may be cyclic and may be unsaturated;
• substituted or unsubstituted aryl or heteroaryl;
• and optionally two or more of the groups R3, R4 and R5 are fused to form a ring;
• the group A is selected from the group consisting of a nucleophilic carbene, and a phosphorus ligand independently selected from the list of groups as defined for group Z, with the provisos that;
• when the complex is a trans complex according to formula II, both groups Z and A are not phosphine and where A is a nucleophilic carbene, Z is not phosphine;
• and
• when the complex is a cis complex according to formula I, when A is a nucleophilic carbene, Z is not
• and
• contacting the reactant with the complex according to formula I for a time and at a temperature capable of causing metathesis polymerisation.