Use of ruthenium complexes in olefin metathesis reaction

Use of a compound of formula 2,

• wherein:
• X1 and X2 are each an anionic ligand;
• X1 and X2 may be interconnected to form a cyclic system;
• G is a halogen atom or a substituent selected from OR′, SR′, S(O)R′, S(O)2R′ N(R′)(R″), P(R′)(R″)(R′″), where R′, R″ and R′″ are the same or different C1-C25 alkyl group, C3-C12 cycloalkyl group, C1-C25 alkoxy group, C2-C25 alkenyl group, C1-C12 perfluoroalkyl, C5-C20 aryl, C5-C24 aryloxy, C2-C20 heterocyclyl, C4-C20, heteroaryl, C5-C20, or which may involve the formation of a substituted or non-substituted cyclic C4-C10 or policyclic C4-C12 systems, which are optionally substituted with at least one C1-C12 alkyl, C1-C12 perfluoroalkyl, C1-C12 alkoxy, C5-C24 aryloxy, C2-C20 heterocyclyl, C4-C20 heteroaryl, C5-C20 heteroaryloxy, may also be substituted with an ester (—COOR′), amide (—CONR′2), formyl (—CHO), ketone (—COR′), hydroxamic (—CON(OR′)(R′)) groups, wherein R′ is C1-C12 alkyl, C3-C12 cycloalkyl, C2-C12 alkenyl, C5-C20 aryl, which are optionally substituted with at least one C1-C12 alkyl, C1-C12 perfluoroalkyl, C1-C12 alkoxy, C5-C20 aryl, C5-C24 aryloxy, C7-C24 aralkyl, C2-C20 heterocycle, C4-C20, heteroaryl, C5-C20 heteroaryloxy, or a halogen atom;
• Ar is an aryl group that is substituted by hydrogen atoms, or optionally is substituted by at least one C1-C12 alkyl, C1-C12 perfluoroalkyl, C1-C12 alkoxy, C5-C24 aryloxy, C2-C20 heterocyclic, C4-C20 heteroaryl, C5-C20 heteroaryloxy, C7-C24 aralkyl, C5-C24 perfluoroaryl groups, or a halogen atom;
• R1, R2, R3, R4 are each a hydrogen atom, a (—S(O)R′) sulphoxide group, a (—SO2NR′2) sulphonamide group, a (—P(O)(OR′)2) phosphonium group, a (—P(O)R′(OR′)) phosphinium group, a (—P(OR′)2) phosphonous group, a (—PR′2) phosphine group, a (—NO2) nitro group, a (—NO) nitroso group, a (—COOH) carboxy group, a (—COOR′) ester group, a (—CHO) formyl group, a (—COR′) ketone group, a —NC(O)R′ group, an amino group, an ammonium group, a (—OMe) alkoxy group, in which groups R′ is C1-C5 alkyl, C1-C5 perfluoroalkyl, C5-C24 aryl, C7-C24 aralkyl, C5-C24 perfluoroaryl, C4-C20 heteroaryl, C5-C20 heteroaryloxy, and wherein R1, R2, R3 and R4 may be interconnected to form a cyclic system;
• R5, R6, R7 and R8 are each a hydrogen atom or a C1-C25, alkyl, C3-C12 cycloalkyl, C1-C5 perfluoroalkyl, C2-C12 alkenyl, C5-C20, aryl C5-C24 aryloxy, C2-C20 heterocycle, C4-C20 heteroaryl, C5-C20 heteroaryloxy, C7-C24 aralkyl C5-C24, which are optionally substituted by at least one C1-C12 alkyl, C1-C12, perfluoroalkyl, C1-C12 alkoxy, C5-C24 aryloxy, C4-C20 heteroaryl, C5-C20 heteroaryloxy or a halogen atom;
• and wherein R5 and R6 and/or R7 and R8 may be interconnected to form a cyclic system;
• in olefin metathesis reactions where at least one compound is formed as the main product containing at least one non-terminal double C═C bond, involving the process of contacting at least one type of olefin in the presence of a compound of formula 2, and wherein the compound of formula 2 is used in an amount of less than 0.1 mol %.