Multicoordinated metal complexes for use in metathesis reactions

Abstract

Improved catalysts useful in alkyne or olefin metathesis are made by bringing into contact a multi-coordinated metal complex comprising a multidentate Schiff base ligand, and one or more other ligands, with a selected activating compound under conditions such that at least partial cleavage of a bond between the metal and the multidentate Schiff base ligand of said metal complex occurs.

What is claimed is: 
     
         1 . A method of modifying a multi-coordinated metal complex, a salt, a solvate or an enantiomer thereof, said multi-coordinated metal complex comprising (i) at least one multidentate Schiff base ligand comprising an imino group and being coordinated to the metal, in addition to the nitrogen atom of said imino group, through at least one further heteroatom selected from the group consisting of oxygen, sulfur and selenium, and (ii) one or more other ligands, wherein said method comprises bringing said multi-coordinated metal complex into contact with an activating compound under conditions such that at least partial cleavage of a bond between the metal and said at least one multidentate Schiff base ligand (i) occurs, and wherein said activating compound is either a metal or silicon compound selected from the group consisting of:
 copper (I) halides,   zinc compounds represented by the formula Zn(R 5 ) 2 , wherein R 5  is halogen, C 1-7  alkyl or aryl,   tin compounds represented by the formula SnR 9 R 10 R 11 R 12  wherein each of R 9 , R 10 , R 11  and R 12  is independently selected from the group consisting of halogen, C 1-20  alkyl, C 3-10  cycloalkyl, aryl, benzyl and C 2-7  alkenyl, and   silicon compounds represented by the formula SiR 13 R 14 R 15 R 16  wherein each of R 13 , R 14 , R 15  and R 16  is independently selected from the group consisting of hydrogen, halogen, C 1-20  alkyl, halo C 1-7  alkyl, aryl, heteroaryl and vinyl,   
       or a compound comprising at least one halogen atom directly bonded to at least one atom having an atomic mass from 27 to 124 and being selected from the group consisting of groups IB, IIB, IIIA, IVB, IVA and VA of the Periodic Table of elements. 
     
     
         2 . A method according to  claim 1 , wherein said conditions include a molar ratio between said activating compound and the metal of said multi-coordinated metal complex being from about 5:1 to about 2,000:1. 
     
     
         3 . A method according to  claim 1 , wherein said conditions include a contact time from about 5 seconds to about 100 hours. 
     
     
         4 . A method according to  claim 1  wherein said conditions include a contact temperature from about −50° C. to about 80° C. 
     
     
         5 . A method according to  claim 1 , wherein at least one of said other ligands (ii) is a constraint steric hindrance ligand having a pKa of at least 15. 
     
     
         6 . A method according to  claim 1 , wherein the number of carbon atoms in said at least one multidentate Schiff base ligand (i), between the nitrogen atom of said imino group and said coordinating heteroatom of said at least one multidentate Schiff base ligand (i), is from 2 to 4. 
     
     
         7 . A method according to  claim 1  wherein at least one of said other ligands (ii) is a carbene ligand selected from the group consisting of N-heterocyclic carbenes, alkylidene ligands, vinylidene ligands, indenylidene ligands, heteroatom-containing alkylidene ligands and allenylidene ligands. 
     
     
         8 . A method according to  claim 1  wherein at least one of said other ligands (ii) is an anionic ligand. 
     
     
         9 . A method according to  claim 1  wherein at least one of said other ligands (ii) is a non-anionic ligand. 
     
     
         10 . A method according to  claim 1  wherein said at least one atom having an atomic mass from 27 to 124 is selected from the group consisting of copper, zinc, tin, silicon, titanium, aluminium and phosphorous. 
     
     
         11 . A method according to  claim 1 , wherein said activating compound includes at least one halogen atom and wherein bringing said multi-coordinated metal complex into contact with said activating compound is effected in the presence of at least one further reactant being an organic acid or having the structural formula RYH, wherein Y is selected from the group consisting of oxygen, sulfur and selenium, and R is selected from the group consisting of hydrogen, aryl, arylalkyl, heteocyclic, heterocyclic-substituted alkyl, C 2-7  alkenyl and C 1-7  alkyl. 
     
     
         12 . A method according to  claim 1 , wherein said activating compound includes at least one halogen atom and wherein bringing said multi-coordinated metal complex into contact with said activating compound is effected in the presence of at least one optionally substituted phenol or C 1-7  alkyl alcohol or C 2-7  alkenyl alcohol or a monocarboxylic or polycarboxylic acid. 
     
     
         13 . A method according to  claim 1 , wherein bringing said multi-coordinated metal complex into contact with said activating compound is effected in the presence of at least one optionally substituted phenol, and wherein said activating compound is selected from the group consisting of methyldichlorosilane, trichlorosilane, alkyltrichlorosilanes, dialkyl-dichlorosilanes, trialkylchlorosilanes and silicon tetrachloride. 
     
     
         14 . A method according to  claim 1 , wherein said activating compound includes at least one halogen atom and wherein bringing said multi-coordinated metal complex into contact with said activating compound is effected in the presence of at least one further reactant being an organic acid or having the structural formula RYH, wherein Y is selected from the group consisting of oxygen, sulfur and selenium, and R is selected from the group consisting of hydrogen, aryl and C 1-4  alkyl, and wherein the molar ratio of said at least one further reactant with respect to said activating compound is such that each labile hydrogen atom of said further reactant is able to react with each halogen atom of said activating compound.