Catalyst compositions and their use for hydrogenation of nitrile rubber

Abstract

This invention relates to novel catalyst compositions based on ruthenium or osmium carbene-complex catalysts, pref. of the Grubbs-I, -II or -III type or fluorenylidene analogues thereof, and terminal olefins, pref. enol ethers such as ethyl vinyl ether (EVE or VEE) as co-catalysts and to a process for selectively hydrogenating nitrile rubbers in the presence of such catalyst compositions, pref. with a preceding metathesis step using the same complex catalyst as in the hydrogenation step.

What is claimed is: 
     
         1 . A catalyst composition obtainable by contacting a complex catalyst based on ruthenium or osmium as central metal and bearing at least one ligand which is bound to the ruthenium or osmium central metal in a carbene-like fashion with at least one co-catalyst in a molar ratio of the complex catalyst to the co-catalyst in a range of from 1:(20-550) wherein the co-catalyst must contain at least one vinyl group. 
     
     
         2 . The catalyst composition according to  claim 1  wherein the co-catalyst has the general formula (1)
   CH 2 ═CRR′  (1)
 
 in which R and R′ are identical or different and shall mean 
 hydrogen or 
 OR 1  wherein R 1  shall mean alkyl, cycloalkyl, alkenyl, alkynyl, aryl, or heteroaryl, C(═O)(R 2 ), —C(═O)N(R 2 ) 2 , —[(CH 2 ) n —X] m R 2 , —[(CH 2 ) n —X] m —CH═CH 2 , or —(CH 2 ) p —C(R 3 ) 2 R 4  
 wherein 
 X is identical or different and means oxygen (O) or NR 2    
 R 2  are identical or different and represent H, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, or heteroaryl, 
 R 3  are identical or different and represent C 1 -C 5  alkyl or —(CH 2 ) n —O—CH═CH 2 , 
 R 4  represents (CH 2 ) p —O—CH═CH 2 , 
 n is in the range of from 1 to 5, 
 m is in the range of from 1 to 10, 
 p is in the range of from 0 to 5, 
 where in the alternative, if R and R′ both represent a group OR 1 , both R 1  may be linked to each other and together represent a divalent group —(C(R 2 ) 2 ) q — with q being 2, 3 or 4 and R 2  being identical or different and having the above defined meanings, or 
 
 SR 5 , SOR 5 , SO 2 R 5  wherein R 5  represents alkyl, cycloalkyl, alkenyl, alkynyl, aryl, or heteroaryl, or 
 N(R 6 R 7 ), P(R 6 R 7 ) wherein R 6  and R 7  are identical or different and shall mean alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, —C(═O)(R 2 ), or
 where in the alternative R 6  and R 7  may form together with such N or P atom to which they both are linked at the same time a saturated, unsaturated or aromatic cyclic structure with 4 to 7 carbon atoms in the cyclic structure wherein one, two or three of said carbon atoms can be replaced by a moiety selected from oxygen, sulfur, nitrogen, N—R 8  or P—R 8  wherein R 8  shall mean alkyl, cycloalkyl, alkenyl, alkynyl, aryl, or heteroaryl; or 
 
 P(═O)(OR 9 ) 2  in which R 9  are identical or different and shall mean alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, 
 however, under the proviso that R and R′ must not both represent hydrogen in formula (1) at the same time. 
 
     
     
         3 . The catalyst composition according to  claim 1  wherein the co-catalyst is selected from the group consisting of formulae (cocat-1) to (cocat-38). 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         4 . The catalyst composition according to any one  claims 1  to  3  wherein the complex catalyst is selected from the group consisting of
 (i) catalysts of general formula (A), 
 
       
         
           
           
               
               
           
         
         
           where 
           M is osmium or ruthenium, 
           X 1  and X 2  are identical or different and are two ligands, preferably anionic ligands, 
           L are identical or different ligands, preferably uncharged electron donors, 
           R are identical or different and are each hydrogen, alkyl, preferably C 1 -C 30 -alkyl, cycloalkyl, preferably C 3 -C 20 -cycloalkyl, alkenyl, preferably C 2 -C 20 -alkenyl, alkynyl, preferably C 2 -C 20 -alkynyl, aryl, preferably C 6 -C 24 -aryl, carboxylate, preferably C 1 -C 20 -carboxylate, alkoxy, preferably C 1 -C 20 -alkoxy, alkenyloxy, preferably C 2 -C 20 -alkenyloxy, alkynyloxy, preferably C 2 -C 20 -alkynyloxy, aryloxy, preferably C 6 -C 24 -aryloxy, alkoxycarbonyl, preferably C 2 -C 20 -alkoxycarbonyl, alkylamino, preferably C 1 -C 30 -alkylamino, alkylthio, preferably C 1 -C 30 -alkylthio, arylthio, preferably C 6 -C 24 -arylthio, alkylsulphonyl, preferably C 1 -C 20 -alkylsulphonyl, or alkylsulphinyl, preferably C 1 -C 20 -alkylsulphinyl, where these groups may in each case optionally be substituted by one or more alkyl, halogen, alkoxy, aryl or heteroaryl moities or, as an alternative, the two groups R together with the common carbon atom to which they are bound are bridged to form a cyclic structure which can be aliphatic or aromatic in nature, may be substituted and may contain one or more heteroatoms, 
         
         (ii) catalysts of general formula (A1), 
       
       
         
           
           
               
               
           
         
         
           where 
           X 1 , X 2  and L can have the same general, preferred and particularly preferred meanings as in the general formula (A), 
           n is 0, 1 or 2, 
           m is 0, 1, 2, 3 or 4 and 
           R′ are identical or different and are alkyl, cycloalkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulphonyl or alkylsulphinyl radicals which may in each case be substituted by one or more alkyl, halogen, alkoxy, aryl or heteroaryl, 
         
         (iii) catalysts of general formula (B), 
       
       
         
           
           
               
               
           
         
         
           where 
           M is ruthenium or osmium, 
           X 1  and X 2  are identical or different and are anionic ligands, 
           R″ are identical or different and are organic moieties, 
           Im is a substituted or unsubstituted imidazoline or imidazolidine ligand and 
           An is an anion, 
         
         (iv) catalysts of general formula (C) 
       
       
         
           
           
               
               
           
         
         
           where 
           M is ruthenium or osmium, 
           R 13  and R 14  are each, independently of one another, hydrogen, C 1 -C 20 -alkyl, C 2 -C 20 -alkenyl, C 2 -C 20 -alkynyl, C 6 -C 24 -aryl, C 1 -C 20 -carboxylate, C 1 -C 20 -alkoxy, C 2 -C 20 -alkenyloxy, C 2 -C 20 -alkynyloxy, C 6 -C 24 -aryloxy, C 2 -C 20 -alkoxycarbonyl, C 1 -C 20 -alkylthio, C 1 -C 20 -alkylsulphonyl or C 1 -C 20 -alkylsulphinyl, 
           X 3  is an anionic ligand, 
           L 2  is an uncharged π-bonded ligand which may either be monocyclic or polycyclic, 
           L 3  is a ligand selected from the group consisting of phosphines, sulphonated phosphines, fluorinated phosphines, functionalized phosphines having up to three aminoalkyl, ammonioalkyl, alkoxyalkyl, alkoxycarbonylalkyl, hydrocarbonylalkyl, hydroxyalkyl or ketoalkyl groups, phosphites, phosphinites, phosphonites, phosphinamines, arsines stibines, ethers, amines, amides, imines, sulphoxides, thioethers and pyridines, 
           Y −  is a noncoordinating anion and 
           n is 0, 1, 2, 3, 4 or 5, 
         
         (v) catalysts of general formula (D), 
       
       
         
           
           
               
               
           
         
         
           where 
           M is ruthenium or osmium, 
           X 1  and X 2  are identical or different and are anionic ligands which can have all meanings of X 1  and X 2  mentioned in the general formulae (A) and (B), 
           L represent identical or different ligands which can have all general and preferred meanings of L mentioned in the general formulae (A) and (B), 
           R 19  and R 20  are identical or different and are each hydrogen or substituted or unsubstituted alkyl, 
         
         (vi) catalysts of general formula (E), (F) or (G), 
       
       
         
           
           
               
               
           
         
         
           where 
           M is osmium or ruthenium, 
           X 1  and X 2  are identical or different and are two ligands, preferably anionic ligands, 
           L is a ligand, preferably an uncharged electron donor, 
           Z 1  and Z 2 are identical or different and are uncharged electron donors, 
           R 21  and R 22  are each, independently of one another, hydrogen alkyl, cycloalkyl, alkenyl, alkynyl, aryl, carboxylate, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, alkylsulphonyl or alkylsulphinyl which are in each case substituted by one or more substituents selected from among alkyl, halogen, alkoxy, aryl or heteroaryl. 
         
         (vii) catalysts (N) comprising the general structural element (N1), where the carbon atom denoted by “*” is bound via one or more double bonds to the catalyst framework having a ruthenium or osmium central metal, 
       
       
         
           
           
               
               
           
         
         
           and where 
           R 25 -R 32  are identical or different and are each hydrogen, halogen, hydroxyl, aldehyde, keto, thiol, CF 3 , nitro, nitroso, cyano, thiocyano, isocyanato, carbodiimide, carbamate, thiocarbamate, dithiocarbamate, amino, amido, imino, silyl, sulphonate (—SO 3   − ), —OSO 3   − , —PO 3   −  or OPO 3   −  or alkyl, cycloalkyl, alkenyl, alkynyl, aryl, carboxylate, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulphonyl, alkylsulphinyl, dialkylamino, alkylsilyl or alkoxysilyl, where all these moieties can each optionally be substituted by one or more alkyl, halogen, alkoxy, aryl or heteroaryl substituents, or, as an alternative, two directly adjacent substituents from the group consisting of R 25 -R 32  together with the ring carbons to which they are bound form a cyclic group, preferably an aromatic system, by bridging or, as an alternative, R 8  is optionally bridged to another ligand of the ruthenium- or osmium-carbene complex catalyst, 
           m is 0 or 1 and 
           A is oxygen, sulphur, C(R 33 R 34 ), N—R 35 , —C(R 36 )═C(R 37 )—, —C(R 36 )(R 38 )—C(R 37 )(R 39 )—, where R 33 -R 39  are identical or different and can each have the same meanings as R 25 -R 32 , and 
         
         (viii) catalysts of general formulae (N2a) or (N2b), 
       
       
         
           
           
               
               
           
         
         
           where 
           M is ruthenium or osmium, 
           X 1  and X 2  are identical or different and are two ligands, preferably anionic ligands, 
           L 1  and L 2  are identical or different ligands, preferably uncharged electron donors, where L 2  can alternatively also be bridged to the radical R 8 , 
           n is 0, 1, 2 or 3, preferably 0, 1 or 2, 
           n′ is 1 or 2, preferably 1, and 
           R 25 -R 32 , m and A have the same meanings as given in general formula (N1). 
         
       
     
     
         5 . The catalyst composition according to  claim 4  wherein a complex catalyst of general formula (A) is used in which one group R is hydrogen and the other group R is C 1 -C 20 -alkyl, C 3 -C 10 -cycloalkyl, C 2 -C 20 -alkenyl, C 2 -C 20 -alkynyl, C 6 -C 24 -aryl, C 1 -C 20 -carboxylate, C 1 -C 20 -alkoxy, C 2 -C 20 -alkenyloxy, C 2 -C 20 -alkynyloxy, C 6 -C 24 -aryloxy, C 2 -C 20 -alkoxycarbonyl, C 1 -C 30 -alkylamino, C 1 -C 30 -alkylthio, C 6 -C 24 -arylthio, C 1 -C 20 -alkylsulphonyl or C 1 -C 20 -alkylsulphinyl, where these moieties may in each case be substituted by one or more alkyl, halogen, alkoxy, aryl or heteroaryl groups. 
     
     
         6 . The catalyst composition according to  claim 4  or  5  wherein a complex catalyst of general formula (A) is used in which X 1  and X 2  are identical and are each halogen, in particular chlorine, CF 3 COO, CH 3 COO, CFH 2 COO, (CH 3 ) 3 CO, (CF 3 ) 2 (CH 3 )CO, (CF 3 )(CH 3 ) 2 CO, PhO (phenoxy), MeO (methoxy), EtO (ethoxy), tosylate (p-CH 3 —C 6 H 4 —SO 3 ), mesylate (CH 3 —SO 3 ) or CF 3 SO 3  (trifluoromethanesulphonate). 
     
     
         7 . The catalyst composition according to any one of  claims 4  to  6  wherein a complex catalyst of general formula (A) is used in which one or both of the ligands L have a structure according to general formulae (IIa)-(IId), wherein the meaning of L can be identical or different in case both ligands L have a structure according to (IIa) to (IId), 
       
         
           
           
               
               
           
         
         where 
         R 8 , R 9 , R 10  and R 11  are identical or different and represent hydrogen, straight-chain or branched C 1 -C 30 -alkyl, C 3 -C 20 -cycloalkyl, C 2 -C 20 -alkenyl, C 2 -C 20 -alkynyl, C 6 -C 24 -aryl, C 7 -C 25 -alkaryl, C 2 -C 20  heteroaryl, C 2 -C 20  heterocyclyl, C 1 -C 20 -alkoxy, C 2 -C 20 -alkenyloxy, C 2 -C 20 -alkynyloxy, C 6 -C 20 -aryloxy, C 2 -C 20 -alkoxycarbonyl, C 1 -C 20 -alkylthio, C 6 -C 20 -arylthio, —Si(R) 3 , —O—Si(R) 3 , —O—C(═O)R, C(═O)R, —C(═O)N(R) 2 , —NR—C(═O)—N(R) 2 , —SO 2 N(R) 2 , —S(═O)R, —S(═O) 2 R, —O—S(═O) 2 R, halogen, nitro or cyano, wherein in all above occurrences relating to the meanings of R 8 , R 9 , R 10  and R 11  the group R is identical or different and represents hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, aryl or heteroaryl, and 
         R 15 , R 16  and R 17  are identical or different and may represent alkyl, cycloalkyl, alkoxy, aryl, aryloxy, or a heterocyclic group. 
       
     
     
         8 . The catalyst composition according to any one of  claims 4  to  6  wherein a complex catalyst of general formula (A) is used in which one or both of the ligands L may have a structure (IIIa) to (IIIu), where in all cases “Ph” means phenyl, “Bu” butyl, “Mes” 2,4,6-trimethylphenyl, “Dipp” 2,6-diisopropylphenyl, and “Dimp” 2,6-dimethylphenyl, and wherein the meaning of L can be identical or different in case both ligands L have a structure according to (IIIa) to (IIIu), 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         9 . The catalyst composition according to any one of  claims 4  to  8  wherein in step a) a catalyst of general formula (A) is used in immobilized form on a support material, preferably as immobilized catalyst having the general formulae (support-1), (support-2), or (support-3), 
       
         
           
           
               
               
           
         
         wherein M, Y, L, X 1 , X 2 , and R may have the meanings given for general formula (A) and wherein “supp” stands for the support material, preferably silica gels or a macromolecular material, more preferably synthetic polymers, most preferably polyethylene glycol, polystyrenes or cross-linked polystyrenes. 
       
     
     
         10 . The catalyst composition according to  claim 4  wherein in step a) a catalyst of the general formulae (E), (F), and (G) is used in which
 M is ruthenium, 
 X 1  and X 2  are both halogen, in particular chlorine, 
 R 1  and R 2  are identical or different and are five- or six-membered monocyclic groups having from 1 to 4, preferably from 1 to 3 and particularly preferably 1 or 2, heteroatoms or bicyclic or polycyclic structures made up of 2, 3, 4 or 5 five- or six-membered monocyclic groups of this type, where all the abovementioned groups may in each case be substituted by one or more moieties selected from the group consisting of alkyl, preferably C 1 -C 10 -alkyl, cycloalkyl, preferably C 3 -C 8 -cycloalkyl, alkoxy, preferably C 1 -C 10 -alkoxy, halogen, preferably chlorine or bromine, aryl, preferably C 6 -C 24 -aryl, or heteroaryl, preferably C 5 -C 23 -heteroaryl, 
 Z 1  and Z 2  are identical or different and five- or six-membered monocyclic groups having from 1 to 4, preferably from 1 to 3 and particularly preferably 1 or 2, heteroatoms or bicyclic or polycyclic structures made up of 2, 3, 4 or 5 five- or six-membered monocyclic groups of this type, where all these abovementioned groups may in each case optionally be substituted by one or more alkyl, preferably C 1 -C 10 -alkyl, cycloalkyl, preferably C 3 -C 8 -cycloalkyl, alkoxy, preferably C 1 -C 10 -alkoxy, halogen, preferably chlorine or bromine, aryl, preferably C 6 -C 24 -aryl, or heteroaryl, preferably C 5 -C 23 -heteroaryl, radicals which may in turn each be substituted by one or more moieties, preferably selected from the group consisting of halogen, in particular chlorine or bromine, C 1 -C 5 -alkyl, C 1 -C 5 -alkoxy and phenyl. 
 R 21  and R 22  are identical or different and are each C 1 -C 30 -alkyl C 3 -C 20 -cycloalkyl, C 2 -C 20 -alkenyl, C 2 -C 20 -alkynyl, C 6 -C 24 -aryl, C 1 -C 20 -carboxylate, C 1 -C 20 -alkoxy, C 2 -C 20 -alkenyloxy, C 2 -C 20 -alkynyloxy, C 6 -C 24 -aryloxy, C 2 -C 20 -alkoxycarbonyl, C 1 -C 30 -alkylamino, C 1 -C 30 -alkylthio, C 6 -C 24 -arylthio, C 1 -C 20 -alkylsulphonyl, C 1 -C 20 -alkylsulphinyl, and 
 L has a structure of the above-described general formula (IIa) or (IIb), in particular one of the formulae (IIIa) to (IIIu). 
 
     
     
         11 . The catalyst composition according to any one of  claims 1  to  3 , wherein in step a) a complex catalyst is used selected from the catalysts shown in the following formulae, wherein in each case “Cy” is cyclohexyl, “Mes” is 2,4,6-trimethylphenyl and “Ph” is phenyl. 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         12 . The catalyst composition according to any one of  claims 1  to  11  wherein the molar ratio of of the complex catalyst to the co-catalyst in a range of from 1:(20 to below 100), preferably 1:(25 to 99.5), more preferably 1:(30 to 99), even more preferably 1:(35 to 98.5) and most preferably 1:(40 to 70). 
     
     
         13 . A process for hydrogenating a nitrile rubber comprising
 a) preparing the catalyst composition by contacting a complex catalyst based on ruthenium or osmium as central metal and bearing at least one ligand which is bound to the ruthenium or osmium central metal in a carbene-like fashion with at least one co-catalyst in a molar ratio of the complex catalyst to the co-catalyst in the range of 1:(20-550) wherein the co-catalyst must contain at least one vinyl group and thereafter   b) hydrogenating the nitrile rubber in the presence of the catalyst composition formed in step a).   
     
     
         14 . The process for hydrogenating a nitrile rubber according to  claim 13 , wherein step a) is performed at a temperature in the range of from −20° C. to 160° C. and preferably in the range of from 20° C. to 80° C. 
     
     
         15 . The process for hydrogenating a nitrile rubber according to  claim 13  or  14 , wherein the ratio of complex catalyst to co-catalyst in step a) is 1:(20-500), preferably 1:(25-475), more preferably 1:(25-450) and most preferably 1:(30-450). 
     
     
         16 . The process for hydrogenating a nitrile rubber according to  claim 13  or  14 , wherein the molar ratio of of the complex catalyst to the co-catalyst in a range of from 1:(20 to below 100), preferably 1:(25 to 99.5), more preferably 1:(30 to 99), even more preferably 1:(35 to 98.5) and most preferably 1:(40 to 70). 
     
     
         17 . The process for hydrogenating a nitrile rubber according to any one of  claims 13  to  16 , wherein the hydrogenation in step b) is carried out at a temperature in the range of from 60° C. to 200° C., preferably from 80° C. to 180° C., most preferably from 100° C. to 160° C. and at a hydrogen pressure in the range of 0.5 MPa to 35 MPa, more preferably of 3.0 MPa to 10 MPa. 
     
     
         18 . The process for preparing a hydrogenated nitrile rubber according to any one of  claims 13  to  17 , wherein the nitrile rubber prior to being hydrogenated is subjected to a molecular weight degradation in a metathesis reaction first comprising contacting the said nitrile rubber in the absence or presence of a co-olefin with a complex catalyst based on ruthenium or osmium as central metal and bearing at least one ligand which is bound to the ruthenium or osmium central metal in a carbene-like fashion, then
 c) contacting the complex catalyst which is present in the reaction mixture obtained after the metathesis reaction with at least one co-catalyst having at least one vinyl group in a molar ratio of the complex catalyst to the co-catalyst in the range of 1:(20-550) to form a catalyst composition and thereafter 
 d) hydrogenating the nitrile rubber in the presence of the catalyst composition.