DE10112358C2 - Transition metal complex catalysts for heterogeneous catalysis, processes for their preparation and their use - Google Patents

Description

The invention relates to solid transition metal complex catalysts for the heterogeneous Catalysis, its production and its use in catalytic reactions in the Liquid phase.

The invention relates to a general heterogenization method for transition metal catalysts in liquid phase reactions. So that such catalysts are a technical Application is a high long-term stability, the good separation of product and Catalyst and effective catalyst recycling are the prerequisites. In the Various efforts have therefore been made in the past to To produce catalysts with the desired properties. So became catalytic active metals, metal oxides, salts or complexes using various techniques inorganic or organic carrier materials applied. Such catalysts often showed an intolerable leaching of the active metal into the liquid phase or insufficient long-term stability.

Ionic transition metal salts (Venturello et al., EP 109273, Bregeault et al. Stud. Surf. Sci. Cat. 82 (1994) 571, Gelbard et al., J. Mol. Cat. A: Chem. 153 (2000) 7, Jacobs et al., Catalysis Today 60 (2000) 209, Hasik et al. J. Catalysis 147 (1994) 544) and ionic  achiral transition metal complexes have been immobilized in solid ion exchangers (Strukul et al., J. Mol. Cat. A: Chem. 151 (2000) 245, Saito et al. Inorg. Chim. Acta 283 (1998) 44, Baird et al., Organomet. 2 (1983) 1138). When making this Catalysts become a metal compound on a preformed support connected, d. H. the catalytically active species and carriers are in two phases. This can hardly lead to a three-dimensional encapsulation of the metal connection by the Carrier material that is a prerequisite for their good restraint. Even one Metal compound with multiple ionic functional groups cannot be suitable Create a micro reaction space through networking, because that would have to be the case preformed rigid polymer carriers are deformed, which is hardly possible. Moreover is the way to manufacture a customized catalyst Adjustment of properties (e.g. polarity, hydrophobicity) of the individual components of the catalyst is not possible or only possible to a limited extent.

Also disadvantageous for the heterogenization of transition metal complex A successive incorporation of ligands and metal precursors into the catalysts can occur Impact carrier. This allows the steric arrangement of the ligands and the Active metal in the heterogeneous catalyst may not be as optimal as that in the homogeneous phase is given. Especially with chiral heterogenized catalysts is a decrease or complete loss of the stereoselectivity of the catalyst Episode. The retention capacity for the active metal is also negatively affected.

The invention is based, transition metal complex catalysts for the task to provide heterogeneous catalysis related to leaching, activity and Selectivity are significantly improved.

According to the invention, transition metal complex catalysts are therefore provided which consist of a transition metal complex, an ionic polymer (polyelectrolyte) and an ionic surface-active compound in different proportions and form a mixed polymeric salt. In this invention, “mixed polymeric salt” is understood to mean a structure as shown in FIG. 1, this being an exemplary illustration.

The catalyst according to the invention thus consists of

• a) a transition metal complex with the general structure
  X _Qn M [(D-) _i Y (-A) _j ] _n
  where the individual structural elements have the following meaning:
  MX _Qn is a metal compound in which one or more metals from the group Ti, V, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au are included;
  X represents one or more, identical or different carbon, nitrogen, phosphorus, oxygen, halogen or sulfur-containing groups, with the ability to form a covalent or coordinative bond to a transition metal atom or ion;
  D stands for a donor group containing nitrogen, phosphorus, oxygen or sulfur, with the ability to form a coordinative bond to a transition metal atom or ion;
  Y represents a substituted or unsubstituted alkylene, alkylphenylene, arylene or heteroarylene group;
  A is a cationic or anionic anchor group capable of forming an ionic bond to an ionic polymer;
  Q is a number that corresponds to the valence of the transition metal and takes the values 1-8;
  n is 1 or 2;
  i and j are numbers from 1 to 4, preferably 1 or 2;
• b) a surface active compound consisting of an alkyl chain with an ionic anchor group and having the general structure ZC, where C is the cationic or anionic anchor group, and Z represents a CH ₃ - (CH ₂ ) _p structure, wherein p is a number from 6 to 18 and wherein the ionic anchor group is capable of forming an ionic bond to an ionic polymeric material; and
• c) a soluble ionic polymeric material, the ionic groups on a has neutral polymers or which is ionically homopolymerized or from ionic Copolymerized monomers or ionic and neutral monomers or is block polymerized.

In the transition metal complexes, the metal can preferably V, Mo, W, Mn, Re, Ru, Os, Rh or Pd, most preferably V, Mo, W, Mn, Ru, or Rh.

The meaning for the group X belong to carbon-containing groups for example cyclooctadiene, norbornadiene, benzene, cymol, cumene, cyclopentadiene.

Nitrogen-containing groups include, for example, tertiary C ₁ -C ₄ -alkylamines, C ₁ -C ₄ -dialkylbenzylamines, pyridine, dipyridyl, pyrimidine, phenanthroline, amines from the group of the china alkaloids.

Groups containing phosphorus include, for example, phosphines, phosphine oxides, Phosphonites, phosphinites, phosphites

Oxygen-containing groups include, for example, alcohols, phenols, ethers, ketones.  

Halogen-containing groups include fluoride, chloride, bromide.

Sulfur-containing groups include, for example, mercaptans, thioethers, Thiophenols.

Donor group D is such a functional group that is capable of forming one Transition metal atom or ion to form a coordinative bond.

Nitrogen-containing donor groups D include, for example, C ₁ -C ₄ alkylamino, C ₁ -C ₄ alkylbenzylamino, pyridyl, dipyridyl, phenanthrolinyl, oxazolinyl groups.

Phosphorus-containing donor groups D include, for example, phosphine, phosphine oxide, Phosphonite, phosphinite, phosphite substituents.

Oxygen-containing donor groups D include, for example, hydroxyl, C ₁ -C ₄ -alkyloxy, phenoxy or keto groups.

Sulfur-containing donor groups D include, for example, mercapto, C ₁ -C ₄ -alkylmercapto, thiophenyl groups.

In the meaning for group Y, alkylene is understood to mean a substituted or unsubstituted C ₁ -C ₁₈ alkylene radical, preferably C ₆ -C ₁₈ alkylene. Alkylphenylene is preferably C ₁ -C ₁₈ alkylphenylene, in particular C ₆ -C ₁₈ alkylphenylene. Arylene is preferably phenylene, tolylene, naphthylene, anthracenylene, biphenylene or terphenylene, in particular phenylene, tolylene, naphthylene, or biphenylene. Heteroarylene is preferably pyridylene, pyrimidylene, bipyridylene, bipyrimidinylene or biindolizinylene, especially pyridylene or bipyridylene.

Y can also be a chiral structural element, such as, for example, binaphthylene or optionally biphenyls.

The cationic or anionic anchor groups A include those cationic Anchor groups, such as the ammonium, phosphonium, arsonium or Stibonium groups, or anionic anchor groups such as the sulfonate, sulfate, Phosphonate, phosphate or carboxylate groups.

Q corresponds to the valence of the metal M. Depending on the valence of the metal M (osmium e.g. 8) and the number of ligands (D-) _i Y (-A) _j (e.g. 2), the difference is the Number of simply bound groups X (e.g. 6).

i and j are numbers from 1 to 4, preferably 1 or 2.

As a cationic or anionic anchor group C, the surface-active compound contains an ammonium, phosphonium, arsonium or stibonium, sulfonate, sulfate, phosphonate, phosphate or carboxylate group. If the ligand (D-) _i Y (-A) _{j has} the structure of a surface-active compound, it can also take over the function of the surface-active compound. In this case, A corresponds to group C, DY corresponds to Z, that is, Z is composed of donor group D and a (CH ₂ ) _p group which represents Y, i and j are each 1.

The ionic polymeric material is made by homopolymerizing an ionic Monomers or by co- or block polymerization of an ionic monomer with a second ionic or neutral monomer.

Ionic monomers include, for example, diallyl-dimethyl-ammonium chloride, 1- Methyl 4-vinylpyridinium chloride, 4-vinylbenzyltrimethylammonium chloride, Methacryloxy-ethyl-trimethyl-ammonium bromide, 2-hydroxy-3-methacryloxy-ethyl- trimethyl-ammonium bromide, 4-vinyl-benzenesulfonic acid, styrenesulfonic acid, 2-propen-1- sulfonic acid (Na salt), 2-methyl-2-propene-1-sulfonic acid (Na salt), methacrylic acid 3- sulfopropyl ester, 4-vinyl-benzoic acid, acrylic acid, methacrylic acid, 4-vinyl benzenephosphonic.

Neutral polymers include allylbenzene, styrene, 2,5-dimethylstyrene, divinylbenzene, Acrylic acid esters (e.g. n-hexyl acrylate, 2-hydroxyethyl acrylate), acrylic acid amide, methacrylic acid esters (e.g. n-hexyl methacrylate, n-octyl methacrylate), methacrylic acid amide.

The ionic polymeric material can also be made by the subsequent introduction of an ionic functional group can be obtained in a neutral polymer. Furthermore, also natural polymers (e.g. alginate, pectinate, κ-carrageenan, chitosan) or modified natural polymers (e.g. sulfoethyl cellulose, cellulose sulfate) can be used.

Functional groups include ammonium, phosphonium, arsonium, stibonium, Understand sulfonate, sulfate, phosphonate, phosphate and carboxylate groups, preferably ammonium, phosphonium, sulfonate, phosphonate and carboxylate groups, most preferably ammonium, sulfonate and phosphonate groups.

The catalysts of the invention contain 1 to 200, preferably 1-50 and in particular 3 to 20 mol of the group (D-) _i Y (-A) _j per mol of metal.

The catalyst according to the invention is prepared in such a way that solutions one in a homogeneous phase from a transition metal compound and one or two Ligands preformed transition metal complex and solutions of an ionic polymeric material combined with a surface-active compound and after formation, the homogeneous solution is brought into a mold and dried or applied to a carrier material and dried on this carrier.

The preforming is carried out in such a way that a transition metal compound is reacted with a ligand (D-) _i Y (-A) _j in solution, and by means of this reaction in a homogeneous phase the components are arranged in such a way that complete complexation of the transition metals is ensured is.

The catalyst systems according to the invention avoid the above-mentioned negative effects of known heterogenized catalysts, such as leaching and lack of activity and selectivity, by adding the preformed transition metal complex in solution to a solution of an ionic polymer in a simple procedure and by adding a suitable surface-active substance [ZC or surface-active ionic ligand (D-) _i Y (-A) _j ] for this mixed solution in the heterogeneous catalyst, hydrophobic and hydrophilic regions or the distribution of polar and non-polar regions can be balanced. This means that e.g. B. a longer hydrophobicity of the catalyst can be achieved by a longer chain in the surface-active compound. The density of the ionic units is also influenced by the amount of surface-active compound. If the region of the catalyst is too polar, it may happen that no or only very little catalytic starting material can diffuse in, so that little or no conversion to a product occurs. By introducing targeted amounts of surface-active compound in selected stoichiometric ratios, the person skilled in the art can "loosen up" the polarization with the aid of the present invention, that is to say reduce the density of the ionic units and thus enable the starting material to be converted to access the catalyst much better. The mass transport of substrates and products can thus be positively influenced.

In addition, the catalyst system according to the invention is excellent for Heterogenization of chiral transition metal complexes is suitable. Since it is known that the special properties of chiral complexes for enantioselective syntheses in Heterogenization can easily be lost, it is particularly valuable with the existing catalysts of the invention have invented a means that Heterogenization of chiral catalysts without loss of enantioselectivity to reach. The chiral heterogeneous catalysts of the invention produced significant enantiomeric excesses in the investigated catalytic reactions, as shown by the examples is substantiated.

The mixed polymeric salt, which all catalyst components of the invention contains, from the solution in which it is, by a suitable method in a Form (e.g. drops, lenses, foils, balls) brought and dried or on a Carrier material (e.g. porous, preferably mesoporous carrier, packing, tissue, Packs, nets) applied and dried on this carrier. The salt is there  preferably in a polar solvent such as water or an alcohol such as Ethanol, before.

The catalysts can also be used in the meantime during the catalytic reaction loosen and after the reaction without leaching the active metal by changing precipitate and reuse the polarity of the solvent. Here is another one Seen advantage of the invention.

The catalysts of the invention are indeed made of known individual Elements formed, namely transition metal complexes, ionic surface-active Compounds and ionic polymers, the combination of the special Structure of these components but catalysts with particularly advantageous, result in innovative properties.

The decisive advantage of the invention is evident from the method of Catalyst preforming in a homogeneous solution. This works particularly well a pronounced three-dimensional encapsulation of the metal complex in the ionic Polymer that prevents leaching of metal and ligands. Are in the solution the metal complex and the ionic polymer (polyelectrolyte) are in the same phase, which is the prerequisite for the high mobility of both components and thus for this intimate wrapping is. The addition of the surface-active compound serves the purpose of To promote encapsulation of the transition metal complex targeted Adjust hydrophilicity / hydrophobicity in the interior of the catalyst and thus the mass transfer to facilitate, to some extent block the functionality of the polyelectrolyte and act as a spacer. It contributes to the stability of the heterogeneous Catalyst system. The functionalization of the transition metal complex or Surfactant compound with more than one ionic group can become one Crosslinking of the ionic polymer and thus for an even better encapsulation and lead to improved retention of the metal complex.

The present invention enables the production of improved catalysts. she are characterized by good retention of the active metal, a good one mechanical and long-term stability and are thermostable in the temperature range up to 120 ° C.

The catalysts of the invention can be used for all reactions that can be catalyzed by complexes of the above-mentioned active metals. The following applies in particular that for selective hydrogenations, carbonylations such as. B. hydroformylations as well Selective oxidations.

The invention will be explained in more detail below by examples that are not as one Limitation of the invention can be seen. With all example reactions that with  oxidation-sensitive transition metal-phosphine complexes are carried out Oxygen excluded.

In the accompanying drawing shows

Fig. 1 is a non-limiting schematic representation of an example of a catalyst according to the invention. The letters A, C, M, X and Z correspond to the meanings given above for the groups in the general formulas, L is the part DY of the ligand (D-) _i Y (-A) _j .

The abbreviations used in the examples mean:
BINAP: 2,2'-bis (diphenylphosphino) -1,1'-binaphthyl
acac: acetylacetonate
PDADMAC: poly (diallyldimethylammonium chloride)
cod: cyclooctadiene
Ph: phenyl
Et: ethyl.

example 1

To 0.12 mmol of BINAP-4,4 '- [P (O) (OH) ₂ ] ₂ in 5 ml of EtOH are added 0.6 mmol [RuCl ₂ (p-cymene)] ₂ and until the Ru is completely reacted -Precursors stirred. 1.26 mmol of decanephosphonic acid in 5 ml of H ₂ O and 1.5 ml of 2N NaOH are combined and then added to the Ru complex solution. 4 mmol of PDADMAC are dissolved in 3 ml of H ₂ O, added to the mixture and stirred for 1 h. The viscous solution is then filled into a syringe with a flat-ground cannula and placed in even drops on a polypropylene plate in the absence of oxygen. The approximately 4 mm large lenticular particles are dried for 24 hours in an inert gas atmosphere, lifted off the polypropylene plate and used as catalysts.

Example 2

0.03 mmol [Rh (OMe) cod] ₂ in 4 ml EtOH and 0.18 mmol (R) - (+) - 2,2'- bis (diphenylphosphino) -4,4'-bisphosphono-1,1 ' -binaphthyl (BINAP-4,4 '- [P (O) (OH) ₂ ] ₂ ) in 2 ml EtOH are combined and stirred for one hour. 1.64 mmol of octanephosphonic acid in 2 ml of 2N NaOH solution are added. Subsequently, 4 mmol PDADMAC (average molecular, M _w 350,000) to be joined in 3 ml H ₂ O, the mixture was stirred for 1 h and, as described in Example 1, catalyst lenses.

Example 3

0.1 mmol of Rh (CO) ₂ acac is added to 2 mmol of Ph ₂ P- (CH ₂ ) ₁₀ -P (O) (ONa) ₂ in 6 ml of H ₂ O and stirred until the rhodium complex is completely reacted. Thereto is added 4 mmol of poly (diallyl dimethyl ammonium chloride) (PDADMAC, medium molecular weight, M _w 350,000) in 2 ml H ₂ O and stirred for 1 h. As described in Example 1, catalyst lenses are produced from the viscous solution.

Example 4

The catalyst is prepared as described in the same manner in Example 1 using 4 mmol PDADMAC (low molecular weight, M _w from 100,000 to 200,000, 20% aqueous solution).

Example 5

The catalyst is prepared in the same way as described in Example 1 using 4 mmol poly (acrylamide-co-diallyl-dimethyl-ammonium chloride (10% aqueous solution).

Example 6

The catalyst is prepared in the same way as described in Example 1 using 4 mmol poly (4-vinyl-pyridinium bromide) (20% aqueous Solution).

Example 7

To 1 mmol of Ph ₂ P (O) - (CH ₂ ) ₁₀ -P (O) (ONa) ₂ in 2 ml of H ₂ O are added 2 mmol of PDADMAC in 3 ml of H ₂ O and stirred for 30 min. Then 1 ml of an in situ prepared aqueous solution of 0.1 mmol Na ₂ [W ₂ O ₃ (O) ₂ ] _{4 is} added dropwise, stirred for 30 min and the resulting viscous solution, as described in Example 1, in drop form on a Polypropylene plate applied and dried.

Example 8

The catalyst is prepared in the same manner as described in Example 7, with the addition of 1 ml of an in situ prepared solution of 0.1 mmol Na ₂ [Mo ₂ O ₃ (O) ₂ ] ₄ .

Example 9

To 0.2 mmol of Ph ₂ P (O) - (CH ₂ ) ₁₀ -P (O) (ONa) ₂ in 6 ml of H ₂ O. 1.8 mmol of decanephosphonic acid and 1.8 ml of 2N NaOH solution in 2 ml of H ₂ O were added, followed by 4 mmol of poly (4-vinyl-pyridinium bromide) (20% aqueous solution) and stirred for 30 min. Then 1 ml of 0.1 N aqueous NaHW ₂ O ₁₁ solution is added and the mixture is stirred for 1 h, the viscous solution is brought in drop form onto a polypropylene plate and dried as described in Example 3.

Example 10

0.2 mmol of Mn ³⁺ tetrakis (sulfophenyl) porphyrin (tetra-Na salt) in 5 ml of H ₂ O and 3.2 mmol of decanesulfonic acid in 2 ml of H ₂ O and 1.6 ml of 2N NaOH solution are combined and stirred for 5 min. 4 mmol of poly (acrylamide-co-diallyl-dimethyl-ammonium chloride) (10% strength aqueous solution) are then added, the mixture is stirred for 1 hour, the droplet-like solution described in Example 3 is placed on a polypropylene plate and dried.

Example 11-14 Hydrogenation of dimethyl itaconate

In a stainless steel reactor equipped with a stirrer, 10 ml Solvent a certain amount of dimethyl itaconate (see table) and the after Example 1 prepared catalyst placed. Then with vigorous stirring at 60 ° C. and hydrogenated 20 bar with hydrogen. Further reaction conditions and test results nisse are shown in Table 2.

Table 1

Example 15 Hydroformylation of vinyl acetate

In a stainless steel reactor, 1 ml of vinyl acetate in 10 ml of toluene in the presence of 300 mg (contains 2 mg of rhodium) of the catalyst prepared according to Example 2 at 60 ° C. and 20 bar over a period of 16 hours with vigorous stirring by means of an equal volume part CO / H ₂ mixture hydroformylated. Sales: 1.4%; Aldehyde selectivity 87%; Regioselectivity (iso: n-aldehydes): 5.7; Enantiomeric excess: 39%.

Example 16-17 Epoxidation of 1-octene

In a glass reactor, the catalyst prepared in Example 7 is stirred in a solution of 15 ml of acetonitrile and 2.5 ml of 30% H ₂ O ₂ for 15 min at RT. Then 1 ml of 1-octene is added, the mixture is warmed to 60 ° C. and the mixture is left to stir for 2 h. Conversion: 6%, epoxy selectivity <98%.

Claims (14)

1. transition metal complex catalysts for heterogeneous catalysis, characterized in that they are a mixed polymeric salt consisting of

• a) a transition metal complex with the general structure
  X _Qn M [(D-) _i Y (-A) _j ] _n
  where the individual structural elements have the following meaning:
  MX _Qn is a metal compound in which one or more metals from the group Ti, V, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au are included;
  X represents one or more, identical or different carbon, nitrogen, phosphorus, oxygen, halogen or sulfur-containing groups, with the ability to form a covalent or coordinative bond to a transition metal atom or ion;
  D represents a donor group containing nitrogen, phosphorus, oxygen or sulfur, with the ability to form a coordinative bond to a transition metal atom or ion and to a radical Y;
  Y represents a substituted or unsubstituted alkyl, alkylphenyl, aryl or heteroaryl group;
  A is a cationic or anionic anchor group capable of forming an ionic bond to an ionic polymer;
  Q is a number that corresponds to the valence of the transition metal and takes the values 1-8;
  n is 1 or 2;
  i and j are numbers from 1 to 4; and
• b) a surface active compound consisting of an alkyl chain with an ionic anchor group and having the general structure ZC, where C is the cationic or anionic anchor group, and Z represents a CH ₃ - (CH ₂ ) _p structure, wherein p is a number from 6 to 18 and wherein the ionic anchor group is capable of forming an ionic bond to an ionic polymeric material; and
• c) a soluble ionic polymeric material which has ionic groups on a neutral polymer or which is homopolymerized from an ionic monomer or copolymerized or block-polymerized from ionic monomers or ionic and neutral monomers.

2. Catalyst according to claim 1, characterized in that the metal V, Mo, W, Mn, Re, Ru, Os, Rh or Pd, preferably V, Mo, W, Mn, Ru, or Rh. 3. Catalyst according to claim 1, characterized in that Y or arylene Heteroarylene is selected from the group consisting of phenylene, tolylene, naphthylene, Binaphthylene, biphenylene, pyridylene and bipyridylene. 4. Catalyst according to claim 1, characterized in that A is a cationic or represents anionic anchor group, which is selected from the cationic anchor groups Ammonium, phosphonium, arsonium and stibonium groups and the anionic Anchor groups sulfonate, sulfate, phosphonate, phosphate and carboxylate groups. 5. Catalyst according to claim 1, characterized in that Y is a chiral Structural element or a structural element with the structure of a surface-active Connection is. 6. Catalyst according to claim 1, characterized in that in the surface-active Compound the cationic or anionic anchor group C an ammonium, Phosphonium, arsonium or stibonium, sulfonate, sulfate, phosphonate, phosphate or carboxylate group. 7. Catalyst according to one of claims 1 to 6, characterized in that it contains 1 to 200, preferably 1-50 and in particular 3 to 20 mol of the group (D-) _i Y (-A) _j per mol of metal. 8. A catalyst according to claim 1, in which the molar ratios (d) of the ionic Charges in the polymer (a), the opposite ionic charges in the Transition metal complexes (b) and in the surface-active compounds (c)  Satisfy equation d = a: [b + c] and (d) is in the range from 0.7 to 3, preferably in Range from 0.8 to 2. 9. A process for the preparation of transition metal complex catalysts according to claim 1 by heterogenization of transition metal complexes, characterized in that in the homogeneous phase from a transition metal compound and ligand (s) preformed transition metal complex in a solution to the solution of an ionic Given polymers with the addition of an ionic surface-active compound and is thereby converted into a mixed polymeric salt. 10. The method according to claim 9, characterized in that for compensation hydrophilic and hydrophobic areas in the polymeric salt Transition metal complexes and surface-active compounds are given, where the molar ratios (d) of the ionic charges in the polymer (a), the opposite ionic charges in the transition metal complexes (b) and in the surface-active compounds (c) satisfy the equation d = a: [b + c] and (d) im Range from 0.7 to 3, preferably in the range from 0.8 to 2. 11. The method according to claim 9, characterized in that the mixed polymer Salt is brought into the form of drops, lenses, spheres or foils and dried. 12. The method according to claim 9, characterized in that the mixed polymer Salt in a solvent on a porous support, packing, tissue, packing or nets are applied and dried. 13. Use of the catalysts according to claim 1 in transition metal complexes catalyzed selective hydrogenations, carbonylations and selective oxidations of organic substrates. 14. Use according to claim 13 of chiral catalysts according to claim 5 in asymmetric reactions.