JP4568803B2 - Production method of polymer-immobilized transition metal catalysts - Google Patents

Description

  The present invention relates to a polymer-immobilized cluster composition prepared by fixing a micro transition metal cluster in an amphiphilic crosslinkable polymer and a method for producing the same.

The reaction using a polymer-immobilized catalyst is easy to separate the catalyst from the product, and can be recovered and reused. Collecting. Therefore, in order to develop a more effective polymer-immobilized catalyst, it is desired to develop a new catalyst immobilization method.
When metal is made into nano-size particles, various properties different from the bulk properties appear. Such fine particles called metal clusters are usually composed of several tens of metals, have a size of several nanometers, and exhibit unique physical properties. When such a metal cluster is used as a catalyst for organic synthesis, the catalytic activity is remarkably improved. However, since the metal cluster is unstable and very easily aggregated, it is difficult to use it as a general-purpose catalyst. One of the techniques for stably obtaining metal clusters is an attempt to obtain metal clusters by reducing metal ions in the presence of a stabilizer. As a stabilization method in this case, it has been reported that it is incorporated into a molecule having a cavity such as cyclodextrin, surrounded by a quaternary ammonium salt such as tetraalkylammonium halide, or supported on a polymer micelle (Non-patent Document 5). However, the stability of the metal cluster obtained by such a method is low, and it is difficult to maintain the structure under various conditions in the chemical reaction, and recovery and reuse are almost impossible.

On the other hand, in the field of chemical industry, reduction of the amount of catalyst used and recovery / reuse after use are required due to serious environmental problems and the necessity of cost reduction. Attempts to immobilize a metal catalyst on a carrier have been made for a long time, but usually the catalytic activity and selectivity of the catalyst are reduced, product contamination due to leakage of the catalyst metal during the reaction, and the catalyst after recovery Since this is accompanied by a decrease in activity, a more effective method for immobilizing a metal catalyst is required.
In recent years, polymer-immobilized catalysts in which a metal catalyst is supported on a polymer using microencapsulation have been developed (Non-Patent Documents 1 to 4). However, even in these polymer-immobilized catalysts, there are problems that the solvent resistance is insufficient or the supported metal leaks depending on the type of reaction (Patent Document 1).
Under these circumstances, the inventors of the present application stably immobilized a palladium catalyst by supporting it as a nano-sized cluster on a polystyrene-based copolymer having a crosslinkable functional group by a microencapsulation method and then thermally cross-linking it. Technology to develop. Palladium in the crosslinked polymer is zero-valent and exists extremely stably while no ligand such as a phosphorus atom is coordinated (Patent Documents 2 and 3, Non-Patent Documents 6 and 7). However, in this method, there are cases where immobilization is difficult depending on the type of metal, salt, or ligand.

JP2002-66330 JP2002-253972 WO2004 / 024323 S. Kobayashi et al. J. Am. Chem. Soc. 120, 2985 (1998). S. Kobayashi et al. Org. Lett. 3, 2649 (2001). T. Ishida et al. Adv. Synth. Catal. 345, 576 (2003). S. Kobayashi et al. Chem. Commun. 2003, 449. J. Am. Chem. Soc. 119, 10116 (1997). K. Okamoto et al. J. Org. Chem. 69, 2871 (2004). K. Okamoto et al. Org. Lett. 6, 1987 (2004).

Metal catalyst obtained by encapsulating the catalyst with an organic polymer coating developed by the present inventors (microencapsulation) and then immobilizing the catalyst by crosslinking the polymer (Patent Document 3, Japanese Patent Application No. In 2004-064520, etc., the metal is immobilized on the polymer as a fine metal cluster, exhibits high activity in various reactions, and can recover and reuse the catalyst. However, there are metals and combinations of metals and ligands that cannot be used in this method, and there is a need for means that can apply this method to a wide range of metals and combinations of metals and ligands.
Therefore, the present invention aims to provide a highly versatile method that can fix metals to a polymer as microclusters even when using raw materials that cannot be sufficiently fixed by the conventional microencapsulation method-crosslinking method. And

The present inventors have found that quaternary ammonium (MT Reetz et al. Chme. Commun. 1996, 1921 .; MT Reetz et al. Chme. Commun, 11, 773 (1999) ), and when the quaternary ammonium is added to the solution or dispersion in the step of coacervating the metal catalyst, the incorporation of the metal catalyst into the polymer is facilitated. I found that the problem could be solved.
The reason for this is considered that quaternary ammonium has the effect of dispersing the metal as nano-scale fine particles, and the subsequent crosslinking reaction easily proceeds by dispersing in this way.

The metal in the obtained catalyst is estimated to be several nanometers or less in diameter because no agglomerated clusters are observed even with an electron microscope. Further, when catalytic hydrogenation reaction was carried out using this catalyst, no metal leakage from the catalyst was observed, and the reaction proceeded rapidly and the desired product was obtained quantitatively.
The polymer-immobilized transition metal catalyst of the present invention has less metal leakage than a conventional immobilized metal catalyst, is easy to recover and reuse, and does not cause a decrease in activity after recovery. Furthermore, it is easy to fix to a carrier such as resin, glass or beads using a crosslinking group.

That is, the present invention homogenizes a crosslinkable polymer having an aromatic side chain, a hydrophilic side chain and a crosslinkable group, and a transition metal compound in a solvent in which the crosslinkable polymer is dissolved. A method for producing a polymer-immobilized metal catalyst comprising precipitating a product and causing a crosslinking reaction in the precipitate, wherein the solvent contains a quaternary ammonium salt. It is a manufacturing method of a catalyst. In this method, the crosslinkable polymer and the transition metal compound is uniform solution causes a phase separation by the addition of different anti-solvent polarity, have preferably be precipitated resulting composition .

  Immobilization of the catalyst by the above-described polymer calcelandization method in the presence of a quaternary ammonium salt revealed that palladium (II) salt, palladium (0) or platinum (0), which had been difficult to immobilize until now, was obtained. It was possible to immobilize minute metal clusters on polymers using catalyst precursors such as olefin complexes. Moreover, the immobilized catalyst obtained by this new method not only shows high activity in various reactions, but can be recovered and reused without causing metal leakage.

  In the method for producing a polymer-immobilized transition metal catalyst of the present invention, a crosslinkable polymer and a transition metal compound are uniformly dissolved or dispersed in a solvent containing a quaternary ammonium salt, and as a result, the transition metal compound is supported. Since a polymer is generated, a crosslinkable group of the crosslinkable polymer in the precipitate is subjected to a crosslinking reaction to obtain a polymer-immobilized transition metal catalyst.

  The crosslinkable polymer of the present invention needs to have an aromatic side chain and a hydrophilic side chain (amphiphilic polymer), and further needs to have a crosslinking group. The polymer may further have a hydrophobic side chain other than the aromatic side chain. These side chains are directly bonded to the main chain of the polymer. You may have multiple types of these side chains. The bridging group may be bonded to any of these side chains, and may be directly bonded to the polymer main chain, but preferably a hydrophobic side chain or a hydrophilic side chain containing an aromatic side chain or Both are more preferably bonded to aromatic side chains.

Aromatic side chains include aryl groups and aralkyl groups.
Examples of the aryl group include those having 6 to 10 carbon atoms, preferably 6 carbon atoms, and specific examples include a phenyl group and a naphthyl group.
In addition, the carbon number defined in this specification shall not include the carbon number of the substituent which the group has.
Examples of the aralkyl group include those having 7 to 12 carbon atoms, preferably 7 to 9 carbon atoms, and specific examples include a benzyl group, a phenylethyl group, and a phenylpropyl group.
The aromatic ring in the aryl group and aralkyl group may have a hydrophobic substituent such as an alkyl group, an aryl group, or an aralkyl group.

  The alkyl group which the aromatic ring may have may be linear, branched or cyclic, and in the case of cyclic, it may be monocyclic or polycyclic and usually has 1 to 20 carbon atoms, preferably 1 ˜12, specifically, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group , Isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, n-hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, n-heptyl group, isoheptyl group, sec-heptyl group, tert- Examples include heptyl group, n-octyl group, sec-octyl group, tert-octyl group, nonyl group, decyl group, cyclopentyl group, cyclohexyl group and the like.

Examples of the aryl group and aralkyl group that the aromatic ring may have include those similar to the aryl group and aralkyl group as the aromatic group as described above.
These aromatic rings optionally have 1 to 5 substituents, preferably 1 to 2 substituents on the aromatic ring in the aryl group and aralkyl group.
Examples of the alkyl group as the hydrophobic side chain include the same alkyl groups that the aromatic ring as described above may have.

  Examples of the hydrophobic side chain other than the aromatic side chain include an alkyl group, an alkenyl group, and an alkynyl group.

As the hydrophilic side chain, —R ⁵ (R ⁵ represents —OH or an alkoxy group, preferably —OH) is bonded to a relatively short alkyl group, for example, an alkylene group having about 1 to 6 carbon atoms. -R ⁶ (OR ⁷ ) _m R ⁵ , -R ⁶ (COOR ⁷ ) _n R ⁵ or -R ⁶ (COOR ⁷ ) _o (OR ⁸ ) _p R ⁵ (wherein R ⁴ is the same as above, R ⁶ represents a covalent bond or an alkylene group having 1 to 6 carbon atoms, preferably a covalent bond or 1 to 2 carbon atoms, and R ⁷ and R ⁸ are each independently 2 to 4 carbon atoms, Preferably, it represents an alkylene group of 2, m, n and p are integers of 1 to 10, and o represents 1 or 2. More preferred hydrophilic side chains include —CH ₂ (OC ₂ H ₄ ) ₄ OH and —CO (OC ₂ H ₄ ) ₄ OH.

  Examples of the crosslinking group include an epoxy group, a carboxyl group, an isocyanate group, a thioisocyanate group, a hydroxyl group, a primary or secondary amino group, and a thiol group, preferably an epoxy group, a carboxyl group, an isocyanate group, and a thioisocyanate group. These crosslinking groups may be used alone or in combination as required.

Preferred combinations of crosslinking groups contained in the polymer include only epoxy groups, epoxy groups and hydroxyl groups, epoxy groups and amino groups, epoxy groups and carboxyl groups, only isocyanate groups or thioisocyanate groups, isocyanate groups and hydroxyl groups, and isocyanate groups. An amino group, an isocyanate group, a carboxyl group, etc. are mentioned. Among these, only an epoxy group and a combination of an epoxy group and a hydroxyl group are preferable.
When the polymer has a plurality of types of crosslinking groups, the bonding position of the crosslinking groups is not limited, but is preferably contained in side chains at different positions.

  On the other hand, the crosslinkable polymer may be any polymer having these side chains, but is preferably a polymer obtained by polymerizing monomers having these side chains. Further, as such a monomer, those having a vinyl group such as a double bond or a triple bond for addition polymerization, such as a vinyl group or an acetylene group, are preferable.

Examples of the crosslinkable polymer of the present invention include the following crosslinkable polymers.
(A) 1) a monomer having an aromatic side chain, a hydrophilic side chain and a polymerizable double bond, 2) a monomer having an aromatic side chain and a polymerizable double bond, and 3) an aromatic side having a crosslinking group A crosslinkable polymer obtained by copolymerizing a monomer having a chain and a polymerizable double bond,
(B) 1) Crosslinkable polymer obtained by polymerizing or copolymerizing at least one monomer having a hydrophobic side chain, a hydrophilic side chain having a crosslinking group, or a hydrophobic side chain and a polymerizable double bond. Or (C) 1) a hydrophobic side chain, a hydrophilic side chain having a crosslinking group and a monomer having a polymerizable double bond, 2) a monomer having a hydrophobic side chain and a polymerizable double bond, and 3) a bridge A crosslinkable polymer obtained by copolymerizing at least two monomers selected from the group consisting of a monomer having a hydrophilic side chain or hydrophobic side chain having a group and a polymerizable double bond, preferably It is a crosslinkable polymer of (A).
Here, the same type of monomer may include two or more different monomers.

  The transition metal compound of the present invention is a suitable compound containing a transition metal (for example, carboxylates such as oxides, halides, cyanides, hydroxides, acetates, acetylacetonate salts, carbonates, phosphates). , Sulfates, sulfites, sulfonates, perchlorates, nitrates, nitrites, complexes with ligands, etc.), but transition metals are complexed with appropriate ligands Is preferred. When a complex with such a ligand is used, the transition metal in the precursor is supported on the polymer by ligand exchange with the aromatic ring of the polymer having the structure as described above. When the transition metal in the transition metal precursor is other than zero valent, the supported transition metal can be made zero valent by performing a reduction treatment at the time of micelle formation. The transition metal to be supported is preferably zero-valent.

  Transition metals used here are Group 8 transition metals such as iron, ruthenium and osmium, Group 9 transition metals such as cobalt, rhodium and iridium, Group 10 transition metals such as nickel, palladium and platinum, copper and silver. , Group 11 transition metals such as gold, Group 12 transition metals such as zinc, cadmium and mercury, among which palladium, cobalt, nickel, rhodium, ruthenium, iridium, platinum and the like are preferable. In addition, you may use these transition metals in combination of 2 or more types.

Examples of a ligand for forming a complex include dimethylphenylphosphine (P (CH ₃ ) ₂ Ph), diphenylphosphinoferrocene (dPPf), trimethylphosphine (P (CH ₃ ) ₃ ), triethylphosphine (P ( Et) _3), tri-tert- butylphosphine _{^{(P (t Bu) 3)}} , tricyclohexylphosphine (PCy _3), trimethoxy phosphine _{(P (OCH 3) 3)} , triethoxy phosphine (P (OEt) _3), Tri-tert-butoxyphosphine (P (O ^t Bu) ₃ ), triphenylphosphine (PPh ₃ ), 1,2-bis (diphenylphosphino) ethane (DPPE), triphenoxyphosphine (P (OPh) ₃ ), tri Organic phosphine ligands such as -o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, 1,5-cyclooctadiene (COD), dibenzylideneacetone (DBA), bipi Lysine (BPY), phenanthroline (PHE), benzonitrile (PhCN), isocyanide (RNC), triethylarsine (As (Et) ₃ ), halogen atoms such as fluorine atom, chlorine atom, bromine atom, iodine atom, acetylacetonato , Cyclooctadiene, cyclopentadiene, pentamethylcyclopentadiene, ethylene, carbonyl, acetate, trifluoroacetate, biphenylphosphine, ethylenediamine, 1,2-diphenylethylenediamine, 1,2-diaminocyclohexane, acetonitrile, hexafluoroacetylacetonate, Examples thereof include sulfonate, carbonate, hydroxide, nitrate, perchlorate, sulfate and the like. Among these, organic phosphine ligands, 1,5-cyclooctadiene (COD), dibenzylideneacetone (DBA), bipyridine (BPY), phenanthroline (PHE), benzonitrile (PhCN), isocyanide (RNC), And triethylarsine (As (Et) ₃ ) are preferable, triphenylphosphine, tritert-butylphosphine, and tri-o-tolylphosphine are more preferable, and triphenylphosphine is particularly preferable.
The number of ligands is usually 1 to 4, although it depends on the type of polymer used in the preparation and the crosslinking reaction conditions.

式中、Ｒ^４は、アルキル基を表し、Ｘはハロゲン原子を表す。 Such a crosslinkable polymer and a transition metal compound are uniformly dissolved or dispersed in a solvent containing a quaternary ammonium salt.
The quaternary ammonium salts have the general formula R ¹ ₄ N ⁺ X ^- is represented by. In the formula, each R ¹ may be the same or different and is a hydrocarbon group having 1 to 16 carbon atoms, preferably methyl, ethyl, benzyl, n-propyl, n-butyl, n-pentyl, n -Hexyl, n-heptyl, n-octyl, n-nonyl, n-dodecyl or n-hexadecyl. X represents a halogen atom.
This quaternary ammonium salt has the general formula R ² = N ⁺ R ³ X ⁻ (wherein R ² is a divalent hydrocarbon group having 1 to 16 carbon atoms, and R ³ is the same as R ¹ ). Contains the salt represented. Examples of such quaternary ammonium salts include N-alkylpyridinium salts represented by the following formula.

In the formula, R ⁴ represents an alkyl group, and X represents a halogen atom.

After this crosslinkable polymer and the transition metal compound are dissolved in a good solvent, a transition metal can be incorporated into the polymer aggregate or micelle-like aggregate by adding a suitable poor solvent and causing phase separation.
The method is, for example, a) dissolving in an appropriate polar good solvent and then aggregating with an appropriate polar poor solvent, b) adding an appropriate nonpolar solvent after dissolving in the polar good solvent and carrying a transition metal Form micelle-like aggregates, and further agglomerate with a polar poor solvent, c) dissolve in a suitable nonpolar good solvent and then agglomerate with a suitable nonpolar poor solvent, d) a nonpolar good solvent After dissolution, an appropriate polar solvent is added to form transition metal-supported micelle-like aggregates, and further aggregated with a nonpolar poor solvent. In this case, in the methods a) and b), the hydrophobic side chains are located in the inner direction and the hydrophilic side chains are located in the outer direction of the formed micelle-like aggregates, and the methods c) and d) Then, the hydrophobic side chain is located in the outward direction of the formed micelle-like aggregate, and the hydrophilic side chain is located in the inward direction.

  Examples of polar good solvents include THF, dioxane, acetone, DMF, and NMP. Nonpolar good solvents include toluene, cyclohexane, dichloromethane, and chloroform. Examples of the polar poor solvent include methanol, ethanol, butanol, and amyl alcohol, and examples of the nonpolar poor solvent include hexane, heptane, and octane.

  At this time, a phenomenon in which some or all of the ligand of the transition metal compound is eliminated is observed. Transition metal ultrafine particles are supported in each micelle-like aggregate by interaction with aromatic side chains. In addition, the transition metal is usually fixed at zero valence, but when the transition metal compound is an ion, it can be fixed as a zero-valent transition metal by reduction treatment during phase separation. Here, the concentration of the polymer in the good solvent is about 1 to 100 mg / ml, the amount of the transition metal compound is 0.01 to 0.5 (w / w) with respect to the polymer, and the amount of the poor solvent is 0.2 to 0.2 with respect to the good solvent. 10 (v / v) is used, and the addition time of the poor solvent is usually 10 minutes to 2 hours. The temperature at the time of phase separation is not particularly limited, but is usually performed at room temperature.

Next, the crosslinking group of the crosslinkable polymer is subjected to a crosslinking reaction.
The crosslinking reaction can be caused to react by heating or ultraviolet irradiation depending on the type of the crosslinkable functional group. In addition to these methods, the crosslinking reaction is a conventionally known method for crosslinking a linear organic polymer compound to be used. For example, a method using a crosslinking agent, a method using a condensing agent, a peroxide or an azo compound. A method using a radical polymerization catalyst such as a compound, a method in which an acid or a base is added and heated, for example, a method in which a dehydrating condensing agent such as carbodiimides is combined with an appropriate crosslinking agent, a reaction method, or the like can be performed. .
The temperature at which the crosslinking group is crosslinked by heating is usually 50 to 200 ° C, preferably 70 to 180 ° C, more preferably 100 to 160 ° C.
The reaction time for the heat crosslinking reaction is usually 0.1 to 100 hours, preferably 1 to 50 hours, more preferably 2 to 10 hours.

The polymer-immobilized transition metal catalyst thus obtained is considered to have a form in which the transition metal is supported as ultrafine particles by interaction with the aromatic ring in the polymer. High catalytic activity for hydrogenation reaction of olefins and ketones and hydrosilylation reaction to olefins.

The following examples illustrate the invention but are not intended to limit the invention.

Production Example 1
Styrene (13.42 g, 128.9 mmol), 4-vinylbenzylglycidyl ether (3.06 g, 16.1 mmol), tetraethylene glycol mono-2-phenyl-2-propenyl ether (5.0 g, 16.1 mmol), AIBN (189.6 mg, 1.15 mmol) was dissolved in chloroform (20 mL) and heated and stirred under reflux conditions for 48 hours under an argon atmosphere. After cooling, the reaction mixture was poured into methanol (600 mL) to solidify the polymer. After decanting and removing the supernatant, the residue was dissolved in a small amount of tetrahydrofuran and poured again into methanol. The precipitated polymer was filtered and dried at room temperature under reduced pressure. 16.2 g of polymer was obtained (76% yield).

^From the measurement of ¹ H-NMR, the ratio of the obtained polymer was (styrene / 4-vinylbenzylglycidyl ether / tetraethylene glycol mono-2-phenyl-2-propenyl ether) ratio of each monomer unit (x / y / z) = 83/11/6. The weight average molecular weight (Mw) was 68434. The structure of the obtained polymer is represented by the following formula.

この混合液に、空気雰囲気下、ヘキサンを加えコアセルベート化を行い、析出したマイクロカプセル化白金をろ別、ヘキサン洗浄、減圧乾燥を行った。その後、無溶媒条件下120℃で2時間加熱して高分子を架橋させた。得られた固体を、THF、水、THFで洗浄し、減圧乾燥することで、高分子固定化白金触媒（以下「PI Pt」という。）（0.15 mmol/g）を146 mg得た。白金クラスターの粒子サイズを透過型電子顕微鏡（TEM）にて観測したところ、大きなクラスターの形成は認められず、<1 nmと推定された。また、PI Ptの元素分析から、窒素原子は含まれていない（誤差0.3%以内である）ことが分った（すなわちアンモニウム塩は取り込まれていない）。更に、全てのろ液と洗浄液を集め、dbaの回収を行ったところ、dbaは定量的に回収された。 Copolymer (200 mg) obtained in Production Example 1, tetrabutylammonium bromide (21.3 mg, 0.066 mmol), and Pt (dba) ₂ (44 mg, 0.066 mmol) in THF (3 mL) at room temperature for 24 hours. Stir. Here, dba is dibenzylideneacetone represented by the following formula.

The mixture was coacervated by adding hexane in an air atmosphere, and the precipitated microencapsulated platinum was filtered, washed with hexane, and dried under reduced pressure. Thereafter, the polymer was crosslinked by heating at 120 ° C. for 2 hours under solvent-free conditions. The obtained solid was washed with THF, water, and THF, and dried under reduced pressure to obtain 146 mg of a polymer-immobilized platinum catalyst (hereinafter referred to as “PI Pt”) (0.15 mmol / g). When the particle size of the platinum cluster was observed with a transmission electron microscope (TEM), the formation of a large cluster was not observed, and it was estimated to be <1 nm. In addition, from the elemental analysis of PIPt, it was found that nitrogen atoms were not contained (the error was within 0.3%) (that is, no ammonium salt was incorporated). Furthermore, when all the filtrates and washings were collected and dba was recovered, dba was recovered quantitatively.

Copolymer (200 mg) obtained in Production Example 1, tetrabutylammonium bromide (43 mg, 0.13 mmol) and palladium (II) acetate Pd (OAc) ₂ (29 mg, 0.13 mmol) in THF (3 mL). Stirring was carried out at 66 ° C. for 5 hours. After cooling the mixed solution to room temperature, hexane was added to form a coacervate in an air atmosphere, and the precipitated microencapsulated palladium was separated by filtration, washed with hexane, and dried under reduced pressure. Thereafter, the polymer was crosslinked by heating at 120 ° C. for 2 hours under solvent-free conditions. The obtained solid was washed with THF, water, THF, methylene chloride, and dried under reduced pressure to obtain 206 mg of a polymer-immobilized palladium catalyst (hereinafter referred to as “PI Pd”) (0.45 mmol / g). . When the particle size of the palladium cluster was observed with a transmission electron microscope (TEM), formation of a large cluster was not observed.

Under argon atmosphere, PI Pt (0.15 mmol / g, 1 mol%), 4-phenyl-1-butene (0.5 mmol), HSiMe ₂ OSiMe ₃ (1.0 mmol), water (1.66 mL), hexane (0.83 mL) Were added in this order, and the mixture was stirred at 40 ° C. for 1 hour. After cooling to room temperature, the reaction mixture was diluted with hexane and the catalyst was filtered off. The filtrate was washed with water, and the organic layer was dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, 1,2,4,5-tetramethylbenzene was added as an internal standard substance, and the product was quantified by ¹ H NMR analysis. As a result, the hydrosilylation product was obtained in a yield of 95%. As a result of measuring the amount of platinum leakage by fluorescent X-ray analysis, no leakage was observed.

To PI Pd (0.45 mmol / g, 5 mol%) and 2,4-diphenyl-2-methyl-4-pentene (0.25 mmol), add THF (3 mL), in a hydrogen atmosphere (using balloons), at room temperature For 1 hour. Thereafter, the reaction mixture was diluted with hexane, and the catalyst was filtered off. The filtrate was concentrated under reduced pressure, 1,2,4,5-tetramethylbenzene was added as an internal standard substance, and the product was quantified by ¹ H NMR analysis. As a result, the hydrogenated product was obtained in a quantitative yield. In addition, as a result of measuring the amount of leakage of palladium by fluorescent X-ray analysis, no leakage was observed.

Comparative Example 1
The same experiment as in Example 2 was performed without using tetrabutylammonium bromide in Example 2. However, the target product (catalyst in which palladium was immobilized on a polymer) was not obtained at all.
The reason is considered to be that the metal does not disperse in the form of nanoscale fine particles, and therefore the crosslinking reaction does not proceed. Since metal species having a small hydrophobic ligand such as acetate in this example are difficult to disperse, it is considered that the addition of a quaternary ammonium salt allows the metal to disperse and crosslink. .

Claims (4)

A crosslinkable polymer having an aromatic side chain, a hydrophilic side chain and a crosslinkable group, and a transition metal compound are homogenized in a solvent that dissolves the crosslinkable polymer, and the resulting composition is precipitated, A method for producing a polymer-immobilized metal catalyst, comprising a crosslinking reaction in a precipitate, wherein the solvent contains a quaternary ammonium salt. 2. The method according to claim 1, wherein phase separation is caused by adding a poor solvent having different polarity to a solution in which the crosslinkable polymer and the transition metal compound are homogenized, and the resulting composition is precipitated. Manufacturing method. The transition metal compound is a complex of a transition metal and a ligand, or an oxide, halide, cyanide, hydroxide, carboxylate, acetylacetonate, carbonate, phosphate, sulfuric acid of a transition metal The process according to claim 1 or 2, which is a salt, sulfite, sulfonate, perchlorate, nitrate or nitrite. The quaternary ammonium salt ^R ₁ 4 ^N + X ^- (In the formula, ^{R 1} may each be the same or different, represent a hydrocarbon group having 1 to 16 carbon atoms, X represents a halogen The manufacturing method as described in any one of Claims 1-3 represented by this.