JP4389024B2 - Ruthenium complex catalyst and method for producing α, β-unsaturated carboxylic acid derivative - Google Patents

Description

  The present invention relates to a ruthenium complex catalyst and a method for producing an α, β-unsaturated carboxylic acid derivative, and in particular, a low-valent ruthenium complex catalyst, a cyclic olefin strained using the catalyst, and an α, β-unsaturated catalyst. The present invention relates to a production method for producing an α, β-unsaturated carboxylic acid derivative substituted at the β-position from a saturated carboxylic acid ester.

  In the field of organic industrial chemistry, dimerization or codimerization of inexpensive olefins obtained from petroleum raw materials is one of the important research subjects, and various dimerization or codimerization reactions have been proposed. .

  One of the cheap olefins obtained from petroleum raw materials is norbornene synthesized from ethylene and cyclopentadiene. The norbornene derivative obtained by using norbornene as a starting material may exhibit various useful functions due to a special structure having a bridging bond. Accordingly, the inventors have repeatedly studied the co-dimerization reaction of norbornenes with α, β-unsaturated carboxylic acid derivatives using a metal complex catalyst.

  Conventionally, a synthesis method using a cross-coupling reaction under a palladium catalyst has been proposed as a method for hydroalkenylation of norbornene (Non-patent Document 1). According to this method, an exo form can be obtained with high selectivity by introducing a norbornyl group into the β-position of an α, β-unsaturated carboxylic acid derivative.

In addition, a reaction in which norbornadiene and an acrylate ester are reacted with each other by light irradiation under an iron catalyst to introduce a norbornenyl group at the β-position of the acrylate ester has been reported (Non-patent Document 2).
Fumiyuki Ozawa, et al., “Palladium-catalyzed asymmetric hydroalkylation of norbornene”, Journal of Chemical Society, Chemical Communication, p1323-1324, (1994) (Fumiyuki Ozawa, et al., J. Chem. Soc. , Chem. Comumun., 1994.p1323-1324.) Schmitt et al., Helvetica Chemical Actor, Vol. 61, p1427 (1978) (H. Schmid, et al., Helv. Chim. Acta, 61, 1427 (1987))

  However, in the method described in Non-Patent Document 1, since the reaction reagent has a leaving group such as a halogen atom or triflate, it is more expensive as a raw material, and an equivalent amount of acid generated by the elimination is removed after the reaction. There is a problem that it is necessary to further neutralize and to remove a large amount of salt generated by the neutralization. On the other hand, the reaction described in Non-Patent Document 2 is a substantially stoichiometric reaction and has a low yield (8% or 27%). For this reason, conventionally, the co-dimerization reaction of norbornenes and α, β-unsaturated carboxylic acid derivatives using a metal complex catalyst has not been put into practical use industrially.

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to provide a α, β-substituted α, β-unsaturated carboxylic acid ester in a co-dimerization reaction. An object of the present invention is to provide a ruthenium complex catalyst capable of obtaining a β-unsaturated carboxylic acid derivative with high yield and high selectivity.

  Another object of the present invention is to provide an α, β-unsaturated carboxylic acid having a β-position substituted from a distorted cyclic olefin and an α, β-unsaturated carboxylic acid ester using the catalyst of the present invention. An object of the present invention is to provide a method for producing an α, β-unsaturated carboxylic acid derivative, which can produce an acid derivative in a high yield and with high selectivity, does not produce a salt by-product, and allows easy isolation of the target compound. .

  As a result of intensive studies, the present inventors have found that co-dimerization of a strained cyclic olefin and an α, β-unsaturated carboxylic acid ester is polydentate on 0, 2, 3, or tetravalent ruthenium. The inventors have found that a ruthenium complex catalyst coordinated with a ligand is effective, and have completed the present invention.

  That is, the present invention relates to a ruthenium complex catalyst used for a codimerization reaction of an olefin and an α, β-unsaturated carboxylic acid ester, which is multidentate to zero-valent, divalent, trivalent, or tetravalent ruthenium. The present invention provides a ruthenium complex catalyst characterized in that a ligand is coordinated. Further, the present invention provides a ruthenium complex catalyst of the present invention, a reducing agent for reducing ruthenium contained in the ruthenium complex catalyst, and a cyclic olefin having distortion, an α, β-unsaturated carboxylic acid in the presence of a solvent. An object of the present invention is to provide a method for producing an α, β-unsaturated carboxylic acid derivative, which reacts with an ester to produce an α, β-unsaturated carboxylic acid derivative substituted at the β-position.

  As described above, according to the present invention, the β-position is substituted from a strained cyclic olefin and an α, β-unsaturated carboxylic acid ester by codimerization using the ruthenium complex catalyst of the present invention. The obtained α, β-unsaturated carboxylic acid derivative can be produced with high yield and high selectivity.

  For example, when norbornenes and norbornadienes are used as the distorted cyclic olefin, an α, β-unsaturated carboxylic acid ester having a norbornyl group or a norbornenyl group introduced at the β-position can be obtained. This ester is promising as a fragrance and a polymerization monomer. Thus, according to the present invention, industrially useful substances can be produced from inexpensive petrochemical raw materials.

  Further, unlike the conventional catalytic reaction utilizing the Heck reaction, when the ruthenium complex catalyst of the present invention is used, a large amount of salt is not by-produced after the reaction is completed. For this reason, isolation of the target compound is easy.

Hereinafter, embodiments of the present invention will be described in detail.
[Summary of Invention]
In the present invention, a cyclic olefin having strain and an α, β-unsaturated carboxylic acid ester are reacted (co-dimerization) in the presence of a ruthenium complex catalyst described later to obtain α, β- substituted at the β-position. The present invention provides a method for producing an α, β-unsaturated carboxylic acid derivative for producing an unsaturated carboxylic acid derivative.

  Typical examples of such a codimerization reaction include a reaction between norbornene and an acrylate ester represented by the following reaction formula (1), and a norbornadiene and an acrylic compound represented by the following reaction formula (2). Reaction with methyl acid is mentioned.

[Ruthenium complex catalyst]
Ruthenium, which is a Group 8 transition metal element in the periodic table, can take various oxidation states. In the present invention, a ruthenium oxide having a ruthenium oxidation state of 0, 2, 3, or 4 is used as a catalyst. As will be described later, the trivalent and tetravalent ruthenium complexes are reduced to divalent or zero-valent by a reducing agent and activated as a catalyst.

  The structure of the ruthenium complex of the present invention is represented by the following general formula (1).

  In the formula, X represents an anionic ligand, Lm represents a polydentate ligand, and m represents an integer of 1 or 2. N represents an integer of 0 to 4. When m is 2, the two Lm's may be different multidentate ligands.

  Examples of the anionic ligand X include a halogen atom such as fluorine, chlorine, bromine and iodine; a hydrogen atom; a diketonate group such as acetylacetonate; a cyclopentadienyl group which may have a substituent, and a substituent. Allyl group, alkenyl group, alkyl group, aryl group, alkoxy group, aryloxy group, alkoxycarbonyl group, carboxyl group, alkyl sulfonate group, aryl sulfonate group, alkylthio group, alkenylthio group which may have , Arylthio group, alkylsulfonyl group, and alkylsulfinyl group. Among these, a halogen atom is preferable.

  As the multidentate ligand Lm, a bidentate ligand or a tridentate ligand is preferable.

  Bidentate ligands include bipyridine (abbreviation bipy), 1,5-cyclooctadiene (abbreviation cod), Schiff base, phenanthroline, orthobenzoquinone derivative, nucleobase, ethylenediamine, 1,3-diaminopropane, 1,2 -Diaminobenzene, 1,1'-binaphthyl-2,2'-diamine, 2,2'-bis (diphenylphosphino) -1,1'-binaphthyl, bis (diarylphosphino) benzene, bis (diarylphosphino ) Ferrocene, 2,2′-bithiophene, p-benzoquinone, amino acid derivatives and the like.

  Among the bidentate ligands, bipyridine and 1,5-cyclooctadiene are preferable, and bipyridine coordinated with a nitrogen atom is particularly preferable. Bipyridine and phenanthroline may have a substituent. Examples of the substituent include an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, a hydroxyl group, an alkoxycarbonyl group, a carboxyl group, an aldehyde group, and an alkylcarbonyl. Group, amide group, alkylthio group, arylthio group, halogen group, amino group and the like. Among these, non-bulky lower alkyl groups such as a methyl group, an ethyl group, a propyl group, and an isopropyl group are preferable.

  As tridentate ligands, terpyridine (abbreviation terpy), 1,3,5-cyclooctatriene (abbreviation cot), diethylenetriamine, Schiff base, triazacycloalkane, tetrakis (2'-aminoethyl) -1,2 -Diaminopropane, octaazabicyclo [6.6.6] eicosane, cyclopentadienyl group, benzene derivative (π-coordinate), 2,6-bis (imino) pyridine, 2,6-bis (oxazolinyl) pyridine, tris ( Pyrazolyl) borate, 1,3-bis (phosphinomethyl) benzene, bis (diarylphosphinoethyl) arylphosphine, trithiacycloalkane and the like.

  Among the tridentate ligands, terpyridine and 1,3,5-cyclooctatriene are preferable, and terpyridine coordinated with a nitrogen atom is particularly preferable. Terpyridine may have a substituent, such as an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, a hydroxyl group, an alkoxycarbonyl group, a carboxyl group, an aldehyde group, an alkylcarbonyl group, Examples include an amide group, an alkylthio group, an arylthio group, a halogen group, and an amino group. Among these, non-bulky lower alkyl groups such as a methyl group, an ethyl group, a propyl group, and an isopropyl group are preferable.

  The number m of the multidentate ligand is 1 or 2 in order to generate a vacant coordination site coordinated by the reaction reagent. The number n of the anionic ligand depends on the valence of ruthenium, the number of coordination atoms of the polydentate ligand, and the number m. For example, in the case of a divalent ruthenium complex, the octahedral 6 Since m takes a coordination structure and n is a tridentate ligand, n is 3.

Specific examples of the ruthenium complex include RuCl ₃ (terpy), RuCl ₃ (tri-t-butylterpy), RuCl ₄ (bipy), Ru (cod) (cot), and the like. Among these, RuCl ₃ (terpy) and RuCl ₄ (bipy) are preferable from the viewpoint of excellent catalytic activity. The official name of tri-t-butylterpy is 4,4 ', 4 "-tri-t-butyl-2,2': 6 ', 2" -terpyridine (4,4', 4 "-tri- t-butyl-2,2 ': 6', 2 "-terpyridine).

The ruthenium complex is synthesized using ruthenium (III) chloride trihydrate (RuCl ₃ .3H ₂ O) as a starting material. For example, RuCl ₃ (terpy) is synthesized by refluxing ruthenium (III) chloride trihydrate and terpyridine in methanol.
[Co-dimerization reaction]
The above-mentioned co-dimerization reaction is a reaction of a strained cyclic olefin with an α, β-unsaturated carboxylic acid ester in the presence of the ruthenium complex catalyst, the reducing agent, and the solvent. This reaction proceeds by adding a reaction raw material, a ruthenium complex catalyst, a reducing agent, and a solvent to a reaction vessel, and stirring the resulting solution with heating. After completion of the reaction, the target compound can be obtained by removing the solvent and isolating the product.

  Note that when the ruthenium complex catalyst contains zero-valent ruthenium, no reducing agent is required.

(Distorted cyclic olefin)
A strained cyclic olefin is a cyclic olefin having a strain in the ring structure. Such cyclic olefins include bicyclic compounds having bridgehead carbon atoms such as norbornenes and norbornadienes, in addition to monocyclic olefins.

  As the monocyclic olefin, a cyclic olefin having 3 to 5 carbon atoms such as cyclopropene, cyclobutene, cyclopentene, or methylcyclopentene can be used. These monocyclic olefins may be substituted, and examples of the substituent include an alkyl group and an aryl group.

  As the norbornenes, norbornenes represented by the following general formula (2) can be used.

In said formula, R < ¹ > -R < ⁶ > represents a hydrogen atom or a lower alkyl group mutually independently.

The lower alkyl group includes carbon such as methyl group, ethyl group, n-propyl group, isopropyl group, i-butyl group, t-butyl group, n-butyl group, n-pentyl group, neopentyl group, and t-pentyl group. Examples thereof include alkyl groups having 1 to 5 numbers. In view of high reactivity, R ^{1 to} R ⁶ are particularly preferably hydrogen atoms.

  Specific examples include norbornene, methyl norbornene, dimethyl norbornene, ethyl norbornene and the like.

  As norbornadiene, norbornadiene represented by the following general formula (3) can be used.

In said formula, R < ⁷ > -R < ¹² > represents a hydrogen atom or a lower alkyl group mutually independently.

The lower alkyl group includes carbon such as methyl group, ethyl group, n-propyl group, isopropyl group, i-butyl group, t-butyl group, n-butyl group, n-pentyl group, neopentyl group, and t-pentyl group. Examples thereof include alkyl groups having 1 to 5 numbers. From the viewpoint of high reactivity, R ^{7 to} R ¹² are particularly preferably hydrogen atoms.

  Specific examples include norbornadiene, methylnorbornadiene, dimethylnorbornadiene, ethylnorbornadiene, and the like.

(Α, β-unsaturated carboxylic acid ester)
As the α, β-unsaturated carboxylic acid ester, an α, β-unsaturated carboxylic acid ester represented by the following general formula (4) can be used.

In said formula, R < ¹³ > -R < ¹⁵ > represents a hydrogen atom or a lower alkyl group mutually independently. R ¹⁶ represents an alkyl group, an alkenyl group, an alkynyl group or an aryl group hydrocarbon group.

As the lower alkyl group representing R ^{13 to} R ¹⁵ , methyl group, ethyl group, isopropyl group, i-butyl group, t-butyl group, n-butyl group, n-pentyl group, neopentyl group, t-pentyl group, etc. And an alkyl group having 1 to 5 carbon atoms. R ¹³ and R ¹⁴ are preferably a hydrogen atom, and R ¹⁵ is preferably a hydrogen atom or a methyl group. That is, the α, β-unsaturated carboxylic acid ester is preferably an acrylic acid ester or a methacrylic acid ester.

The hydrocarbon group representing R ¹⁶ may be linear or branched. As the alkyl group representing R ¹⁶ , methyl group, ethyl group, n-propyl group, isopropyl group, i-butyl group, t-butyl group, n-butyl group, n-pentyl group, neopentyl group, t-pentyl group Etc. Examples of the alkenyl group representing R ¹⁶ include a vinyl group, an allyl group, a propenyl group, and an isopropenyl group. Examples of the alkynyl group representing R ¹⁶ include ethynyl group and 2-propynyl group.

Examples of the aryl group representing R ¹⁶ include a phenyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 2,4-dimethylphenyl group, a 2,6-diethylphenyl group, 2,6- A diisopropylphenyl group, a mesityl group, etc. are mentioned.

The hydrocarbon group representing R ¹⁶ is preferably a lower alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a t-butyl group, or an n-butyl group.

(Reducing agent)
It is presumed that the reducing agent activates the ruthenium complex catalyst by reducing trivalent or tetravalent ruthenium contained in the ruthenium complex to divalent or zero valent. As such a reducing agent, zinc, aluminum, iron, a zinc-copper couple, or the like can be used. Among these, zinc is particularly preferable from the viewpoint of improving the reaction yield. In order to increase the contact area, it is more preferable to use powdered zinc. For example, powdered zinc manufactured by Nacalai can be used. The addition amount of the reducing agent is preferably about 10 equivalents relative to the catalyst. The reaction yield improves by making the addition amount of a reducing agent into said range.

(solvent)
As the reaction solvent, when the above reducing agent is used, a primary or secondary alcohol such as methanol, ethanol, isopropanol, or n-butanol is used. These alcohols function as a reducing aid that promotes the reducing action of the reducing agent. For example, primary alcohols such as methanol and ethanol are preferably used.

  On the other hand, when no reducing agent is used, in addition to alcohol solvents, nonpolar solvents such as n-pentane, n-hexane and toluene, ether solvents such as diethyl ether and tetrahydrofuran, dichloromethane, 1,2-dichloroethane, etc. These chlorinated solvents can be used.

  The amount of the solvent is adjusted so that the concentration of the catalyst in the solvent is 0.017 to 0.05 mol / liter, preferably about 0.05 mol / liter. By setting the concentration of the catalyst in the solvent within the above range, the reaction yield is improved.

(Additive)
When norbornadiene is used as a reaction raw material, it is preferable to add phosphine to the reaction solution. By adding a phosphine having a high coordination ability, bidentate coordination of norbornadiene can be suppressed and a decrease in reactivity of norbornadiene can be prevented.

  The phosphine is preferably a secondary or tertiary phosphine from the viewpoint of improving the reaction yield, and more preferably a tertiary phosphine such as triphenylphosphine.

  The phosphine substituent is preferably an alkyl group or an aryl group, more preferably an aryl group. As the alkyl group, an alkyl group having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms is usually used, and examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. As the aryl group, an aryl group having 6 to 24 carbon atoms, preferably 6 to 10 carbon atoms is usually used, and examples thereof include phenyl, naphthyl, tolyl, and xylyl.

  Specifically, in addition to triphenylphosphine and tris (fluorophenyl) phosphine, the following phosphines can be used.

  Diphenylmethylphosphine, diphenyl (methoxyphenyl) phosphine, diphenylethylphosphine, diphenylpropylphosphine, ditolylmethylphosphine, ditolylethylphosphine, di (fluorophenyl) methylphosphine, di (chlorophenyl) methylphosphine, di (bromophenyl) methyl Phosphine, dixylylmethylphosphine, di (methoxyphenyl) methylphosphine, dinaphthylmethylphosphine, phenyltolylmethylphosphine,

  Tris (halophenyl) phosphine, bis (halophenyl) phenylphosphine, diphenylhalophenylphosphine, tris (methoxyphenyl) phosphine, bis (methoxyphenyl) phenylphosphine, tris (trifluoromethylphenyl) phosphine, bis (trifluoromethylphenyl) phenyl Phosphine, diphenyl (trifluoromethylphenyl) phosphine, tolylylphosphine, ditolylphenylphosphine, diphenyltolylphosphine, tris (dimethylaminophenyl) phosphine, bis (dimethylaminophenyl) phenylphosphine, diphenyl (dimethylaminophenyl) phosphine, etc. Is mentioned.

  The amount of phosphine added is preferably about 10 equivalents relative to the catalyst. The reaction yield improves more by making the addition amount of a phosphine into said range.

(Reaction conditions)
The reaction temperature is appropriately set according to the boiling point of the solvent, but the reaction temperature is preferably in the range of 80 to 100 ° C. from the viewpoint of improving the reaction yield, selectivity, shortening the reaction time, and the like. By setting the reaction temperature within the above range, the reaction yield and selectivity are further improved. Moreover, although reaction time is suitably set according to the reaction raw material (substrate), it is preferable to make reaction time into the range of 1 to 12 hours from a viewpoint of reaction yield improvement. As the reaction vessel, it is preferable to use a corrosion-resistant glass vessel or the like.

  Since ruthenium complex catalysts are generally unstable in air, the reaction is preferably carried out in an inert gas atmosphere. Nitrogen gas, argon gas, etc. can be used as the inert gas. Further, since the ruthenium complex catalyst is difficult to dissolve uniformly in the solvent, it is preferable to stir the reaction solution. Examples of the stirring method include mechanical stirring and ultrasonic stirring.

  The reaction molar ratio of olefin to α, β-unsaturated carboxylic acid ester is preferably 2 to 7 times. By setting the reaction molar ratio within the above range, the reaction yield and selectivity are further improved. From the viewpoint of improving the reaction yield, the reaction molar ratio is more preferably 5 to 7 times.

(Confirmation and isolation of target compound)
By the above-mentioned co-dimerization reaction, an α, β-unsaturated carboxylic acid ester substituted at the β-position is produced in a high yield. When norbornenes or norbornadienes are used as reaction raw materials, an exo-trans isomer in which a substituent is introduced on the same side as the bridgehead with respect to the olefin can be obtained with high selectivity.

  Confirmation of the target compound and reaction yield can be carried out using ordinary analytical means such as gas-liquid chromatography (GLC). After completion of the reaction, the solvent is removed from the reaction solution, and the target compound is separated from the residue by distillation. As a result, the catalyst and the target compound are separated. Depending on the reaction conditions, isomers other than the exo-trans isomer are by-produced. This isomer and the exo-trans isomer can be separated by, for example, column chromatography.

  An α, β-unsaturated carboxylic acid ester in which a norbornyl group or the like is introduced at the β-position has a fruit-like fragrance and is promising as a fragrance. In addition, an α, β-unsaturated carboxylic acid ester in which a norbornenyl group or the like is introduced at the β-position has two polymerization sites, and two types of polymers can be obtained by different types of polymerization reactions. Therefore, it is also promising as a monomer.

  For example, as shown below, when an acrylic ester (1a) having a norbornyl group introduced therein is copolymerized with ethylene, a polymer (1) having the norbornyl group introduced into the side chain can be obtained.

  On the other hand, in the acrylic ester (9a) having a norbornenyl group introduced, a polymer (2) having a five-membered ring structure and an olefin introduced into the main chain is obtained by ring-opening metathesis polymerization of the olefin moiety of the norbornene skeleton. Can do.

  As in the above polymers (1) and (2), polymers in which a cyclic structure is introduced into the main chain or side chain are attracting attention as functional materials, and are used for various applications such as photoresist materials. Application is possible.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
Example 1
Co-dimerization reaction of 2-norbornene and ethyl acrylate shown below was performed.

Under argon atmosphere, 2-norbornene 470 mg (5.0 mmol), ethyl acrylate 100 mg (1.0 mmol), RuCl ₃ (terpy) 22 mg (0.050 mmol), zinc powder 33 mg (0.50 mmol) and ethyl alcohol 1.0 ml The mixture was placed in a 20 ml glass reaction vessel made of Pyrex (R) equipped with a three-way cock and a magnetic rotor, and this mixture was heated and stirred in a 90 ° C. hot bath for 1 hour. After completion of the reaction, the reaction solution was distilled under reduced pressure using a Kugelrohr distiller, followed by silica gel column chromatography (silica gel: “silica gel 60N” manufactured by Kanto Chemical Co., Inc., spherical, neutral, 40-50 μm; eluent: hexane / Ethyl acetate = 50/1) was performed to obtain 122 mg of the exo-trans isomer shown in the above reaction formula. The obtained exo-trans isomer was a colorless oily liquid. The reaction yield of the exo-trans isomer calculated from the GLC peak was 78%, and the isolation yield was 63%. The proportion of the exo-trans isomer in the produced codimer was 93%, which was a high selectivity. The results are shown in Table 1. In Table 1, the reaction temperature represents the bath temperature.

The identification data of the obtained codimer is shown below.
exo-Ethyl (2E) -3-bicyclo [2.2.1] hept-2-ylprop-2-enoate. Bp 120-130 ° C (10.0 mmHg), IR spectrum (neat): 1720, 1649 cm ⁻¹ . ¹ H NMR (CDCl ₃ , 400 MHz): δ6.85 (dd, J = 7.6, 15.6 Hz, 1H) , 5.71 (dd, J = 1.0, 15.6 Hz, 1H), 4.17 (q, J = 6.8, 2H), 2.28-2.22 (m, 2H), 2.15 (s, 1H), 1.60-1.50 (m, 4H) , 1.40-1.32 (m, 2H), 1.28 (t, J = 6.8, 3H), 1.25-1.15 (m, 2H) 13 C NMR (CDCl 3, 100 MHz):. δ167.27, 153.77, 118.69, 60.09 , 44.59, 41.83, 36.89, 36.55, 35.79, 29.63, 28.87, 14.27. MS (EI) m / z 194 (M ⁺ ). Anal. Calcd for C ₁₂ H ₁₈ O ₂ : C, 74.19; H, 9.34. : C, 74.15; H, 9.16.

The analysis conditions by GLC and the yield calculation method are shown below.
GLC equipment: “Shimadzu GC-14B” manufactured by Shimadzu Corporation
Glass column: ID 3.2 mm x 3.0 m
Filler: “Silicone OV-17” manufactured by GL Sciences Inc.
(2% on Chromosorb W (AW-DMCS), 60-80 mesh)
Using naphthalene as an internal standard substance, it was quantified by the internal standard method, and the yield was calculated.

(Examples 2 to 4)
As shown in Table 1, the catalyst and reaction conditions were variously changed, and a co-dimerization reaction was performed in the same manner as in Example 1. The results are also shown in Table 1.

(Comparative Examples 4 to 8)
As shown in Table 1, the catalyst and reaction conditions were variously changed, and a co-dimerization reaction was performed in the same manner as in Example 1. The results are also shown in Table 1.

  As can be seen from Table 1, when a ruthenium complex catalyst having a polydentate ligand such as terpyridine was used (Examples 1 to 4), the reaction proceeded in a high yield. When a catalyst containing zero-valent ruthenium was used (Example 4), the reaction proceeded without using a reducing agent such as zinc or an alcohol solvent. On the other hand, when a catalyst having only a monodentate ligand was used (Comparative Examples 1 to 4), the yield was very low or the reaction did not proceed.

(Example 5)
Co-dimerization reaction of 2-norbornene and methyl acrylate shown below was performed.

Under an argon atmosphere, 2-norbornene 470 mg (5.0 mmol), methyl acrylate 86 mg (1.0 mmol), RuCl ₃ (terpy) 22 mg (0.050 mmol), zinc powder 33 mg (0.50 mmol) and methyl alcohol 1.0 ml The mixture was placed in a 20 ml glass reaction vessel made of Pyrex (R) equipped with a three-way cock and a magnetic rotor, and the mixture was heated and stirred in a warm bath at 80 ° C. for 1 hour. After completion of the reaction, the reaction solution was distilled under reduced pressure using a Kugelrohr distiller, and then silica gel column chromatography (silica gel: Kanto Chemical Silica Gel 60N, spherical, neutral, 40-50 μm; eluent: hexane / ethyl acetate = 50 / 1), 129 mg of the exo-trans isomer shown in the above reaction formula was obtained. The obtained exo-trans isomer was a colorless oily liquid. The reaction yield of the exo-trans isomer calculated from the GLC peak was 85%, and the isolation yield was 70%. The analysis conditions and yield calculation method by GLC are the same as in Example 1. The results are shown in Table 2. The ratio of the exo-trans isomer in the produced codimer was as high as 95%. In Table 2, the reaction temperature represents the bath temperature.

The identification data of the obtained codimer is shown below.
exo-Methyl (2E) -3-bicyclo [2.2.1] hept-2-ylprop-2-enoate. Bp 110-120 ° C (10.0 mmHg), IR spectrum (neat): 1727, 1652 cm ^-1 . ¹ H NMR (CDCl ₃ , 400 MHz): δ6.85 (dd, J = 7.8, 15.7 Hz, 1H), 5.72 (dd, J = 1.0, 15.7 Hz, 1H), 3.71 (s, 3H), 2.29-2.22 (m, 2H), 2.15 (s, 1H), 1.60-1.43 (m, 4H), 1.40-1.32 (m, 2H), 1.28-1.15 (m, 2H). ¹³ C NMR (CDCl ₃ , 100 MHz) : δ167.27, 153.88, 118.14, 51.39, 44.69, 41.94, 37.01, 36.66, 35.88, 29.74, 28.98.MS (EI) m / z 180 (M ⁺ ). Anal.Calcd for C ₁₁ H ₁₆ O ₂ : C , 73.30; H, 8.95. Found: C, 73.15; H, 9.16.

(Examples 6 to 9)
As shown in Table 2, a co-dimerization reaction was performed in the same manner as in Example 1 except that various solvents and alkyl groups (R groups) derived from the alcohol component of the acrylate ester were changed. The results are also shown in Table 2.

(Comparative Examples 5-7)
As shown in Table 2, the codimerization reaction was carried out in the same manner as in Example 1 except that R = methyl and the solvent was changed. The results are also shown in Table 2.

When a RuCl ₃ (terpy) catalyst containing trivalent ruthenium is used, a reducing agent such as zinc is required. In the presence of RuCl ₃ (terpy) catalyst and zinc, as can be seen from Table 2, when primary alcohol or secondary alcohol is used as the solvent (Examples 5 to 9), the reaction is performed in a high yield. Progressed. This is considered to be because alcohol having α-hydrogen acts as a reducing aid. When an ester is reacted in an alcohol solvent, a transesterification reaction may occur. Therefore, it is common to use an alcohol solvent of the same type as the alcohol component of the ester. However, R = t-butyl is used as the solvent. When n-butanol was used (Example 9), the transesterification reaction did not occur and the reaction proceeded in a high yield. On the other hand, when a hydrocarbon solvent (Comparative Example 2) and an ether solvent (Comparative Example 3) were used, no reaction occurred. In addition, no reaction occurred when a tertiary alcohol was used (Comparative Example 1).

(Example 10)
Codimerization reaction of 2,5-norbornadiene and methyl acrylate shown below was performed.

Under argon atmosphere, 2,5-norbornadiene 644 mg (7.0 mmol), methyl acrylate 86 mg (1.0 mmol), RuCl ₃ (terpy) 22 mg (0.050 mmol), zinc powder 33 mg (0.50 mmol), tris (p -Fluorophenyl) phosphine (163 mg, 0.50 mmol) and methyl alcohol (1.0 ml) were placed in a 20 ml glass reaction vessel made by Pyrex (R) equipped with a three-way cock and a magnetic rotor, and the mixture was placed in a 80 ° C hot bath. The mixture was heated and stirred for 12 hours. After completion of the reaction, the reaction solution was distilled under reduced pressure using a Kugelrohr distiller, and then silica gel column chromatography (silica gel: Kanto Chemical Silica Gel 60N, spherical, neutral, 40-50 μm; eluent: hexane / ethyl acetate = 50 / 1), 103 mg of the exo-trans isomer shown in the above reaction formula was obtained. The obtained exo-trans isomer was a colorless oily liquid. The reaction yield calculated from the GLC peak was 70%, and the isolation yield was 58%. The analysis conditions and yield calculation method by GLC are the same as in Example 1. The results are shown in Table 3. The proportion of the exo-trans isomer in the produced codimer was 97%, which was a high selectivity. In Table 3, the reaction temperature represents the bath temperature.

The identification data of the obtained codimer is shown below.
exo-Methyl (2E) -3-bicyclo [2.2.1] hept-5-en-2-ylprop-2-enoate. Bp 110-120 ° C (10.0 mmHg), IR spectrum (neat): 1724, 1652, ^{. 1649 cm -1 1 H NMR (} CDCl 3, 400 MHz): δ6.98 (dd, J = 8.8, 15.6 Hz, 1H), 6.12 (t, J = 2.0 Hz, 2H), 5.83 (dd, J = 1.0, 15.6 Hz, 1H), 2.93 (s, 1H), 2.70 (d, J = 1.4 Hz, 1H), 2.17 (ddd, J = 4.4, 8.8, 13.2 Hz, 1H), 1.47-1.36 (m, 4H ¹³ C NMR (CDCl ₃ , 100 MHz): δ167.00, 154.05, 137.36, 135.75, 119.40, 51.42, 47.81, 45.56, 42.37, 41.52, 32.60.MS (EI) m / z 178 (M ⁺ ). Anal. Calcd for C ₁₁ H ₁₄ O ₂ : C, 74.13: H, 7.92. Found: C, 74.13; H, 7.92.

(Examples 11 to 16)
As shown in Table 3, a co-dimerization reaction was carried out in the same manner as in Example 10 except that the additive, its addition amount, and the reaction time were changed. The results are also shown in Table 3.

As can be seen from Table 3, when 10 equivalents of phosphine was added to the catalyst (Example 10), the reaction proceeded in a high yield. Further, a considerable reaction proceeded even in a short time with an addition amount of 5 equivalents to the catalyst (Examples 11 to 16). The yield was improved when triarylphosphine was used (Examples 10, 11, and 14), particularly when triarylphosphine having an electron-withdrawing group was used (Examples 10 and 14).

Claims (19)

  A ruthenium complex catalyst used in a co-dimerization reaction between an olefin and an α, β-unsaturated carboxylic acid ester, in which a multidentate ligand is coordinated to zero-valent, bivalent, trivalent, or tetravalent ruthenium. A ruthenium complex catalyst characterized by that.   The ruthenium complex catalyst according to claim 1, wherein the multidentate ligand is coordinated to ruthenium by a nitrogen atom.   The ruthenium complex catalyst according to claim 1 or 2, wherein the polydentate ligand is a substituted or unsubstituted terpyridine.   The ruthenium complex catalyst according to claim 1 or 2, wherein the polydentate ligand is a substituted or unsubstituted bipyridine. The ruthenium complex catalyst according to any one of claims 1 to 4, which is represented by the following general formula (1).

In the formula, X represents an anionic ligand, and Lm represents a multidentate ligand. m represents an integer of 1 or 2, and n represents an integer of 0 to 4. When m is 2, the two Lm's may be different multidentate ligands. The ruthenium complex catalyst according to claim 1, which is Ru (Cl) ₃ (terpy). In the presence of a ruthenium complex catalyst in which a multidentate ligand is coordinated to zero-valent ruthenium,
Reaction of strained cyclic olefin with α, β-unsaturated carboxylic acid ester,
A method for producing an α, β-unsaturated carboxylic acid derivative, which produces an α, β-unsaturated carboxylic acid derivative substituted at the β-position. Ruthenium complex catalyst in which a multidentate ligand is coordinated to bivalent, trivalent, or tetravalent ruthenium, a reducing agent for reducing ruthenium contained in the ruthenium complex catalyst, and the presence of a solvent that acts as a reducing aid Below,
Reaction of strained cyclic olefin with α, β-unsaturated carboxylic acid ester,
A method for producing an α, β-unsaturated carboxylic acid derivative, which produces an α, β-unsaturated carboxylic acid derivative substituted at the β-position.   The method for producing an α, β-unsaturated carboxylic acid derivative according to claim 8, wherein the reducing agent contains zinc.   The method for producing an α, β-unsaturated carboxylic acid derivative according to claim 8 or 9, wherein the solvent is a primary alcohol or a secondary alcohol.   The α, β-unsaturated carboxylic acid according to any one of claims 7 to 10, wherein the strained cyclic olefin comprises at least one of a 3-membered ring, a 4-membered ring, and a 5-membered ring. A method for producing an acid derivative.   The method for producing an α, β-unsaturated carboxylic acid derivative according to any one of claims 7 to 10, wherein the strained cyclic olefin is a bicyclo compound. The method for producing an α, β-unsaturated carboxylic acid derivative according to any one of claims 7 to 12, wherein the cyclic olefin having strain is a norbornene represented by the following general formula (2).

In the formula, R ^{1 to} R ⁶ each independently represent a hydrogen atom or a lower alkyl group. The method for producing an α, β-unsaturated carboxylic acid derivative according to any one of claims 7 to 12, wherein the cyclic olefin having distortion is a norbornadiene represented by the following general formula (3).

In the formula, R ^{7 to} R ¹² each independently represent a hydrogen atom or a lower alkyl group. The α, β-unsaturated carboxylic acid ester according to any one of claims 7 to 14, wherein the α, β-unsaturated carboxylic acid ester is an α, β-unsaturated carboxylic acid ester represented by the following general formula (4). A method for producing an unsaturated carboxylic acid derivative.

In formula, R < ¹³ > -R < ¹⁵ > represents a hydrogen atom or a lower alkyl group mutually independently. R ¹⁶ represents an alkyl group, an alkenyl group, an alkynyl group or an aryl group. The α, β-unsaturated product according to any one of claims 7 to 15, wherein the α, β-unsaturated carboxylic acid ester is an acrylic acid ester or a methacrylic acid ester represented by the following general formula (5). A method for producing a carboxylic acid derivative.

In the formula, R ¹⁵ represents a hydrogen atom or a lower alkyl group. R ¹⁶ represents an alkyl group, an alkenyl group, an alkynyl group or an aryl group.   The α, β-unsaturated carboxylic acid according to any one of claims 14 to 16, wherein phosphine is further added when the strained cyclic olefin is a norbornadiene represented by the general formula (3). A method for producing an acid derivative.   The method for producing an α, β-unsaturated carboxylic acid derivative according to claim 17, wherein the phosphine is a tertiary phosphine.   The method for producing an α, β-unsaturated carboxylic acid derivative according to any one of claims 7 to 18, wherein the α, β-unsaturated carboxylic acid ester is a methyl ester or an ethyl ester.