JPH1180041A - Production of triene compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound useful as a raw material for a polymer, etc., in a high yield with a small amount of by-product, by reacting a specific metallacyclopentadienyl with a metal halide and a prescribed acetylene compound and reacting the reaction product with a specified acid. SOLUTION: (A) A compound of formula I [R1 to R4 are each a 1-20C (substituted) alkyl, alkenyl, aromatic group, etc.; M is a transition metal; L is a ligand; (n) is 0-4] is reacted with (B) a metal halide and (C) a compound of formula II (R<5> and R<6> are each as shown for R1 ) at <=0 deg.C (preferably the molar amounts of the components B and C used are 0.3-50 times and 0.5-50 times that of the component A, respectively) and then reacted with (D) Bronsted acid to give a compound of formula III (R<1> , R<2> , R<3> and R<4> are each as shown for R1 , R2 , R3 and R4 ).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a triene compound. Triene compounds are useful substances as raw materials and modifiers for synthetic polymers, synthetic intermediates for pharmaceuticals and agricultural chemicals, nonlinear optical materials, and the like.

[0002]

2. Description of the Related Art Conventionally, a compound obtained by reacting three molecules of acetylenes in the presence of a transition metal or a metal halide of Group 4 of the periodic table is disclosed in J. Chem. Soc., Chem. Commun., 1995, 36.
As shown in "1", it is a benzene derivative or a Dewar benzene derivative. That is, a method for synthesizing a triene compound directly from acetylenes is not known.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a novel method for producing a conjugated triene compound having a specific structure directly from acetylenes. It is in.

[0004]

That is, the gist of the present invention is that, at a temperature of 0 ° C. or less, first, the following general formula (1)
Wherein a metallacyclopentadienyl represented by the following formula is reacted with a metal halide and an acetylene compound represented by the following general formula (2), and then a Bronsted acid is reacted. The present invention relates to a method for producing a triene compound represented by the formula:

[0005]

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In the general formulas (1) to (3), R ^{1 to} R ⁶ each represent an alkyl group, an alkenyl group, an aromatic group, a silyl group, an alkoxy group, or an ester group. However, these groups have 1 to 20 carbon atoms and may have a substituent. In the general formula (1), M represents a transition metal, L represents a ligand, and n represents an integer of 0 to 4.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
First, metallacyclopentadienyl represented by the following general formula (1) will be described.

[0008]

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In the general formula (1), M represents a transition metal. The transition metal means a metal belonging to Groups 3 to 10 on the periodic table. Although it does not specifically limit as a transition metal, Preferably it is 3-6.
Group 4 transition metals, more preferably Group 4 transition metals such as titanium, zirconium and hafnium.

In the general formula (1), L represents a ligand, and specific examples thereof include cyclopentadienyl group, indenyl group, fluorenyl group, azulenyl group, hydrocarbonoxy group, amide group, acetylacetonate. Group, a carboxyl group, a phosphine ligand, an amine ligand, an ether ligand, and compounds having a ligand in which these are linked by an appropriate crosslinking group. Incidentally, each of the above groups,
It may have a substituent. In the general formula (1), n
Represents an integer of 0 to 4, preferably 1 or 2. And
When n is 2 or more, each ligand may be the same or different.

In the general formula (1), R ^{1 to} R ⁴ each represent
Represents an alkyl group, an alkenyl group, an aromatic group, a silyl group, an alkoxy group, or an ester group. However, these groups have 1 to 20 carbon atoms and may have a substituent.

Specific examples of R ^{1 to} R ⁴ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, neopentyl, hexyl, octyl, nonyl, decyl, cyclopentyl, cyclohexyl, cyclooctyl. Alkyl groups such as vinyl,
Allyl, 1-propenyl, 1, 2 or 3-butenyl, 1
Alkenyl groups such as 5-hexenyl, cyclopentenyl, cyclohexenyl, and cyclooctenyl; aromatic groups such as phenyl, naphthyl, tolyl, and xylyl; trimethylsilyl, triethylsilyl, trimethoxysilyl, triethoxysilyl, diphenylmethylsilyl, and dimethylphenylsilyl , Silyl groups such as triphenylsilyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, alkoxy groups such as t-butoxy, phenoxy, allyloxy groups such as naphthoxy, methyl carboxylate, ethyl carboxylate, propyl carboxylate, Ester groups such as isopropyl carboxylate, butyl carboxylate, isobutyl carboxylate, t-butyl carboxylate and phenyl carboxylate; That.

Of the above, methyl, ethyl, n-butyl, t-butyl, hexyl, phenyl, trimethylsilyl, methyl carboxylate, ethyl carboxylate, t-butyl carboxylate and phenyl carboxylate are preferred, and ethyl, n-butyl carboxylate are preferred. Butyl, t-butyl,
Hexyl, trimethylsilyl and methylcarboxylate are more preferred.

The metallacyclopentadienyl represented by the general formula (1) can be obtained by reacting a corresponding organic transition metal compound with an acetylene compound represented by the following general formulas (4) and (5). I can do it. The meanings of R ^{1 to} R ⁴ in formulas (4) and (5) are the same as those in formula (1).

[0015]

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Examples of the organic transition metal compound include compounds having the above-mentioned ligands. Preferred specific examples thereof are as shown in the following (i) to (iii).

(I) Group 4 transition metal compound having at least two halogens (a) and a chemical reagent capable of substituting this halogen with an alkyl group having 2 or more carbon atoms (b)
(Ii) a metallacycle compound or a substituted metallacycle compound having a group 4 transition metal in the ring (iii) a divalent group 4 transition metal compound

The compound (i) can be converted into the compound (ii) or (iii) depending on the reaction conditions.
Is convertible into the compound of (ii).

The chemical reagent (a) used in the synthesis of the compound (i) includes zirconium tetrachloride, zirconocene dichloride, zirconocene dibromide, zirconocene diiodide, cyclopentadienyl zirconium trichloride, bis (methylcyclohexane) (Pentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium dichloride, bis (trimethylcyclopentadienyl) zirconium dichloride, bis (tetramethylcyclopentadienyl) zirconium dichloride, bis (pentamethylcyclopentadienyl) Zirconium dichloride,
Bis (trimethylsilylcyclopentadienyl) zirconium dichloride, bis (indenyl) zirconium dichloride, bis (dimethylamido) zirconium dichloride and the like can be mentioned. Examples of the chemical reagent (b) used in the synthesis of the compound (i) include ethyl lithium, n-butyl lithium, ethyl Grignard, butyl Grignard and the like.

Specific examples of the compound (ii) include compounds in which hydrogen such as zirconacyclopentane, zirconacyclopentene, zirconacyclopentadiene, and cyclopentadienyl has been substituted with a methyl group or a trimethylsilyl group; Compounds in which cyclopentadiedienyl is substituted with indenyl may, for example, be mentioned.

Specific examples of the compound of the above (iii) include:
Zirconocene and the like. In addition, the above (i) to (ii)
Compounds having titanium or hafnium in place of zirconium in the compound of i) can also be exemplified at the same time.

The reaction between the organic transition metal compound and the acetylene compound represented by the general formulas (4) and (5) will be described later.

Next, the acetylene compound represented by the following general formula (2) will be described.

[0024]

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The meanings of R ⁵ and R ^{6 in} the general formula (2) are the same as those of R ^{1 to} R ⁴ in the general formula (1).

In the present invention, the metallacyclopentadienyl represented by the general formula (1) and the general formula (2)
By reacting with an acetylene compound represented by the formula, a triene compound represented by the following general formula (3) is produced.

[0027]

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The meanings of R ^{1 to} R ^{6 in} the general formula (3) are the same as R ^{1 to} R ⁴ in the general formula (1) and R ⁵ and R ⁶ in the general formula (2).

Next, the metal halide will be described. As metal halides, lithium halide, magnesium halide, aluminum halide, gallium halide,
Indium halide, tin halide, zinc halide, cadmium halide, copper halide, nickel halide, manganese halide and the like can be mentioned. Among these, aluminum halide, copper halide, and zinc halide are preferable, and aluminum chloride, copper chloride, copper bromide, and copper iodide are more preferable.

Next, the Bronsted acid will be described. Examples of Bronsted acids include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and ammonium chloride, and carboxylic acids such as acetic acid, oxalic acid, and butyric acid, and organic acids such as phenols. Among them, hydrochloric acid, sulfuric acid, nitric acid and acetic acid are preferred, and hydrochloric acid is more preferred.

Next, the reaction mechanism in the production method of the present invention will be described. The reaction mechanism in the production method of the present invention is estimated as shown in an example of the following reaction formula. The following reaction formula includes the above-mentioned synthesis reaction step (a) of metallacyclopentadienyl for easy understanding,
In the production method of the present invention, the steps (a) to (d) may be performed consistently.

[0032]

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In the step (a), 2,4-metallacyclopentadiene is produced from the organic transition metal compound and two molecules of the acetylene compound. In the step (b), a transmetallation reaction occurs between the metallacyclopentadiene and the metal halide, and in the step (c), an acetylene compound is formed between the metal-carbon bond newly generated in the transmetallation reaction. Inserted. And
In the step (d), the metal-
The carbon bond is broken.

Each of the above steps is preferably carried out in an inert gas atmosphere such as nitrogen or argon or an ethylene gas atmosphere in the presence of an aprotic solvent. Examples of the aprotic solvent include hydrocarbon solvents such as toluene, halogenated hydrocarbon solvents such as chlorobenzene and methylene chloride, and ether solvents such as ethyl ether, tetrahydrofuran and dimethoxymethane. Of these, tetrahydrofuran is preferred.

In the above step (a), the ratio of acetylene to the organic transition metal compound is usually 0.5
The amount is from 50 to 50 times, preferably from 0.5 to 10 times.
The reaction temperature is usually -100 to 100C, preferably -8.
5 to 80 ° C. The reaction time is usually 10 to 120 minutes,
Preferably, it is 30 to 60 minutes.

In the present invention, first, as a first-stage reaction, the metallacyclopentadienyl represented by the general formula (1) is reacted with a metal halide and the acetylene compound represented by the general formula (2) ( b to c steps), and then
As a subsequent reaction, a Brnsted acid is reacted (step d). In the above first-stage reaction, unlike the embodiment shown in the above reaction formula, a metal halide and an acetylene compound may be simultaneously present in the reaction system. The ratio of metal halide to metallacyclopentadienyl is usually 0.1%.
3 to 50 times mol, preferably 0.3 to 10 times mol, the use ratio of acetylenes is usually 0.5 to 50 times mol, preferably 0.5 to 10 times mol, the use ratio of Bronsted acid is Usually, it is at least equimolar.

In the present invention, it is important that the above reaction (steps b to c) is performed at a temperature of 0 ° C. or lower. 0 ° C
At a higher reaction temperature, a benzene derivative is obtained, and the triene compound intended in the present invention cannot be obtained. The reaction temperature is preferably -20C or lower. The reaction time is generally 10 to 120 minutes, preferably 30 to 60 minutes.

[0038]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. The tetrahydrofuran (THF) used as the reaction solvent was dehydrated. The compound was isolated by column chromatography, and the identification was performed by ¹ H-NMR, ¹³ C-NMR, and HRMS.

Example 1 A triene compound represented by the following chemical formula was produced.

[0040]

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Under a nitrogen atmosphere, 730 mg of zirconocene dichloride was placed in a 50 mL Schlenk tube.
(2.5 mmol) and 20 mL of THF were added. -78
Cooled to ℃, n-BuLi hexane solution (5 mmol)
Was dropped with a syringe. After the reaction solution was stirred at -78 ° C for 1 hour, 3-hexyne (2 mmol) was added thereto. Furthermore, dimethylacetylenedicarboxylate (284 mg, 2 mmol) and CuCl (19
(8 mg, 2 mmol). After reacting at −78 ° C. for 1 hour, it was reacted with 3N HCl at this temperature. The yield of the triene compound was 78%. In this example, dimethyl (3,4,5,6-tetraethyl) phthalate obtained in Examples 2 and 3 and Comparative Example 1 described later did not produce by-products.

Example 2 In Example 1, the reaction temperature after adding 3-hexyne (2 mmol) was changed from -78 ° C to -50 ° C,
The reaction was carried out in the same manner as in Example 1 except that the reaction time after adding dimethyl acetylenedicarboxylate and CuCl was changed to 30 minutes. The yield of the same triene compound as in Example 1 was 34%. In this example, dimethyl (3,4,5,6-tetraethyl) phthalate was by-produced at a yield of 47%.

Example 3 In Example 1, the reaction temperature after adding 3-hexyne (2 mmol) was changed from −78 ° C. to −30 ° C.
The reaction was carried out in the same manner as in Example 1 except that the reaction time after adding dimethyl acetylenedicarboxylate and CuCl was changed to 30 minutes. The yield of the same triene compound as in Example 1 was 10%. In this example, dimethyl (3,4,5,6-tetraethyl) phthalate was by-produced in a yield of 74%.

Example 4 Triene compound (a) represented by the following chemical formula: (methyl-3-methoxycarbonyl-4,5-diethyl-6-butyl-7-trimethylsilyl- (2Z, 4Z, 6E)-
2,4,6-heptatrienoate) and a triene compound (b): (methyl-3-methoxycarbonyl-4-trimethylsilyl-5-butyl-6-ethyl- (2Z, 4
E, 6E) -2,4,6-nonatrienoate).

[0045]

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Under a nitrogen atmosphere, 730 mg of zirconocene dichloride was placed in a 50 mL Schlenk tube.
(2.5 mmol) and 20 mL of THF were added. -78
Cooled to ℃, n-BuLi hexane solution (5 mmol)
Was dropped with a syringe. The reaction solution was cooled to -78 ° C under nitrogen.
After stirring for 1 hour, ethylene was blown for 1 hour, and the temperature was gradually returned to room temperature. To this was added 1-trimethylsilyl-1-hexyne (2 mmol) at room temperature under an ethylene atmosphere, and the mixture was stirred for 1 hour. Further, 3-hexyne (0.23 mL, 2 mmol) was added, and the mixture was stirred at 50 ° C. for 1 hour under a nitrogen atmosphere. Here, dimethyl acetylene dicarboxylate (2 mmol), CuCl
(2 mmol) was added at -78 ° C. Stirred at −78 ° C. for 1 hour and reacted with 3N HCl at this temperature. The reaction solution was extracted with diethyl ether, washed with water, sodium hydrogen carbonate, brine and water in that order, and dried over magnesium sulfate. Two target triene compounds (a)
And (b) were isolated on a column (4: 1 ratio between former and latter). The yield of the combined triene compound was 64%.

Example 5 In Example 1, 730 mg of zirconocene dichloride was used.
(2.5 mmol) instead of titanocene dichloride 7
The reaction was carried out in the same manner as in Example 1, except that 30 mg (2.5 mmol) was used. The yield of the same triene compound as in Example 1 was 76%.

Example 6 A triene compound represented by the following chemical formula was produced.

[0049]

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In Example 1, 730 mg (2.5 mmol) of titanocene dichloride was used instead of 730 mg (2.5 mmol) of zirconocene dichloride, and 5-decyne (2 mmol) was used instead of 3-hexyne (2 mmol).
The reaction was carried out in the same manner as in Example 1 except that was used.
The yield of the triene compound was 60%.

Comparative Example 1 A reaction was carried out in the same manner as in Example 1 except that the reaction temperature after adding 3-hexyne (2 mmol) was changed from -78 ° C to 23 ° C. No triene compound was produced, and the dimethyl (3,4,4)
Only 5,6-tetraethyl) phthalate was isolated in 86% yield.

[0052]

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[0053]

According to the present invention described above, a novel method for producing a conjugated triene compound having a specific structure directly from acetylenes is provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07C 43/15 C07C 43/15 43/166 43/166 67/347 67/347 69/602 69/602 C07F 7/00 C07F 7 / 00 AZ 7/08 7/08 J 7/28 7/28 Z

Claims (2)

[Claims] At a temperature of 0 ° C. or lower, first, a metallacyclopentadienyl represented by the following general formula (1) is reacted with a metal halide and an acetylene compound represented by the following general formula (2), Then, a method for producing a triene compound represented by the following general formula (3), characterized by reacting a Bronsted acid. Embedded image (In the general formulas (1) to (3), R ^{1 to} R ⁶ each represent an alkyl group, an alkenyl group, an aromatic group, a silyl group, an alkoxy group, or an ester group. The number may be 1 to 20 and may have a substituent, and in the general formula (1), M is a transition metal, L is a ligand, n
Represents an integer of 0 to 4. ) 2. The method according to claim 1, wherein the transition metal represented by M in the general formula (1) is a transition metal belonging to Group 4 of the periodic table.