JPH11255678A - Production of conjugated diene having different halogens bound to 1-and 4-positions - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject conjugated diene useful as a synthetic raw material for medicines and agrochemicals, etc., in good selectivity by reacting a metalacyclopentadiene compound with a specific halogenating agent and then reacting the resultant compound with a different halogenating agent. SOLUTION: (A) One mol of a metalacyclopentadiene compound represented by formula I [M is a transition metal, preferably a group 4 element of the periodic table; L is a ligand; (n) is an integer of 0-5; R<1> to R<4> are each independently H, a 1-24C hydrocarbon, silyl, etc.], is reacted with (B) preferably 1-5 mol of a compound having a halogen (X<1> ) bound to a group 15 element of the periodic table and the resultant compound is then reacted with (C) preferably 1-10 mol of a compound having another halogen (X<2> ) bound to the group 15 element of the periodic table or molecules (X<2> 2 ) of the halogen to thereby afford (D) a conjugated diene represented by formula II and having the different halogens bound to the 1- and 4-positions. The components B and C are preferably N-halogenosuccinimides, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a conjugated diene in which different halogens are bonded at the 1-position and the 4-position, respectively. The conjugated diene produced by the method of the present invention is useful as a raw material for synthesizing medicines, agricultural chemicals and the like, because the two bonded halogens have different reactivities. It is also useful as a raw material for synthesizing a polyacetylene derivative using a coupling reaction with a halogen atom.

[0002]

2. Description of the Related Art A method for producing a conjugated diene in which the same halogen is bonded at the 1-position and 4-position is known (Tetrahedron Lett).
er 1997.38.2829 page). However, there is no known method for selectively producing a conjugated diene in which different halogens are bonded at the 1-position and the 4-position. Therefore, the present invention
It is an object of the present invention to provide a method for selectively producing such a conjugated diene.

[0003]

According to the present invention, a metallacyclopentadiene compound represented by the general formula (1) is reacted with a compound having a halogen (X ¹ ) bonded to an element of Group 15 of the periodic table, compound or of the halogen molecule has other halogens bound to the periodic table group 15 element in the product (X ²⁾ then (X ² ₂ ), A conjugated diene represented by the general formula (2) in which different halogens are bonded to the 1-position and 4-position can be produced with high selectivity.

[0004]

Embedded image

(In these formulas, M represents a transition metal.
And L represents a ligand. n shows the integer of 0-5. n is
In the case of an integer of 2 or more, plural Ls are different from each other.
You may. R¹~ R^FourAre each independently a hydrogen source
Having an oxygen atom and / or a nitrogen atom in the carbon chain
Hydrocarbon group, silyl group, alkoxy group, aryl
Roxy group, or alkoxy or aryloxyca
Represents a rubonyl group. However, these groups have 1 to 2 carbon atoms.
4 and may have a substituent. Further R ¹~
R^FourTwo of the following are joined together to form a ring,
In this case, R¹And R^TwoAnd / or R^ThreeAnd R^Four
The ring formed by may be an aromatic ring. )

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A metallacyclopentadiene compound represented by the general formula (1), which is a raw material for producing a conjugated diene having different halogens at the 1-position and the 4-position according to the method of the present invention, is represented by M. As the transition metal, a metal belonging to Groups 3 to 10 of the periodic table is used. Usually a Group 3-6 metal, preferably titanium, zirconium,
Group 4 metals such as hafnium are used. Examples of the ligand represented by L include a cyclopentadienyl group, an indenyl group, a fluorenyl group, an azulenyl group, a hydrocarbon oxy group, an amide group, an acetylacetonate group, a carboxyl group, a halogen atom, and a phosphine ligand. , Amine ligands, ether ligands, and ligands in which these are linked by an appropriate crosslinking group. In addition, any of the above groups may have a substituent. The number of coordination of these ligands to the metal (M) is 0 to 5, preferably 1 or 2.

The substituents represented by R ^{1 to} R ⁴ include
(Cyclo) alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, neopentyl, hexyl, octyl, nonyl, decyl, cyclopentyl, cyclohexyl, cyclooctyl, vinyl, allyl, 1-propenyl, 1, 2, or 3-
Alkenyl groups such as butenyl, 1-5-hexenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl,
Aromatic groups such as phenyl, naphthyl, tolyl, and xylyl;
Trimethylsilyl, toluethylsilyl, trimethoxysilyl, triethoxysilyl, diphenylmethylsilyl,
Dimethylphenylsilyl, silyl groups such as triphenylsilyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, alkoxy groups such as t-butoxy, phenoxy, aryloxy groups such as naphthoxy, methoxycarbonyl groups, ethoxycarbonyl groups, Propoxycarbonyl group, isopropoxycarbonyl group,
Butoxycarbonyl group, isobutoxycarbonyl group, t
-An alkoxy or aryloxycarbonyl group such as a butoxycarbonyl group and a phenoxycarbonyl group. Among these, an alkyl group such as methyl, ethyl, propyl, and butyl, a phenyl group, a 1-cyclohexenyl group, and the like are preferable. The ring formed by bonding two adjacent ones out of R ^{1 to} R ⁴ includes an aromatic ring such as a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring; a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, and a cycloheptane ring. Ring, cycloalkane ring such as cyclooctane ring; cyclobutene ring, cyclopentene ring,
Cycloalkene ring such as cyclohexene ring, cycloheptene ring, cyclooctene ring; pyridine ring, quinoline ring,
Heterocycles such as a pyrrole ring, an indole ring, a furan ring, a benzofuran ring, a dihydrofuran ring, a tetrahydrofuran ring, a thiophene ring, and a benzothiophene ring. Substituents may be further bonded to these rings.
Among these, a benzene ring, a cyclopentane ring, a cyclohexane ring and the like are preferable.

The metallacyclopentadiene compound 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 (3) and (4). . In the general formulas (3) and (4), R ^{1 to} R ^{4 have} the same meaning as in the general formula (1).

[0009]

Embedded image R ¹ —C≡C—R ² (3) R ³ —C≡C—R ⁴ (4)

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) a reaction metal obtained by reacting a transition metal compound (a) having at least two halogens with a group 4 transition metal of the periodic table and a chemical reagent (b) capable of substituting the halogen with an alkyl group having 2 or more carbon atoms. (Ii) a metallacycle compound or a substituted metallacycle compound having a group 4 transition metal in the periodic table in the ring (iii) a divalent group 4 transition metal compound in the periodic table according to the reaction conditions Is convertible to the compound of (ii) or (iii), and the compound of (iii) is convertible to the compound of (ii).

The transition metal compound (a) belonging to Group 4 of the periodic table used in the synthesis of the compound (i) includes zirconium tetrachloride, zirconocene dichloride, zirconocene dibromide, zirconocene diiodide, cyclopentadienyl zirconium trichloride. Chloride, bis (methylcyclopentadienyl) 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. 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 dicyclopentadienyl zirconacyclopentane, dicyclopentadienyl zirconacyclopentene, dicyclopentadienyl zirconacyclopentadiene, and cyclopentadienyl. Compounds in which the hydrogen of the group is substituted with a methyl group or a trimethylsilyl group, and compounds in which a cyclopentadienyl group is substituted with an indenyl group are exemplified.
Specific examples of the compound (iii) include zirconocene. Compounds having titanium or hafnium instead of zirconium in the compounds (i) to (iii) can also be exemplified. The formation reaction of the metallacyclopentadiene compound from the acetylene compounds of the general formulas (3) and (4) and the organic transition metal compound is represented by the following formula, for example.

[0013]

Embedded image

The above reaction is preferably carried out in the presence of an aprotic solvent in an atmosphere of an inert gas such as nitrogen or argon or an ethylene gas. As the aprotic solvent,
Examples 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 reaction, the ratio of acetylene to the organic transition metal compound is usually 0.5 to 50.
It is twice mole, preferably 0.5 to 10 times mole. The reaction temperature is generally -100 to 100C, preferably -85 to 8C.
0 ° C. The reaction time is generally 10 to 120 minutes, preferably 30 to 60 minutes. As the compound having a halogen bonded to an element of Group 15 of the periodic table to be reacted with the metallocyclopentadiene compound, a compound having a structure in which any of fluorine, chlorine, bromine, and iodine is bonded to nitrogen or phosphorus is usually used. . Preferably, a compound to which any one of chlorine, bromine and iodine is bonded is used. Some of them are shown as chlorine-bound compounds.

[0016]

Embedded image

[0017]

Embedded image

[0018]

Embedded image

And the like. In addition, a compound in which chlorine is replaced with another halogen in the above compounds may also be used. Among these, N-halogenosuccinimide, N-halogenoglutarimide and N-halogenophthalimide are preferred. Particularly preferred are N-chlorosuccinimide and N-bromosuccinimide. As the halogenating agent, in addition to the compound having a structure in which a halogen is bonded to nitrogen or phosphorus, each molecule of fluorine, chlorine, bromine, and iodine can be used. Of these, chlorine, bromine and iodine molecules are preferred, with iodine molecules being most preferred.

The reaction between the metallacyclopentadiene compound and the halogenating agent is usually performed in an aprotic solvent. As the solvent, for example, hydrocarbons such as toluene, xylene, chlorobenzene, halogenated hydrocarbons such as methylene chloride, ethyl ether, tetrahydrofuran,
Ethers such as dimethoxyethane are used. Among them, it is preferable to use tetrahydrofuran. The reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon, or an ethylene gas atmosphere.

The ratio of the metallacyclopentadiene compound to be subjected to the reaction to the compound having a halogen (X ¹ ) bonded to an element of Group 15 of the periodic table (this is referred to as halogenating agent (1)) is determined by the ratio of the metallacyclopentadiene compound 1
The amount of the halogenating agent (1) is 1 to 5 mol, preferably 1 to 2 mol, per mol. Reaction temperature is -100 to 150
C., preferably -80 to 50C, and the reaction time is 5 minutes to 12 hours, preferably 30 minutes, depending on the reaction temperature.
Minutes to 5 hours.

[0022] The reaction mixture of meta La cyclopentadiene compound with a halogenating agent (1), the compound or a halogen molecule (X ² ₂₎ having a halogen bound to elements of the periodic table group 15 (X ²⁾ (halogen this (Referred to as an agent (2)), and further reacted to produce a conjugated diene in which different halogens are bonded at the 1-position and the 4-position. Halogenating agent (2)
Is 1 to 10 mol of a halogenating agent per 1 mol of a metallacyclopentadiene compound, and preferably 1 to 10 mol.
2 moles. The reaction temperature is -100 to 150C, preferably -80 to 50C, and the reaction time is 5 minutes to 12 hours, preferably 30 minutes to 6 hours.

[0023]

The present invention will be described more specifically with reference to the following examples. The zirconapentadiene compounds used in these examples were synthesized according to the following literature. Buc
hwald et al. Am. Chem. Soc. 198
6,108,7411; Takahashi et al. O
rg. Chem. 1995, 60, 4444; Taka
Hashi et al., Tetrahedron Lett. 1
993, 34, 687; Takahashi et al., Tet.
rahedron Lett. 1986, 27, 282
9. The product was identified by ¹ H-NMR and ¹³ C-NMR.
(CDCl ₃ , Me ₄ Si) and HRMS.

Examples 1 to 7 In a nitrogen atmosphere, a zirconapentadiene compound (1.0 m
mol) in tetrahydrofuran solution, 1.1 mmol of N-bromosuccinimide (NBS) or 1.0 mmol of N-chlorosuccinimide (NCS) was added as a halogenating agent (1) at 0 ° C., and the mixture was stirred at room temperature for 3 hours. did. Next, 1.0 mmol of the halogenating agent (2) was added to the reaction product at room temperature. After stirring at room temperature for 1 to 3 hours, 3N-hydrochloric acid was added to stop the reaction.
The reaction product was extracted with diethyl ether, and the obtained diethyl ether solution was washed with water and brine, and dried over magnesium sulfate. The diethyl ether solution was evaporated from the diethyl ether solution under reduced pressure, and the residue was purified by chromatography using hexane as an eluent. The results are shown in Table 1. In Table 1, the yield is the yield determined by analyzing the reaction product liquid by gas chromatography, and the number in parentheses is the isolation yield. The analysis data of the product was as follows.

[0025]

[Table 1]

[0026]

[Table 2]

Example 1 ¹ H NMR (CDCl ₃ , Me ₄ Si) δ 0.90
(T, J = 7.3 Hz, 3H), 1.04 (t, J =
7.4 Hz, 3H), 1.27-1.48 (m, 2
H), 1.66-1.76 (m, 2H), 2.22-
2.63 (m, 4H), 6.91-7.86 (m, 4
H). ¹³ C NMR (CDCl ₃ , Me ₄ Si) δ1
3.61, 14.08, 20.91, 1.13, 3
5.88, 36.72, 98.56, 127.80, 1
28.28, 129.72, 133.01, 139.1
0, 139.42, 146.22. HRMS C ₁₄ H ₁₈
Calculated value 348.0141 as ICl, measured value 34
8.0128

Example 2 ¹ H NMR (CDCl ₃ , Me ₄ Si) δ 0.90
(T, J = 7.4 Hz, 3H), 1.04 (t, J =
7.4 Hz, 3H), 1.26-1.47 (m, 2
H), 1.66-1.76 (m, 2H), 2.20-
2.74 (m, 4H), 7.00-7.85 (m, 4
H). ¹³ C NMR (CDCl ₃ , Me ₄ Si) δ1
3.45, 14.00, 21.02, 21.63, 3
6.07, 38.71, 98.23, 126.93, 1
27.73, 128.23, 129.63, 139.0
4,142.41,147.85. HRMS C ₁₄ H ₁₈
Calculated value 391.9636 as IBr, measured value 39
1.9651

Embodiment 3¹ H NMR (CDCl_Three, Me_FourSi) δ 1.86
(S, 3H), 2.42 (s, 3H), 7.06-7.
26 (m, 10H).¹³C NMR (CDCl _Three, Me
_FourSi) δ 17.67, 24.94, 101.36,
118.72, 127.31, 127.65, 127.
85,127.92,129.80,129.97,1
30.25, 136.96, 140.65, 143.8
2,150.45. HRMS C₁₈H₁₆As ICl
Calculated value 393.9998, measured value 393.9998

Example 4 ¹ H NMR (CDCl ₃ , Me ₄ Si) δ 0.94
(T, J = 7.3 Hz, 3H), 1.35-1.43
(M, 2H), 1.58-1.74 (m, 4H), 2.
26-2.53 (m, 6H), 7.18-7.63
(M, 5H). ¹³ C NMR (CDCl ₃ , Me ₄ Si)
δ 13.93, 21.68, 21.85, 28.7
7, 29.45, 33.13, 36.92, 93.8
2,127.79,127.84,129.04,12
9.59, 138.24, 144.37, 148.0
2. Calculated 386 as HRMS C ₁₇ H ₂₀ ICl.
0297, measured value 386.0295

Example 5 ¹ H NMR (CDCl ₃ , Me ₄ Si) δ 0.94
(T, J = 7.3 Hz, 3H), 1.34-1.43
(M, 2H), 1.59-1.71 (m, 4H), 2.
31-2.45 (m, 6H), 7.22-7.47
(M, 5H). ¹³ C NMR (CDCl ₃ , Me ₄ Si)
δ 13.93, 21.78, 21.86, 29.0
0, 29.55, 33.51, 37.00, 116.7
2,127.77,128.17,128.66,12
9.66,135.91,140.95,141.1
0. Calculated for HRMS C ₁₇ H ₂₀ ClBr 33
8.0436, found 338.0448

Example 6 ¹ H NMR (CDCl ₃ , Me ₄ Si) δ 1.00
−1.17 (m, 12H), 2.12-2.65 (m,
8H). ¹³ C NMR (CDCl ₃ , Me ₄ Si) δ
12.80, 13.03, 13.09, 14.08, 2
5.33, 25.74, 30.70, 34.70, 3
4.54, 108.15, 126.60, 143.0
2,146.50. HRMS Calculated for C ₁₂ H ₂₀ BrI 369.9792, found 369.9792.

Example 7 ¹ H NMR (CDCl ₃ , Me ₄ Si) δ 0.90
−0.98 (m, 12H), 1.39-1.50 (m,
4H), 1.52-1.69 (m, 4H), 2.00-
2.11 (m, 2H), 2.21-2.53 (m, 6
H). ¹³ C NMR (CDCl ₃ , Me ₄ Si) δ 1
3.20, 13.45, 14.55, 14.66, 2
0.91,21.47,21.57,21.76,3
4.63, 35.08, 36.88, 38.95, 12
5.41, 131.34, 137.38, 138.97 Elemental analysis value Calculated value for C H C ₁₆ H ₂₈ ClBr 57.24% 8.41% Found 57.39% 8.36%

Comparative Example 1 The procedure of Example 3 was repeated except that I ₂ (1.1 mmol) was used as the halogenating agent (1) and NBS was used as the halogenating agent (2). The obtained halogen compound has two iodine (Z) -4-iodo-5- (2-iodophenyl)
-4-onten. 90% yield. In addition, a compound having both iodine and bromine was not obtained.

Comparative Example 2 Comparative Example 1 except that NCS was used as the halogenating agent (2).
The same was done. The resulting halogen compound contains iodine in 2
(Z) -4-iodo-5- (2-iodophenyl) -4-oneten. 90% yield. A compound having both iodine and chlorine was not obtained.

Claims (4)

[Claims] 1. A metallacyclope represented by the general formula (1)
C bonded to an element of group 15 of the periodic table
Logen (X¹Reacting the compound having
Other halogens (X
^Two) Or a molecule of the halogen (X^Two _Two )
Characterized by the following general formula (2):
Conjugated diene having different halogens bonded at the 1-position and 4-position
Manufacturing method. Embedded image(In these formulas, M represents a transition metal, and L represents
Indicates a child. n shows the integer of 0-5. n is an integer of 2 or more
In the case, the plurality of Ls may be different from each other. R
¹~ R^FourAre each independently a hydrogen atom or a carbon chain
Hydrocarbon optionally having an oxygen atom and / or a nitrogen atom
Group, silyl group, alkoxy group, aryloxy group, or
Represents an alkoxy or aryloxycarbonyl group
You. However, these groups have 1 to 24 carbon atoms, and
It may have a substituent. Further R ¹~ R^FourNext to
Two contacting groups may combine to form a ring.
R if¹And R^TwoAnd / or R^ThreeAnd R^FourRing formed by
May be an aromatic ring. ) 2. R ^{1 to} R ⁴ are each independently a hydrocarbon group, or two of R ^{1 to} R ⁴ are bonded to each other to form a hydrocarbon ring, and The method for producing a conjugated diene according to claim 1, wherein the two are independently a hydrocarbon group. 3. The method for producing a conjugated diene according to claim 1, wherein the transition metal is an element belonging to Group 4 of the periodic table. 4. The method for producing a conjugated diene according to claim 1, wherein the compound having a halogen bonded to an element of Group 15 of the periodic table is N-halogenosuccinimide.