JPS6092297A - Preparation of eta5-substituted cyclopentadienyl cobalt polyene complex - Google Patents

Abstract

PURPOSE:To produce the titled compound useful as a catalyst for the synthesis of a pyridine derivative from alkynes and nitriles, economically in an industrial scale, by reacting eta<5>-substituted cyclopentadienyl cobalt monohalogenide with a specific polyene and a specific reducing agent. CONSTITUTION:The objective compound of formula II (R is 4-16C polyene wherein the diene part forms a coordinate bond with Co) is produced by reacting (A) the eta<5>-substituted cyclopentadienyl cobalt monohalogenide of formula I (A is 1-4C alkyl or phenyl; B is 1-3C alkoxycarbonyl or 1-4C acyl; m and n are 1 or 2; X is halogen) with (B) a 4-16C polyene (having 2-4 double bonds; excluding the polyenes composed solely of aromatic unsaturated bonds) (e.g. cyclooctadiene) and (C) a reducing agent selected from the group of amalgam, borohydride, aluminum hydride and hydride of alkali metal; alkyl aluminum; and alkyl zinc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing η5-substituted cyclopentadienyl cobalt complexes. Furthermore, it relates to the application of the material obtained here as a catalyst to the synthesis reaction of pyridine derivatives from alkynes and nitriles.

η55-cyclobentadienylcobal i form, especially η5
-Cyclopentadienylcobalt-η4-boriene complex is a known substance, and a method for producing pyridine derivatives by reacting alkynes and nitriles using this substance as a catalyst is already known. For example, it is possible to produce a cycloalkagenyl cobalt cycloalkadiene filler or a cobalt salt treated with a reducing agent in the presence of nitriles or alkynes, and to carry out the above reaction using this substance as a catalyst. It is known to proceed. (JP-A-50-135084, JP-A-58-25
No. 780, USP 4,287,329) However, the formula (H) n B+.

[However, in the formula, A is an alkyl group having 1 to 4 carbon atoms and/or a phenyl group, and the number of substitutions n is O to 2;
B is selected from an alkoxycarbonyl group (the number of carbon atoms in the alkoxy moiety is 1 to 3) or an acyl group (the number of carbon atoms is 1 to 4), and the number of substitutions m represents 1 or 2. Further, R is a polyene having 4 to 16 carbon atoms (the number of double bonds is 2 to 4, excluding polyenes consisting only of aromatic unsaturated bonds), and the diene portion coordinates with cobalt. form a bond. ] It is difficult to construct #J of a cyclopentadienyl cobalt polyene complex in which an electron-withdrawing substituent is attached to a cyclopentadienyl group as shown in the following, and it is unknown in the literature.However, the present inventors have We succeeded in producing such a complex, and
It has been found that this substance is a particularly excellent catalyst for the synthesis of pyridine derivatives through the above reaction.

The present invention provides a new method for easily and inexpensively producing a cyclopentadienylcobal I/polyene complex having such an electron-withdrawing substituent. That is, the present invention provides the following: 1) Formula (T) n 8m [However, in the formula, A is an alkyl group having 1 to 4 carbon atoms and/or a phenyl group, and the number of substitutions n represents O to 2;
B is selected from an alkoxycarbonyl group (the number of carbon atoms in the alkoxy moiety is 1 to 3) or an acyl group (the number of carbon atoms is 1 to 4), and the number of substitutions m is 1 or 2. Atom or halogen atom. ] η5-substituted cyclopentadienyl cobalt monohalogenide represented by ii) a polyene having 4 to i6 carbon atoms (the number of double bonds is 2 to
There are 4 groups. However, polyenes consisting only of aromatic unsaturated bonds are excluded. ), and further reacting with a reducing agent selected from the group of alkali metal amalgam, polohydride, aluminum hydride or hydride; alkyl aluminum; or alkyl zinc. A method for producing a η5-substituted cyclopentadienyl cobalt polyene complex represented by formula (IT) having an electron-withdrawing substituent, and i) formula (III) n I11 [E, where A is 1 carbon number ~4 alkyl groups and/
or a phenyl group, and the number of substitutions n is O~2, while B is an alkoxycarbonyl group (the alkoxy moiety has 1 to 3 carbon atoms) or an acyl group (the number of carbon atoms is 1 to 4.4@
), where m represents 1 or 2. M is an alkali metal. a substituted cyclopentadienyl alkali metal complex represented by 1, ii) cobalt (If) halide, and ■) carbon number 4
~1B polyene (the number of double bonds is 2 to 4 sets. However, polyenes consisting only of aromatic unsaturated bonds are excluded.

) are mixed and reacted with one or more of each group, and further iV) alkali metal amalgam, polohydride, aluminum hydride, or hydride;
A method for producing η5-5-substituted cyclobentadienylcobaltboriene represented by formula (II) having an electron-withdrawing substituent by acting with a reducing agent selected from the group of alkylaluminum; or alkylzinc. be.

In addition, in this process, the polyenes of the ni) group are divided into the i) group and the ii
) may be added after the reaction of the group.

Although cyclopentadienyl cobalt monohalogenide is a known substance, all of the substituted cyclopentadienyl cobalt heptanohalogenides shown in the present invention are new substances. The substituted cyclopentadienyl cobalt heptanohalogenide can be produced by reacting the ll cyclopentadienyl alkali metal complex of formula (1) with cobalt (IF) halide. In this case, it has been found that it is important to react the two in a ratio as close to equimolar as possible. Too little cobalt salt results in an increase in cobaltocene-type by-products, while too much cobalt salt increases unreacted substances, neither of which gives good results. The method of reaction is -20 to 50' in the presence of a solvent.
This can be easily done by keeping it at 0.

As the solvent, inert solvents such as hydrocarbons, ethers, etc. can be suitably used, but it is also a good method to include the above-mentioned polyenes. Substituted cyclopentadienyl monohalogenide can be separated and obtained from the reaction product solution thus obtained, but this reaction solution can also be immediately subjected to the next reaction.

It has been found that substituted cyclopentadienyl cobalt monohalogenides and polyenes can be easily converted into substituted cyclopentadienyl cobalt polyene complexes by the action of a reducing agent. Conventionally, attempts have been made to convert cobalt salts and alkynes or nitriles into active catalysts for the synthesis of pyridine derivatives in the presence of reducing agents, but substituted cyclopentadienyl cobal as shown in the present invention: There are no known examples using monohalogenides as starting materials. According to the present invention, a method for producing a substituted cyclopentadienyl cobaltboriene complex easily and in good yield has been discovered for the first time.

The abundance ratio of the substituted cyclopentadienyl cobalt monohalogenide of formula (I) and the polyene is suitably in the range of 1 to 200 times by mole. Suitable polyenes include those having 4 to 16 carbon atoms and 2 to 4 double bonds. For example, butadiene, imprene,
norbornagene, indene, azulene, cyclooctadiene.

Examples thereof include cyclododecatriene and alkyl, alkoxycarbonyl, phenyl, cyano, and cyanomethylene substituted products thereof. However, compounds such as benzene, toluene, and xylene in which unsaturated bonds consist only of aromatic rings are unsuitable because they do not react. On the other hand, as the reducing agent, alkali metal amalgam, hydride, polyhydride, aluminum hydride, etc., alkyl aluminum or alkyl zinc can be used.

It is desirable that the reducing agent be present in an amount equal to or more than the amount of cobalt. The reaction takes place in the presence or absence of a solvent.
The temperature is 0 to 100°C.

Hydrocarbons and ethers can be suitably used as solvents.
The polyenes, which are also reaction raw materials, or the system of the above-mentioned process may be applied to this reaction as is. The reaction atmosphere is preferably an inert atmosphere that does not contain oxygen, moisture, acidic gas, etc., and the reaction may be carried out at normal pressure or under increased pressure. The reaction time varies depending on the temperature, solvent, etc., but is usually within 1 hour.

1-1 The method of the present invention can be achieved by reacting a substituted cyclopentadienyl cobalt halogenide of formula (T) as a starting material, but it can also be achieved by reacting a substituted cyclopentadienyl cobalt alkali metal complex of formula (Ill) with cobalt(
An advantageous option is also an integrated process starting from a IT) halide and passing through a substituted cyclopentadienyl cobalt heptanohalogenide as an intermediate.

A pure substance of the η5-substituted cyclopentadienyl cobalt-η4-polyene complex can be obtained by separation and purification from the reaction product liquid thus obtained. This separation operation can be easily performed. However, in order to apply 32 as a complex catalyst of the present invention, such separation operation is not necessarily required, and the reaction product liquid can be used as it is.

The substances obtained by the method of the present invention include novel substances.

Furthermore, the substance obtained according to the present invention exhibits particularly high activity when used as a catalyst in a reaction for producing pyridine derivatives from alkynes and nitriles.

The amount of catalyst used is 0.1 m in terms of cobalt atoms in the reaction system.
It is effective at a concentration of mol/1 or higher. and 1
It is usually not necessary to make it 0 h mol/1 or more. Regarding the reaction raw materials, the catalyst of the present invention can be applied to a wide range of alkynes and nitriles as in the prior art.

Alkynes include terminal alkynes such as acetylene, alkyl-, alkenyl- and allyl-acetylene;
Disubstituted acetylenes such as dialkyl-, diallyl-, alkylalkenyl-acetylenes and alkylaryl-acetylenes, these alkynes may also be mixtures of different alkynes. Further, ether or alcohol derivatives of these alkynes may be used.

On the other hand, nitriles include hydrogen cyanide, alkyl-
Mononitriles such as , allyl-, and alkenyl-nitriles, as well as polyfunctional nitriles in which a plurality of nitrile groups are present, can be suitably used.

A feature of the method of the present invention is that a highly active catalyst can be synthesized with simple operations, and this, together with the advantage of recycling and reusing the catalyst, is an important industrial advantage. For example, it can be said that the present invention has made it possible to industrially easily produce vinylpyridine, α-picoline, pyridine, etc. from acetylene and nitrile.

The embodiments of the present invention will be described below with reference to Examples, but the scope of the present invention is not limited by these embodiments.

Example 1 Anhydrous cobal chloride (1) in a 1001 container under nitrogen flow
．． 0g (7,7+ mol), tetrahydrofuran 15
Add 3 ml of 1 and 1,5-cyclooctadiene. Under stirring, a solution of sodium methoxycarbonylcyclopentadienyl in tetrahydrofuran 51 (7a+ mo
1) slowly dropwise. The mixed liquid, which was a non-uniform blue color, became dark red and uniform as it was dropped.

Sodium mercury amalgam (made from 0.7 g of sodium) and tetrahydrofuran 101 prepared in a separate container
Add the above solution to the system under stirring at 15°C.

After stirring for 10 minutes, the supernatant is separated and the solvent is evaporated under reduced pressure. Dilute the remaining liquid with a small amount of benzene/hexane (1:1
) and applied column chromatography on alumina (added with 5% water) to remove the reddish-brown band that flows out and distill off the solvent to obtain the target product, η4-1.5-cyclooctadiene-η5-methoxycarbonylcyclo. Pentagenyl cobalt precipitates as crystals. This was washed with a small amount of hexane and dried under reduced pressure to obtain a yield of 1320 mg.

Melting point 8B-87°C. Analysis value CB2, 13%, He
, 5'lL G+fHI? 0□CO calculation value CB2.07%, 86.80X, IR (Nujo
l): 1720.1700cm −' (C=0),
'H-NMR (CDCH3): 6 δ1. O3,2,38,3,58(Col'l+2)
;3-95 (CH3);4.40°5, O3ppm
(C5H4) ・Example 2 ethanol/tetrahydrofuran (1
: 3) Add 1.51 1.5-octadiene to solution 301 (containing 4 ts mol as cobalt), and further add
At 0° C., 0.25 g of sodium polyhydride was added with stirring, and the mixture was reacted for 30 minutes. The reaction product solution was prepared in Example 1.
140 g of η4-1.5-cyclooctadiene-η5-methoxycarbonylcyclopentagenyl cobalt crystals as in Example 1 were obtained.

Example 3 Anhydrous cobalt chloride and methoxycarbonylcyclopentagenyl sodium, equivalent mole (8.5 mmol) to 0
A methoxycarbonylcyclopentadienyl cobalt 1,000-halogenide complex was prepared at °C.

On the other hand, butadiene was bubbled into tetrahydrofuran 201 at room temperature to prepare a saturated solution, and the sodium 7 amalgam and the above complex were added to the solution at 0° C. to perform a reaction.

The yield of the obtained η4-1,3-butadiene-η5-methoxycarbonylcyclopentadienyl cobalt crystals was 4
It was 38 mg.

Melting point 40-42°C (in nitrogen-filled capillary).

IR (Nujol): 1710cm-' (G-0)
, 'H-NMR (CH12CI2): δ-0,28
, 1, 84, 5, 11 (04H6); 3.74 ((l
) H3); 4.138, 5.29PP Garden (CsHa).

Example 4 Anhydrous cobalt iodide 7 in a 1001 container under nitrogen flow
15 ml of tetrahydrofuran and 41 ml of norbornadiene were charged. While stirring, add 7 mo of acetylcyclopentadienyl sodium solution in tetrahydrofuran.
1 (7 ml) was slowly added dropwise at 0°C, and the reaction solution turned reddish brown. This solution was slowly added to the sodium amalgam and toluene system previously used in Example 1 while stirring, and reacted at a temperature of 40° C. for 15 minutes. The solvent was distilled off from the reaction solution under reduced pressure, and the solution was dissolved in a small amount of benzene/hexane (1:1) solvent, then subjected to alumina column chromatography, and the reddish-brown band was extracted with benzene. By distilling off the solvent, 1250 mg of η4-norbornadiene-η5-acetylcyclopentadienyl cobalt crystals were obtained.

Melting point 97-99℃, elemental analysis value C: 65.413L H
: 5.85%, C+4H1aOCOTOL "C calculation value C: 85.12%, H: 5.86%, IR absorption (N
ujol): 11345c+s-' (C=0), N
MR (inCDCI3): δ0.81, 2.9B, 3.
18 (G7Hs);4. EiO.

5.17 pp■ (C5H4).

Example 5 In Example 4, the reaction was carried out using acetyl and benzylcyclopentadienyllithium instead of acetylcyclopentadienyl sodium. After distilling off the solvent, η4-norbornadien-η5-acetylhenzylcyclopentadienyl cobalt was obtained as a dark red viscous liquid in a yield of 160 μg.

Example 6 Literature [Chew, Peters, J., Chew, Soc.
, 1757 (1958)], dimethoxycarbonylcyclopentagenyl sodium was synthesized. This powder? m mol and anhydrous cobalt chloride 7IIfflol
Then, by the method of Example 4, η4-cyclooctadiene-η
5-dimethoxycarbonylcyclopentadienyl cobalt was collected from the yellow-orange band, and two types of reddish-brown crystals were obtained. Total yield: approximately 85mg.

[First crystal] Melting point 115-118°0. IR absorption (N
ujol): 1725.1710cm' (C=O)
, elemental analysis value G: 5B, 71%.

H: 8.09%, C, 7H2104Co, Teno calculation value C: 5B, 83%.

H: Ei, 08%, NMR (in CDCh):
δ1.7, 2.4, 3.8C, H, □); 3.9B (0
(H3); 4.54 (t, IH), 4.1112 (d,
2H)C5H3)・ [Second crystal] Melting point! 311-100℃, IR absorption (N
ujol): 1730.1710cm −' (C:=
O), elemental analysis value C: 58.67'X.

H: 8.12%, C+7Hz104Co and Shiteno calculated value C: 58.83 LH: 8.08%, NMR (in
CDCh): δ1.7, 2.4, 3. El(C
o H+z); 3.85 (OCH3); 4.94 (d,
2H), 5.18(t, IH) (C5H3).

The former is 1,3-dimethoxycarbonyl, the latter is l,2-
It was identified as a dimethoxycarbonyl substituted product. The production ratio 9 was 1:1.8.

Example 7 η'- obtained in Example 1 was placed in a 1001 autoclave.
75.8 mg (0,
28 intestine o1), add 20g of acrylonitrile and 801 toluene, temperature 150'O1 pressure 13kg/c
Vinylpyridine was synthesized by reacting with m2G for 60 minutes. It was analyzed using a gas chromatograph, and the results are shown in Table 1 as Example 1.

Similarly, the substances obtained in Examples 3 to 6 were used as catalysts to react, and the results are shown in the respective columns of Examples in Table 1.

In addition, vinylpyridine was synthesized in the same manner using the reaction product solution of Example 1 (supernatant solution treated with sodium amargate) and is shown in Table 1 as Example (1).

10 Example 8 Catalyst 2 obtained in Example 2 was placed in a 1001 autoclave.
8mg (0.08m mol), acetonitrile 83
1 was added thereto and reacted for 60 minutes at a temperature of 150° C. and a pressure of 13 kg/cm 2 G to synthesize α-picoline. As a result of gas chromatograph analysis, the catalyst efficiency was 1000 mol.
/Gog atom.Example 9 The η'- obtained in Example 6 was placed in a 1001 autoclave.
1,5-cyclooctadiene-η5-1,3-dimethoxycarbonylcyclopentadienyl cobalt 45+ag
(0.13 mmol) was added thereto, and under a nitrogen atmosphere, a toluene solution 431 containing about 2.51 parts of hydrogen cyanide was added, and the mixture was replaced with acetylene gas. After heating to 150°C, the acetylene pressure was increased to 18 kg/cm2G, and the mixture was stirred for 60 minutes to react. After cooling, the reaction solution was analyzed using a gas chromatograph. The catalyst efficiency for pyridine production is 30a+ol/Co
The by-product ratio of benzene in terms of g atoms was 0.13 O1/pyridine mol.

Example 10 3 8.7 mg of the l:l mixture of the crystals obtained in Example 6 (
0,025+w a+ol), 121 g of benzene, 121 g of acetonitrile, and about 4 g of methylacetylene were sealed in an ampoule under an argon atmosphere, heated to 95° C., and reacted for 29 hours. As a result of analyzing the product with a gas chromatograph, 2
,3.8-1-limethylpyridine I11.3m mol
, 2,4.6-drimethylpyridine 9.9 m mol,
1,2.4-trimethylbenzene, 3.5m sol,
0.6+a mol of 1,3.51-limethylbenzene was produced.

Applicant RIKEN Denki Kagaku Kogyo Co., Ltd. Agent Yutaka] ■ Yoshio 4 Procedural Amendment Written November 24, 1981 Kazuo Wakasugi, Commissioner of the Patent Office 1, Case Indication Patent Application No. 1981-199941 2. Name of the invention Process for producing η5-substituted cyclopentadienyl cobalt polyene complex 3. Person making the amendment Relationship to the case Patent applicant 2-1 Hirosawa, Wako City, Saitama Prefecture (879) Representative Miya, RIKEN Ryuko Shima 1-4-1 (328) Yurakucho, Chiyoda-ku, Tokyo Denki Kagaku Kogyo Co., Ltd. Representative Akira Shinohara 4, Agent Room 204, Sanshin Building, 1-4g1 Yurakucho, Chiyoda-ku, Tokyo Telephone 501-21385; Column 6 of “Detailed Description of the Invention” of the specification to be amended, content of the amendment (1) “Unexamined Japanese Patent Publication No. 58-257, page 6, lines 4-5 of the specification”
80'' is corrected to ``Unexamined Japanese Patent Publication No. 52-25780.''

(2) In the specification, page 17, line 11, "same" is corrected to "same structure."

(3) In Table 1 on page 22 of the specification, “By-product benzene (benzene mall/vinylhiscine mo
l) Correct J to [by-product benzene (benzene moJL/vinylpyridine l1ou) J.

Claims (2)

[Claims] (1) i) Formula (I) n 8m [However, in the formula, A is an alkyl group having 1 to 4 carbon atoms and/or a phenyl group, and the number of substitutions n represents O to 2;
B is selected from an alkoxycarbonyl group (the number of carbon atoms in the alkoxy moiety is 1 to 3) or an acyl group (the number of carbon atoms is 1 to 4), and the number of substitutions m is 1 or 2. Furthermore, X is a halogen atom. ] and ii) a polyene having 4 to 16 carbon atoms (the number of double bonds is 2 to 16);
There are 4 groups. However, polyenes consisting only of aromatic unsaturated bonds are excluded. ) are mixed with one or more of each group, and further treated with a reducing agent selected from the group of alkali metal amalgam, polohydride, aluminum hydride or hydride; alkyl aluminum; or alkyl zinc. Formula (IF) ^n 8m [However, in the formula, A is an alkyl group having 1 to 4 carbon atoms and/or a phenyl group, the number of substitutions n represents O to 2, and
B is selected from an alkoxycarbonyl group (the number of carbon atoms in the alkoxy moiety is 1 to 3) or an acyl group (the number of carbon atoms is 1 to 4), and the number of substitutions m is 1 or 2. R is a polyene with 4 to 1B carbon atoms (the number of double bonds is 2 to 4, excluding polyenes consisting only of aromatic unsaturated bonds), and the diene part is cobalt and cobalt. form a positional bond. ] η5 single layer substituted cyclopentadienylcobal I・
Method for producing polyene complex. (2) i) Formula (III) n Il [However, in the formula, A is an alkyl group having 1 to 4 carbon atoms and/or a phenyl group, and the number of substitutions n represents θ to 2;
B is selected from an alkoxycarbonyl group (l&prime number of the alkoxy moiety is 1 to 3) or an acyl group (1 to 4 carbon atoms), and m is 1 or 2. M is an alkali metal. ] A substituted cyclopentadienyl alkali metal complex represented by the following, it) cobalt (II) halide, and in) a polyene having 4 to 18 carbon atoms (the number of double bonds is 2 to 4. However, aromatic (excluding polyenes consisting only of sexually unsaturated bonds);
Formula (II) n 8m characterized in that it is treated with a reducing agent selected from the group of aluminum alkyl; or zinc alkyl [wherein A is an alkyl group having 1 to 4 carbon atoms and/or a phenyl group] Yes, the number of substitutions n is O~2, and on the other hand,
B is selected from an alkoxycarbonyl group (the alkoxy moiety has 1 to 3 carbon atoms) or an acyl group (1'R prime number is 1 to 4), and the number of substitutions m is 1 or 2. Further, R is a polyene having 4 to 16 carbon atoms (the number of double bonds is 2 to 4, excluding polyenes consisting only of aromatic unsaturated bonds), and the diene portion coordinates with cobalt. form a bond. ] A method for producing η5-5-substituted cyclobentadienyl cobaltboriene.