JPH101446A - Cyclo-dimerization of conjugated diolefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vinylcyclohexene by cyclo-dimerizing a conjugated diolefin by using a highly active and easy to handle catalytic system comprising an onium salt of tricarbonylnitrosyl ferrate with a halogenated metal as precursors for the catalyst. SOLUTION: This method for cyclo-dimerizing a conjugated diolefin, is to obtain a vinylcyclohexene by cyclo-dimerizing a conjugated diolefin (e.g.; 1,3-butadiene) in a short period of time, in a high conversion rate and in a high selectivity by using an easy to handle catalytic system excellent in activity comprising an onium salt of tricarbonylnitrosyl ferrate expressed by formula I (A<+> is an onium ion) (e.g.; tetrabutylammonium tricarbonylnitrosyl ferrate) and a halogenated metal expressed by formula II [M is a metal atom of 3-14 groups in the Periodic Table; X is a halogen; R is an alkyl or an aryl; (m) is 0 or an integer of >=1; (n) is an integer of >=1; (m+n) is equal to the valence number of the metal atom expressed by M] (e.g.; FeCl2 ) as precursors of the catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for cyclizing and dimerizing a conjugated diolefin. More specifically,
The present invention relates to a method for producing vinylcyclohexenes by cyclodimerization of a conjugated diolefin.

[0002]

2. Description of the Related Art Methods for producing vinylcyclohexenes by cyclodimerization of conjugated diolefins such as 1,3-butadiene and isoprene are well known, and the use of the following catalyst systems has been proposed. I have. Tokiko Sho44
No. 29451 includes tris (acetylacetonate)
A ternary catalyst comprising an iron compound such as iron, a phosphorus compound such as bis (diphenylphosphino) ethane, and an alkylaluminum such as triethylaluminum has been proposed. However, the selectivity of 4-vinylcyclohexene, which is the target compound, is low, and the use of expensive phosphorus compounds and alkyl aluminum which is unstable in air and moisture has been a problem in industrial production.

Also, US Pat. No. 5,329,057 discloses a catalyst system characterized by appropriately adjusting the water content of a catalyst obtained by impregnating and calcining a Cu-salt on a silica-alumina carrier. -The calcined prepared catalyst has problems in industrialization due to the problem of life and regeneration, and it is necessary to use an impregnated-calcined catalyst which has low activity but is advantageous for life and catalyst regeneration. In that patent,
In order to achieve a high conversion, a multi-stage reaction or a high-temperature reaction is required. Also, according to the description of the patent, there is a problem that impurities are generated with a slightly lower selectivity.

A zero-valent dinitrosyl iron compound is known as a catalyst species having high activity and high selectivity in the cyclization dimerization reaction of a conjugated diolefin.
atalysis 24 (1986) 1-15), and various methods for preparing iron dinitrosyl halide have been studied mainly as preparation methods thereof. French Patent No. 1,502,141 discloses a catalyst system comprising a combination of iron dinitrosyl halide and a reducing agent as an advantageous catalyst system capable of achieving cyclodimerization of butadiene. In the presence of this catalyst, butadiene is quantitatively converted to 4-vinylcyclohexene at temperatures below 30 ° C. However, this catalyst system requires the use of an expensive reducing agent such as allyl magnesium bromide, and cannot be an industrially advantageous method for preparing a catalyst. Further, French Patent 1,535,936 describes a catalyst system in which dihalo (πallyldinitrosyliron) tin or germanium is prepared and used in the system for the cyclodimerization of butadiene. However, this catalyst system also has the disadvantage of requiring the use of expensive organometallic tin or germanium compounds.

US Pat. No. 4,238,301 discloses a method for reducing dinitrosyl iron halide by electrolytic reduction, but electrolytic reduction is not an industrially advantageous reduction method, and has not yet been commercialized. As a method using an inexpensive reducing agent, US Pat. No. 4,234,454 discloses a method using zinc metal or metal tin as a reducing agent. However, the amount of 4-vinylcyclohexene produced per catalyst is not sufficient, and it has not been industrialized. Further, as is common to all the above catalyst systems, the instability of dinitrosyl iron halide is also a problem, and storage is industrially difficult. As a method for solving this problem, WO 9410110 provides a method characterized in that storage and reaction of dinitrosyl iron halide are performed under NO gas pressure. However, the patent method
It is extremely complicated as an industrial production method such as the necessity of ancillary equipment using NO gas and the centrifugal recovery of metal zinc used excessively as a reducing agent.

As a method for producing a zero-valent dinitrosyl iron compound by a method other than reduction of dinitrosyl iron halide, Japanese Patent Publication No. 57-19086 discloses M ⁺ [Fe (CO) ₃
NO] ^- (M: alkali metal) and a method of reacting with a metal halide or metal acetylacetonate are disclosed. However, alkali metal tricarbonylnitrosylferrate proposed in Japanese Patent Publication No. 57-19086 is a compound that is extremely unstable and difficult to handle, and requires special care such as handling at a relatively low temperature in an inert gas. Is known to those skilled in the art and is disadvantageous for industrial use. Further, according to the patent, in the butadiene dimerization reaction, the amount of 4-vinylcyclohexene produced per catalyst is not satisfactory. On the other hand, tetracarbonylammonium tricarbonylnitrosyl ferrate is soluble in an organic solvent and can be easily synthesized in a two-phase system of an aqueous phase / organic phase,
It is also known to be a stable substance (Journal of the Chemical Society of Japan, 1985, No. 3, p 271-281). However, it is also known that its reactivity is significantly lower than that of Na ⁺ [Fe (CO) ₃ NO] ^- (J. Organom).
et. Chem. 376 (1989) C20-C2
2).

[0007]

As mentioned above, some iron-based catalysts have a high activity, but their precursors are unstable and their industrial use has been severely restricted.
Therefore, the problem to be solved by the present invention is to have a satisfactory reactivity and selectivity as an industrial production method, to be easy to handle, and to be easily supplied to a reactor as a solution such as an aromatic hydrocarbon. It is an object of the present invention to provide a catalyst system for a cyclized dimerization reaction of a conjugated diolefin which is advantageous in terms of process.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies for the above purpose, and found that the catalyst prepared in a system from onium tricarbonylnitrosylferrate and metal halide, which was considered to have low activity, was used. Is used for the cyclization dimerization reaction of conjugated diolefins, it is possible to carry out the reaction at a relatively high reaction temperature, and to achieve high yield and high selectivity in a short time even if the amount of catalyst is significantly reduced Heading, the present invention has been reached.

That is, the gist of the present invention is that when cyclizing and dimerizing a conjugated diolefin in the presence of a catalyst, the onium tricarbonylnitrosylferrate represented by the general formula (1) and the general formula (2) The present invention resides in a method for cyclizing and dimerizing a conjugated diolefin, which comprises using a metal halide represented as a catalyst precursor. A ⁺ [Fe (CO) ₃ NO] ^- (1) (where A ⁺ represents an onium ion) RmMXn (2) (where M is a metal atom selected from Groups 3 to 14 of the periodic table, X is a halogen atom, R is an alkyl group or an aryl group, m is 0 or an integer of 1 or more, n is an integer of 1 or more, and m + n is the valence of the metal atom represented by M.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The diolefin usable in the present invention can be used without particular limitation as long as it is a conjugated diolefin. Preferred examples thereof include 1,3-butadiene and isoprene (2-methyl-1,3 -Butadiene), 2,3
Chain conjugated dienes such as dimethyl-1,3-butadiene, chloroprene and piperylene (1,3-pentadiene), and cyclic conjugated dienes such as 1,3-cyclohexadiene and norbornadiene. These may be used for the reaction as it is, or may be dissolved in an appropriate solvent and used for the reaction. Alternatively, a mixture containing these may be supplied to the reaction as a diolefin source to carry out the reaction.

The onium tricarbonylnitrosylferrate represented by the general formula (1) in the present invention may be any of various onium salts without particular limitation, but is preferably represented by A ⁺ in the general formula (1). Onium ions are represented by R ₁ R ₂
R ₃ R ₄ N ⁺ , R ₁ R ₂ R ₃ R ₄ P ⁺ (R ₁ , R ₂ , R
₃ and R ₄ are any alkyl, aralkyl or aryl groups), specifically tetraalkylammonium, tetraalkylphosphoniums, specifically tetramethylammonium, tetraethylammonium, tetrabutylammonium, tetraphenylammonium, benzyltrimethyl Ammonium, phenyltrimethylammonium, benzyltriethylammonium, methyltriphenylammonium, and their corresponding phosphonium analogs, and iminium represented by R ₅ ＮN ⁺ ＲR ₆ (R ₅ and R ₆ are optional substituents) Examples include, but are not limited to, oniums such as bis (triphenylphosphine) iminium. The method for producing the onium tricarbonylnitrosylferrate is not particularly limited, and a method produced by any method can be used. In addition, a plurality of them on the same molecule,
It may be present, and more specifically, may be one immobilized on a resin such as an anion exchange resin.

As the metal halide represented by the general formula (2) used in the present invention, for example, when m = 0, a metal arbitrarily selected from metals of Groups 3 to 14 of the periodic table And halides such as Cl salt, Br salt and I salt. These salts can be used either as anhydrous salts or hydrates, and also can be used as complex compounds in which pyridine, phosphine or the like is coordinated to a metal halide.
When M is a trivalent or higher polyvalent metal and m is an integer of 1 or more, metal halides having mn alkyl groups or aryl groups can also be used. In this case, n is
The number of halogens is at least 1 and preferably 2 per metal atom. Examples of the alkyl group include a methyl group and an ethyl group, and examples of the aryl group include a phenyl group.
It is not limited to these. Preferred specific examples of the metal halide of the general formula (2) are scandium trichloride, titanium tetrachloride, vanadium trichloride, chromium trichloride, manganese dichloride, manganese trichloride, ferrous chloride, ferric chloride, Cobalt dichloride, nickel chloride, copper chloride, cupric chloride, zinc chloride, aluminum trichloride, gallium trichloride,
Metal chlorides such as indium trichloride, silicon tetrachloride, germanium tetrachloride, tin dichloride, tin tetrachloride, etc., and bromides corresponding to the above chlorides such as ferrous bromide, cobalt dibromide, nickel bromide, And iodide. Examples of the hydrate include ferrous chloride tetrahydrate and ferric chloride hexahydrate, and examples of the complex compound include ferrous chloride dipyridine and ferrous chloride diphosphine. Preferred specific examples of the metal halide having an alkyl group or an aryl group include ethyl aluminum dichloride, diethyl aluminum chloride, dimethyl silicon dichloride, diphenyl silicon dichloride, dimethyl tin dichloride, dibutyl tin dichloride, diphenyl tin dichloride, and the like. However, the present invention is not limited to this.

The charge ratio of the onium tricarbonylnitrosylferrate of the general formula (1) to the metal halide of the general formula (2) is in the range of 0.1 to 5 in terms of molar ratio, preferably 0.5 to 5. Range. These catalyst precursors can be independently supplied to the reactor as they are, that is, as a solid if solid, or as a liquid if liquid. Alternatively, it can be fed to the reactor as a solution or suspension in a suitable solvent.

The amount of the catalyst precursor to be used relative to the starting diolefin is not particularly limited, and it is used in a wide range of ratio. There is no restriction on the concentration of the diolefin and the mixture containing the diolefin. However, in general, from the viewpoint of economy, the molar ratio of diolefin / onium tricarbonylnitrosylferrate is preferably 500 or more, and the concentration of onium tricarbonylnitrosylferrate used in the reaction system is 0.01 mmol / 1 or more. More preferably, it is 0.1 mmol / 1 or more.

The two kinds of catalyst precursors are supplied to the reactor independently as they are, and are heated and stirred at the dimerization reaction temperature in the presence of diolefin to become a catalytically active species in the system, and the cyclized dimerization of diolefin is performed. Progresses. In other words, raw materials,
The reaction can be performed after all the catalyst precursors and the like have been charged at once. Alternatively, two kinds of catalyst precursors may be supplied to the reactor and subjected to a pretreatment of stirring in a suitable solvent in the absence of diolefin, and then the diolefin may be supplied to the reactor to carry out the reaction. By this catalyst pretreatment, there may be a case where the reaction rate is superior to the batch preparation. The temperature of the pretreatment is from room temperature to 60 ° C, preferably 30 to 50 ° C.

In the method of the present invention, it is not necessary to use a solvent. However, in order to supply onium tricarbonylnitrosylferrate to the reactor without industrial difficulty, the onium tricarbonylnitrosylferrate is dissolved in a suitable solvent. Supplying the solution or suspension to the reactor is advantageous in terms of the production process. Also, a diolefin as a raw material,
When the solubility of the catalyst precursor in the mixture containing the catalyst precursor and the diolefin is low, the use of a solvent for the purpose of dissolving the catalyst precursor in the reaction mixture is advantageous in terms of the reaction yield. Examples of usable solvents include aromatic compounds such as benzene, toluene, ethylbenzene, xylene, and mesitylene; tetrahydrofuran (THF);
Examples thereof include ethers such as diethyl ether, but are not particularly limited as long as the catalyst precursor and the raw materials can be dissolved. Further, depending on the purpose of the reaction, the cyclized dimerization product itself can be used as a solvent. In this case, there is an advantage that the step of separating the solvent can be omitted.

The reaction can be carried out at a temperature in the range of 20 ° C. to 150 ° C .; This relatively high reaction temperature is one of the advantages of using the onium tricarbonylnitrosyl ferrate of the present invention.
The reaction is carried out under a pressure sufficient to maintain the diolefin as a liquid phase, or at a pressure sufficient to maintain the diolefin in the liquid phase when a solvent is used. The reaction pressure is not particularly limited, and the internal pressure of the reactor may be increased by using an inert gas in order to maintain the diolefin in a liquid phase. May be. The reaction pressure varies depending on the reaction temperature, the composition of the mixture containing the diolefin compound, and the like.
MPa, preferably the vapor pressure of diolefin to 5MPa
It is selected from the range of a.

According to the method for cyclizing and dimerizing a conjugated diolefin of the present invention described above, a special process at a low temperature for producing active species of a catalyst in a reaction system is not required, and further, a higher temperature than a conventional one is required. It is also possible to carry out the reaction,
It has also become possible to reduce the amount of catalyst and the reaction time.

[0019]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist of the present invention. Example 1-Example 14 A 100 cc stainless steel autoclave was charged with tetrabutylammonium tricarbonylnitrosylferrate {(C ₄
H ₉ ) ₄ N ⁺ [Fe (CO) ₃ NO] ^- ｝ 41.2 mg
(0.100 mmol), a metal halide (predetermined amount described in Table 1) and 40 ml of toluene were charged under nitrogen. After injecting 30 g of liquid butadiene there, the butadiene injection amount was increased to 27.05 g (0.5
0 mol). At this time, the internal pressure was about 0.15 MPa, which is the vapor pressure of butadiene at room temperature. The contents were heated and stirred at 100 ° C. for 2 hours to cause a reaction. After the reaction, the autoclave was cooled, the product was identified by gas chromatography analysis of the reaction mixture, and the product and unreacted butadiene were quantified using toluene added as an internal standard. Material balance after reaction is all 1
The range was 00 ± 1%. 4 which is a cyclized dimerization product
-Vinylcyclohexene (hereinafter referred to as 4-VCH) yield (based on charged butadiene) and 4-VCH selectivity are shown in Table-1. When the yield is 95% or less, the yield is further improved by extending the reaction time.

[0020]

[Table 1] Table 1 Example Metal halide 4-VCH yield (%) 4-VCH selectivity (%) ────────────────────── １ 1 FeCl ₂ 0.050 mmol 96.1 100 2 FeCl ₃ 0.050 91.2 100 3 ZnCl ₂ 0.050 97.9 100 4 CrCl ₃ 0.050 53.0 100 5 VCl ₃ 0.050 47.8 100 6 CoBr ₂ 0.050 66.9 100 7 CuBr ₂ 0.050 54.1 100 8 AlCl ₃ 0.050 88.9 100 9 GaCl ₃ 0.050 97.6 100 10 InCl ₃ 0.050 98.2 100 11 SiCl ₄ 0.050 66.6 100 12 GeCl ₄ 0.050 61.3 100 13 SnCl ₂ 0.050 91.1 100 14 SnCl ₄ 0.050 92.1 100 ── ─────────────────────────────────

[Comparative Example 1] The same operation as in Example 1 was performed without using a metal halide. As a result, the yield of 4-VCH was 0.6%, and the selectivity of 4-VCH was 92.0%. Was.

Examples 15 to 16 The same operation as in Example 1 was carried out using hydrates of iron salts shown in Table 2 as metal halides. Table 2 shows the results.

[0023]

[Table 2] Table 2 Example Metal halide 4-VCH yield (%) 4-VCH selectivity (%) ────────────────────── １５ 15 FeCl ₂ 4H ₂ O 0.050 mmol 89.4 100 16 FeCl ₃ 6H ₂ O 0.050 86.0 100 ────────────────── ─────────────────

Examples 17 to 22 The same operation as in Example 1 was carried out using a predetermined amount of an alkyl metal halide shown in Table 3 as the metal halide. Table 3 shows the results.

[0025]

[Table 3] Table 3 Example Metal halide 4-VCH yield (%) 4-VCH selectivity (%) ────────────────────── １７ 17 EtAlCl ₂ 0.075 mmol 84.1 100 18 Et ₂ AlCl 0.075 48.5 100 19 Me ₂ SiCl ₂ 0.075 73.4 100 20 Ph ₂ SiCl ₂ 0.050 82.2 100 21 Me ₂ SnCl ₂ 0.050 82.6 100 22 Ph ₂ SnCl ₂ 0.050 59.4 100 ─────────────────────────────────── Note Et: C ₂ H _{5 - Me: CH 3 - Ph} : C 6 H 5 - represent.

Comparative Example 2-3 The same operation as in Example 1 was performed using the metal acetylacetonate shown in Table 4 instead of the metal halide. As shown in Table 4, almost no 4-VCH was formed.

[0027]

[Table 4] Table 4 Comparative Example Metal acetylacetonate 4-VCH yield (%) 4-VCH selectivity (%) ───────────────────── ────────────── 2 Fe (acac) ₃ 0.050 mmol 0.9 92 3 Zn (acac) ₂ 0.050 1.0 92 ───────────────── ────────────────── Note acac: CH ₃ COCH ₂ COCH ₂ −

Examples 23 to 25 In a 100 cc stainless steel autoclave, tetrabutylammonium tricarbonylnitrosyl ferrate (41.2) was added.
mg (0.100 mmol), metal halide (Table-
5) and 5 ml of toluene were charged under nitrogen. The autoclave was heated and stirred at 40 ° C. for 1 hour, and after returning to room temperature, 35 ml of toluene was added to the autoclave. After that, butadiene 27.
05 g (0.50 mol) were introduced, and the content was brought to 85 ° C., 2
After heating and stirring for an hour, the reaction was completed. Table 5 shows the results.

[0029]

[Table 5] Table-5 Example Metal halide 4-VCH yield (%) 4-VCH selectivity (%) ────────────────────── ２３ 23 FeCl ₂ 0.050 mmol 92.4 100 24 FeCl ₃ 0.050 97.1 100 25 ZnCl ₂ 0.050 94.0 100

Example 26 Tetrabutylammonium tricarbonylnitrosylferrate was converted to tetrabutylphosphonium tricarbonylnitrosylferrate {(C ₄ H ₉ ) ₄ P ⁺ [Fe (CO) ₃ N
O] ^- ｝, and similar operations were performed under the same conditions as in Example 1. The mixture was heated and stirred for 2 hours to complete the reaction, and was analyzed by gas chromatography. As a result, the yield of 4-VCH was 95.0%,
The 4-VCH selectivity was 100%.

Examples 27 to 34 The same operation as in Example 1 was carried out except that the kind and amount of the solvent coexisting in the reaction system were changed. The results are shown in Table-6.

[0032]

Table 6 Table 6 Example Solvent type Solvent amount 4-VCH yield (%) 4-VCH selectivity (%) ───────────────────── ２７ 27 toluene 5 ml 89.8 100 28 toluene 10 ml 94.0 100 29 ethylbenzene 5 ml 94.3 100 30 ethylbenzene 10 ml 97.3 100 31 ethylbenzene 40 ml 96.1 100 32 THF 5 ml 94.5 100 33 THF 10 ml 97.2 100 34 THF 40 ml 91.1 100

[0033]

According to the present invention, the use of the onium salt of tricarbonylnitrosylferric acid facilitates preparation of the catalyst precursor, is excellent in safety, and is easy to store. Since the catalyst precursor of the present invention can be dissolved or suspended in an organic solvent and supplied to the reaction system, it is easy to handle particularly when the reaction is performed on an industrial scale. Moreover, the activity of the catalyst generated from the precursor of the present invention is excellent, and the cyclization dimerization reaction of the conjugated diolefin can be carried out in a short time at a high conversion and a high selectivity with a small amount of the catalyst.

Claims (6)

[Claims] 1. An onium tricarbonylnitrosylferrate represented by the general formula (1) and a metal halide represented by the general formula (2) when cyclizing and dimerizing a conjugated diolefin in the presence of a catalyst. A method for cyclizing and dimerizing a conjugated diolefin, comprising using as a catalyst precursor. A ⁺ [Fe (CO) ₃ NO] ^- (1) (where A ⁺ represents an onium ion) RmMXn (2) (where M is a metal atom selected from Groups 3 to 14 of the periodic table, X is a halogen atom, R is an alkyl group or an aryl group, m is 0 or an integer of 1 or more, n is an integer of 1 or more, and m + n is equal to the valence of the metal atom represented by M. 2. The onium salt of tricarbonylnitrosylferrate of the general formula (1), wherein the onium ion represented by A ⁺ is at least one selected from an ammonium ion, an iminium ion and a phosphonium ion. The method for cyclizing and dimerizing a conjugated diolefin according to claim 1. 3. The method according to claim 1, wherein the metal halide represented by the general formula (2) is ferrous chloride, ferric chloride, a hydrate thereof, zinc chloride, aluminum chloride, gallium trichloride, indium trichloride, dichloride. 3. The method for cyclizing and dimerizing a conjugated diolefin according to claim 1, wherein the method is at least one selected from tin, tin tetrachloride, ethylaluminum dichloride, diphenylsilicon dichloride and dimethyltin dichloride. 4. The conjugated diolefin is a conjugated diolefin selected from 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, chloroprene, piperylene, 1,3-cyclohexadiene and norbornadiene. The method for cyclizing and dimerizing a conjugated diolefin according to any one of claims 1 to 3. 5. A benzene, toluene, ethylbenzene,
The cyclization of the conjugated diolefin according to any one of claims 1 to 4, wherein the reaction is performed in the presence of at least one solvent selected from xylene, mesitylene, tetrahydrofuran, and diethyl ether. Dimerization method. 6. The use amount of the onium tricarbonylnitrosylferrate represented by the general formula (1) to the metal halide represented by the general formula (2) is 0.1 to 5 in a molar ratio. A method for cyclizing and dimerizing a conjugated diolefin according to any one of claims 1 to 4.