KR102156368B1 - Fe Complex Catalyst, And Preparing Method of Cyclic Carboates Using The Same - Google Patents

Abstract

여기서,
IP = 2-iminopyridine
R = EtOH, Mes(mesityl), Ph, Cy(cyclohexyl), Pr(propyl), Pr(OH)₂
X = Cl, Br, I The present invention relates to an iron complex catalyst composed of the same kind of Fe-bisiminopyridine complexes of the formula (2) used to prepare cyclic carbonates by cyclization of oxide and CO2.
Formula (2)
[Fe(IPR)3]X ₂

here,
IP = 2-iminopyridine
R = EtOH, Mes(mesityl), Ph, Cy(cyclohexyl), Pr(propyl), Pr(OH) ₂
X = Cl, Br, I

Description

Iron complex catalyst and cyclic carbonate production method using the catalyst {Fe Complex Catalyst, And Preparing Method of Cyclic Carboates Using The Same}

The present invention relates to a multifunctional iron complex catalyst and a method for producing a cyclic carbonate using the same.

Investigating chemical reactions that can recycle CO ₂ as a chemical raw material for the production of industrially attractive chemicals, plastic precursors and fuels is considered a practical way to contribute to reducing the total amount of anthropogenic CO ₂ released into the atmosphere. come.

Synthesis of cyclic carbonates by the addition of epoxides represents one of several processes using CO ₂ , and this reaction is thermodynamically preferred because the ring-opening of the epoxide releases the ring-transformation energy.

In addition, the efficient transformation of the carbon dioxide (CO ₂ ) into useful compounds such as formic acid, methanol, ureas, carboxylates, polycarbonates and polyurethanes is the potential for CO ₂ to be in organic synthesis. It is very attractive because it is an inexpensive and abundant C1 building block.

Among these compounds, cyclic carbonates produced by the cycloaddition of CO ₂ to epoxides are attractive chemicals.

These compounds are commonly used as electrolyte components, polar aprotic solvents, and chemical intermediates in lithium-ion batteries. Typically, these compounds are synthesized using toxic and dangerous reagents such as phosgene.

Therefore, the demand for the efficient catalyst for the conversion of carbon dioxide is increasing. Various metal-based catalysts have shown activity for the coupling of epoxides to carbon dioxide.

In catalyst systems for cyclic carbonate synthesis, Lewis acidic compounds such as metal-organic complexes or hydrogen bond donors activate the epoxide ring opening with a significant acceleration of the reaction rate. At the same time, the quaternary ammonium or phosphonium salt and the nucleophilic counter anion in the ionic liquid advance the epoxide ring opening by nucleophilic attack.

Following the cooperative step of ring-opening, CO ₂ provides an alkoxy carbonate intermediate in which cyclization yields a cyclic carbonate product by inserting a metal alkoxide bond. Consequently, most catalysts for the cycloaddition of carbon dioxide to epoxides have been known as binary systems consisting of Lewis acids ("catalyst") and nucleophilic components ("cocatalyst").

Until now, metalosalen complexes of Al, Cr, Mn, Co, or Zn are fundamental characteristics of salen-ligands, namely the ease of reaction, the possibility of chelation by most metal ions, and the axial direction. Much attention has been drawn to the planar geometry with empty space for epoxide activation.

On the other hand, the use of a metal-free system has also been extensively studied, and currently commercially used cyclic carbonate synthesis catalysts are hydrogen bond donors having quaternary ammonium or phosphonium (R-OH, R-NH ₂ and their protons It is based on salts.

However, since systems using organic substances require high temperature and high concentration of substrates, continuous research has been conducted on metal-based systems showing strong Lewis acidity in order to carry out the reaction under milder conditions. In recent years, Lewis acidity and nucleophilicity The study of multifunctional single component catalysts showing all components has been considered a sustainable approach to CO2 conversion under mild conditions.

As for the metal-based single component catalyst, a widely developed method is to introduce a nucleophilic component as a quaternary onium salt linked to a ligand. Bifunctional Al (salen), Co (salen) and Zn (salpyr) complexes with ammonium or pyridinium halides have been reported to be more active compared to the binary catalyst analogs. Metalporphyrins of Mg and Zn with ammonium bromide, phosphonium bromide or imidazolium bromide are also developed to show higher catalytic activity without any cocatalyst. Became.

In addition, in the bisimidazole-functionalized cobalt-porphyrin system, imidazole attacked the metal center, thereby promoting the dissociation of the nucleophilic chloride coordinated to the metal. As a neutral nucleophile, the tertiary aliphatic amine of the N-methylhomopiperazine residue was designed to be introduced into the Al (salen)-based ligand to directly attack the epoxide.

A synergistic effect was observed when multiple sites for epoxide activation were introduced. Various hydrogen bond donors such as phenolic hydroxyl groups, N-H groups, and protonated tertiary ammonium groups have been involved in supplying additional Bronsted acid components and improving catalyst performance.

Studies related to hydrogen bond donors have been developed in depth in organic catalyst systems, but the application of metal-ligand complexes has rarely been studied. In addition, despite the growing interest in iron catalysts, there have been few reports of functionalized iron-ligand systems for a sustainable, carbon-balanced approach to carbon dioxide conversion worth the challenge.

The present invention is the invention for a catalyst to form cyclic carbonates from epoxides and carbon dioxide under mild conditions of 80° C. and 5 bar pressure using a multifunctional and sustainable Fe catalyst. In the present invention, a halide counter anion and a hydrogen bond donor for activating epoxide ring opening are provided for an optimal catalyst, and a cocatalyst and a single component catalyst system are provided.

It is an object of the present invention to provide a method for preparing a cyclic carbonate compound by introducing a ligand having various functional groups to an iron core metal to prepare a multifunctional catalyst, and using it as a catalyst for the cyclic addition reaction of CO ₂ and epoxide. have.

In order to solve the above problem, the present invention is composed of the same kind of Fe-bisiminopyridine complexes of formula (2) used to prepare a cyclic carbonate by cyclization addition reaction of oxide and CO2. It provides an iron complex catalyst.

Formula (2)

[Fe(IP ^R ) ₃ ]X ₂

here,

IP = 2-iminopyridine

R = EtOH, Mes(mesityl), Ph, Cy(cyclohexyl), Pr(propyl), Pr(OH) ₂

X = Cl, Br, I

In addition, the present invention is an iron complex composed of heterogeneous Fe-iminopyridine complexes of the following formulas (3) to (5) used to prepare a cyclic carbonate by cyclization addition reaction of oxide and CO2 Provides a catalyst.

Formula (3)

[Fe(BIP ^R )(dhbpy)X]X

Formula (4)

[Fe(tpy)(bpy)X]X

Formula (5)

[Fe(tpy)(dhbpy)X]

here,

BIP = disubstituted-2,6-bisiminopyridine

tpy = terpyridine, bpy = bipyridine, dhbpy = dihydroxybipyridine

R = PrOH, Pr(OH) ₂ ,PrIm(propyl-1 H -imidazole)

X = Cl, Br, I

In addition, the present invention comprises preparing a cyclic carbonate having 3 to 4 carbon atoms by adding a mono- or di-substituted oxide and CO ₂ under a catalyst composed of a Fe-iminopyridine complex, mono- or di-substituted It provides a method for producing cyclic carbonates.

In addition, in the present invention, the monosubstituted oxide is styrene oxide, p-chloro styrene oxide, p-bromo styrene oxide, alkyl or alkyl having 1 to 10 carbon atoms. Ren oxide, glycidol (phenyl glycidyl ether), allyl glycidyl ether (Allyl glycidyl ether), methacrylate oxide (methacrylate oxide), chloromethyl oxide (chloromethyl oxide) It provides a method for producing characteristic cyclic carbonates.

In addition, the present invention provides a method for producing cyclic carbonates characterized in that the disubstituted oxide is cyclopentene oxide or cyclohexene oxide.

The present invention is effective in securing a homogeneous organometallic catalyst technology for CO ₂ conversion by using a multifunctional catalyst by introducing a ligand having various functional groups to the iron core metal and developing a high value-added carbon compound production technology using a resource-resourced carbon source.

1 is a ¹ H-NMR of the reaction of a chloroalkoxy intermediate and propylene oxide in a solvent DMSO-d ₆ .
2 is an explanatory diagram for the mechanism of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail. First, in describing the present invention, detailed descriptions of related known functions or configurations are omitted so as not to obscure the subject matter of the present invention.

The terms'about','substantially', etc. of the degree used in the present specification are used at or close to the numerical value when manufacturing and material tolerances specific to the stated meaning are presented, and are used in the sense of the present invention. To assist, accurate or absolute figures are used to prevent unfair use of the stated disclosure by unscrupulous infringers.

The present invention is the following formula (1) and formula (2) of the same type of Fe-polypyridine complex (homoleptic Fe-polypyridine complexes) catalyst, heterogeneous Fe-iminopyridine complex (heteroleptic Fe-iminopyridine complexes) catalyst and the following formula ( It is composed of heterogeneous Fe-bisiminopyridine complexes (3) ~ (5) or heterogeneous Fe complex catalysts,

The present invention relates to the development of a technology for producing a high value-added carbon compound using a carbon raw material used as a resource and securing a homogeneous organometallic catalyst technology for CO ₂ conversion by using a multifunctional catalyst, which is a catalyst of the present invention, by introducing a ligand having various functional groups to the iron core metal. .

Formula (1)

Fe(L) _n X _m

(n, m = 2 or 3)

here,

L = phen(1,10-phenanthroline), bpy(2,2'-bipyridine), tpy(2,2′:6′,2′′-terpyridine), 5-NO ₂ phen(5-nitro-1, 10-phenanthroline), 4,7-(MeO) ₂ bpy(4-4′-Dimethoxy-2-2′-bipyridine), BIP ^R (2,6-bisiminopyridine)

R = EtOH, PrOH, PrIm (propyl-1 H -imidazole)

X = Cl, Br, PF ₆ , OAc

Formula (2)

[Fe(IP ^R ) ₃ ]X ₂

here,

IP = 2-iminopyridine

R = EtOH, Mes(mesityl), Ph, Cy(cyclohexyl), Pr(propyl), Pr(OH) ₂

X = Cl, Br, I

Formula (3)

[Fe(BIP ^R )(dhbpy)X]X

Formula (4)

[Fe(tpy)(bpy)X]X

Formula (5)

[Fe(tpy)(dhbpy)X]

here,

BIP = disubstituted-2,6-bisiminopyridine

tpy = terpyridine, bpy = bipyridine, dhbpy = dihydroxybipyridine

R = PrOH, Pr(OH) ₂ ,PrIm(propyl-1 H -imidazole)

X = Cl, Br, I

The method of preparing the catalyst is as shown in Reaction Formulas (1) to (5) below.

Scheme (1)

Scheme (2)

Scheme (3)

Scheme (4)

Scheme (5)

First, the present invention is iminopyridine functionalized by the condensation reaction of 2-pyridinecarboxaldehyde (picolinealdehyde) or 2,6-pyridinedicarboxaldehyde (2,6-pyridinedicarboxaldehyde) with an amine. , IP) or bis imino pyridine (BIP) ligands are prepared.

Scheme (1) is FeX ₂ or FeX ₃ (X = Cl, PF ₆ , OAc) and ligands phen(1,10-phenanthroline), bpy(2,2'-bipyridine), tpy(2,2′:6′,2′′-terpyridine) , 5-NO ₂ phen(5-nitro-1,10-phenanthroline), 4,7-(MeO) ₂ bpy(4-4′-Dimethoxy-2-2′-bipyridine), BIPdisubstituted-(2,6- bisiminopyridine), BIP ^R (disubstituted-2,6-bisiminopyridine) (refer to entries 11 to 13 in Table 1) is prepared by reacting with any one of.

Reaction Scheme (2) is an iminopyridine (IP ^R ) ligand produced by the condensation reaction of 2-pyridinecarboxaldehyde (picolinealdehyde) and a primary amine (RNH ₂ ) FeX ₂ (X = Cl, Br, It was prepared by reacting with I). Homoleptic Fe-iminopyridine complexes were used to synthesize the ligand of iminopyridine by aggregation and form the complex of Fe-ligand in a single step for self-assembly. As a result, it is possible to control the stereoscopic and electronic properties through the change of the functional group of the amine.

Heteroleptic ligand iron catalysts of Schemes (3) to (4) are synthesized by sequentially introducing each ligand.

Reaction Scheme (3) is a bisiminopyridine (BIP ^R ) ligand produced by the condensation reaction of 2,6-pyridinedicarboxaldehyde (2,6-pyridinedicarboxaldehyde) and a primary amine (RNH ₂ ) is FeX ₂ (X = Cl, Br, I) After reacting with, further reacting with dihydroxybipyridine (dhbpy) and LiX,

Reaction formula (4) or (5) is by the reaction of terpyridine (tpy) and FeX ₃ The intermediate product Fe(tpy)X ₃ (X = Cl, Br, I) is characterized by an additional reaction with bipyridine (bpy) or dihydroxybipyridine (dhbpy).

After selectively introducing one tridentate ligand (terpyridine or bisiminopyridine), a dihydroxybipyridine (dhbpy) ligand is complexed to form an axial halide, allowing a halide nucleophile that can dissociate from the Lewis acid iron center.

The following is a mono- or di-substituted cyclic carbonate comprising preparing a cyclic carbonate having 3 to 4 carbon atoms by a cyclization addition reaction of a mono- or di-substituent oxide and CO ₂ using the iron complex catalyst of the present invention. It is a description of the manufacturing method.

First, Tables 1 and 2 show a method for preparing cyclic carbonates of styrene oxide using homooleptic Fe-complexes of Formulas (1) and (2).

The yield was determined by 1 H NMR analysis using 1,1,2,2-tetrachloroethane as an internal standard. (Yield of styrene oxide in parentheses)

Items 1-5 in Table 1 mean that among the counter anions of the Fe-ligand complex, halide acts as a nucleophile required for ring opening of the epoxide in particular. In addition, when the electronic properties were changed by introducing a substituent (MeO, NO ₂ ) to the ligand of item 7,8, no improvement in reactivity was observed. Items 6,9,10 are the results of using the catalyst of the three ligands tpy (terpyridine) and BIP (bisiminopyridine) instead of the two ligands phen (phenanthroline) and bpy (bipyridine), compared to tpy (terpyridine). When used, the reaction efficiency increased. In the two-letter ligand catalyst system of item 11-13, in particular, only item 11, which is a saturated form of a halide in the metal center, acted as an effective catalyst at a carbon dioxide pressure of 100 ^o C and 5 bar. This is the case when one halide is dissociated from the metal center through inversion and can act as a nucleophile.

a. The yield was determined by 1 H NMR analysis using 1,1,2,2-tetrachloroethane as internal standard (yield of styrene oxide in parentheses); b. Reaction with 1.0 mol% TBAB.

As expected, the FeBr ₂ salt did not show any catalytic activity at 100 ^° C. and 10 bar of carbon dioxide pressure in the synthesis of cyclic carbonates (item 1). When the reaction was carried out in the presence of Fe(IP ^EtOH ) ₃ Cl ₂ and Fe(IP ^EtOH ) ₃ Br ₂ (0.5 mol%), the target styrene carbonate was obtained at 55% and 96% conversion, respectively (Items 2 and 3 ).

Entry (item) 5 is a solvent containing 1.0 mol% of tetrabutylammonium bromide (TBAB). An important difference in the reaction result of Fe(IP ^EtOH ) ₃ SO ₄ using TBAB is the opposite of the Fe-iminopyridine complex. It means that the action plays an important role, and the nucleophilic halide of Fe(IP ^EtOH ) ₃ Br ₂ works well as a single component catalyst.

In order to clarify the role of the hydroxy group in the iminopyridine ligand, the reactivity of the Fe-ligand complex containing aryl, alkyl, monohydroxy and dihydroxy groups was compared (item 6-9), and with the hydrogen bond donor. The reaction proceeded more efficiently even under a reduced 5 bar of CO ₂ pressure.

When the temperature was further lowered to 80 ^o C, a sharp decrease in the yield of styrene carbonate was observed (item 11), but the reaction efficiency increased to 95% when the nucleophile of the complex was replaced by bromide to iodide (item 12). As a result of Table 1, the activity of the counter anion appeared in the order of nucleophilicity such as Cl <Br <1, and this behavior is due to the fact that the bromide anion is a stronger hydrogen bond acceptor than iodide.

Next, Table 3 shows a method for preparing disubstituted cyclic carbonates of styrene oxide using heteroeptic Fe-bisiminopyridine complexes.

a. The yield was determined by 1H NMR analysis using 1,1,2,2-tetrachloroethane as an internal standard (yield of styrene oxide in parentheses). Dcbpy = 4,4'-dicarboxy-2,2'-bipyridyl (4,4-dicarboxy-2,2-bipyridyl). Dhbpy = 6,6'-dihydroxyl-2,2'-bipyridyl (6,6-dihydroxyl-2.2-bipyridyl).

Table 3 of the present invention shows a heterogeneous Fe-iminopyridine complex containing a halide nucleophile unlike a hydrogen bond donor due to the low reactivity of the catalyst of the homogeneous Fe-iminopyridine complexes below 80 ^o C. (heteroleptic Fe-bisiminopyridine complexes).

Initially, the effect of introducing a hydroxyl group into the ligand according to the type of [Fe(tpy)(ligand)Cl]Cl was investigated (items 1 to 3). The bipyridine (bpy) complex was found to act as an effective catalyst at 120 ^° C and 10 bar of carbon dioxide.

Unlike the dcbpy ligand complex having a 4,4'-dicarboxyl group, the dhbpy ligand complex having a 6,6'-dihydroxyl group showed a significant improvement even under milder conditions. When the chloride ligand was converted to bromide, the yield was compared to half the amount of catalyst (0.25 mol%), and this result can be interpreted as the dissociation rate of the axial halide and the nucleophilicity of the free halide (Item 4).

However, it was observed that the catalytic activity significantly decreased when the temperature was slightly lowered from 100°C to 80°C using the ligand combination. To solve this problem, the tridentate ligand was converted from terpyridine (tpy) to bisiminopyridine (BIP), which can easily introduce the desired functional group.

It was found that as the number of hydrogen bond donors (hydroxyl groups) increased, the activity of the bisiminopyridine (BIP) induction catalyst increased, and [Fe(BIP ^Pr(OH)2 )(dhbpy)Br]Br was the most effective. . As with the results of the homoleptic Fe catalyst in Table 2, it was tested whether the use of a complex containing iodide would be useful, but the reactivity did not reach the expected level (item 9-12).

The final optimum conditions showed that the mole% of the catalyst was reduced from 0.5 to 0.25 and the carbon dioxide pressure was also reduced at 5 to 3 bar when compared to the results of the homoleptic Fe-iminopyridine catalyst.

Next, Table 4 shows the types of mono- or di-substituted cyclic carbonates produced by reacting with homoreptic and heterooptic Fe complex catalysts suitable for oxides having various mono- or di-substituents.

Here, Method A is catalyst (0.5 mol%), CO ₂ (5bar), 80℃, 20h conditions (a), and Method B conditions are catalyst (0.25mol%), CO ₂ (3bar), 80℃, 15h(b ), (c) DMF (10M); (d) DMF (10M), 100°C; (e) CO ₂ (5 bar), 50° C.; (f) Catalyst (10 mol%), CO ₂ (10 bar); (g) Catalyst (0.5 mol%), CO ₂ (10 bar), 20 h (h); (h) Catalyst ( _2.5 mol%), CO ₂ (10 bar), 20 h.

The epoxides with halogenated phenyl or methyl substituents were converted to the corresponding cyclic carbonates (2a-2d) in good or good yield. When a longer alkyl group is substituted with an epoxide in the epoxide, poor solubility of the Fe complex is observed under pure conditions, and a suitable solvent (DMF) is required to smoothly perform the reaction (2e-g).

Glycidol, its derivatives, and epichlorohydrin showed excellent reactivity to provide the corresponding cyclic carbonate (2h-2l) (72-99% yield), whereas the methacrylate unit The substrate with is bonded to the iron-bisiminopyridine complex (Fe-bisiminopyridine complex) under low temperature conditions (50 ℃) (2k).

In addition, the double-substituted epoxide generally has difficulty in the substrate due to its large volume. Therefore, its reaction is carried out with a higher amount of catalyst (1.0-2.5 mol%) at a high pressure of 10 bar and a temperature of 100°C.

Carbonate (2m), which is a result of the addition reaction of CO ₂ of cyclopentene oxide, was reported. The related polymer was not detected under the Fe catalyst, but the yield of 2n was only 28-34%, and the selectivity for the cyclic carbonate in Table 3 was all 99% or more. This reflected the absence of any other reaction products including polymers and diols.

Next, the reaction process with cyclic carbonates by reacting with oxide and Fe complex catalyst will be described.

1 relates to 1H-NMR monitoring of a chloroalkoxy intermediate (○) and propylene oxide (□) in a solvent DMSO-d ₆ .

The ¹ H-NMR confirms the reaction intermediate. To confirm the cyclo addition reaction mechanism to which the Fe complex catalyst is added, the stoichiometric reaction between the Fe complex catalyst and propylene oxide can be viewed.

In Table 4, the optimal Fe-complex in Method A and Method B exhibits a complex pattern in the range of 1.0-5.0ppm, so Simplified Fe(BIP ^Ph )Cl ₂ The composite was used.

As shown in Figure 1, after mixing the Fe complex and propylene oxide in DMSO-d ₆ for 30 minutes at 60 ℃, using unreacted propylene oxide (marked □) chloro alkoxy group by epoxide ring opening ( ○ Indication) It provides information about chloride-mediated ring opening. This result confirms that a system without a cocatalyst can be provided by providing a metal alkoxide intermediate by attacking the epoxide activated by the halide counter anion of the Fe catalyst.

In Table 5, the catalytic performance of simple physical mixtures such as FeX ₂ and ligands was evaluated to study the effect of integrating multifunctional groups in a single component catalyst.

a The yield is determined by ¹ H NMR analysis (yield of styrene oxide in parentheses); b Reaction conditions are CO ₂ (5bar), 20 hours; c Reaction conditions: CO ₂ (3bar), 15 hours. serinol = 2-amino-1,3-propanediol

Surprisingly, when each component including FeI ₂ , picolinaldehyde and serinol was treated simultaneously (Item 1), the reaction was found to be as effective as the initial conditions of Method A.

Compared with the results of the reaction proceeded with each component (item 2 to 4), the [Fe(IP ^Pr(OH)2 ) ₃ ]I ₂ complex is in its original position by self-assembly from FeI ₂ and ligand components. -situ) to activate the reaction.

Heteroleptic Fe-bisiminopyridine systems were tested for multifunctional performance in items 5 and 6. The simply mixed catalyst system exhibits almost no catalytic activity compared to [Fe(BIP ^Pr(OH)2 )(dhbpy)Br]Br, showing superiority in integrating functional groups within a single molecule.

In addition, a gram-scale (50 mmol) reaction of styrene oxide and CO ₂ was performed as shown in Reaction Formula (6) below. The multifunctional Fe complex in Scheme (6) showed high catalytic activity even in the reduced catalytic amount (0.1 mol%), which is the most effective Fe used in a system without a cocatalyst for the reaction of epoxide and carbon dioxide (CO ₂ ). It indicates that it is one of the complexes.

Scheme (6)

Finally, a mechanism with high possibility for the present invention will be described. 2 is an explanatory diagram of a mechanism based on the experimental results discussed above. The activity pattern of the multifunctional Fe catalyst can be rationalized for the arrangement of hydrogen bond donors, Lewis acidic iron centers and nucleophilic halogen counter anions in a single component catalyst system.

The epoxide is activated by the Lewis acidic center and the hydroxyl group of the ligand to promote the ring opening of the epoxide. At the same time, the nucleophilic attack of the halide occurs at the site with less steric hindrance of the epoxide, which opens the ring and produces a haloalkoxy anionic species.

The insertion of CO ₂ into the Fe-O bond leads to the formation of a haloalkoxy carbonate intermediate. Intramolecular cyclization leads to the formation of cyclic carbonates with the regeneration of the catalyst.

Recently, there is a shortage of supply for the most useful metal ore (rare metal), but iron (Fe) is one of the five most abundant metals in the earth's crust.

The development of sustainable Fe substitutes as catalysts for large-scale production of cyclic carbonates is a meaningful study. Fe(II)-iminopyridine and bisiminopyridine complexes exist with a nucleophilic halogen compound in which a Lewis acid Fe center and a hydrogen bond donor are bonded in one molecule. The catalytic activity of forming cyclic carbonates from CO ₂ was high.

This approach represents environmentally friendly CO ₂ recycling that provides valuable chemicals for potential industrial applications.

The present invention described above is not limited by the above-described embodiments and the accompanying drawings, and various substitutions, modifications and changes are possible within the scope of the technical spirit of the present invention. It will be obvious to those who have the knowledge of.

Claims (5)

Used to prepare cyclic carbonate by cyclization addition reaction of oxide and CO ₂
The iron complex catalyst composed of the same kind of Fe-iminopyridine complexes of the following formula (2).

Formula (2)
[Fe(IP ^R ) ₃ ]X ₂

here,
IP = 2-iminopyridine
R = EtOH, Mes(mesityl), Ph, Cy(cyclohexyl), Pr(propyl), Pr(OH) ₂
X = Cl, Br, I
Used to prepare cyclic carbonate by cyclization addition reaction of oxide and CO2
Iron complex catalyst consisting of heterogeneous Fe-bisiminopyridine complexes of the following formulas (3) to (5).

Formula (3)
[Fe(BIP ^R )(dhbpy)X]X

Formula (4)
[Fe(tpy)(bpy)X]X
Formula (5)
[Fe(tpy)(dhbpy)X]
here,
BIP = disubstituted-2,6-bisiminopyridine
tpy = terpyridine, bpy = bipyridine, dhbpy = dihydroxybipyridine
R = PrOH, Pr(OH) ₂ ,PrIm(propyl-1 H -imidazole)
X = Cl, Br, I
Under the catalyst composed of the Fe-iminopyridine complex according to any one of claims 1 to 2,
A method for producing mono- or di-substituted cyclic carbonates, comprising preparing a cyclic carbonate having 3 to 4 carbon atoms by a cyclization addition reaction of a mono- or di-substituted oxide and CO ₂ .
The method of claim 3,
The monosubstituted oxide is styrene oxide, p-chloro styrene oxide, p-bromo styrene oxide, alkyl or alkylene oxide having 1 to 10 carbon atoms, and glycine. Cyclic, characterized by being glycidol, phenyl glycidyl ether, allyl glycidyl ether, methacrylate oxide, and chloromethyl oxide Method for producing carbonates.
The method of claim 3,
The bi-substituent oxide is a method of producing cyclic carbonates characterized in that it is cyclopentene oxide or cyclohexene oxide.

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