KR102100611B1 - Metal complex catalysts for selective formation of cyclic carbonates and process for preparing cyclic carbonate using the same - Google Patents

Abstract

The present invention relates to a novel metal complex compound for producing a cyclic carbonate and a method for preparing a cyclic carbonate using the same as a catalyst, and more specifically, a catalyst for a metal complex compound containing a novel structure of a ligand compound and a divalent metal It relates to a method for selectively producing a cyclic carbonate with a high conversion rate with a high conversion rate compared to a conventional catalyst using epoxide compounds and carbon dioxide of various structures as raw materials.

Description

Metal complex catalysts for selective formation of cyclic carbonates and process for preparing cyclic carbonate using the same}

The present invention relates to a novel metal complex compound for producing a cyclic carbonate and a method for producing a cyclic carbonate by reacting an alkylene oxide compound with carbon dioxide using the catalyst.

Cyclic carbonates are one of the important compounds used in a wide range of applications as organic solvents, synthetic fiber processing agents, pharmaceutical raw materials, cosmetic additives, and electrolyte solvents for lithium batteries, and further, as intermediates for alkylene glycol and dialkyl carbonate synthesis.

Conventionally, this cyclic carbonate was synthesized by reacting epoxide and carbon dioxide in the presence of a homogeneous catalyst and under appropriate pressure conditions. As such a homogeneous catalyst, halides such as alkali metals and onium salts such as quaternary ammonium salts are known from the past and are also used industrially.

For example, in Chinese Patent No. 101921257, 5-membered cyclic carbonate was synthesized using a catalyst composed of a strong basic spherical styrene ion exchange resin having different halogen ions, and Japanese Patent Publication No. 56-128778 discloses an alkali metal compound and a crown. A cyclic carbonate was prepared in a catalyst system composed of a compound, Japanese Patent Publication No. 59-13776 used quaternary ammonium and alcohol, and Japanese Patent No. 2006-151891 discloses an epoxy compound in the presence of Bu ₂ SnI ₂ and InCl ₃ And CO2 were reacted to prepare a cyclic carbonate, and WO 2005/003113 used tetraalkyl phosphnium halide, and Korean Patent Publication No. 2005-0115694 discloses a catalyst system composed of a metal salt and an aliphatic amine salt. I am using it.

However, according to their synthesis method, under a mild reaction condition, the reaction yield is low, and a high temperature and a long reaction time are required to increase the yield, and there is a problem in that the moisture content of carbon dioxide and alkylene oxides, which are raw materials, must be controlled to several hundred ppm or less. .

Chinese Patent No. 101921257 Japanese Patent Publication No. 56-128778 Japanese Patent Publication No. 59-13776 Japanese Patent Publication No. 2006-151891 WO 2005/003113 Korean Patent Publication No. 2005-0115694

It is an object of the present invention to provide a novel complex ligand compound and a metal complex compound containing the same.

Another object of the present invention is to provide a method for producing a highly efficient and selectively cyclic carbonate by reacting alkylene oxide and carbon dioxide using the metal complex compound as a catalyst.

The present invention provides a metal complex containing a ligand represented by Formula 1 and a Group 2, 6, 8, 9, 10, 11 or 12 divalent metal on the periodic table.

[Formula 1]

(In the formula 1,

R ₁ and R ₂ are each independently hydrogen, C 1 -C 10 alkyl, halogen or nitro;

R ₃ and R ₄ are each independently hydrogen, C 1 -C 10 alkyl, halo C 1 -C 10 alkyl or C 6 -C 20 aryl, or R ₃ and R ₄ may be connected to each other to form a ring.)

In addition, the present invention provides a ligand compound represented by Formula 1 below.

[Formula 1]

(In the formula 1,

R ₁ and R ₂ are each independently hydrogen, C 1 -C 10 alkyl, halogen or nitro;

R ₃ and R ₄ are each independently hydrogen, C 1 -C 10 alkyl, halo C 1 -C 10 alkyl or C 6 -C 20 aryl, or R ₃ and R ₄ may be connected to each other to form a ring.)

In addition, the present invention comprises the steps of preparing an aldehyde compound of formula C by reacting a bis (4-hydroxyphenyl) compound of formula A and hexamethylenetetramin of formula B; And preparing a ligand compound of Formula 1 by reacting an aldehyde compound of Formula C and a 2-aminophenol compound of Formula D.

[Formula A]

[Formula B]

[Chemical Formula C]

[Formula D]

(In the above formula A, C and D,

R ₁ and R ₂ are each independently hydrogen, C 1 -C 10 alkyl, halogen or nitro;

R ₃ and R ₄ are each independently hydrogen, C 1 -C 10 alkyl, halo C 1 -C 10 alkyl or C 6 -C 20 aryl, or R ₃ and R ₄ may be connected to each other to form a ring.)

In addition, the present invention provides a method for selectively preparing a cyclic carbonate by reacting an alkylene oxide compound with carbon dioxide using the metal complex compound as a catalyst.

The metal complex compound according to the present invention is a complex compound containing a ligand compound of a novel structure and a group 2, 6, 8, 9, 10, 11 or 12 divalent metal on the periodic table, reacting epoxide and carbon dioxide It is useful as a catalyst used to synthesize cyclic carbonates.

In addition, the cyclic carbonate can be produced at a high conversion rate by the method for producing a cyclic carbonate using the metal complex compound of the present invention.

Figure 1-Crystal structure of the metal complex Zn-1a prepared in Example 6 (Red: O, Gray: C, White: H, Blue: N, Purple: Zn)

Hereinafter, the present invention will be described in detail. At this time, unless there are other definitions in the technical terms and scientific terms used, those skilled in the art to which this invention belongs have meanings that are commonly understood, and the following description may unnecessarily obscure the subject matter of the present invention. Descriptions of known functions and configurations are omitted.

The term "alkyl" described in the present invention refers to a monovalent straight-chain or ground saturated hydrocarbon radical consisting only of carbon and hydrogen atoms, examples of such alkyl radicals being methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t- Butyl, pentyl, hexyl, octyl, dodecyl, and the like.

The term "haloalkyl" described in the present invention means an alkyl radical substituted with a halogen atom as defined above, and examples of haloalkyl include fluoromethyl, difluoromethyl, trifluoromethyl, fluoroethyl, and difluoro Ethyl, bromopropyl, and the like.

The term "aryl" described in the present invention is an organic radical derived from an aromatic hydrocarbon by removal of one hydrogen, single or fused, preferably containing 4 to 7, preferably 5 or 6 ring atoms in each ring. It includes a ring system, and includes a form in which a plurality of aryls are connected by a single bond. Specific examples include, but are not limited to, phenyl, naphthyl, biphenyl, anthryl, indenyl, fluorenyl, and the like.

The present invention relates to a novel metal complex compound for producing a cyclic carbonate and a method for producing a cyclic carbonate by reacting an alkylene oxide compound with carbon dioxide using the catalyst.

The metal complex compound of the present invention includes a ligand compound represented by the following Chemical Formula 1 and a Group 2, 6, 8, 9, 10, 11 or 12 divalent metal in the periodic table.

[Formula 1]

(In the formula 1,

R ₁ and R ₂ are each independently hydrogen, C 1 -C 10 alkyl, halogen or nitro;

R ₃ and R ₄ are each independently hydrogen, C 1 -C 10 alkyl, halo C 1 -C 10 alkyl or C 6 -C 20 aryl, or R ₃ and R ₄ may be connected to each other to form a ring.)

In the ligand compound according to an embodiment of the present invention, R ₁ is hydrogen, C ₁ -C 7 alkyl or halogen; R ₂ is hydrogen or nitro; R ₃ and R ₄ are each independently C 1 -C 7 alkyl, halo C 1 -C 7 alkyl or C 6 -C 12 aryl, or R ₃ and R ₄ may be connected to C 2 -C 7 alkylene to form an alicyclic ring.

More preferably, R ₁ is hydrogen, C ₁ -C 4 alkyl or halogen; R ₂ is hydrogen or nitro; R ₃ and R ₄ are each independently C 1 -C 4 alkyl, halo C 1 -C 4 alkyl or C 6 -C 12 aryl, or R ₃ and R ₄ may be connected to C ₄ -C 5 alkylene to form an alicyclic ring.

In the ligand compound according to an embodiment of the present invention, the ligand compound of Formula 1 may be selected from the following structures, but is not limited thereto:

(R ₁ is C ₁ -C 4 alkyl or halogen, more preferably methyl, butyl or chloro; R ₃ and R ₄ are each independently C 1 -C 4 alkyl, halo C 1 -C 4 alkyl or C 6 -C 12 aryl, more preferably It is methyl, ethyl, propyl, butyl, trifluoromethyl or phenyl.)

In addition, the present invention relates to a method for preparing the ligand compound of Formula 1, wherein the ligand of Formula 1 can be efficiently prepared through a Duff's reaction and an imidation reaction.

More specifically, the ligand compound of Formula 1 can be prepared by the following steps:

Preparing a aldehyde compound of formula C by reacting a bis (4-hydroxyphenyl) compound of formula A and a hexamethylenetetraamine of formula B; And

Reacting an aldehyde compound of formula C and a 2-aminophenol compound of formula D to prepare a ligand compound of formula 1.

[Formula 1]

[Formula A]

[Formula B]

[Chemical Formula C]

[Formula D]

(In the formula 1, A, C and D,

R ₁ and R ₂ are each independently hydrogen, C 1 -C 10 alkyl, halogen or nitro;

R ₃ and R ₄ are each independently hydrogen, C 1 -C 10 alkyl, halo C 1 -C 10 alkyl or C 6 -C 20 aryl, or R ₃ and R ₄ may be connected to each other to form a ring.)

Specific examples of the bis (4-hydroxyphenyl) compound of Chemical Formula A are 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane (2,2-Bis (4-hydroxyphenyl) hexafluoropropane), 2,2-bis (4-hydroxyphenyl) -4-methylpentane (2,2-Bis (4-hydroxyphenyl) -4-methylpentane), bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxyphenyl) butane (2, 2-Bis (4-hydroxyphenyl) butane), 1,1-bis (4-hydroxyphenyl) -1-phenylethane (1,1-Bis (4-hydroxyphenyl) -1-phenylethane), 4,4'- Cyclohexylidene bisphenol (4,4'-Cyclohexylidenebisphenol), and the like, but is not limited thereto.

An aldehyde compound (Formula C) in which a formyl group is introduced at the ortho position of the hydroxy group of the bis (4-hydroxyphenyl) compound of Formula A is prepared using a known Duff's reaction. That is, an aldehyde compound of Formula C is prepared by reacting a bis (4-hydroxyphenyl) compound of Formula A with hexamethylenetetraamine of Formula B.

The formylation reaction can be carried out in the presence of an acid, and it is preferable to use a strong acid such as trifluoroacetic acid, methanesulfonic acid or polyphosphoric acid as a solvent.

The hexamethylenetetraamine of Formula B is used in excess with respect to the bis (4-hydroxyphenyl) compound of Formula A, preferably 30 to 50 equivalents with respect to 1 equivalent of bis (4-hydroxyphenyl) compound of Formula A Use as

The ligand compound of Formula 1 is prepared by reacting the aldehyde compound of Formula C with the 2-aminophenol compound of Formula D. The 2-aminophenol compound of Formula D is used in at least 4 equivalents based on 1 equivalent of the aldehyde compound of Formula C. The imidization reaction can be preferably performed at 20 to 40 ° C.

The preparation of the ligand compound of Formula 1 may be performed under an organic solvent, and there is no need to limit the organic solvent as long as it can dissolve the reactant. Solvents of the reaction include methanol, ethanol, isopropanol, acetone, ethyl acetate, acetonitrile, isopropyl ether, methyl ethyl ketone, methylene chloride, dichlorobenzene, chlorobenzene, dichloroethane, tetrahydrofuran, toluene, benzene and An inert solvent selected from the group consisting of xylene is preferable in view of the solubility of the reactants and ease of removal, and more preferably, methanol, ethanol, or a mixed solvent thereof.

All of the reactions are completed by confirming that all starting materials have been consumed through TLC or the like. When the reaction is completed, the solvent may be distilled under reduced pressure as necessary, and then the target product may be separated and purified through conventional methods such as filtration, tube chromatography, and recrystallization.

The metal complex compound of the present invention is more specifically represented by the following formula (2).

[Formula 2]

(In the formula 2,

M is a Group 2, 6, 8, 9, 10, 11 or 12 divalent metal on the periodic table;

R ₁ and R ₂ are each independently hydrogen, C 1 -C 10 alkyl, halogen or nitro;

R ₃ and R ₄ are each independently hydrogen, C 1 -C 10 alkyl, halo C 1 -C 10 alkyl or C 6 -C 20 aryl, or R ₃ and R ₄ may be connected to each other to form a ring.)

In the ligand compound according to an embodiment of the present invention, the M is Mg ^{2 +} , Cr ^{2 +} , Fe ²⁺ , Co ^{2 +} , Ni ^{2 +} , Cu ^{2 +} , or Zn ^{2 +} ; R ₁ is hydrogen, C1-C7 alkyl or halogen; R ₂ is hydrogen or nitro; R ₃ and R ₄ are each independently C 1 -C 7 alkyl, halo C 1 -C 7 alkyl or C 6 -C 12 aryl, or R ₃ and R ₄ may be connected to C 2 -C 7 alkylene to form an alicyclic ring.

In the ligand compound according to an embodiment of the present invention, the ligand compound of Formula 1 may be selected from the following structures, but is not limited thereto:

(Wherein M is Mg ^{2 +,} Cr ^{2 +,} Fe ^{2 +,} Co ^{2 +,} Ni ^{2 +,} Cu ^{2 +} or Zn ^{2 +} a; R ₁ is C1-C4 alkyl or halogen, more preferably methyl, butyl Or chloro; R ₃ and R ₄ are each independently C 1 -C 4 alkyl, halo C 1 -C 4 alkyl or C 6 -C 12 aryl, more preferably methyl, ethyl, propyl, butyl, trifluoromethyl or phenyl.)

The metal complex compound of Formula 2 may be prepared by reacting the ligand compound of Formula 1 with a metal acetate, that is, M (OAc) ₂ , wherein M is a Group 2, 6, 8, 9, or 10 periodic table. , Group 11 or 12 is a divalent metal.

In addition, the present invention provides a method for preparing a cyclic carbonate by reacting carbon dioxide and alkylene oxide using the metal complex compound as a catalyst, and the reactant alkylene oxide includes one or more epoxides in the compound structure, and carbon dioxide When reacting with all epoxides can react to form cyclic carbonates.

In one embodiment of the present invention, the metal complex compound may be a metal complex compound of Formula 2.

More specifically, a method for preparing a cyclic carbonate represented by the following Chemical Formula 4 is provided by reacting carbon dioxide and an alkylene oxide represented by the following Chemical Formula 3 using the metal complex compound of the Chemical Formula 2 as a catalyst.

[Formula 3]

[Formula 4]

(In the formulas 3 and 4,

R _a and R _b are each independently hydrogen, C 1 -C 10 alkyl or C 6 -C 20 aryl, or R _a and R _b may be linked by C 3 -C 7 alkylene with or without fused rings to form a ring. .)

In the method for producing a cyclic carbonate according to an embodiment of the present invention, the alkylene oxide represented by Chemical Formula 3 may be specifically selected from the following structures, but is not limited thereto.

(The above R _b is C1-C7 alkyl or C6-C12 aryl.)

In the method for producing a cyclic carbonate according to an embodiment of the present invention, the amount of the metal complex compound of Formula 2 is not particularly limited, but 0.05 to 1.0 mol%, more preferably, with respect to the alkylene oxide of Formula 3 Can be used in 0.1 to 1.0 mol%. Appropriate reaction rates and selectivity can be exhibited within the above range.

In the method for producing a cyclic carbonate according to an embodiment of the present invention, an ammonium-based or amine-based cocatalyst may be further included for improved reaction rate and high yield. 0.1 to 5.0 mol%, preferably 0.3 to 1.0 mol%, more preferably 0.3 to 0.5 mol%, relative to the alkylene oxide of 3. As the ammonium-based cocatalyst, an aliphatic amine salt, an aromatic amine salt or a heteroaromatic amine salt can be used, and specifically, tetrabutylammonium bromide (NBu ₄ Br), tetramethylammonium bromide (NMe ₄ Br), tetraethylammonium Tetrafluoroborate (NEt ₄ BF4), tetrapropylammonium bromide (NPr ₄ Br), tetrahexylammonium chloride (N [(CH ₂ ) ₅ CH ₃ ] ₄ Cl), tetrapentylammonium bromide (N [(CH ₂ ) ₄ CH ₃ ] ₄ Br), tetraheptylammonium bromide (N [(CH ₂ ) ₆ CH ₃ ] ₄ Br), tetraoctylammonium bromide (N [CH ₂ ) ₇ CH ₃ ] ₄ Br), trimethyldodecylammonium chloride (CH ₃ (CH ₂ ) ₁₁ N (CH ₃ ) ₃ Cl), trimethyltetradecylammonium bromide (CH ₃ (CH ₂ ) ₁₃ N (CH ₃ ) ₃ Br), trimethylhexadecylammonium chloride (CH ₃ (CH _{2 ) 15 N (CH 3) 3} Cl), methyl trioctyl ammonium chloride _{(CH 3 N [(CH 2} ) 7 CH 3] 3 Cl), tetrabutyl ammonium Fluoride (NBu ₄ F), tetrabutylammonium chloride (NBu ₄ Cl), tetrabutylammonium iodide (NBu ₄ I), 1- butyl-3-methylimidazolium bromide ([bmim] Br), 1- Butyl-3-methylimidazolium chloride ([bmim] Cl), bis (triphenylphosphine) iminium chloride ([((C ₆ H ₅ ) ₃ P) ₂ N] Cl, PPNCl) The amine-based cocatalyst may be specifically triethylamine (Et ₃ N), 1,8-diazabicyclone-7-kin (DBU), pyridine (C ₅ H ₅ N) and 4-dimethylamino It may be selected from the group consisting of pyridine (C ₇ H ₁₀ N ₂ , DMAP), it is preferable to use tetrabutylammonium bromide (NBu ₄ Br) as the cocatalyst.

In the method for preparing a cyclic carbonate according to an embodiment of the present invention, the reaction temperature is preferably 40 to 100 ° C, and if the reaction temperature is too low, the reaction rate becomes slow, and if the reaction temperature is too high, the raw material alkylene oxide May decompose and the final yield may deteriorate. In addition, carbon dioxide in the reaction is supplied to the reactor at a pressure of 1 to 10 bar. If the reaction pressure is less than 1 bar, the reaction rate becomes significantly slower, and if it exceeds 10 bar, there is no effect of enhancing the reaction rate, which is uneconomical.

In the method for preparing a cyclic carbonate according to an embodiment of the present invention, the reaction may be carried out under an organic solvent or in a neat. Neat is to react carbon dioxide and alkylene carbonate without using an organic solvent. In some cases, an organic solvent may be used to prevent rapid heat generation. As the usable organic solvent, a solvent surface commonly used in the art may be employed. For example, organic solvents such as methylene chloride, chloroform, ethyl acetate, tert-methylbutyl ether, toluene, isopropyl alcohol, dioxane, acetonitrile, and alkylene carbonate can be used, but are not limited thereto.

Hereinafter, the configuration of the present invention will be described in more detail through examples, but the following examples are provided to help understanding of the present invention, and the scope of the present invention is not limited thereto.

Commercially available reagents and carbon dioxide (99.99%) were used without further purification or drying. All reactions were carried out in a 150 ml stainless steel reactor (bomb reactor).

[Examples 1 to 5] Preparation of ligands 1a to 1e

Preparation of compound C

2,2-bis (4-hydrophenyl) propane (Compound A) (3.00 g, 13 mmol) and hexamethylenetetraamine (HMTA, Compound B) (73,7 g, 526 mmol) in a 250 mL round bottom flask Was added and trifluoroacetic acid (TFA) (100 mL) was slowly added while stirring in an ice bath. After removing the ice bath, it was refluxed at 110 ° C. under nitrogen atmosphere for 7 days. After completion of the reaction, 4 M hydrochloric acid aqueous solution (600 mL) was added and stirred for 2 days. The resulting pale yellow precipitate was dissolved in chloroform and filtered under reduced pressure to remove insoluble impurities. The filtrate was taken and the yellow precipitate produced by evaporating chloroform was dissolved in methylene chloride, and purified by column chromatography using ethyl acetate as a developing solution to obtain the title compound C (yield: 1.40 g, yield: 31.3%).

¹ H NMR (300 MHz, CDCl ₃ -d ₁ ); δ 1.77 (s, 6H), 7.83 (s, 2H), 10.22 (s, 4H), 11.56 (s, 2H).

Preparation of ligand 1a ( Example  One)

In a 100 mL beaker, add compound C (1 g, 2.94 mmol) and methanol (50 mL) and stir at room temperature, 2-aminophenol dissolved in methanol (50 mL) (Compound Da, 1.35 g, 11.7 mmol, 4 equiv) .) Was added. After stirring for one day, the dark red precipitate was filtered and washed with methanol to obtain the title compound, ligand 1a, as a dark red solid (yield: 1. 80 g, yield: 87%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.82 (s, 6H), 6.85 (t, 4H), 6.93 (d, 4H), 7.10 (t, 4H), 7.30 (d, 4H), 7.98 (s, 4H), 9.07 (s, 4H), 9.49 (br, 4H), 15.26 (br, 2H)

Preparation of ligand 1b ( Example  2)

The reaction was carried out in the same manner as in the preparation of ligand 1a of Example 1, except that 2-amino-4-methylphenol (Compound Db, 11.7 mmol, 4 equiv.) Was used instead of 2-aminophenol (Compound Da). To give ligand 1b (brown solid, yield: 83%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.81 (s, 6H), 2.24 (s, 12H), 6.82 (d, 4H), 6.90 (d, 4H), 7.13 (s, 4H), 7.97 (s, 4H), 9.06 (s, 4H), 9.23 (br, 4H), 15.29 (br, 2H)

Preparation of ligand 1c ( Example  3)

The same method as in Preparation of Ligand 1a of Example 1, except that 2-amino-4-t-butylphenol (Compound Dc, 11.7 mmol, 4 equiv.) Was used instead of 2-aminophenol (Compound Da). Reaction was carried out to obtain ligand 1c (dark brown solid, yield: 80%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.27 (s, 36H), 1.88 (s, 6H), 6.55 (d, 4H), 7.02 (d, 4H), 7.53 (s, 4H), 7.78 (s, 4H), 8.97 (s, 4H), 9.73 (br, 4H), 14.89 (br, 2H)

Preparation of ligand 1d ( Example  4)

The reaction was carried out in the same manner as in the preparation of ligand 1a in Example 1, except that 2-amino-4-chlorophenol (Compound Dd, 11.7 mmol, 4 equiv.) Was used instead of 2-aminophenol (Compound Da). To give ligand 1d (brown solid, yield: 35%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.73 (s, 6H), 6.94 (d, 4H), 7.13 (d, 4H), 7.38 (s, 4H), 7.98 (s, 4H), 9.06 (s, 4H), 9.83 (br, 4H), 14.89 (br, 2H)

Preparation of Ligand 1e ( Example  5)

Except for using 2-amino-5-nitrophenol (Compound De, 11.7 mmol, 4 equiv.) Instead of 2-aminophenol (Compound Da), in the same manner as in Preparation of Ligand 1a of Example 1. Reaction gave ligand 1e (brown solid, yield: 10%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.73 (s, 6H), 7.23 (d, 4H), 7.32 (d, 4H), 7.76 (s, 4H), 7.86 (s, 4H), 9.18 (s, 4H), 9.83 (br, 4H), 14.89 (br, 2H)

Preparation of metal complex compounds Zn-1a, Zn-1b, Zn-1c, Zn-1d and Zn-1e

[Example 6] Preparation of metal complex compound Zn-1a

Zn (OAc) ₂ (312 mg, 1.70 mmol, 4 equiv.) Dissolved in methanol (20 mL) was added to a mixture of ligand 1a (300 mg, 0.42 mmol) and THF (20 mL), followed by stirring for 3 hours. Did. After the stirring was completed, the resulting orange solid was filtered and washed with THF and methanol to obtain the metal complex Zn-1a as the title compound (yield: 89%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.77 (s, 6H), 1.89 (s, 6H), 6.37 (t, 4H), 6.60 (d, 4H), 6.96 (t, 4H), 7.55 (d, 4H), 7.72 (s, 4H), 8.97 (s, 4H); Crystals required for structural analysis through X-ray diffraction were obtained by slowly diffusing pentane into a saturated pyridine solution of Zn-1a [FIG. 1].

[Example 7] Preparation of metal complex compound Zn-1b

The metal complex compound Zn-1b was obtained by reacting in the same manner as in the method for preparing the metal complex compound Zn-1a of Example 6, except that ligand 1b (0.42 mmol) was used instead of the ligand 1a (yield: 87%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.76 (s, 6H), 1.90 (s, 6H), 2.17 (s, 12H), 6.54 (d, 4H), 6.81 (d, 4H), 7.40 (s, 4H), 7.73 (s, 4H), 8.94 (s, 4H)

[Example 8] Preparation of metal complex compound Zn-1c

The metal complex compound Zn-1c was obtained by reacting in the same manner as the method for preparing the metal complex compound Zn-1a of Example 6, except that ligand 1c (0.42 mmol) was used instead of the ligand 1a (yield: 81%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.27 (s, 36H), 1.83 (s, 6H), 1.88 (s, 6H), 6.56 (d, 4H), 7.03 (d, 4H), 7.54 (s, 4H), 7.78 (s, 4H), 8.97 (s, 4H)

[Example 9] Preparation of metal complex compound Zn-1d

The metal complex compound Zn-1d was obtained by reacting in the same manner as the method for preparing the metal complex compound Zn-1a of Example 6, except that ligand 1d (0.42 mmol) was used instead of the ligand 1a (yield: 85%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.76 (s, 6H), 1.88 (s, 6H), 6.57 (d, 4H), 6.94 (d, 4H), 7.64 (s, 4H), 7.78 (s, 4H), 9.01 (s, 4H)

[Example 10] Preparation of metal complex compound Zn-1e

The metal complex compound Zn-1e was obtained by reacting in the same manner as in the method for preparing the metal complex compound Zn-1a of Example 6, except that ligand 1e (0.42 mmol) was used instead of the ligand 1a (yield: 25%).

¹ H NMR (300 MHz, DMSO-d ₆ ): δ 1.75 (s, 6H), 1.88 (s, 6H), 7.26 (d, 4H), 7.30 (s, 4H), 7.76 (d, 4H), 7.86 (s, 4H), 9.17 (s, 4H)

[Example 11] Preparation of cyclic carbonate using carbon dioxide and propylene oxide

In a 150 mL Teflon container, a metal complex catalyst (0.1 mol%), tetrabutylammonium bromide (NBu ₄ Br, TBAB, 0.4 mol%), and propylene oxide (3.24 mL, 52.02 mmol) were added. The Teflon vessel was placed in a stainless steel reactor (bomb reactor), and after the process of filling and emptying 5 bar of CO ₂ into the reactor, 10 bar of CO ₂ was finally filled. Then, after the reactor was locked, the reaction proceeded with stirring at the temperature shown in Table 1 below. After the reaction was completed, a portion of the reaction mixture was suspended, dissolved in CDCl ₃ , and analyzed using ¹ H-NMR to show the results in Table 1 below.

The catalyst, temperature, reaction time and conversion rate of the product used in Table 1 are described.

catalyst Temperature (℃) Time (h) Conversion rate (%) Zn-1a 60 8 75 60 12 84 60 16 94 60 20 93 60 24 92 60 30 99 40 8 68 40 30 91 Zn-1b 60 30 80 40 30 62 Zn-1c 60 30 70 40 30 55 Zn-1d 60 30 88 40 30 71 Zn-1e 60 30 94 40 30 78 ¹ H NMR of cyclic carbonate I (300 MHz, CDCl ₃ -d ₁ ): δ 1.51 (d, 3H), 4.05 (m, 1H), 4.60 (m, 1H), 4.90 (m, 1H)

[Example 12] Preparation of cyclic carbonate using carbon dioxide and styrene oxide

The reaction was carried out in the same manner as in the preparation of a cyclic carbonate using propylene oxide, except that styrene oxide (5.96 mL, 52.18 mmol) was used instead of propylene oxide (3.24 mL). It is described in Table 2.

catalyst Temperature (℃) Time (h) Conversion rate (%) Zn-1a 100 8 81 100 24 99 Zn-1b 100 8 77 100 24 93 Zn-1c 100 8 78 100 24 93 Zn-1d 100 8 75 100 24 91 Zn-1e 100 8 80 100 24 97 ¹ H NMR of cyclic carbonate II (300 MHz, CDCl ₃ -d ₁ ): δ4.28 (d, 1H), 4.74 (d, 1H), 5.65 (m, 1H), 4.90 (m, 1H), 7.32 -7.40 (m, 5H)

[Example 13] Preparation of cyclic carbonate using carbon dioxide and cyclohexene oxide

The reaction was carried out in the same manner as in the preparation of a cyclic carbonate using propylene oxide, except that cyclohexene oxide (5.27 mL, 52.19 mmol) was used instead of propylene oxide (3.24 mL). It is listed in Table 3.

catalyst Temperature (℃) Time (h) Conversion rate (%) Zn-1a 90 24 51 Zn-1c 90 24 52 Zn-1e 90 24 55 ¹ H NMR of cyclic carbonate III (300 MHz, CDCl ₃ -d ₁ ): δ4.73 (m, 2H), 2.06-1.88 (m, 4H), 1.74-1.53 (m, 2H), 1.43-1.33 ( m, 2H)

From the above results, it was found that when producing the cyclic carbonate using carbon dioxide and the epoxide compound of various structures, when the metal complex compound of the present invention was used as a catalyst, the cyclic carbonate was produced with a high conversion rate of 50% or more.

Claims (15)

A metal complex containing a ligand represented by Formula 1 and a Group 2, 11 or 12 divalent metal on the periodic table:
[Formula 1]

(In the formula 1,
R ₁ is hydrogen, C1-C10 alkyl or halogen;
R ₂ is hydrogen or nitro;
R ₃ and R ₄ are each independently hydrogen or C1-C10 alkyl.) According to claim 1,
The metal complex compound is a metal complex compound represented by the following formula (2):
[Formula 2]

(In the formula 2,
M is a Group 2, 11 or 12 divalent metal on the periodic table;
R ₁ is hydrogen, C1-C10 alkyl or halogen;
R ₂ is hydrogen or nitro;
R ₃ and R ₄ are each independently hydrogen or C1-C10 alkyl.) According to claim 2,
M is Mg ²⁺ , Cu ²⁺ , or Zn ²⁺ ; R ₁ is hydrogen, C1-C7 alkyl or halogen; R ₂ is hydrogen or nitro; R ₃ and R ₄ are each independently C1-C7 alkyl, a metal complex. According to claim 3,
A metal complex compound selected from the following compounds.

(M is Mg ²⁺ , Cu ²⁺ or Zn ²⁺ ;
R ₁ is C1-C4 alkyl or halogen;
R ₃ and R ₄ are each independently C1-C4 alkyl.) Ligand compound represented by the following formula (1).
[Formula 1]

(In the formula 1,
R ₁ is hydrogen, C1-C10 alkyl or halogen;
R ₂ is hydrogen or nitro;
R ₃ and R ₄ are each independently hydrogen or C1-C10 alkyl.) The method of claim 5,
R ₁ is hydrogen, C ₁ -C 7 alkyl or halogen; R ₂ is hydrogen or nitro; R ₃ and R ₄ are each independently C1-C7 alkyl, a ligand compound. Preparing a aldehyde compound of formula C by reacting a bis (4-hydroxyphenyl) compound of formula A and a hexamethylenetetraamine of formula B; And
Preparing a ligand compound of Formula 1 by reacting an aldehyde compound of Formula C and a 2-aminophenol compound of Formula D;
Method for preparing a ligand compound of Formula 1 comprising:
[Formula 1]

[Formula A]

[Formula B]

[Chemical Formula C]

[Formula D]

(In the formula 1, A, C and D,
R ₁ is hydrogen, C1-C10 alkyl or halogen;
R ₂ is hydrogen or nitro;
R ₃ and R ₄ are each independently hydrogen or C1-C10 alkyl.) A method for preparing a cyclic carbonate by reacting carbon dioxide and alkylene oxide using the metal complex compound according to any one of claims 1 to 4 as a catalyst. The method of claim 8,
The alkylene oxide is represented by the following formula (3), and the cyclic carbonate is a production method represented by the following formula (4).
[Formula 3]

[Formula 4]

(In the formulas 3 and 4,
R _a and R _b are each independently hydrogen, C 1 -C 10 alkyl or C 6 -C 20 aryl, or R _a and R _b may be linked by C 3 -C 7 alkylene with or without fused rings to form a ring. .) The method of claim 8,
The metal complex is a manufacturing method characterized in that it is used in an amount of 0.05 to 1.0 mol% with respect to the alkylene oxide. The method of claim 8,
Production method characterized in that it further comprises an ammonium-based co-catalyst or an amine-based co-catalyst. The method of claim 11,
The ammonium-based co-catalyst or amine-based cocatalyst is a manufacturing method characterized in that it is used in an amount of 0.1 to 5.0 mol% with respect to the alkylene oxide. The method of claim 11,
The ammonium-based cocatalyst is tetrabutylammonium bromide (NBu ₄ Br), tetramethylammonium bromide (NMe ₄ Br), tetraethylammonium tetrafluoroborate (NEt ₄ BF4), tetrapropylammonium bromide (NPr ₄ Br), tetra Hexylammonium chloride (N [(CH ₂ ) ₅ CH ₃ ] ₄ Cl), tetrapentylammonium bromide (N [(CH ₂ ) ₄ CH ₃ ] ₄ Br), tetraheptylammonium bromide (N [(CH ₂ ) ₆ CH ₃ ] ₄ Br), tetraoctylammonium bromide (N [CH ₂ ) ₇ CH ₃ ] ₄ Br), trimethyldodecylammonium chloride (CH ₃ (CH ₂ ) ₁₁ N (CH ₃ ) ₃ Cl), trimethyltetradecylammonium Bromide (CH ₃ (CH ₂ ) ₁₃ N (CH ₃ ) ₃ Br), trimethylhexadecylammonium chloride (CH ₃ (CH ₂ ) ₁₅ N (CH ₃ ) ₃ Cl), methyltrioctylammonium chloride (CH ₃ N [ (CH ₂ ) ₇ CH ₃ ] ₃ Cl), tetrabutylammonium fluoride (NBu ₄ F), tetrabutylammonium chloride (NBu ₄ Cl), tetrabutylammonium iodide (NBu ₄ I), 1-butyl-3-methylimidazolium bromide ([bmim] Br), 1-butyl-3-methylimidazolium chloride ([bmim] Cl), bis (triphenylphosphine) already One or two or more mixtures selected from the group consisting of nium chloride ([(((C ₆ H ₅ ) ₃ P) ₂ N] Cl, PPNCl), wherein the amine-based cocatalyst is triethylamine (Et ₃ N), 1 One or more mixtures selected from the group consisting of, 8-diazabicyclone-7-kin (DBU), pyridine (C ₅ H ₅ N) and 4-dimethylaminopyridine (C ₇ H ₁₀ N ₂ , DMAP) Manufacturing method characterized in that. The method of claim 8,
The reaction temperature is 40 to 100 ℃, the reaction pressure is a production method characterized in that 1 to 10 bar. The method of claim 8,
The reaction is a production method characterized in that the neat (neat) reaction.

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