KR102267100B1 - Catalyst for preparing cyclic carbonates and manufacturing cyclic carbonates - Google Patents

Abstract

Disclosed is a catalyst for preparing a cyclized carbonate by reacting an epoxide containing at least one compound of the compound represented by Formula 1 and at least one compound represented by Formula 2 with carbon dioxide.

Description

A catalyst for preparing cyclized carbonates and a method for preparing cyclized carbonates {Catalyst for preparing cyclic carbonates and manufacturing cyclic carbonates}

It relates to a catalyst for the production of cyclized carbonate and a method for preparing the cyclized carbonate.

The increase in the concentration of carbon dioxide in the atmosphere has caused many environmental problems such as global warming due to the greenhouse effect, and reducing the concentration of carbon dioxide has become a global problem that must be solved to maintain society. Carbon dioxide is a good candidate as _{a C 1} synthon for a variety of chemical reactions because it is safe, inexpensive, abundant, and renewable. The chemical conversion of carbon dioxide into industrially useful compounds such as urea, methanol, cyclized carbonates, poly(alkylenecarbonates) and sodium 2-hydroxy benzoate is an active area of research for carbon dioxide fixation and green chemistry. In this field, the most active research area for carbon dioxide conversion is the combination of carbon dioxide and epoxide to produce the corresponding cyclic carbonate, which is an aprotic solvent, an electrolyte for a lithium ion battery, a monomer for polymerization, and a pharmaceutical intermediate. can be used as To date, many catalyst systems, including metal-based catalysts and organic catalysts, have been developed for the synthesis of cyclic carbonates from carbon dioxide and epoxides. Although the synthesis of cyclic carbonates from carbon dioxide and epoxides is a thermodynamically advantageous process, the synthesis of cyclic carbonates on an industrial scale requires high reaction temperature and high carbon dioxide pressure to complete this reaction, so overall this process consumes more energy and is associated with additional indirect carbon dioxide emissions. Therefore, there is a need to develop an efficient catalyst system for the efficient synthesis of cyclic carbonates from carbon dioxide and epoxides under ambient temperature (room temperature) and ambient pressure (atmospheric pressure).

Several catalyst systems, including metal-based catalysts and organic catalysts, have been reported to convert carbon dioxide into cyclic carbonates at room temperature and in a carbon dioxide atmosphere of 1 bar (see Non-Patent Document 1).

Aluminum, the most abundant metal in the earth's crust, is an attractive metal because of its low cost, low toxicity, and high Lewis acidity. However, only a few examples of efficient non-toxic catalysts having an aluminum metal core capable of operating at ambient temperature (room temperature) and 1 bar carbon dioxide are known (see Non-Patent Document 2).

Styrene oxide is generally used as a model substrate for a coupling reaction with carbon dioxide because of its low reactivity, high toxicity, and high boiling point compared to other epoxides. However, non-toxic aluminum based catalysts require catalyst loadings greater than 2.5 mol % and long reaction times of 24 hours to reach high conversions to styrene carbonate under ambient conditions (room temperature and atmospheric pressure). Their catalytic activity is defined as a turnover number (TON) of 8.4-39.2 and ^{a turnover frequency (TOF) of 0.63-3.73 h −1} , which is slightly higher than that of organic catalysts, but organic catalysts are more It is the least active catalyst among the catalysts for synthesis. Therefore, there is a need for the development of new active aluminum catalyst systems that allow lower catalyst loading (<1.0 mol%) and provide high TON (>100) under ambient conditions.

Korean Patent Registration 10-1864998

Chem. Commun. 2019, 55, 1360-1373 ACS Catal. 2015, 5, 3398-3402

It is an object of one aspect of the present invention to provide a novel catalyst capable of producing a high yield of a cyclized carbonate using a small amount of the catalyst at room temperature and atmospheric pressure.

Another object of the present invention is to provide a method for preparing a cyclized carbonate by reacting carbon dioxide with an epoxide compound using a novel catalyst.

In order to achieve the above object, in one aspect of the present invention

A catalyst for preparing a cyclized carbonate by reacting carbon dioxide with an epoxide including at least one compound of a compound represented by the following Chemical Formula 1 and a compound represented by Chemical Formula 2 is provided.

<Formula 1>

<Formula 2>

(In Formula 1 and Formula 2,

R ₁ to R ₅ are each independently hydrogen (H) or a C ₁ to C ₁₀ alkyl group,

Ar ₁ is a 5- or 6-membered heteroaryl group including N, O or S,

n is 0 to 2.)

In addition, in another aspect of the present invention

There is provided a method for producing a cyclized carbonate comprising reacting an epoxide with carbon dioxide in the presence of a catalyst comprising at least one of a compound represented by the following formula (1) and a compound represented by the formula (2).

<Formula 2>

(In Formula 1 and Formula 2,

R ₁ to R ₅ are each independently hydrogen (H) or a C ₁ to C ₁₀ alkyl group,

Ar ₁ is a 5- or 6-membered heteroaryl group including N, O or S,

n is 0 to 2.)

The catalyst provided in one aspect of the present invention is a catalyst for producing a cyclized carbonate by reacting an epoxide with carbon dioxide, and exhibits superior catalytic activity than a conventional aluminum catalyst. Carbonate can be manufactured, and high yield, high turnover number, and high turnover frequency can be secured.

In one aspect of the invention

A catalyst for preparing a cyclized carbonate by reacting carbon dioxide with an epoxide including at least one compound of a compound represented by the following Chemical Formula 1 and a compound represented by Chemical Formula 2 is provided.

<Formula 1>

<Formula 2>

(In Formula 1 and Formula 2,

R ₁ to R ₅ are each independently hydrogen (H) or a C ₁ to C ₁₀ alkyl group,

Ar ₁ is a 5- or 6-membered heteroaryl group including N, O or S,

n is 0 to 2.)

Hereinafter, a catalyst for preparing a cyclized carbonate by reacting an epoxide and carbon dioxide provided in an aspect of the present invention will be described in detail.

The catalyst provided in one aspect of the present invention is used as a catalyst for linking carbon dioxide and epoxide under carbon dioxide conditions at ambient temperature and ambient pressure (carbon dioxide at room temperature and atmospheric pressure), and has excellent catalytic activity compared to conventional catalysts under the same reaction conditions indicates

The alkyl group means a straight-chain or branched hydrocarbon, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, and the like, but is not limited thereto.

The heteroaryl group includes both aromatic compounds containing hetero atoms and partially reduced derivatives thereof.

The R ₁ to R ₅ may each independently be hydrogen (H) or a C ₁ to C ₄ alkyl group, hydrogen (H) or a C ₁ to C ₂ alkyl group, hydrogen (H) or a methyl group. have.

The Ar ₁ may be a 5- or 6-membered heteroaryl group including N or O, or a 5- or 6-membered heteroaryl group including N. Examples of the heteroaryl group include pyridinyl, furanyl, thiophenyl, and the like.

The catalyst may be, for example, a compound represented by the following Chemical Formulas 5 to 10, but is not limited thereto.

<Formula 5>

<Formula 6>

<Formula 7>

<Formula 8>

<Formula 9>

<Formula 10>

In addition, in another aspect of the present invention

There is provided a method for producing a cyclized carbonate comprising reacting an epoxide with carbon dioxide in the presence of a catalyst comprising at least one of the compound represented by the formula (1) and the compound represented by the formula (2).

Hereinafter, a method for producing a cyclized carbonate provided in another aspect of the present invention will be described in detail.

The method for producing a cyclized carbonate provided in another aspect of the present invention comprises reacting an epoxide with carbon dioxide in the presence of a catalyst comprising at least one of the compound represented by Formula 1 and the compound represented by Formula 2 include

Since the catalyst is the same as described above, a detailed description thereof will be omitted below.

The epoxide may be a compound represented by Formula 3 below.

<Formula 3>

(In Formula 3,

R ₁ to R ₄ are hydrogen, alkyl having 1 to 20 carbons, aryl having 6 to 20 carbons, alkylaryl having 7 to 20 carbons, arylalkyl having 7 to 20 carbons, aryloxy having 6 to 20 carbons, aryloxy having 6 to 20 carbons of alkoxyaryl, heterocycloalkyl having 3 to 20 carbon atoms, heteroaryl having 6 to 20 carbon atoms, or silyl ether having 1 to 20 carbon atoms,

R ₂ and R ₃ are connected to each other _{and together with the carbon to which R 2} and R ₃ are connected, are cycloalkyl or heterocycloalkyl having 3 to 7 carbon atoms, and heterocycloalkyl includes N, O or S.)

The epoxide is a specific example, ethylene oxide (ethylene oxide), propylene oxide (propylene oxide), 1,2-butylene oxide (1,2-butylene oxide), 1,2-hexylene oxide (hexylene oxide), stye Styrene oxide, methyl glycidyl ether, tert-butyl glycidyl ether, 6-oxabicyclo[3.1.0]hexane, 3,6-dioxabicyclo[3.1 .0]hexane, 7-oxabicyclo[4.1.0]heptane, 9-oxabicyclo[6.1.0]nonane, trans-2,3-dimethyloxirane, cis-2,3-dimethyloxirane, trans-2,3-diphenyloxirane, cis It may be -2,3-diphenyloxirane, etc., but is not limited thereto.

In addition, the step of reacting the epoxide with carbon dioxide may be performed by additionally including a co-catalyst.

The promoter may be an ammonium-based promoter, and in specific examples, tetrabutylammonium bromide (Tetrabutylammonium bromide, ( n Bu) ₄ NBr), tetrabutylammonium chloride (Tetrabutylammonium chloride, ( n Bu) ₄ NCl), tetrabutylammonium Tetrabutylammonium iodide (( n Bu) ₄ NI), Tetrabutylphosphonium bromide ( n Bu) ₄ PBr), bis(triphenylphosphoranylidene) ammonium chloride (PPNCl) ) and bis(triphenylphosphoranylidene) ammonium bromide (PPNBr), for example, may be tetrabutylammonium bromide.

Furthermore, the catalyst may be added in 0.1 mol% to 2.0 mol%, 0.5 mol% to 1.5 mol%, and 0.7 mol% to 1.2 mol%, based on the epoxide compound.

In addition, the catalyst may be added in 0.1 mol% to 2.0 mol% based on the epoxide compound, and the cocatalyst may be added in 0.1 mol% to 2.0 mol% based on the epoxide compound. The catalyst and cocatalyst may be used in a molar ratio of 0.1:1.0 to 1.0:0.1, may be used in a molar ratio of 0.4:1.0 to 1.0:0.4, and may be used in a molar ratio of 0.5:1.0 to 1.0:0.5, 0.8: It can be used in a molar ratio of 1.0 to 1.0:0.8.

Furthermore, the step of reacting the epoxide with carbon dioxide may be performed in a temperature range of 15° C. to 200° C. under a pressure condition of 1 bar to 20 bar. For example, it may be carried out under a pressure condition of 1 bar to 15 bar, 1 bar to 10 bar, 1 bar to 5 bar, 1 bar to 2 bar, and 15 °C to 175 °C, 15 °C to 150 °C, 20 °C to 125°C, 20°C to 100°C, 25°C to 75°C, and may be performed in a temperature range of 25°C to 50°C.

The cyclized carbonate may be represented by the following formula (4).

<Formula 4>

(In Formula 4,

R ₁ to R ₄ are hydrogen, alkyl having 1 to 20 carbons, aryl having 6 to 20 carbons, alkylaryl having 7 to 20 carbons, arylalkyl having 7 to 20 carbons, aryloxy having 6 to 20 carbons, aryloxy having 6 to 20 carbons of alkoxyaryl, heterocycloalkyl having 3 to 20 carbon atoms, heteroaryl having 6 to 20 carbon atoms, or silyl ether having 1 to 20 carbon atoms,

R ₂ and R ₃ are connected to each other _{and together with the carbon to which R 2} and R ₃ are connected, are cycloalkyl or heterocycloalkyl having 3 to 7 carbon atoms, and heterocycloalkyl includes N, O or S.)

Hereinafter, the present invention will be described in detail through Examples and Experimental Examples.

However, the following examples and experimental examples are only for illustrating the present invention, and the content of the present invention is not limited by the following examples and experimental examples.

General considerations

All experiments were performed in a nitrogen atmosphere using a standard dual manifold Schlenk line. Nitrogen was passed through an activated Cu catalyst to remove residual oxygen and passed through a dryer to remove residual moisture. All chemicals were purchased from commercial sources (purity > 95 %) and used as received unless otherwise specified. Solvents such as toluene and n-hexane were purified by a Grubbs solvent purification system under a nitrogen atmosphere, and stored in an activated molecular sieve (4 Å). Carbon dioxide (99.999%) was used as received without further purification. All epoxides were purified by treatment with calcium hydride to remove residual water. CDCl ₃ was dried with activated molecular sieves and vacuum transferred to a Schlenk tube equipped with a J. Young valve before use.

Measure

¹ H and ¹³ C NMR spectra were obtained at ambient temperature using a Bruker DPX-500 MHz NMR spectrometer with standard parameters. All chemical shifts are expressed in ppm based on the _{residual CDCl 3} (δ=7.24 ppm for ^{1 H NMR; δ=77.00 ppm for 13 C NMR).} Elemental analysis was performed with an EA 1110-FISONS analyzer. High-resolution mass spectrometry (HRMS) data were collected on a high-resolution Q-TOF mass spectrometer (ionization mode: ESI).

manufacturing example One

2- methyl -1-[(pyridine-2- ylmethyl )Amino]propan-2-ol (2-Methyl-1-[( pyridin Preparation of -2-ylmethyl)amino]propan-2-ol)

0.72 g (10 mmol) of isobutylene oxide and 1.08 g (10 mmol) of pyridin-2-ylmethanamine were added to a 25 mL screw cap vial containing a stir bar. The vial was tightly sealed with Teflon tape and paraffin film. The mixture was kept at room temperature overnight and then heated at 55° C. for 3 days. The volatiles were removed under reduced pressure to give the desired product as a colorless oil (80%, 1.44 g).

¹ H NMR (CDCl ₃ ): δ=8.47 (m, 1H, pyridine-H), 7.57 (m, 1H, pyridine-H), 7.20 (m, 1H, pyridine-H), 7.08 (m, 1H, pyridine —H), 3.88 (s, 2H, CMe ₂ CH ₂ NHCH ₂ ), 2.51 (s, 2H, CMe ₂ CH ₂ NHCH ₂ ), 1.11 (s, 6H, CMe ₂ CH ₂ NHCH ₂ ); ¹³ C NMR (CDCl ₃ ): δ=159.6, 149.1, 136.4, 122.1, 121.9 (pyridine), 69.28 (CMe ₂ CH ₂ NHCH ₂ ), 59.92 (CMe ₂ CH ₂ NHCH ₂ ), 55.52 (CMe ₂ CH ₂ NHCH) ₂ ), 27.27 (CMe ₂ CH ₂ NHCH ₂ ); HRMS: m/z calcd for [C ₁₀ H ₁₆ N ₂ O + H] 181.1341; found: 181.1335.

manufacturing example 2

1-[(furan-2- ylmethyl )amino]-2- methyl propane -2-ol (1-[( Furan Preparation of -2-ylmethyl)amino]-2-methylpropan-2-ol)

Prepared in the same manner as in the synthesis method of Preparation Example 1, but from 0.72 g (10 mmol) of isobutylene oxide and 0.97 g (10 mmol) of furan-2-ylmethanamine % (1.40 g).

¹ H NMR (CDCl ₃ ): δ=7.26 (q, 1H, J =1.0 Hz, furan-H), 6.21 (q, 1H, J =2.0 Hz, furan-H), 6.07 (dd, 1H, J _{1 )} =4.0 Hz, J ₂ =0.5 Hz, furan-H), 3.72 (s, 2H, CMe ₂ CH ₂ NHCH ₂ ), 2.44 (s, 2H, CMe ₂ CH ₂ NHCH ₂ ), 1.08 ppm (s, 6H, CMe ₂ CH ₂ NHCH ₂ ); ¹³ C NMR (CDCl ₃ ): δ=153.9, 141.5, 109.9, 106.5 (furan), 69.18 (CMe ₂ CH ₂ NHCH ₂ ), 59.33 (CMe ₂ CH ₂ NHCH ₂ ), 46.58 (CMe ₂ CH ₂ NHCH ₂ ) , 27.13 ppm (CMe ₂ CH ₂ NHCH ₂ ); HRMS: m/z calcd for [C ₉ H ₁₅ NO ₂ + H] 170.1181; found: 170.1176.

manufacturing example 3

2- methyl -1-[(thiophene-2- ylmethyl )Amino]propan-2-ol (2-Methyl-1-[( thiophen Preparation of -2-ylmethyl)amino]propan-2-ol)

Prepared in the same manner as in the synthesis method of Preparation Example 1, but from 0.72 g (10 mmol) of isobutylene oxide and 1.13 g (10 mmol) of thiophen-2-ylmethanamine It was prepared in a yield of 83% (1.54 g).

¹ H NMR (CDCl ₃ ): δ=7.19 (dd, 1H, J ₁ =6.0 Hz, J ₂ =1.5 Hz, thiophene-H), 6.93 (m, 1H, thiophene-H), 6.90 (m, 1H, thiophene-H), 4.02 (d, 2H, J =1.0 Hz, -CMe ₂ CH ₂ NHCH ₂ ), 2.57 (s, 2H, CMe ₂ CH ₂ NHCH ₂ ), 1.16 ppm (s, 6H,CMe ₂ CH _{2 )} NHCH ₂ ); ¹³ C NMR (CDCl ₃ ): δ=144.2, 126.5, 124.6, 124.3 (thiophene), 69.30 (CMe ₂ CH ₂ NHCH ₂ ), 59.34 (CMe ₂ CH ₂ NHCH ₂ ), 48.87 (CMe ₂ CH ₂ NHCH ₂ ) , 27.25 ppm (CMe ₂ CH ₂ NHCH ₂ ); HRMS: m/z calcd for [C ₉ H ₁₅ NOS + H] 186.0953; found: 186.0948.

manufacturing example 4

2- methyl -One-[ Methyl (pyridin-2-ylmethyl) amino ] Preparation of propan-2-ol (2-Methyl-1- [methyl (pyridin-2-ylmethyl) amino] propan-2-ol)

Prepared in the same manner as in the synthesis method of Preparation Example 1, but 0.72 g (10 mmol) of isobutylene oxide and N-methyl-1- (pyridin-2-yl) methanamine (N-methyl-1- (pyridin-2-yl)methanamine) was prepared in a yield of 90% (1.75 g) from 1.22 g (10 mmol).

N-methyl-1-(pyridin-2-yl)methanamine was prepared and used in the same manner as in the prior art ( J. Med . Chem . 2017, 60, 10245-10256.).

¹ H NMR (CDCl ₃ ): δ=8.51 (m, 1H, pyridine-H), 7.62 (m, 1H, pyridine-H), 7.28 (m, 1H, pyridine-H), 7.12 (m, 1H, pyridine —H), 3.80 (s, 2H, CMe ₂ CH ₂ NMeCH ₂ ), 2.50 (s, 2H, CMe ₂ CH ₂ NMeCH ₂ ), 2.39 (s, 3H, CMe ₂ CH ₂ NMeCH ₂ ), 1.14 ppm (s) , 6H, CMe ₂ CH ₂ NMeCH ₂ ); ¹³ C NMR (CDCl ₃ ): δ=159.5, 149.1, 136.5, 122.6, 122.1 (pyridine), 70.28 (CMe ₂ CH ₂ NMeCH ₂ ), 68.47 (CMe ₂ CH ₂ NMeCH ₂ ), 65.51 (CMe ₂ CH ₂ NMeCH) ₂ ), 45.61 (CMe ₂ CH ₂ NMeCH ₂ ), 27.84 ppm (CMe ₂ CH ₂ NMeCH ₂ ); HRMS: m/z calcd for [C ₁₁ H ₁₈ N ₂ O + H] 195.1497; found: 195.1492.

manufacturing example 5

[(furan-2- ylmethyl )( methyl )amino]-2- methyl propane -2-ol ([( Furan Preparation of -2-ylmethyl) (methyl) amino] -2-methylpropan-2-ol)

Prepared in the same manner as in the synthesis method of Preparation Example 1, but 0.72 g (10 mmol) of isobutylene oxide and 1-(furan-2-yl)-N-methylmethanamine (1-(furan-2) -yl)-N-methylmethanamine ) was prepared in a yield of 94% (1.72 g) from 1.11 g (10 mmol).

1-(furan-2-yl)-N-methylmethanamine was prepared and used in the same manner as in the prior art ( J. Med . Chem . 2017, 60, 972-986.).

¹ H NMR (CDCl ₃ ): δ=7.35 (q, 1H, J =1.0 Hz, furan-H), 6.29 (m, 1H, furan-H), 6.17 (m, 1H, furan-H), 3.65 ( s, 2H, CMe ₂ CH ₂ NMeCH ₂ ), 3.20 (s, 1H, HOC-Me ₂ CH ₂ NMeCH ₂ ), 2.42 (s, 2H, CMe ₂ CH ₂ NMeCH ₂ ), 2.38 (s, 3H, CMe _{2 )} CH ₂ NMeCH ₂ ), 1.15 ppm (s, 6H, CMe ₂ CH ₂ NMeCH ₂ ); ¹³ C NMR (CDCl ₃ ): δ=152.9, 142.2, 110.1, 108.5 (furan), 70.12 (CMe ₂ CH ₂ NMeCH ₂ ), 67.18 (CMe ₂ CH ₂ NMeCH ₂ ), 56.18 (CMe ₂ CH ₂ NMeCH ₂ ) , 45.26 (CMe ₂ CH ₂ NHCH ₂ ), 27.97 ppm (CMe ₂ CH ₂ NHCH ₂ ); HRMS: m/z calcd for [C ₁₀ H ₁₇ NO ₂ + H] 184.1338; found: 184.1332.

manufacturing example 6

2- methyl -One-[ Methyl (thiophen-2-ylmethyl) amino ] Preparation of propan-2-ol (2-Methyl-1- [methyl (thiophen-2-ylmethyl) amino] propan-2-ol)

Prepared in the same manner as in the synthesis method of Preparation Example 1, but 0.72 g (10 mmol) of isobutylene oxide and N-methyl-1- (thiophen-2-yl) methanamine (N-methyl-1 -(thiophen-2-yl)methanamine) was prepared in a yield of 95% (1.89 g) from 1.27 g (10 mmol).

N-methyl-1-(thiophen-2-yl)methanamine was prepared and used in the same manner as in the prior art (J. Med . Chem . 2017, 60, 972-986.).

¹ H NMR (CDCl ₃ ): δ=7.20 (m, 1H, thiophene-H), 6.93 (m, 1H, thiophene-H), 6.87 (m, 1H, thiophene-H), 3.83 (s, 2H, CMe) ₂ CH ₂ NMeCH ₂ ), 2.44 (s, 2H, CMe ₂ CH ₂ NMeCH ₂ ), 2.36 (s, 3H, CMe ₂ CH ₂ NMeCH ₂ ), 1.17 ppm (s, 6H, CMe ₂ CH ₂ NMeCH ₂ ); ¹³ C NMR (CDCl ₃ ): δ=142.6, 126.4, 125.7, 124.7 (thiophene), 70.03 (CMe ₂ CH ₂ NMeCH ₂ ), 67.43 (CMe ₂ CH ₂ NMeCH ₂ ), 58.60 (CMe ₂ CH ₂ NMeCH ₂ ) , 44.68 (CMe ₂ CH ₂ NHCH ₂ ), 27.79 ppm (CMe ₂ CH ₂ NHCH ₂ ); HRMS: m/z calcd for [C ₁₀ H ₁₇ NOS + H] 200.1109; found: 2001104.

Example One

Preparation of [Me ₂ Al{OCMe ₂ CH ₂ NHCH ₂ (C ₅ H ₄ N)}] ₂ (hereinafter, Pyr ^H )

AlMe ₃ 1.0 mL (2.0 m solution in toluene, 2.0 mmol) was added to a stirred solution of 0.36 g (2.0 mmol) of the compound of Preparation Example 1 in toluene at 0°C. The mixture was warmed to room temperature and stirred overnight. The residue obtained by removing the solvent under vacuum was washed with n-hexane and recrystallized from toluene. After storing this solution in a freezer at 20° C. for several days, the desired product Pyr ^H was obtained as colorless crystals isolated (80% 0.47 g). The Pyr ^H may be represented by the following Chemical Formula 11.

<Formula 11>

¹ H NMR (CDCl ₃ ): δ=8.56 (m, 2H, pyridine-H), 7.62 (m, 2H, pyridine-H), 7.17 (m, 4H, pyridine-H), 3.80 (d, J =6.5 Hz, 4H, pyridine-CH ₂ N), 2.37 (d, 4H, J =8.6 Hz, CH ₂ CMe ₂ ), 1.24 (s, 12H, CMe ₂ ), 0.93 ppm (s, 12H, AlMe); ¹³ C NMR (CDCl ₃ ): δ=157.3, 149.7, 136.5, 122.8, 122.3 (pyridine), 70.36 (CMe ₂ O), 59.83 (pyridine-CH ₂ N), 52.38 (CH ₂ CMe ₂ ), 27.64 (CMe) ₂ O), 5.98 ppm (AlMe); elemental analysis calcd (%) for C ₂₄ H ₄₂ N ₄ O ₂ Al ₂ : C 61.00, H 8.96, N 11.86; found: C 60.97, H 8.94, N 12.05.

Example 2

Preparation of [Me ₂ Al{OCMe ₂ CH ₂ N(Me)CH ₂ (C ₅ H ₄ N)}] ₂ (hereinafter, Pyr ^Me )

Prepared in the same manner as in Example 1, but using _{1.0 mL of AlMe 3} (2.0 m solution in toluene, 2.0 mmol) and 0.39 g (2.0 mmol) of the compound of Preparation Example 4 in a yield of 75% (0.38 g) was prepared with The Pyr ^Me may be represented by the following formula (12).

<Formula 12>

¹ H NMR (CDCl ₃ ): δ=8.49 (d, 2H, J =4.3 Hz, pyridine-H), 7.56 (m, 2H, pyridine-H), 7.23 (d, 2H, J =7.7 Hz, pyridine- H), 7.10 (m, 2H, pyridine-H), 3.77 (s, 4H, pyridine-CH ₂ N), 2.59 (s, 4H, CH ₂ CMe ₂ ), 2.19 (s, 6H, N-Me), 1.23 (s, 12H, CMe ₂ ), 0.87 ppm (s, 12H, AlMe); ¹³ C NMR (CDCl ₃ ): δ=156.9, 149.2, 136.2, 124.5, 122.3 (pyridine), 72.98 (CMe ₂ O), 67.20 (pyridine-CH ₂ N), 64.41 (CH ₂ CMe ₂ ), 43.89 (N) -Me), 30.68 (CMe ₂ O), 5.95 ppm (AlMe); elemental analysis calcd (%) for C ₂₆ H ₄₆ N ₄ O ₂ Al ₂ : C 62.38, H 9.26, N 11.19; found: C 62.37, H 9.32, N 11.07.

Example 3

Preparation of [Me ₂ Al{OCMe ₂ CH ₂ NHCH ₂ (C ₄ H ₃ O)}] ₂ (Fur ^H )

Prepared in the same manner as in Example 1, but using _{1.0 mL of AlMe 3} (2.0 m solution in toluene, 2.0 mmol) and 0.34 g (2.0 mmol) of the compound of Preparation Example 2 in a yield of 87% (0.39 g) was prepared with The Fur ^H may be represented by the following Chemical Formula 13.

<Formula 13>

¹ H NMR (CDCl ₃ ): δ=7.37 (m, 2H, furan-H), 6.32 (m, 2H, furan-H), 6.19 (d, 2H, J =3.2 Hz, furan-H), 3.72 ( d, 4H, J =7 Hz, furan-CH ₂ N), 2.40 (d, 4H, J =8.8 Hz, CH ₂ CMe ₂ ), 2.09 (t, 2H, J =7.5 Hz, NH), 1.21 (s) , 12H, CMe ₂ ), 0.96 ppm (s, 12H, AlMe); ¹³ C NMR (CDCl ₃ ): δ=151.8, 142.5, 110.3, 108.3 (furan), 70.39 (CMe ₂ O), 59.42 (furan-CH ₂ NH), 44.16 (CH ₂ CMe ₂ ), 27.63 (CMe ₂ O) ), 6.16 ppm (AlMe); elemental analysis calcd (%) for C ₂₂ H ₄₀ N ₂ O ₄ Al ₂ : C 58.65, H 8.95; N 6.22; found: C 58.42, H 9.08, N 6.17.

Example 4

Preparation of [Me ₂ Al{OCMe ₂ CH ₂ N(Me)CH ₂ (C ₄ H ₃ O)}] ₂ (hereinafter, Fur ^Me )

Prepared in the same manner as in Example 1, but using _{1.0 mL of AlMe 3} (2.0 m solution in toluene, 2.0 mmol) and 0.37 g (2.0 mmol) of the compound of Preparation Example 5 in a yield of 90% (0.43 g) was prepared with The Fur ^Me may be represented by the following Chemical Formula 14.

<Formula 14>

¹ H NMR (CDCl ₃ ): δ=7.39 (m, 2H, furan-H), 6.34 (m, 2H, furan-H), 6.23 (d, 2H, J =3.1 Hz, furan-H), 3.73 ( s, 4H, furan-CH ₂ N), 2.51 (s, 4H, CH ₂ CMe ₂ ), 2.24 (s, 6H, N-Me), 1.32 (s, 12H, CMe ₂ ), 0.83 ppm (s, 12H) , AlMe); ¹³ C NMR (CDCl ₃ ): δ=150.0, 142.5, 110.6, 110.2 (furan), 70.83 (CMe ₂ O), 65.90 (furan-CH ₂ N), 53.48 (CH ₂ CMe ₂ ), 43.27 (N-Me) ), 31.58 (CMe ₂ O), 6.22 ppm (AlMe); elemental analysis calcd (%) for C ₂₄ H ₄₄ N ₂ O ₄ Al ₂ : C 60.23, H 9.27, N 5.85; found: C 60.34, H 9.13, N 5.81.

Example 5

Preparation of [Me ₂ Al{OCMe ₂ CH ₂ NHCH ₂ (C ₄ H ₃ S)}] ₂ (hereinafter, Thio ^H )

Prepared in the same manner as in Example 1, but using _{1.0 mL of AlMe 3} (2.0 m solution in toluene, 2.0 mmol) and 0.37 g (2.0 mmol) of the compound of Preparation Example 3 in 89% yield (0.43 g) was prepared with Thio ^H may be represented by the following formula (15).

<Formula 15>

¹ H NMR (CDCl ₃ ): δ=7.24 (m, thiophene-H), 6.98 (m, 2H, thiophene-H), 6.92 (d, 2H, J =2.8 Hz, thiophene-H), 3.92 (d, 4H, J =6.9 Hz, thiophene-CH ₂ N), 2.47 (d, 4H, J =8.8 Hz, CH ₂ CMe ₂ ), 1.82 (d, 2H, J =7.3 Hz, NH), 1.22 (s, 12H) , CMe ₂ ), 0.91 ppm (s, 12H, AlMe); ¹³ C NMR (CDCl ₃ ): δ=140.9, 127.2, 126.7, 125.4 (thiophene), 70.46 (CMe ₂ O), 59.19 (thiophene-CH ₂ N), 46.01 (CH ₂ CMe ₂ ), 27.65 (CMe ₂ O) ), 5.91 ppm (AlMe); elemental analysis calcd (%) for C ₂₂ H ₄₀ N ₂ O ₂ S ₂ Al ₂ : C 54.75, H 8.35, N 5.80; found: C 54.61, H 8.51, N 5.84.

Example 6

Preparation of [Me ₂ Al{OCMe ₂ CH ₂ N(Me)CH ₂ (C ₄ H ₃ S)}] ₂ (hereinafter, Thio ^Me )

Prepared in the same manner as in Example 1, but using _{1.0 mL of AlMe 3} (2.0 m solution in toluene, 2.0 mmol) and 0.40 g (2.0 mmol) of the compound of Preparation Example 6 in a yield of 88% (0.45 g) was prepared with Thio ^Me may be represented by the following formula (16).

<Formula 16>

¹ H NMR (CDCl ₃ ): δ 7.26 (m, thiophene-H), 6.98 (m, 2H, thiophene-H), 6.91 (d, 2H, J =3.0 Hz, thiophene-H), 3.94 (s, 4H) , thiophene-CH ₂ N), 2.54 (s, 4H, CH ₂ CMe ₂ ), 2.27 (s, 6H, NMe), 1.34 (s, 12H, CMe ₂ ), 0.79 ppm (s, 12H, AlMe); ¹³ C NMR (CDCl ₃ ): δ=136.9, 128.6, 126.7, 125.7 (thiophene), 71.92 (CMe ₂ O), 66.11 (thiophene-NMe), 56.23 (thiophene-CH ₂ N), 43.14 (CH ₂ CMe _{2 )} ), 31.20 (CMe ₂ O), 6.02 ppm (AlMe); elemental analysis calcd (%) for C ₂₄ H ₄₄ N ₂ O ₂ S ₂ Al ₂ : C 56.44, H 8.68, N 5.49; found: C 56.17, H 8.68, N 5.37.

comparative example One

Preparation of [Me ₂ Al(OCMe ₂ CH ₂ NHCH ₂ CH ₂ NMe ₂ )] ₂ (hereinafter, NMe2 ^H )

NMe2 ^H was prepared in the same manner as in the prior art ( Organometallics 2014, 33, 2770-2775.). The NMe2 ^H may be represented by the following Chemical Formula 17.

<Formula 17>

comparative example 2

Preparation of [Me ₂ Al(OCMe ₂ CH ₂ N(Me)CH ₂ CH ₂ NMe ₂ )] ₂ (hereinafter, NMe2 ^Me )

Prepared in the same manner as in Example 1, except that _{1.0 mL of AlMe 3} (2.0 m solution in toluene, 2.0 mmol) and 1-[(2-(dimethylamino)ethyl)(methyl)amino]-2-methylpropane It was prepared in a yield of 85% (0.39 g) by using 0.35 g (2.0 mmol) of -2-ol (1-[(2-(dimethylamino)ethyl)(methyl)amino]-2-methylpropan-2-ol). . The NMe2 ^Me may be represented by the following formula (18).

The 1-[(2-(dimethylamino)ethyl)(methyl)amino]-2-methylpropan-2-ol was prepared and used in the same manner as in the prior art (J. Inorg. Chem. 2014, 2002-2010.) did.

<Formula 18>

¹ H NMR (CDCl ₃ ): δ=2.68 (t, 4H, J =7.9 Hz, Me ₂ NCH ₂ ) 2.49 (s, 4H, CH ₂ CMe ₂ ), 2.43 (t, 4H, J =5.5 Hz, Me ₂ NCH ₂ CH ₂ ), 2.31 (s, 6H, NMe), 1.29 (s, 12H, CMe ₂ ), 0.87 ppm (s, 12H, AlMe); ¹³ C NMR (CDCl ₃ ): δ=71.39 (NCH ₂ CMe ₂ ), _{68.07 (NCH 2} CH ₂ NMe ₂ ), 56.67 (NCH ₂ CH ₂ NMe ₂ ), 54.28 (NCH ₂ CMe ₂ ), 45.92 (NMe _{2 )} ), 43.77 (NMe), 31.27 (NCH ₂ CMe ₂ ), 5.91 ppm (AlMe); elemental analysis calcd (%) for C ₂₂ H ₅₄ N ₄ O ₂ Al ₂ : C 57.36, H 11.82, N 12.16; found: C 57.30, H 11.97, N 12.01.

comparative example 3

Preparation of [Me ₂ Al(OCMe ₂ CH ₂ )HNCH ₂ CH ₂ OMe] ₂ (hereinafter, OMe2 ^H )

OMe2 ^H was prepared in the same manner as in the prior art ( Organometallics 2014, 33, 2770-2775.). The OMe2 ^H may be represented by the following Chemical Formula 19.

<Formula 19>

comparative example 4

Preparation of [Me ₂ Al(OCMe ₂ CH ₂ NHMe)] ₂ (hereinafter, H ^H )

Prepared in the same manner as in Example 1, except that _{1.0 mL of AlMe 3} (2.0 m solution in toluene, 2.0 mmol) and 1-[(2-methoxyethyl)(methyl)amino]-2-methylpropane-2 -ol (1-[(2-methoxyethyl)(methyl)amino]-2-methylpropan-2-ol) was prepared in a yield of 78% (0.25 g) using 0.21 g (2.0 mmol). The H ^H may be represented by the following Chemical Formula 20.

<Formula 20>

¹ H NMR (CDCl ₃ ): δ=2.42 (d, 4H, J =8.9 Hz, -CH ₂ N), 2.35 (d, 6H, J =6.2 Hz, N-Me), 1.75 (t, 2H, J =6.4 Hz, NH), 1.23 (s, 12H, CMe ₂ ), 1.01 ppm (s, 12H, AlMe); ¹³ C NMR (CDCl ₃ ): δ=70.06 (CMe ₂ O), 62.45 (CH ₂ N), 34.37 (N-Me), 27.68 (CMe ₂ O), 4.97 ppm (AlMe); elemental analysis calcd (%) for C ₁₄ H ₃₆ N ₂ O ₂ Al ₂ : C 52.81, H 11.40, N 8.80; found: C 52.66, H 11.51, N 8.62.

comparative example 5

[Me ₂ Al(OCMe ₂ CH ₂ NMe ₂ )] ₂ (hereinafter, H ^Me ) Preparation of

H ^Me was prepared in the same manner as in the prior art ( J. Inorg . Chem . 2015, 2323-2329.). The H ^Me may be represented by the following Chemical Formula 21.

<Formula 21>

Experimental example 1: Synthesis and Characterization

The free ligand HOCMe ₂ CH ₂ N(R)CH ₂ X was synthesized in the same manner as in the prior art by reaction of _{RNHCH 2} X with isobutylene oxide in almost quantitative yield. Alcoholysis of trimethylaluminum (Trimethylaluminium, AlMe ₃₎ is a useful synthetic route for accessing the _two dimeric aluminum compounds, which are _{[Al (OCMe 2 CH 2 N} (R) CH 2 X)]. In all cases, the aluminum complexes were prepared under an inert atmosphere. As shown in Scheme 1 below, _{direct complexation of AlMe 3} and N-substituted amino-2-methylpropan-2-ol in toluene is of methane gas. It proceeds rapidly with release to give the aluminum compounds of Examples 1-6 and Comparative Examples 1-5 in high yield (75-90%).

<Scheme 1>

The reaction temperature (0° C.) and reaction time (12 hours) were optimized to give the maximum yield of aluminum compound. The compounds were purified by washing with n-hexane, and after recrystallization from toluene, an analytically pure aluminum compound was obtained as colorless crystals. Although not stable in air, it is thermally stable at a temperature of 130°C. ^{In particular, the catalysts of Examples 1 (Pyr H} ) and Example 2 (Pyr ^Me ), which are aluminum complexes having a heterocyclic structure attached to nitrogen, are similar aluminum complexes without a heterocyclic structure, Comparative Example 4 (H ^H ) and the catalyst of Comparative Example 5 (H ^{Me ).} All compounds ^{were characterized by 1} H NMR spectroscopy, ¹³ C NMR spectroscopy and elemental analysis.

¹ H NMR spectra and ¹³ C NMR spectra came out consistent with the expected structures, and all chemical shifts of protons and carbon atoms were within the expected ranges. The ¹ H NMR spectrum of the aluminum compound [Al(OCMe ₂ CH ₂ N(R)CH ₂ X)] ₂ was not significantly different _{from the free ligand HOCMe 2} CH2N(R)CH _{2 X .} However, it was confirmed that the ligand was successfully complexed with the aluminum center through strongly shielded resonance for Al-Me at δ ≒ -1.0 ppm in ¹ H NMR spectrum and δ ≒ - 6.0 ppm in ^{13 C NMR spectrum.} The Al-Me resonances for all X ^Me complexes (Example 2, Example 4, Example 6, Comparative Example 2, Comparative Example 5) are identical to the corresponding X ^H complex (Example 1, Example 3, Example 5, A shift to the downfield was greater than for Comparative Example 1, Comparative Example 3, and Comparative Example 4). Unlike the complex X ^Me _{, the -OCMe 2} CH ₂ NHCH ₂ -methylene proton in the ^{X H} complex appears doubly due to the presence of a proton on the nitrogen atom.

Experimental example 2: Cyclized carbonate synthesis

As shown in Scheme 2 below, 1 mol% ( n Bu) ₄ NBr and 1 mol% catalyst (catalysts of Examples 1-6 and Comparative Examples 1-5) were used at 25° C. and 1 bar without a solvent for 24 hours. The synthesis of styrene oxide (1a) in carbon dioxide and styrene carbonate (2a) from carbon dioxide was performed, and each reaction ^{was analyzed by 1} H NMR spectroscopy to determine the conversion of 1a to 2a. (TON) and turnover frequency (TOF) are shown.

Specifically, styrene oxide (10 mmol), each catalyst (0.1 mmol) and Tetrabutylammonium bromide, ( n Bu)4NBr) (32mg, 0.1mmol) were mixed in a glove box with a 20 mL round bowl containing a magnetic stir bar. The bottom flask was filled. After connecting a rubber balloon containing about 2 L of carbon dioxide to the flask, the reaction vessel was well sealed with parafilm. The reaction vessel was stirred at 25° C. for 24 hours. When the desired time was reached, an aliquot of the reaction mixture was transferred to an NMR cell and the conversion of styrene oxide to styrene carbonate ^{was determined by 1} H NMR spectroscopy.

<Scheme 2>

catalyst Conversion rate (%) TON TOF (h ^-1 ) Example 1 (Pyr ^H ) 99 99 4.1 Example 2 (Pyr ^Me) 90 90 3.8 Example 3 (Fur ^H ) 76 76 3.2 Example 4 (Fur ^Me ) 32 32 1.3 Example 5 (Thio ^H ) 32 32 1.3 Example 6 (Thio ^Me ) 27 27 1.1 Comparative Example 1 (NMe2 ^H) 31 31 1.3 Comparative Example 2 (NMe2 ^Me) 20 20 0.83 Comparative Example 3 (OMe ^H ) 23 23 0.96 Comparative Example 4 (H ^H ) 7 7 0.29 Comparative Example 5 (H ^Me ) 5 5 0.21

^{(* Conversion: Determine conversion by 1} H NMR spectroscopy of an aliquot of the reaction mixture after 24 hours. Turnover number (TON) = (moles consumed in 1a)/(moles consumed in catalyst). turnover frequency (turnover frequency) = TONh ^-1 .)

As shown in Table 1, 1a was readily converted to 2a with high selectivity (>99%) without polymerized by-products. The aluminum complexes (or catalysts) synthesized in Examples 1-6 and Comparative Examples 1-5 showed various catalytic activities for the synthesis of 2a under ambient conditions. Among them, the catalyst of Example 1 (Pyr ^H ) almost completely converted 1a to 2a at 1 atm of carbon dioxide and 25° C. after 24 hours. ( n Bu) It _{was confirmed that the catalyst of Example 1 in the presence of 4} NBr exhibits the highest activity with a turnover number (TON) of 99 and a turnover frequency (TOF) of 4.1 h ^{-1. The catalyst of Example 2 (Pyr Me} ) containing a sterically hindered methyl group instead of a hydrogen atom in nitrogen under the same conditions was lower than the catalyst of Example 1 with a turnover number (TON) of 90 and a turnover frequency (TOF) of 3.8 h ^-1 values are shown. A similar trend was observed between the catalyst of Example 3 (Fur ^H ) and the catalyst of Example 4 (Fur ^Me ) and the catalyst of Example 5 (Thio ^H ) and the catalyst of Example 6 (Thio ^{Me ).}

In particular, the catalyst of Example 1 ^{has 3.2 times higher activity than the catalyst of Comparative Example 1 (NMe2 H} ) having a dimethylamino group, and 4.3 times higher than the catalyst of Comparative Example 3 (OMe ^H ) having a methoxy group, and a nitrogen substituent It was confirmed that the activity was 14.1 times higher than that of the catalyst (H ^{H ) of Comparative Example 10 without} In addition, it was confirmed that the catalyst of Example 1 ^{had 4.9 times higher activity than the catalyst of Comparative Example 2 (NMe2 Me} ), and 19.8 times higher than the catalyst of Comparative Example 6 (H ^{Me ).}

In addition, the synthesis of styrene oxide (1a) and styrene carbonate (2a) from carbon dioxide was performed at 25° C. and 1 bar carbon dioxide without a solvent for 24 hours using 1 mol% cocatalyst and 1 mol% catalyst of Example 1, Each reaction ^{was analyzed by 1} H NMR spectroscopy to determine the conversion of 1a to 2a, and the conversion rate, turnover number (TON), and turnover frequency (TOF) are shown in Table 2 below.

Specifically, styrene oxide (10 mmol), Example 1 catalyst (0.1 mmol) and a cocatalyst (0.1 mmol) such as (n Bu)4NBr were charged into a 20 mL round bottom flask containing a magnetic stir bar in a glove box. After connecting a rubber balloon containing about 2 L of carbon dioxide to the flask, the reaction vessel was well sealed with parafilm. The reaction vessel was stirred at 25° C. for 24 hours. When the desired time was reached, an aliquot of the reaction mixture was transferred to an NMR cell and the conversion of styrene oxide to styrene carbonate ^{was determined by 1} H NMR spectroscopy.

cocatalyst Conversion rate (%) TON TOF (h ^-1 ) ( n- Bu) ₄ NCl 18 18 0.75 ( n- Bu) ₄ NBr 99 99 4.1 ( n -Bu) ₄ NI 77 77 3.2 ( n- Bu) ₄ PBr 34 34 1.4 PPNCl 23 23 0.96 PPNBr 25 25 1.0

As shown in Table 2, it was confirmed that the activity was changed according to the type of cocatalyst, and it was confirmed that excellent catalytic activity was exhibited when (n- Bu)4NBr was used as a cocatalyst.

Furthermore, it was confirmed that the catalyst loading of styrene oxide (1a) and 1 bar carbon dioxide at 25° C. can be reduced in the coupling reaction of styrene oxide (1a) with 1 bar carbon dioxide at 25° C. with the best catalyst system using (n Bu) 4 NBr as the catalyst and co-catalyst of Example 1.

Specifically, styrene oxide (10 mmol), the catalyst of Example 1 ( 0-0.1 mmol), and a cocatalyst (0-0.1 mmol) such as (n Bu) 4 NBr were mixed in a glove box with a 20 mL round bowl containing a magnetic stir bar. The bottom flask was filled. After connecting a rubber balloon containing about 2 L of carbon dioxide to the flask, the reaction vessel was well sealed with parafilm. The reaction vessel was stirred at 25° C. for 24 hours. When the desired time was reached, an aliquot of the reaction mixture was transferred to an NMR cell and the conversion of styrene oxide to styrene carbonate ^{was determined by 1} H NMR spectroscopy, and Table 3 below shows conversion, turnover number (TON), and turnover frequency. (TOF) is shown.

Catalytic amount (mol%) Amount of cocatalyst (mol%) Conversion rate (%) TON TOF (h ^-1 ) 1.0 0 15 15 0.63 0 1.0 7 7 0.29 1.0 1.0 99 99 4.1 1.0 0.5 42 42 1.8 0.5 0.5 31 62 2.6 0.5 1.0 48 96 4.0 0.1 0.1 8 80 3.3 0.05 0.05 4 80 3.3

As shown in Table 3, it was confirmed that a very high synergistic effect was expressed by using the catalyst and the cocatalyst at the same time. On the other hand, when the loading of the catalyst is reduced while maintaining the ratio of the catalyst and the cocatalyst to 1:1 (from 1.0 mol% to 0.5 mol%, 0.1 mol% or 0.05 mol%), the yield of styrene carbonate is 99% It was confirmed that they gradually decreased to 31%, 8%, and 4%, respectively. In addition, when the ratio of the catalyst to the cocatalyst was 2:1, a conversion rate of 42% was confirmed, and when the ratio of the catalyst and the cocatalyst was performed at 1:2, a conversion rate of 48% was confirmed. Preferably, 1 mol % of the catalyst of Example 1 and 1 mol % of ( n Bu) ₄ NBr can be used when the epoxide is screened at 25° C. and 1 bar carbon dioxide for 24 hours.

In addition, epoxides (1a-1n) and carbonates cyclized from carbon dioxide (2a-2n) at 25° C. and 1 bar carbon dioxide without solvent for 24 hours using 1 mol% cocatalyst and 1 mol% catalyst of Example 1 was performed, and each reaction ^{was analyzed by 1} H NMR spectroscopy to determine the conversion of the epoxide to the cyclized carbonate, and the conversion rate, yield, turnover number (TON), turnover frequency ( TOF) was shown.

Specifically, epoxide (10 mmol), Example 1 catalyst (0.1 mmol) and ( n Bu) ₄ NBr (0.1 mmol) were charged to a 20 mL round bottom flask containing a magnetic stir bar in a glove box. After connecting a rubber balloon containing about 2 L of carbon dioxide to the flask, the reaction vessel was well sealed with parafilm. The reaction vessel was stirred at 25° C. for 24 hours. When the desired time was reached, an aliquot of the reaction mixture was transferred to an NMR cell and the conversion of the epoxide to the cyclized carbonate ^{was determined by 1} H NMR spectroscopy.

Epoxide type Conversion rate (%) Yield (%) TON TOF (h ^-1 ) 1a 99 97 99 4.1 1b 99 93 99 4.1 1c 99 99 99 4.1 1d 99 98 99 4.1 1e 67 65 67 2.8 1f 56 53 56 2.3 1 g 98 95 98 4.1 1h 94 92 94 3.9 1i 94 90 94 3.9 1j 99 98 99 8.3 1k 99 97 99 8.3 1l 99 96 99 4.1 1m 99 97 99 4.1 1n 95 91 95 4.0

(styrene oxide (1a), propylene oxide (1b), 1,2-epoxybutane (1c), 1,2-epoxyhexane (1d), 1,2-epoxydecane (1e), 1,2-epoxydodecane (1f), 1 ,2-epoxy-3-methoxypropane (1g), 1,2-epoxy-3-phenoxypropane (1h), tert-butyl glycidyl ether (1i), epichlorohydrin (1j), epibromohydrin (1k), 2-(4-fluorophenyl )oxirane (1l), 2-(4-chlorophenyl)oxirane (1m), and 2-(4-bromophenyl)oxirane (1n).)

As shown in Table 4 above, in all cases except for epoxides 1e and 1f, excellent yields (> 90% isolated product) and conversions (> 94%) to cyclized carbonates corresponding to these epoxides can be confirmed. have. Epoxides 1a-1d showed complete conversion within 24 hours, indicating that chain length and steric hindrance from the substituents on the epoxide did not affect the catalytic activity. On the other hand, long straight-chain octyl (1e) and decyl substituents (1f) on the epoxide reduced the conversion, but still showed high activity. The presence of heteroatoms in the substituents on the epoxide and steric hindrance from the substituents can result in a slight decrease in activity because the heteroatoms of the epoxide can bond to the aluminum center. As expected, the highly reactive epichlorohydrin (1j) and epibromohydrin (1k) were completely converted within 12 hours. In addition, other epoxides containing halogen and aromatic halogen (1j-1n) showed excellent reactivity.

Further, cis-cyclopentene oxide (cis-cyclopentene oxide, 1o), cis-3,4-epoxytetrahydrofuran (cis-3,4-epoxytetrahydrofuran, 1p), cis-cyclohexene oxide (cis-cyclohexene oxide, 1q) ), cis-cyclooctene oxide (1r), trans-2,3-butylene oxide (1s) and trans-stilbene oxide (1t) ) was confirmed by using the same epoxide as the synthesis of cyclized carbonate. The cyclized carbonate produced by this reaction, conversion, yield, selectivity, turnover number (TON), and turnover frequency (TOF) are shown in Scheme 3 below.

<Scheme 3>

The coupling reaction was carried out over 36 hours at 75° C. and 1 bar of carbon dioxide using 1.0 mol% of the catalyst of Example 1 (Pyr ^H )/( n Bu) _{4 NBr.} All of the epoxides (1o-1t) were converted to the corresponding cyclized carbonate (2o-2t) without polymeric by-products (selectivity >99%). Epoxide 1o with 5-membered ring was more reactive than epoxide 1p with hetero ring and epoxide 1q with 6-membered ring. On the other hand, epoxide 1r having an 8-membered ring did not show any catalytic activity. On the other hand, the activity was rapidly decreased due to the steric hindrance of the substituent from methyl (1s) to phenyl (1t). The stereochemical structures for all epoxides were observed and, as expected, the cyclized carbonate obtained from the 1,2-disubstituted epoxide exhibited conservation of coordination in _{two successive S N 2 reactions.} This means that during the reaction two stereochemical inversions occur at the carbon atom of the epoxide. Therefore, the mechanism for the synthesis of cyclized carbonates from epoxides and carbon dioxide by using the catalyst of Example 1 (Pyr ^H ) in the presence of ( n Bu) _{4 NBr as a co-catalyst is shown in Scheme 5 below.} This mechanism is similar to that previously proposed for the synthesis of cyclized carbonates using other catalyst systems.

<Scheme 5>

As shown in Scheme 5, the catalyst of Example 1 is Intermediate I. The epoxide is then attached to the aluminum atom of intermediate I and consequently complex II is activated by the bromide anion of the promoter. Nucleophilic ring opening of the epoxide gives carbonato species III, which is converted to coordinated aluminum complex VI by insertion of carbon dioxide. Finally, cyclized carbonate and regenerated intermediate I are produced as final products. The ¹ H NMR spectrum of the catalyst of Example 1 (Pyr ^H ) with and without styrene oxide clearly confirms the presence of Intermediate I. A clear downfield shift was observed from δ = 0.934 ppm to δ = 0.917 ppm of the Al-Me signal of the catalyst of Example 1, indicating that the epoxide binds to the aluminum metal center to produce intermediate I.

As such, in the present invention, an aluminum catalyst effective for producing cyclized carbonate by the coupling reaction of epoxide and carbon dioxide under ambient temperature and carbon dioxide pressure was developed.

Claims (11)

Catalyst for preparing a cyclized carbonate by reacting carbon dioxide with an epoxide comprising at least one compound of the compound represented by the following formula (1) and the compound represented by the formula (2):
<Formula 1>

<Formula 2>

(In Formula 1 and Formula 2,
R ₁ to R ₅ are each independently hydrogen (H) or a C ₁ to C ₁₀ alkyl group,
Ar ₁ is a 5- or 6-membered heteroaryl group including N,
n is 0 to 2). According to claim 1,
The R _{1 To} R ₅ are each independently hydrogen (H) or a C _{1 To} C ₄ Alkyl group of the catalyst. delete A method for preparing a cyclized carbonate comprising reacting an epoxide with carbon dioxide in the presence of a catalyst comprising at least one of a compound represented by the following formula (1) and a compound represented by the formula (2):
<Formula 1>

<Formula 2>

(In Formula 1 and Formula 2,
R ₁ to R ₅ are each independently hydrogen (H) or a C ₁ to C ₁₀ alkyl group,
Ar ₁ is a 5- or 6-membered heteroaryl group including N,
n is 0 to 2). 5. The method of claim 4,
The epoxide is a method for preparing a cyclized carbonate, which is a compound represented by the following Chemical Formula 3.
<Formula 3>

(In Formula 3,
R ₁ to R ₄ are hydrogen, alkyl having 1 to 20 carbons, aryl having 6 to 20 carbons, alkylaryl having 7 to 20 carbons, arylalkyl having 7 to 20 carbons, aryloxy having 6 to 20 carbons, aryloxy having 6 to 20 carbons of alkoxyaryl, heterocycloalkyl having 3 to 20 carbon atoms, heteroaryl having 6 to 20 carbon atoms, or silyl ether having 1 to 20 carbon atoms,
R ₂ and R ₃ are connected to each other _{and together with the carbon to which R 2} and R ₃ are connected are cycloalkyl or heterocycloalkyl having 3 to 7 carbon atoms, and heterocycloalkyl includes N, O or S). 5. The method of claim 4,
The step of reacting the epoxide with carbon dioxide is a method for producing a cyclized carbonate that is performed by additionally comprising a cocatalyst. 7. The method of claim 6,
The promoter is tetrabutylammonium bromide (Tetrabutylammonium bromide, ( n Bu) ₄ NBr), tetrabutylammonium chloride (Tetrabutylammonium chloride, ( n Bu) ₄ NCl), tetrabutylammonium iodide (Tetrabutylammonium iodide, ( n Bu) ₄ NI), Tetrabutylphosphonium bromide (( n Bu) ₄ PBr), bis(triphenylphosphoranylidene) ammonium chloride (PPNCl) and bis(triphenylphosphoranyl) Ridine) ammonium bromide (bis (triphenylphosphoranylidene) ammonium bromide, PPNBr) method for producing at least one cyclized carbonate selected from the group consisting of. 5. The method of claim 4,
The catalyst is 0.1 mol% to 2.0 mol% of the epoxide compound is a method for producing a cyclized carbonate input. 7. The method of claim 6,
The catalyst is added in 0.1 mol% to 2.0 mol% based on the epoxide compound, and the cocatalyst is added in 0.1 mol% to 2.0 mol% based on the epoxide compound. 5. The method of claim 4,
The step of reacting the epoxide with carbon dioxide is a method for producing a cyclized carbonate that is carried out in a temperature range of 15 °C to 200 °C under a pressure condition of 1 bar to 20 bar. 5. The method of claim 4,
The cyclized carbonate is a method for producing a cyclized carbonate represented by the following formula 4:
<Formula 4>

(In Formula 4,
R ₁ to R ₄ are hydrogen, alkyl having 1 to 20 carbons, aryl having 6 to 20 carbons, alkylaryl having 7 to 20 carbons, arylalkyl having 7 to 20 carbons, aryloxy having 6 to 20 carbons, aryloxy having 6 to 20 carbons of alkoxyaryl, heterocycloalkyl having 3 to 20 carbon atoms, heteroaryl having 6 to 20 carbon atoms, or silyl ether having 1 to 20 carbon atoms,
R ₂ and R ₃ are connected to each other _{and together with the carbon to which R 2} and R ₃ are connected are cycloalkyl or heterocycloalkyl having 3 to 7 carbon atoms, and heterocycloalkyl includes N, O or S).