Method for preparing cyclic carbonate by using a binary system of sulfonated metal salen and polyether ionic liquid as catalyst

Abstract

The present application relates to a kind of sulfonated metal Salen and polyether ionic liquid binary system catalysis method for preparing cyclic carbonate by the ring addition of CO2 and epoxide;In order to improve the shortcomings that metal complex catalyst is difficult to realize recycling and organic catalyst has lower catalytic activity, the present application combines metal complex catalyst with organic catalyst, creates a kind of sulfonated metal Salen and polyether ionic liquid binary catalytic system, realizes the efficient synergistic catalysis of sulfonated metal Salen and polyether ionic liquid;The binary catalyst has the advantages of simple construction, high catalytic activity and selectivity, easy separation cycle, long life and low loss, meets the process requirements of green synthesis.

Description

Technical Field

[0001] This invention relates to the field of chemical engineering technology, specifically to a method for preparing cyclic carbonates by catalytic cycloaddition of CO2 and epoxides using a binary system of sulfonated metal salen and polyether ionic liquid. Background Technology

[0002] Carbon dioxide (CO2) is a major greenhouse gas contributing to global warming, but it is also an inexhaustible, inexpensive, non-toxic, and recyclable green C1 resource on Earth. Realizing the resource utilization of CO2 is of significant strategic importance for reducing CO2 emissions, improving the environment, and decreasing human dependence on fossil fuels. In recent years, cyclic carbonates, as high-value-added chemicals, have been widely used in fine chemicals, lithium battery manufacturing, and the synthesis of polycarbonates and polyurethanes. The cycloaddition reaction of CO2 with epoxides to prepare cyclic carbonates is a green chemical method with 100% atom economy. As an alternative to the toxic phosgene synthesis method, it is one of the important pathways for the efficient resource utilization of CO2 and has received considerable attention from academia and industry. However, CO2 is a thermodynamically stable molecule, and the key to achieving efficient CO2 conversion lies in the research and development of efficient catalysts. Metal-based catalysts (Dalton Trans. 2018, 47, 13281–13313.), especially metal complexes such as metalloporphyrins or metal salens, typically exhibit high catalytic activity. However, these metal complex catalysts are often difficult to separate from the products, hindering recycling and significantly limiting their industrial applications. In recent years, organic catalysts (Green Chem. 2021, 23, 77–118; Catal. Sci. Technol. 2017, 7, 2651–2684.) have attracted widespread attention due to their relatively simple synthesis and ease of recycling. However, the catalytic activity of organic catalysts is significantly lower than that of metal complexes. Therefore, combining the advantages of metal complex catalysts and organic catalysts could potentially create highly efficient and recyclable CO2 cycloaddition catalysts. Currently, there are two main methods for combining metal complex catalysts and organic catalysts: one is to covalently bond the metal complex catalyst with the organic catalyst to form a new integrated organometallic hybrid catalyst.For example, Jing et al. reported bifunctionalized metalloporphyrins (Chin. J. Catal. 2010, 31, 176–180.) and metals (ChemCatChem 2009, 1, 379–383; J. Catal. 2015, 329, 317–324.), as well as diimidazole-functionalized Coloporphyrins (Green Chem. 2016, 18, 3567–3576.); Ji et al. synthesized imidazole ionic liquid-modified Znloporphyrins (Sustainable Energy Fuels 2018, 2, 125–132.) and polyether imidazole ionic liquid-functionalized metals (Green Chem. 2016, 18, 3567–3576.). Chem. 2014, 16, 1496–1506; J. CO2 Util. 2017, 19, 257–265.; Tadashi Ema et al. also reported bifunctionalized metalloporphyrins (J. Am. Chem. Soc. 2014, 136, 15270-15279.); Liu et al. reported pyridinium salt-functionalized metals (ACS Catal. 2012, 2, 2029-2035.), and so on. However, the aforementioned catalysts with "organo-metal hybrid" characteristics often suffer from lengthy and complex synthetic routes. Another approach is to combine metal complex catalysts with organic catalysts to form binary catalytic systems. For example, Darensbourg et al. reported Cr-Salen / quaternary ammonium salt and Al-Salen / quaternary ammonium salt binary catalysts (Inorg. Chem. 2004, 43, 1831-1833; Inorg. Chem. 2005, 44, 1433-1442); Lu and Berkessel et al. reported Co-Salen / quaternary ammonium salt binary catalysts for asymmetric cycloaddition reactions (J. Am. Chem. Soc. 2004, 126, 3732-3733; Org. Lett. 2006, 8, 4401-4404); Ren et al. reported an Al-Salen / TBAB binary catalytic system (RSC Adv., 2018, 8, 39182–39186), and so on. However, the limitation of binary catalytic systems is that metal complexes or quaternary ammonium salts are easily lost into the organic phase, causing the activity of the binary catalyst to continuously decline in subsequent cycles.

[0003] Therefore, developing efficient metal complex / organic catalyst binary catalytic systems with ultra-long service life is of great significance for the efficient catalytic conversion of CO2 into cyclic carbonates. Summary of the Invention

[0004] To address the limitations of the existing technologies, this invention creates a binary system of sulfonated metal Salen and polyether ionic liquid, and applies it to the reaction of catalytic cycloaddition of CO2 and epoxide to prepare cyclic carbonates.

[0005] Compared with the prior art, the binary catalytic system of sulfonated metal Salen and polyether ionic liquid of the present invention has the following outstanding advantages:

[0006] (1) The binary catalytic system is simple to construct:

[0007] The binary catalytic system can be constructed by physically mixing sulfonated metal Salen and polyether ionic liquid in advance, or by adding sulfonated metal Salen and polyether ionic liquid directly to epoxide without physical mixing, without complicated steps;

[0008] (2) High catalytic activity and selectivity:

[0009] In this binary catalytic system, the sulfonated metal Salen and the polyether ionic liquid synergistically catalyze the catalyst, thus efficiently combining the advantages of metal complex catalysts and organic catalysts. For example, the metal center of the Salen acts as a Lewis acid site to activate the epoxide molecule; the halide anion of the polyether ionic liquid acts as a nucleophile to achieve the key step of nucleophilic ring-opening of the epoxide, forming a cyclic carbonate; and the polyether chain has CO2-loving properties, which can solubilize CO2, etc. Therefore, it exhibits high catalytic activity and selectivity, with a TOF value reaching up to 1934.6 h. -1 ;

[0010] (3) Homogeneous catalysis-two-phase separation:

[0011] Polyether ionic liquids can effectively regulate the solubility of binary catalytic systems, making the catalyst readily soluble in epoxides to achieve homogeneous catalysis; at the same time, they are poorly soluble in weakly polar solvents, and liquid-liquid extraction can achieve two-phase separation of the catalyst and the product cyclic carbonate, thus realizing the efficient recycling of the catalyst in this catalytic system.

[0012] (4) Long lifespan and low loss:

[0013] The introduction of sulfonate groups gives the sulfonated metal salen strong polarity, resulting in low solubility in the extracted organic phase and reducing the loss of metal active catalyst components, with a metal loss rate of less than 0.3%. Simultaneously, the polyether ionic liquid exhibits high chemical and thermal stability, enabling the catalyst to remain stable over a long period during cycling. Furthermore, the polyether side chains significantly increase the molecular weight of the ionic liquid, thereby reducing the relative loss of ionic liquid components and extending the catalyst's lifespan. The cumulative TON value reaches 4000-8000.

[0014] To achieve the objectives of this invention, the technical solution adopted is as follows:

[0015] A binary catalytic system of sulfonated metal Salen and polyether ionic liquid, characterized in that the binary catalytic system is composed of sulfonated metal Salen and polyether ionic liquid, wherein the structural formula of the sulfonated metal Salen is as follows:

[0016]

[0017] In the formula, M 1 For Zn, Co, or Mn; M 2 For Li + Na + or K + ;

[0018] The structural formula of the polyether ionic liquid is as follows:

[0019]

[0020] In the formula, R 1 For C1-C 16 Alkyl or phenyl; R 2 It is a C1-C4 alkyl group; R 3 H or methyl; n is the average degree of polymerization of ethoxy group, n = 4-240; X - For Cl - , Br - or I - .

[0021] A method for preparing cyclic carbonate compounds, characterized by using carbon dioxide and epoxides as raw materials, and employing a binary catalytic system of sulfonated metal Salen and polyether ionic liquid to catalyze the synthesis of cyclic carbonate compounds; after the reaction, an extraction solvent is added, and the catalyst is separated by liquid / liquid phase separation; the supernatant is then purified of solvent to obtain the corresponding cyclic carbonate compounds; the structural formula of the sulfonated metal Salen in the binary system is as follows:

[0022]

[0023] In the formula, M 1 For Zn, Co, or Mn; M 2 For Li + Na + or K + The structural formula of the polyether ionic liquid is as follows:

[0024]

[0025] In the formula, R 1 For C1-C 16 Alkyl or phenyl; R2 It is a C1-C4 alkyl group; R 3 H or methyl; n is the average degree of polymerization of ethoxy group, n = 4-240; X - For Cl - , Br - or I - ;

[0026] The structure of epoxide is:

[0027]

[0028] In the structural formula, when R 5 When =H, R 4 For H, nC k H 2k+1 (k = 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10), ClCH2, Ph, p-CH3Ph, p-CH3OPh, p-ClPh, p-BrPh, CH2=CH-(CH2) j (j = 1, 2, 3 or 4), HOCH2, CH2 = CH-CH2O(CH2) h (h = 1, 2, 3 or 4) or PhO(CH2) i (i = 1, 2, 3 or 4); when R 5 When ≠H, the epoxide is cyclohexane oxide.

[0029] When a binary catalytic system catalyzes the cycloaddition reaction of CO2 and epoxide, the molar ratio of sulfonated metal salen to polyether ionic liquid is 1 / 1 to 1 / 10, the molar ratio of sulfonated metal salen to epoxide is 0.1 / 1000 to 2 / 1000, the carbon dioxide pressure is 0.1 to 5.0 MPa, the reaction temperature is 80 to 130 °C, and the reaction time is 1 to 48 hours.

[0030] The extraction solvent is methyl tert-butyl ether or diethyl ether. Detailed Implementation

[0031] The present invention will be further described below with reference to the embodiments, but the scope of protection of the present invention is not limited to the scope shown in the embodiments.

[0032] Comparative Example 1

[0033] Zn-Salen-catalyzed cycloaddition reaction of CO2 and styrene oxide (SO4)

[0034]

[0035] In a 60 mL stainless steel high-pressure reactor, Zn-Salen catalyst and 10.5 mmol of styrene oxide (R) were added. 4=Ph,R 5 =H), Zn-Salen / SO = 1 / 1000 (mol / mol), and the internal standard biphenyl were reacted with stirring at a CO2 pressure of 1.0 MPa and a reaction temperature of 120 °C for 4 h. After the reaction was completed, the product was extracted with methyl tert-butyl ether, and the extract was then subjected to GC for quantitative analysis using the internal standard method. The SO conversion rate was 15.1%, the cyclic carbonate selectivity was 0.6%, and the cyclic carbonate yield was 0.1%.

[0036] Note: Zn-Salen alone is essentially inactive, indicating that ionic liquids are essential as co-catalysts.

[0037] Comparative Example 2

[0038] Zn-Salen(SO3Na)2(M 1 =Zn,M 2 =Na + Catalytic cycloaddition reaction of CO2 and styrene oxide (SO)

[0039] The catalyst was replaced with Zn-Salen(SO3Na)2(M 1 =Zn,M 2 =Na + Other operations were the same as in Comparative Example 1, with SO conversion of 23.9%, cyclic carbonate selectivity of 0.5%, and cyclic carbonate yield of 0.1%.

[0040] Note: Zn-Salen(SO3Na)2 alone is essentially inactive, indicating that ionic liquids are essential as co-catalysts.

[0041] Comparative Example 3

[0042] [MeIM(CH2CH2O) 16 Me][Br](R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0043] The catalyst was replaced with [MeIM(CH2CH2O)]. 16 Me][Br](R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br), [MeIM(CH2CH2O) 16 Me][Br] / SO = 1 / 500 (mol / mol), other operations are the same as in Comparative Example 1, SO conversion is 51.5%, cyclic carbonate selectivity is 71.0%, and cyclic carbonate yield is 36.6%.

[0044] Note: Single polyether ionic liquids have certain catalytic activity.

[0045] Comparative Example 4

[0046] [MeIM(CH2CH2O) 16 Me][I](R 1 =Me,R 2 =Me,R 3 =H, n=16, X=I) Catalytic cycloaddition reaction of CO2 and styrene oxide (SO)

[0047] The catalyst was replaced with [MeIM(CH2CH2O)]. 16 Me][I](R 1 =Me,R 2 =Me,R 3 =H, n=16, X=I), [MeIM(CH2CH2O) 16 Me][I] / SO = 1 / 500 (mol / mol), other operations are the same as in Comparative Example 1, SO conversion is 54.1%, cyclic carbonate selectivity is 62.1%, and cyclic carbonate yield is 33.6%.

[0048] Note: Single polyether ionic liquids have certain catalytic activity, with iodide salts showing slightly lower activity than bromine salts.

[0049] Comparative Example 5

[0050] [MeIM(CH2CH2O) 16 Ph][Br](R 1 =Ph,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0051] The catalyst was replaced with [MeIM(CH2CH2O)]. 16 Ph][Br](R 1 =Ph,R 2 =Me,R 3 =H, n=16, X=Br), [PhIM(CH2CH2O) 16 Me][Br] / SO = 1 / 500 (mol / mol), other operations are the same as in Comparative Example 1, SO conversion is 50.6%, cyclic carbonate selectivity is 65.8%, and cyclic carbonate yield is 33.3%.

[0052] Note: Single polyether ionic liquids have certain catalytic activity.

[0053] Comparative Example 6

[0054] [PhCH2CH2IMMe][Br](R 1 =Me,R 2 =PhCH2CH2,R 3 =H, n=0, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0055] The catalyst was replaced with [PhCH2CH2IMMe][Br](R) 1 =Me,R 2 =PhCH2CH2,R 3 =H, n=0, X=Br), [PhCH2CH2IMMe][Br] / SO=1 / 500 (mol / mol), other operations are the same as Comparative Example 1, SO conversion 48.3%, cyclic carbonate selectivity 59.8%, cyclic carbonate yield 28.9%.

[0056] Note: This indicates that polyether chains can enhance catalytic activity.

[0057] Comparative Example 7

[0058] Zn-Salen / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0059] Zn-Salen and polyether ionic liquid [MeIM(CH2CH2O)] 16 Me][Br] was physically mixed and stirred at 70°C for 1 hour to form Zn-Salen / [MeIM(CH2CH2O]. 16 Me][Br] = 1 / 2 (mol / mol), yielding Zn-Salen / [MeIM(CH2CH2O)] 16 Me][Br] binary catalyst. Zn-Salen / [MeIM(CH2CH2O] was added to a 60 mL stainless steel high-pressure reactor. 16 Me][Br] binary catalyst, 10.5 mmol styrene oxide (R 4 =Ph,R 5 =H), Zn-Salen / [MeIM(CH2CH2O) 16Me][Br] / SO = 1 / 2 / 1000 (mol / mol / mol), and the internal standard biphenyl, were reacted with stirring at a CO2 pressure of 1.0 MPa and a reaction temperature of 120 °C for 4 h. After the reaction, the product was extracted with methyl tert-butyl ether, and the extract was then subjected to GC quantification using the internal standard method. The SO conversion was 96.9%, the cyclic carbonate selectivity was 95.8%, the cyclic carbonate yield was 92.8%, and the TOF value at which the SO conversion reached 50% was 1863 h. -1 .

[0060] Note: The significantly improved catalytic activity of the binary system indicates a synergistic catalytic effect between the two components.

[0061] Comparative Example 8

[0062] Zn-Salen(SO3Na)2 / [PhCH2CH2IMMe][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =PhCH2CH2,R 3 =H, n=0, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0063] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [PhCH2CH2IMMe][Br], and other operations were the same as in Comparative Example 7. The SO conversion was 89.6%, the cyclic carbonate selectivity was 94.7%, the cyclic carbonate yield was 84.9%, and the TOF value at which the SO conversion reached 50% was 644 h. -1 .

[0064] Note: In the binary system, the lack of polyether chains in the ionic liquid component leads to a significant decrease in activity, indicating that polyether chains have a significant promoting effect on catalytic activity.

[0065] Example 9

[0066] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0067] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)]. 16 Me][Br], other operations were the same as in Comparative Example 7, SO conversion was 97.8%, cyclic carbonate selectivity was 97.3%, cyclic carbonate yield was 95.2%, and the TOF value at which SO conversion reached 50% was 1931 h. -1 .

[0068] Note: Comparing Example 9 and Comparative Example 7, replacing Zn-Salen with Zn-Salen(SO3Na)2 resulted in a significant improvement in catalytic activity.

[0069] Example 10

[0070] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][I] binary catalytic system (M) 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=I) Catalytic cycloaddition reaction of CO2 and styrene oxide (SO)

[0071] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)]. 16 [Me][I], other operations were the same as in Comparative Example 7, SO conversion was 85.6%, cyclic carbonate selectivity was 95.6%, cyclic carbonate yield was 81.8%, and the TOF value at which SO conversion reached 50% was 1030 h. -1 .

[0072] Example 11

[0073] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Ph][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Ph,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0074] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)]. 16Ph][Br], other operations were the same as in Comparative Example 7, SO conversion was 95.8%, cyclic carbonate selectivity was 95.9%, cyclic carbonate yield was 91.9%, and the TOF value at which SO conversion reached 50% was 1287 h. -1 .

[0075] Example 12

[0076] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 (nC 16 H 33 [Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Ph,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0077] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)]. 16 (nC 16 H 33 [Br], other operations were the same as in Comparative Example 7, SO conversion was 97.6%, cyclic carbonate selectivity was 97.9%, cyclic carbonate yield was 95.6%, and the TOF value at which SO conversion reached 50% was 2108 h. -1 .

[0078] Example 13

[0079] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)4Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=4, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0080] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)4Me][Br], and other operations were the same as in Comparative Example 7. The SO conversion was 88.5%, the cyclic carbonate selectivity was 95.4%, the cyclic carbonate yield was 84.4%, and the TOF value at which the SO conversion reached 50% was 702 h. -1 .

[0081] Example 14

[0082] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 240 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=240, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0083] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)]. 240 Me][Br], other operations were the same as in Comparative Example 7, SO conversion was 98.5%, cyclic carbonate selectivity was 97.6%, cyclic carbonate yield was 96.1%, and the TOF value at which SO conversion reached 50% was 1889 h. -1 .

[0084] Example 15

[0085] Co-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Co,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0086] The binary catalyst was replaced with Co-Salen(SO3Na)2 / [MeIM(CH2CH2O)]. 16 Me][Br], other operations were the same as in Comparative Example 7, SO conversion was 97.8%, cyclic carbonate selectivity was 81.4%, and cyclic carbonate yield was 64.4%.

[0087] Example 16

[0088] Mn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Mn,M 2 =Na + R 1 =Me,R 2 =Me,R 3=H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0089] The binary catalyst was replaced with Mn-Salen(SO3Na)2 / [MeIM(CH2CH2O)] 16 Me][Br], other operations were the same as in Comparative Example 7, SO conversion was 64.8%, cyclic carbonate selectivity was 82.7%, and cyclic carbonate yield was 53.6%.

[0090] Example 17

[0091] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0092] Zn-Salen(SO3Na)2 / SO = 0.5 / 1000 (mol / mol / mol), reaction time 24 h, other operations are the same as in Example 9, SO conversion rate 96.9%, cyclic carbonate selectivity 94.6%, cyclic carbonate yield 91.7%.

[0093] Example 18

[0094] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0095] The reaction temperature was 80℃, the reaction time was 8h, and other operations were the same as in Example 9. The SO conversion rate was 96.4%, the cyclic carbonate selectivity was 95.1%, and the cyclic carbonate yield was 91.6%.

[0096] Example 19

[0097] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1=Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0098] The CO2 pressure was 0.1 MPa, the reaction time was 48 h, and other operations were the same as in Example 9. The SO conversion rate was 95.8%, the cyclic carbonate selectivity was 96.0%, and the cyclic carbonate yield was 92.0%.

[0099] Example 20

[0100] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0101] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] = 1 / 5 (mol / mol), other operations are the same as in Example 9, SO conversion is 97.7%, cyclic carbonate selectivity is 96.5%, cyclic carbonate yield is 94.3%, and the TOF value at which SO conversion reaches 50% is 2574 h. -1 .

[0102] Example 21

[0103] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene (SO) oxide.

[0104] Zn-Salen(SO3Na)2 and polyether ionic liquid [MeIM(CH2CH2O)] 16Without prior physical mixing, Zn-Salen(SO3Na)2 and [MeIM(CH2CH2O)] were added to a 60mL stainless steel high-pressure reactor. 16 Me][Br] and 10.5 mmol styrene oxide (R 4 =Ph,R 5 =H), Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] / SO = 1 / 2 / 1000 (mol / mol / mol), and the internal standard biphenyl, were reacted with stirring at a CO2 pressure of 1.0 MPa and a reaction temperature of 120 °C for 4 h. After the reaction, the product was extracted with methyl tert-butyl ether, and the extract was then subjected to GC quantification using the internal standard method. The SO conversion was 97.5%, the cyclic carbonate selectivity was 97.6%, the cyclic carbonate yield was 95.1%, and the TOF value at which the SO conversion reached 50% was 1906 h. -1 .

[0105] Example 22

[0106] Zn-Salen(SO3Na)2 / [(Me)4AG(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene oxide (SO)

[0107] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [(Me)4AG(CH2CH2O)] 16 Me][Br], other operations are the same as in Example 9, SO conversion rate 98.5%, cyclic carbonate selectivity 97.5%, cyclic carbonate yield 96.0%, TOF value at SO conversion rate of 50% is 2123h. -1 .

[0108] Example 23

[0109] Zn-Salen(SO3Na)2 / [N-(CH2CH2O) 16 MePy][Br] binary catalytic system (M 1 =Zn,M 2 =K + R 1 =Me, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene oxide (SO)

[0110] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [N-(CH2CH2O)] 16 MePy][Br], other operations are the same as in Example 9, SO conversion is 97.5%, cyclic carbonate selectivity is 96.8%, cyclic carbonate yield is 94.4%, and the TOF value at which SO conversion reaches 50% is 1895 h. -1 .

[0111] Example 24

[0112] Zn-Salen(SO3Na)2 / [(Et)3N(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Et, n=16, X=Br) Catalytic cycloaddition reaction of CO2 and styrene oxide (SO)

[0113] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [(Et)3N(CH2CH2O)] 16 Me][Br], other operations are the same as in Example 9, SO conversion rate 96.8%, cyclic carbonate selectivity 96.5%, cyclic carbonate yield 93.4%, TOF value at SO conversion rate of 50% is 1768h. -1 .

[0114] Example 25

[0115] Zn-Salen(SO3Na)2 / [(Et)3P(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Et, n=16, X=Br) Catalytic cycloaddition reaction of CO2 and styrene oxide (SO)

[0116] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [(Et)3P(CH2CH2O)] 16 Me][Br], other operations are the same as in Example 9, SO conversion rate is 97.4%, cyclic carbonate selectivity is 97.3%, cyclic carbonate yield is 94.8%, and the TOF value at which SO conversion reaches 50% is 1821 h. -1 .

[0117] Example 26

[0118] Zn-Salen(SO3Na)2 / [MePi(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene oxide (SO)

[0119] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [MePi(CH2CH2O)]. 16 Me][Br], other operations are the same as in Example 9, SO conversion rate 97.8%, cyclic carbonate selectivity 97.0%, cyclic carbonate yield 94.9%, TOF value at SO conversion rate of 50% is 1908h. -1 .

[0120] Example 27

[0121] Zn-Salen(SO3Na)2 / [MeMor(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene oxide (SO)

[0122] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [MeMor(CH2CH2O)]. 16 Me][Br], other operations are the same as in Example 9, SO conversion rate 97.0%, cyclic carbonate selectivity 96.2%, cyclic carbonate yield 93.3%, TOF value at SO conversion rate of 50% is 1850 h. -1 .

[0123] Example 28

[0124] Zn-Salen(SO3Na)2 / [MePyr(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and styrene oxide (SO)

[0125] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [MePyr(CH2CH2O)]. 16 Me][Br], other operations are the same as in Example 9, SO conversion rate 96.4%, cyclic carbonate selectivity 96.5%, cyclic carbonate yield 93.0%, TOF value at SO conversion rate of 50% is 1763h. -1 .

[0126] Example 29

[0127] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) catalyzes the cycloaddition reaction of CO2 and propylene oxide (PO).

[0128] Epoxide replaced with propylene oxide (R 4 =Me,R 5 =H), other operations are the same as in Example 9, PO conversion rate is 99.0%, cyclic carbonate selectivity is 98.2%, and cyclic carbonate yield is 97.2%.

[0129] Example 30

[0130] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and hexane oxide.

[0131] Epoxide replaced with hexane oxide (R 4 =nC k H 2k+1 R 5 =H, k=4), other operations are the same as in Example 9, epoxide conversion rate is 99.1%, cyclic carbonate selectivity is 87.2%, and cyclic carbonate yield is 86.4%.

[0132] Example 31

[0133] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and epichlorohydrin.

[0134] Epoxide replaced with epichlorohydrin (R 4 =ClCH2,R 5 =H), other operations are the same as in Example 9, epichlorohydrin conversion rate is 95.7%, cyclic carbonate selectivity is 99%, and cyclic carbonate yield is 95.7%.

[0135] Example 32

[0136] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and epoxide.

[0137] Epoxide replaced with epoxide (R 4 =nC k H 2k+1 R 5 =H, k=2), other operations are the same as in Example 9, epoxide conversion rate is 96.9%, cyclic carbonate selectivity is 94%, and cyclic carbonate yield is 91.1%.

[0138] Example 33

[0139] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and allyl ethylene oxide

[0140] The epoxide was replaced with allyl ethylene oxide (R4 =CH2=CH-(CH2) j R 5 =H, j=1), other operations are the same as in Example 9, allyl ethylene oxide conversion rate is 95.3%, cyclic carbonate selectivity is 94.8%, and cyclic carbonate yield is 90.3%.

[0141] Example 34

[0142] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and allyl glycidyl ether.

[0143] Epoxide replaced with allyl glycidyl ether (R 4 =CH2=CH-CH2O(CH2) h R 5 =H, h=1), other operations are the same as in Example 9, allyl glycidyl ether conversion rate is 99.1%, cyclic carbonate selectivity is 96.7%, and cyclic carbonate yield is 95.8%.

[0144] Example 35

[0145] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and phenyl glycidyl ether.

[0146] Epoxide replaced with phenyl glycidyl ether (R 4 =PhO(CH2) i R 5 =H, i=1), other operations are the same as in Example 9, phenyl glycidyl ether conversion rate is 98.9%, cyclic carbonate selectivity is 99%, and cyclic carbonate yield is 98.9%.

[0147] Example 36

[0148] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 =H, n=16, X=Br) Catalyzes the cycloaddition reaction of CO2 and cyclohexane oxide.

[0149] The epoxide was replaced with cyclohexane oxide, the reaction time was 24 h, and other operations were the same as in Example 9. The conversion rate of cyclohexane oxide was 92.1%, the selectivity of cyclic carbonate was 93%, and the yield of cyclic carbonate was 85.7%.

[0150] Examples 37-43

[0151] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 Catalyst stability test for the cycloaddition reaction of CO2 and propylene oxide (PO) (H=n=16, X=Br)

[0152] Zn-Salen(SO3Na)2 and polyether ionic liquid [MeIM(CH2CH2O)] 16 Me][Br] was physically mixed and stirred at 70°C for 1 hour to form Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O]. 16 Me][Br] = 1 / 2 (mol / mol), yielding Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)] 16 Me][Br] binary catalyst. Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O] was added to a 60 mL stainless steel high-pressure reactor. 16 Me][Br] binary catalyst, 10.5 mmol propylene oxide (PO), Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O] 16Me][Br] / PO = 1 / 2 / 1000 (mol / mol / mol), and the internal standard biphenyl, were reacted with stirring at a CO2 pressure of 1.0 MPa and a reaction temperature of 120 °C for 4 h. After the reaction, the product was extracted with methyl tert-butyl ether, and the supernatant was used as the product phase. The binary catalyst was separated by liquid / liquid phase separation. The supernatant was subjected to GC for quantitative analysis using the internal standard method. The binary catalyst was then recycled for another cycle. A total of 7 cycles were performed. The results are shown in Examples 37-43 in Table 1. The total TON value reached 6621, and the Zn loss was 0.2-0.3%.

[0153] Table 1. Recycling performance of catalysts for the cycloaddition reaction of PO and CO2

[0154]

[0155] Note: Experiments show that Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)] 16 The Me][Br] binary catalytic system underwent seven cycles in the catalytic cycloaddition reaction of PO and CO2, and the catalytic activity, selectivity and yield showed no significant decreasing trend during the process, proving that the binary catalytic system catalyst has excellent stability.

[0156] Examples 44-51

[0157] Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 Catalyst stability test for the cycloaddition reaction of CO2 and styrene (SO4) with H = n = 16 and X = Br.

[0158] Zn-Salen(SO3Na)2 and polyether ionic liquid [MeIM(CH2CH2O)] 16 Me][Br] was physically mixed and stirred at 70°C for 1 hour to form Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O]. 16 Me][Br] = 1 / 2 (mol / mol), yielding Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)] 16 Me][Br] binary catalyst. Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O] was added to a 60 mL stainless steel high-pressure reactor. 16Me][Br] binary catalyst, 10.5 mmol styrene (SO) oxide, Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O] 16 Me][Br] / SO = 1 / 2 / 1000 (mol / mol / mol), and the internal standard biphenyl, were reacted with stirring at a CO2 pressure of 1.0 MPa and a reaction temperature of 120 °C for 4 h. After the reaction, the product was extracted with methyl tert-butyl ether, and the supernatant was used as the product phase. The binary catalyst was separated by liquid / liquid phase separation. The supernatant was subjected to GC for quantitative analysis using the internal standard method. The binary catalyst was then recycled for another cycle. A total of 8 cycles were performed. The results are shown in Examples 44-51 in Table 2. The total TON value reached 7424, and the Zn loss was 0.2-0.3%.

[0159] Table 2. Catalyst Recycling Performance in the Cycloaddition Reaction of SO and CO2

[0160]

[0161] Note: Experiments show that Zn-Salen(SO3Na)2 / [MeIM(CH2CH2O)] 16 The Me][Br] binary catalytic system underwent eight cycles in the catalytic cycloaddition reaction of SO and CO2, and the catalytic activity, selectivity and yield showed no significant decreasing trend during the process, proving that the binary catalytic system catalyst has excellent stability.

[0162] Comparative Examples 52-56

[0163] Zn-Salen(SO3Na)2 / [BIMI]Br binary catalytic system (M 1 =Zn,M 2 =Na + Catalyst stability test for the cycloaddition reaction of CO2 and styrene (SO) oxide

[0164]

[0165] The binary catalyst was replaced with Zn-Salen(SO3Na)2 / [BIMI]Br, and other operations were the same as in Examples 44-51. The cycle was repeated 5 times, and the results are shown in Examples 52-56 in Table 3.

[0166] Table 3. Catalyst Recycling Performance in the Cycloaddition Reaction of SO and CO2

[0167]

[0168] Note: Experiments show that after replacing the polyether imidazolium ionic liquid with the ordinary imidazolium ionic liquid [BIMI]Br, the activity and selectivity of the binary catalyst decreased significantly after three cycles, indicating that the ordinary imidazolium ionic liquid was lost in large quantities, while the polyether ionic liquid reduced the loss rate.

[0169] Comparative Examples 57-59

[0170] Zn-Salen / [MeIM(CH2CH2O) 16 Me][Br] binary catalytic system (M 1 =Zn,M 2 =Na + R 1 =Me,R 2 =Me,R 3 Catalyst stability test for the cycloaddition reaction of CO2 and styrene (SO4) with H = n = 16 and X = Br.

[0171] The binary catalyst was replaced with Zn-Salen / [MeIM(CH2CH2O)]. 16 Me][Br], other operations are the same as in Examples 44-51, and the cycle is repeated 3 times. The results are shown in Examples 57-59 in Table 4. The Zn loss is 20-30%.

[0172] Table 4. Catalyst Recycling Performance in the Cycloaddition Reaction of SO and CO2

[0173]

[0174] Note: Experiments show that after replacing Zn-Salen(SO3Na)2 with Zn-Salen, the activity and selectivity of the binary catalyst decreased significantly after one cycle, indicating that ordinary Zn-Salen was lost in large quantities (20-30%), while Zn-Salen(SO3Na)2 significantly reduced the loss rate (<0.3%).

Claims

1. A binary catalytic system of sulfonated metal salen and polyether ionic liquid, characterized in that... The binary catalytic system consists of a sulfonated metal Salen and a polyether ionic liquid, wherein the structural formula of the sulfonated metal Salen is as follows: ； In the formula, M 1 For Zn, Co, or Mn; M 2 For Li + Na + or K + ; The structural formula of the polyether ionic liquid is as follows: ； In the formula, R 1 For C1-C 16 Alkyl or phenyl; R 2 It is a C1-C4 alkyl group; R 3 H or methyl; n is the average degree of polymerization of ethoxy group, n = 4-240; X - For Cl - , Br - or I - .

2. A method for preparing a cyclic carbonate compound, characterized in that... Cyclic carbonate compounds were synthesized using carbon dioxide and epoxides as raw materials via a binary catalytic system of sulfonated metal Salen and polyether ionic liquid. After the reaction, an extraction solvent was added, and the catalyst was separated by liquid / liquid phase separation. The supernatant was then purified of solvent to obtain the corresponding cyclic carbonate compounds. The structural formula of the sulfonated metal Salen in the binary system is as follows: ； In the formula, M 1 For Zn, Co, or Mn; M 2 For Li + Na + or K + The structural formula of the polyether ionic liquid is as follows: ； In the formula, R 1 For C1-C 16 Alkyl or phenyl; R 2 It is a C1-C4 alkyl group; R 3 H or methyl; n is the average degree of polymerization of ethoxy group, n = 4-240; X - For Cl - , Br - or I - .

3. The method for preparing a cyclic carbonate compound according to claim 2, characterized in that... The structure of one of the raw materials, the epoxide, is as follows: In the structural formula, when R 5 When = H, R 4 For H, nC k H 2k+1 k = 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, ClCH2, Ph, p-CH3Ph, p-CH3OPh, p-ClPh, p-BrPh, CH2=CH-(CH2) j j = 1, 2, 3 or 4, HOCH2, CH2=CH-CH2O(CH2) h h = 1, 2, 3 or 4 or PhO(CH2) I , i = 1, 2, 3 or 4; when R 5 When H is not equal to H, the epoxide is cyclohexane oxide.

4. The method for preparing a cyclic carbonate compound according to claim 2, characterized in that, When a binary catalytic system catalyzes the cycloaddition reaction of CO2 and epoxide, the molar ratio of sulfonated metal salen to polyether ionic liquid is 1 / 1 to 1 / 10, the molar ratio of sulfonated metal salen to epoxide is 0.1 / 1000 to 2 / 1000, the carbon dioxide pressure is 0.1 to 5.0 MPa, the reaction temperature is 80 to 130°C, and the reaction time is 1 h to 48 h.

5. The method for preparing a cyclic carbonate compound according to claim 2, characterized in that, The extraction solvent is methyl tert-butyl ether or diethyl ether.

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