Method for catalyzing and fixing carbon dioxide by using halogen-free octafunctional cage-type ion pair catalyst

Abstract

The invention discloses a method for catalyzing and fixing carbon dioxide by using a halogen-free octafunctional cage-type ion pair catalyst, which comprises the following steps: introducing carbon dioxide into the octafunctional cage-type ion pair catalyst with a chemical structural formula as shown in a formula (I), epoxide as shown in a formula (II) and carbon dioxide under a solvent-free condition, and reacting to obtain the halogen-free octafunctional cage-type ion pair catalyst. The catalyst can be recycled and reused through a one-step method; according to the present invention, the halogen-free octafunctional group cage type ion pair catalyst is used in the catalysis system, the epoxy substrate is activated through the hydrogen bond interaction of HBD, the carbon dioxide is fixed by the oxygen anion of the pyridine anion, and the catalyst system is relatively simple;

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for catalytic fixation of carbon dioxide using a halogen-free octagonal cage-type ion-pair catalyst. Background Technology

[0002] Due to the thermodynamic stability and chemical inertness of carbon dioxide, suitable catalysts are needed to lower the activation energy required for the reaction to achieve industrialization. Various homogeneous and heterogeneous catalytic systems have been developed for the catalytic conversion of CO2. Homogeneous catalysts include organometallic compounds (Angew. Chem. Int. Ed., 2011; 50, 8510), organic catalysts (Chem. Sus. Chem., 2012; 5, 2032), and nanoparticle catalysts (Polymer., 2020; 186, 122004), each with its own unique characteristics. Metal catalysts have been extensively and thoroughly studied.

[0003] However, metal catalysis can lead to trace metal residues in cyclic carbonate products, potentially causing environmental pollution and limiting their direct application in fields such as biomedicine and microelectronics where metal residue levels are strictly controlled. While homogeneous catalysts provide simple models for mechanistic studies, they face significant challenges in catalyst recovery and product separation. In contrast, heterogeneous catalysts can effectively address these issues. In fact, homogeneous catalysts can indeed be recovered, although reports on their recovery are relatively limited (ACS Catal., 2024; 14, 7289). Therefore, achieving the optimal balance between the high conversion efficiency of homogeneous catalysts and the ease of recovery of heterogeneous catalysts in CCE reactions remains a major challenge when designing catalysts.

[0004] Possession alkyl sesquioxanes (POSS) exhibit rich chemical properties in the design of hybrid nanocomposites and polymer materials, and their potential in catalysis is also considerable. However, POSS-based catalysts for the cycloaddition reaction of carbon dioxide with epoxides have not been fully developed. Functionalized polyhedral oligomeric silsesquioxanes have been reported as useful adsorbents in carbon dioxide capture or conversion, POSS catalysts based on metal complexes (Chem. Eur. J., 2020; 26, 13686), and POSS-based polymer ionic liquids (ACS Sustainable Chem. Eng., 2019; 7, 16907) catalyzing the cycloaddition reaction of carbon dioxide with epoxides. A porous cation framework based on POSS has been previously designed (Chem. Commun., 2018; 54, 12174). Building upon this work, a silanol-rich violet (1,1'-disubstituted-4,4'-bipyridine)-based ionic porous hybrid polymer has been developed (ACS Sustainable Chem. Eng., 2019; 7, 16907). Although previous studies have reported extensive use of POSS nanocatalysts for CCE reactions, most have focused on polyPOSS systems as heterogeneous catalysts, with only one example involving the use of a single POSS molecule as a homogeneous catalyst (ChemCatChem., 2016; 8, 1685). However, previous studies have not addressed the recycling of POSS composites as homogeneous catalysts. POSS-based CCE catalysts all employ halides as co-catalysts, with halide anions being indispensable in the key ring-opening step of the epoxy reaction. Halogens offer advantages such as high reactivity and selectivity, but this can cause irreversible corrosion and damage to the reaction vessel, as well as severe environmental damage, limiting the practical application of this reaction in industrial settings. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0007] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for catalytic fixation of carbon dioxide using a halogen-free octagonal cage-type ion-pair catalyst.

[0008] To solve the above technical problems, the present invention provides the following technical solution: a method for catalytic fixation of carbon dioxide using a halogen-free octagonal cage-type ion-pair catalyst, characterized in that: it includes passing carbon dioxide through an octagonal cage-type ion-pair catalyst with a chemical structure as shown in formula (I), an epoxide as shown in formula (II), and carbon dioxide under solvent-free conditions to obtain a cyclic carbonate, and the catalyst can be recycled and reused in one step.

[0009]

[0010] HBD is selected from conjugate acids of organic bases containing N atoms; wherein the organic base is a C1-C4 alkyl-substituted quaternary ammonium base compound, a C1-C4 alkyl-substituted guanidine or an unsubstituted guanidine, or an imidazopyridine compound; R1 and R2 are selected from hydrogen, n-butyl, halogen-substituted alkyl, phenyl, benzyl, R3-O-CH2-, wherein R3 is selected from phenyl, phenyl linked by 1-3 carbon atoms, phenyl substituted by alkyl of 1-3 carbon atoms, halogen-substituted phenyl, allyl, or branched or straight-chain alkyl of 1-4 carbon atoms, wherein R1 and R2 have the same or different structures.

[0011] In a preferred embodiment of the preparation method described in this invention, the C1-C4 alkyl-substituted quaternary ammonium base compound is selected from tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, and tetraethylammonium hydroxide.

[0012] The amidine organic bases are selected from 1,8-diazobisspirocyclic [5.4.0]undec-7-ene;

[0013] The alkyl-substituted or unsubstituted guanidine organic bases are selected from tetramethylguanidine, guanidine, and 1,1-dimethylguanidine;

[0014] The bicyclic guanidine organic base is selected from 1,5,7-triazidobicyclo(4.4.0)dec-5-ene and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene;

[0015] The aminopyridine compound is selected from 4-dimethylaminopyridine.

[0016] In a preferred embodiment of the method described in this invention, the molar ratio of the epoxide as shown in formula (II) to the halogen-free catalyst as shown in formula (I) is 100:0.15 to 0.28.

[0017] In a preferred embodiment of the method described in this invention, the reaction temperature is 100–120°C, the reaction time is 6–24 h, and the initial pressure of carbon dioxide is 1–2 MPa.

[0018] As a preferred embodiment of the method described in this invention, the recovery involves lowering the reaction solution to room temperature, allowing the catalyst to flocculate and precipitate naturally, or adding ethyl acetate, filtering, and then washing and drying with ethyl acetate.

[0019] Another objective of this invention is to overcome the shortcomings of the prior art and provide a method for preparing an octagonal cage-type ion-pair catalyst:

[0020] The method includes combining an imine-linked modified polyhedral oligomeric silsesquioxane as shown in formula (Ⅲ) with an organic base, neutralizing the mixture in the organic solvent methanol, and reacting it at room temperature.

[0021]

[0022] In a preferred embodiment of the preparation method described in this invention, the molar ratio of the polyhedral oligomeric silsesquioxane modified with imine bonds to the organic base is 1 to 10:1.

[0023] As a preferred embodiment of the preparation method described in this invention, the acid-base neutralization reaction in the organic solvent methanol is carried out at a temperature of 0–25°C and at room temperature for a reaction time of 6–24 h.

[0024] Beneficial effects of this invention:

[0025] (1) The present invention can efficiently synthesize cyclic carbonates with high added value through the above-mentioned catalytic system. Compared with the cyclic carbonates synthesized by metal catalysts (magnesium-aluminum mixed oxides) and halogen catalysts in the prior art, it has the characteristics of high yield, no metal residue, no halogen residue, and wide application.

[0026] (2) The reaction process does not require the use of solvents, thus avoiding the toxicity of organic solvents. The separation of products from catalysts is simple, achieving a green chemical process.

[0027] (3) The catalytic system of the present invention uses a halogen-free octagonal cage-type ion pair catalyst, which activates the epoxy substrate through the hydrogen bonding of HBD and fixes carbon dioxide with the oxygen anion of pyridine anion. The catalyst system is relatively simple.

[0028] (4) The catalytic reaction of the catalytic system of the present invention is simple, the required equipment is simple, and it is suitable for industrial scale-up.

[0029] (5) The catalytic system used in this invention is inexpensive and easy to prepare, and the amount of catalyst used is small. The catalyst has 8 catalytic active sites, and the proximity effect makes the catalyst have the characteristics of efficient quantitative conversion. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0031] Figure 1 This is the hydrogen spectrum of the carbonate product from Example 1 of the present invention.

[0032] Figure 2 This is the carbon spectrum of the carbonate product of Example 1 of the present invention.

[0033] Figure 3 This is the hydrogen spectrum of the carbonate product in Example 8 of the present invention.

[0034] Figure 4 This is the carbon spectrum of the carbonate product in Example 8 of the present invention.

[0035] Figure 5 This is the hydrogen spectrum of the carbonate product in Example 9 of the present invention.

[0036] Figure 6 This is the carbon spectrum of the carbonate product in Example 9 of the present invention.

[0037] Figure 7 The hydrogen spectrum of the carbonate product in the embodiment of the present invention is shown.

[0038] Figure 8 This is the carbon spectrum of the carbonate product in the embodiment of the present invention.

[0039] Figure 9 The above is the hydrogen spectrum of the carbonate product in Example 11 of this invention.

[0040] Figure 10 This is the carbon spectrum of the carbonate product in Example 11 of the present invention.

[0041] Figure 11 The hydrogen spectrum of the 12-carbonate product in this embodiment of the invention is shown.

[0042] Figure 12 The carbon spectrum of the 12-carbonate product in this embodiment of the invention is shown.

[0043] Figure 13 The hydrogen spectrum of the carbonate product in Example 13 of this invention is shown.

[0044] Figure 14 The carbon spectrum of the carbonate product in Example 13 of this invention is shown.

[0045] Figure 15 The hydrogen spectrum of the carbonate product 14 in this embodiment of the invention is shown.

[0046] Figure 16 The carbon spectrum of the carbonate product in Example 14 of this invention is shown.

[0047] Figure 17 The hydrogen spectrum of the carbonate product in Example 15 of this invention is shown.

[0048] Figure 18 The carbon spectrum of the carbonate product in Example 15 of this invention is shown.

[0049] Figure 19 The above is the hydrogen spectrum of the 16-carbonate product in the embodiments of the present invention.

[0050] Figure 20 The carbon spectrum of the 16-carbonate product in this embodiment of the invention is shown.

[0051] Figure 21 This is the hydrogen spectrum of the catalyst in Example 2 of the present invention.

[0052] Figure 22 The image shows the carbon spectrum of catalyst 2 in Example 2 of this invention.

[0053] Figure 23 This is the hydrogen spectrum of the catalyst in Example 1 of the present invention.

[0054] Figure 24 The hydrogen spectrum of catalyst 3 in Example 3 of this invention is shown.

[0055] Figure 25 The hydrogen spectrum of catalyst 4 in Example 4 of this invention is shown.

[0056] Figure 26 This is the hydrogen spectrum of the catalyst recovered in Example 17 of the present invention.

[0057] Figure 27 The chemical structural formula of the functional cage-type ion-pair catalyst in Embodiment 8 of the present invention is shown.

[0058] The method for synthesizing polyhedral oligomeric silsesquioxanes (POSS) modified by imine bonds is shown in Formula (A).

[0059] Detailed Implementation

[0060] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0061] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0062] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0063] Unless otherwise specified, all raw materials used in the embodiments of this invention are commercially available and were purchased from Alfa Aesar.

[0064] The 1H NMR spectra involved in the examples were measured using a Bruker Ascend TM-400 NMR spectrometer, and the deuterated reagents used were deuterated chloroform (CDCl3) or deuterated DMSO (DMSO-d6).

[0065] Example 1

[0066] (1) Catalyst POSS-3-OP - 〃TBDH + The preparation method is as follows: A MeOH dispersion (40 mL) of OAP-POSS-CF3SO3 (1.0410 g, 0.5 mmol) was stirred at room temperature for 30 min, followed by the addition of triethylamine (1.39 mL, 10 mmol). A MeOH solution (10 mL) of 5-hydroxypyridinecarboxaldehyde (0.6281 g, 5 mmol) was added dropwise to the solution. After stirring for 0.5 hours, the precipitate formed by filtration was washed with ethyl acetate to obtain a yellow solid, POSS-3-HOP. POSS-3-HOP (0.1033 g, 0.06 mmol) was dissolved in 10 mL of methanol, and then TBD was added dropwise to the solution (0.0861 g, 0.6 mmol). After the reaction, the solvent was removed under vacuum.

[0067] The precipitate was then washed three times with ethyl acetate to obtain the pure product, a yellow solid (POSS-3-OP). - 〃TBDH + ).

[0068] Hydrogen spectrum as shown Figure 23 As shown (1H NMR spectrum, 400Hz, TFAA-d).

[0069] The spectral data is as follows: 1H NMR(400MHz,TFAA-d)δ10.17(s,8H),8.82(d,J=2.5Hz,8H),8.68(d,J=8.8Hz,8H),8.46(dd,J=8.8, 2.6Hz,8H),3.57–3.53(m,64H),3.42(s,16H),2.25(q,J=5.9Hz,48H),2.08(s,16H),0.98(s,16H).

[0070] (2) Styrene epoxide (0.28 ml, 2.5 mmol, 1.0 equiv) and POSS-3-OP prepared in step (1) were oxidized. - 〃TBDH + (0.015 g, 0.005 mmol, 0.002 equiv) was added to a stainless steel pressure reactor. The stainless steel pressure reactor was sealed, and the air in the reactor was replaced three times with CO2. Then, CO2 was introduced into the reactor until the initial pressure was 1 MPa, and the temperature was raised to 120 °C. The reaction time was 24 h. After the reaction was completed, the stainless steel pressure reactor was cooled to 0 °C with an ice-water mixture to release the residual gas. 2 ml of ethyl acetate solution was added, and the mixture was filtered to obtain the catalyst POSS-3-OP. - 〃TBDH + The catalyst was washed three times with ethyl acetate and dried to obtain a pure catalyst.

[0071] (3) After passing the filtrate through column chromatography (petroleum ether: ethyl acetate = 5:1), a mixed solution containing the product was obtained. The solution was evaporated to dryness on a rotary evaporator to obtain a yellow solid styrene carbonate. The solid was dried to constant weight, with a conversion rate of 85% and a selectivity of 90%.

[0072] The proton NMR spectrum of the product is as follows Figure 1 As shown (1H NMR spectrum, 400Hz, CDCl3).

[0073] The spectral data is as follows:

[0074] 1 H NMR (400MHz, Chloroform-d) δ7.44–7.37(m,3H),7.36–7.30(m,2H),5.65(t,J=8.0Hz,1H),4.77(t,J=8.4Hz,1H),4.29(dd,J=8.6,7.8Hz,1H).

[0075] The carbon spectrum of the product is as follows Figure 2 As shown (carbon NMR spectrum, 101 Hz, CDCl3).

[0076] The spectral data is as follows:

[0077] 13 C NMR (101MHz, Chloroform-d) δ154.11,134.98,128.77,128.28,125.07,77.16,70.31.

[0078] Example 2

[0079] (1) Catalyst POSS-4-OP - 〃TBDH + Preparation method: A MeOH dispersion (40 mL) of OAP-POSS-CF3SO3 (1.0410 g, 0.5 mmol) was stirred at room temperature for 30 min, followed by the addition of triethylamine (1.39 mL, 10 mmol). POSS-4-HOP (0.3445 g, 0.2 mmol) was dissolved in 20 mL of methanol, and then TBD (0.2870 g, 2 mmol) was added dropwise to the solution. After the reaction, the solvent was removed under vacuum.

[0080] The precipitate was washed several times with ethyl acetate, and then the pure product, a yellow solid (POSS-4-OP), was obtained. - 〃TBDH + ).

[0081] Hydrogen spectrum as shown Figure 21 As shown (1H NMR spectrum, 400Hz, TFAA-d).

[0082] The spectral data are as follows: 1H NMR (400MHz, TFAA-d) δ 9.09 (d, J = 17.8Hz, 16H), 8.42 (d, J = 7.3Hz, 8H), 7.67–7.26 (m, 8H), 4.33 (d, J = 24.1Hz, 16H), 3.71 (tq, J = 8.6, 5.6Hz, 64H), 2.41 (h, J = 7.7, 6.0Hz, 48H), 1.23 (s, 16H).

[0083] Carbon spectrum as shown Figure 22 As shown (carbon NMR spectrum, 101 Hz, TFAA-d).

[0084] The spectral data is as follows: 13 C NMR(101MHz,TFAA-d)δ151.90,150.38,141.34,120.77,66.55,55.08,47.33,38.80,20.66,12.62.

[0085] (2) Styrene epoxide (0.28 ml, 2.5 mmol, 1.0 equiv) and POSS-4-OP prepared in step (1) were oxidized. - 〃TBDH + (0.015 g, 0.005 mmol, 0.002 equiv) was added to a stainless steel pressure reactor. The stainless steel pressure reactor was sealed, and the air in the reactor was replaced three times with CO2. Then, CO2 was introduced into the reactor until the initial pressure was 1 MPa, and the temperature was raised to 120 °C. The reaction time was 24 h. After the reaction was completed, the stainless steel pressure reactor was cooled to 0 °C with an ice-water mixture to release the residual gas. 2 ml of ethyl acetate solution was added, and the catalyst was obtained by filtration. The catalyst was washed three times with ethyl acetate and dried to obtain a pure catalyst.

[0086] (3) After passing the filtrate through column chromatography (petroleum ether: ethyl acetate = 5:1), a mixed solution containing the product was obtained. The solution was evaporated to dryness on a rotary evaporator to obtain a yellow solid styrene carbonate. The solid was dried to constant weight, with a conversion rate of 98% and a selectivity of 99%.

[0087] Example 3

[0088] (1)POSS-4-OP - 〃MTBDH + The preparation method is as follows: A MeOH dispersion (40 mL) of OAP-POSS-CF3SO3 (1.0410 g, 0.5 mmol) was stirred at room temperature for 30 min, followed by the addition of triethylamine (1.39 mL, 10 mmol). POSS-4-HOP (0.0435 g, 0.025 mmol) was dissolved in 10 mL of methanol, and then MTBD (0.0306 g, 0.2 mmol) was added dropwise to the solution. After the reaction, the solvent was removed under vacuum.

[0089] The precipitate was washed several times with ethyl acetate, and then the pure product, a yellow solid (POSS-4-OP), was obtained. - 〃MTBDH + ).

[0090] Hydrogen spectrum as shown Figure 24 As shown (1H NMR spectrum, 400Hz, TFAA-d).

[0091] The spectral data is as follows:

[0092] 1H NMR(400MHz,TFAA-d)δ9.06(d,J=23.9Hz,16H),8.37(s,8H),7.39(s,8H),4.26(s,1 6H), 3.69 (td, J=12.0, 6.0Hz, 64H), 3.30 (s, 24H), 2.57–2.18 (m, 48H), 1.18 (s, 16H).

[0093] (2) Styrene epoxide (0.28 ml, 2.5 mmol, 1.0 equiv) and POSS-4-OP prepared in step (1) were oxidized. - 〃MTBDH + (0.015 g, 0.005 mmol, 0.002 equiv) was added to a stainless steel pressure reactor. The stainless steel pressure reactor was sealed, and the air in the reactor was replaced three times with CO2. Then, CO2 was introduced into the reactor until the initial pressure was 1 MPa, and the temperature was raised to 120 °C. The reaction time was 24 h. After the reaction was completed, the stainless steel pressure reactor was cooled to 0 °C with an ice-water mixture to release the residual gas. 2 ml of ethyl acetate solution was added, and the catalyst was obtained by filtration. The catalyst was washed three times with ethyl acetate and dried to obtain a pure catalyst.

[0094] (3) After passing the filtrate through column chromatography (petroleum ether: ethyl acetate = 5:1), a mixed solution containing the product was obtained. The solution was evaporated to dryness on a rotary evaporator to obtain a yellow solid styrene carbonate. The solution was dried to constant weight, with a conversion rate of 78% and a selectivity of 85%.

[0095] Example 4

[0096] (1)POSS-4-OP - 〃DBUH + The preparation method is as follows: A MeOH dispersion (40 mL) of OAP-POSS-CF3SO3 (1.0410 g, 0.5 mmol) was stirred at room temperature for 30 min, followed by the addition of triethylamine (1.39 mL, 10 mmol). POSS-4-HOP (0.0435 g, 0.025 mmol) was dissolved in 10 mL of methanol, and then DBU (0.03 mL, 0.2 mmol) was added dropwise to the solution. After the reaction, the solvent was removed under vacuum. The precipitate was washed several times with ethyl acetate, and then the pure product, a yellow solid (POSS-4-OP), was obtained. - 〃DBUH + ).

[0097] Hydrogen spectrum as shown Figure 24 As shown (1H NMR spectrum, 400Hz, TFAA-d).

[0098] The spectral data is as follows:

[0099] 1 H NMR(400MHz,TFAA-d)δ9.23–8.92(m,16H),8.40(d,J=7.7Hz,8H),7.43(s,8H),4.33(d,J=29.5Hz,16H),3. 92(dt,J=21.5,5.5Hz,32H),3.75(t,J=5.8Hz,16H),2.58–2.26(m,32H),2.24–2.02(m,64H),1.19(s,16H).

[0100] (2) Styrene epoxide (0.28 ml, 2.5 mmol, 1.0 equiv) and the ion-pair catalyst POSS-4-OP prepared in step (1) were oxidized. - 〃DBUH + (0.015 g, 0.005 mmol, 0.002 equiv) was added to a stainless steel pressure reactor. The stainless steel pressure reactor was sealed, and the air in the reactor was replaced three times with CO2. Then, CO2 was introduced into the reactor until the initial pressure was 1 MPa, and the temperature was raised to 120 °C. The reaction time was 24 h. After the reaction was completed, the stainless steel pressure reactor was cooled to 0 °C with an ice-water mixture to release the residual gas. 2 ml of ethyl acetate solution was added, and the catalyst was obtained by filtration. The catalyst was washed three times with ethyl acetate and dried to obtain a pure catalyst. The filtrate was subjected to column chromatography (petroleum ether: ethyl acetate = 5:1) to obtain a mixed solution containing the product. The solution was evaporated to dryness on a rotary evaporator to obtain a yellow solid styrene carbonate. After drying to constant weight, the conversion rate was 67% and the selectivity was 75%.

[0101] Example 5

[0102] The difference from Example 2 is that in step (2), the ion-pair catalyst OAP-POSS-CF3SO3 is 0.010 g, 0.004 mmol, and 0.0015 equiv. The rest is the same as in Example 2. Yellow solid styrene carbonate is obtained, dried to constant weight, with a conversion rate of 83% and a selectivity of 75%.

[0103] Example 6

[0104] The difference from Example 2 is that in step (2), the ion-pair catalyst OAP-POSS-CF3SO3 is 0.020 g, 0.007 mmol, and 0.0028 equiv. The rest is the same as in Example 2. A yellow solid is obtained, which is dried to constant weight. The conversion rate is 95% and the selectivity is 87%.

[0105] Example 7

[0106] The difference from Example 2 is that in step (2), CO2 is introduced into the reactor to an initial pressure of 2 MPa. Otherwise, it is the same as Example 2. Yellow solid styrene carbonate is obtained, dried to constant weight, with a conversion rate of 95% and a selectivity of 99%.

[0107] Example 8

[0108] The difference from Example 2 is that in step (2), the epoxide styrene oxide (0.28 ml, 2.5 mmol, 1.0 equiv) was replaced with the epoxide bromopropane (0.21 ml, 2.5 mmol, 1.0 equiv). Otherwise, it was the same as Example 2, and a yellow solid 4-(Bromomethyl)-1,3-dioxolan-2-one was obtained. After drying to constant weight, the conversion rate was 97% and the selectivity was 99%.

[0109] The proton NMR spectrum of the product is as follows Figure 3 As shown (1H NMR spectrum, 400Hz, CDCl3).

[0110] The spectral data is as follows:

[0111] 1 H NMR (400MHz, Chloroform-d) δ 4.95 (dq, J = 8.2, 5.3Hz, 1H), 4.59 (dd, J = 8.9, 8.2Hz, 1H), 4.35 (dd, J = 8.9, 5.9Hz, 1H), 3.58 (d, J = 5.2Hz, 2H).

[0112] Carbon spectrum as shown Figure 4 As shown, the spectral data is as follows:

[0113] 13 C NMR (101MHz, Chloroform-d) δ154.23,74.09,68.23,31.42.

[0114] Example 9

[0115] The difference from Example 2 is that in step (2), the epoxide styrene oxide (0.28 ml, 2.5 mmol, 1.0 equiv) is replaced with the epoxide epichlorohydrin (0.20 ml, 2.5 mmol, 1.0 equiv). Otherwise, it is the same as Example 2. A yellow solid chloromethyldioxacyclophenone is obtained, which is dried to constant weight. The conversion rate is 98% and the selectivity is 99%.

[0116] The proton NMR spectrum of the product is as follows Figure 5 As shown (1H NMR spectrum, 400Hz, CDCl3).

[0117] The spectral data is as follows:1 H NMR(400MHz,Chloroform-d)δ4.99(ddt,J=8.3,5.7,3.9Hz,1H),4.55(t,J=8.7Hz,1H), 4.33(dd,J=8.9,5.7Hz,1H), 3.80(dd,J=12.5,4.3Hz,1H), 3.69(dd,J=12.5,3.7Hz,1H).

[0118] Carbon spectrum as shown Figure 6 As shown, the spectral data is as follows:

[0119] 13 C NMR (101MHz, Chloroform-d) δ154.50,74.48,66.86,44.19.

[0120] Example 10

[0121] The difference from Example 2 is that in step (2), epoxide styrene oxide (0.28 ml, 2.5 mmol, 1.0 equiv) was replaced with epoxide tert-butyl glycidyl ether (0.37 ml, 2.5 mmol, 1.0 equiv). Otherwise, it was the same as Example 2, and a yellow solid 4-(tert-butoxymethyl)-1,3-dioxolan-2-one was obtained. After drying to constant weight, the conversion rate was 84% ​​and the selectivity was 85%.

[0122] The proton NMR spectrum of the product is as follows Figure 7 As shown (1H NMR spectrum, 400Hz, CDCl3).

[0123] The spectral data is as follows:

[0124] 1 H NMR (400MHz, Chloroform-d) δ4.82–4.69 (m, 1H), 4.47 (t, J = 8.2 Hz, 1H), 4.38 (dd, J = 8. 3,5.8Hz,1H),3.61(dd,J=10.3,4.6Hz,1H),3.53(dd,J=10.3,3.6Hz,1H),1.19(s,9H).

[0125] Carbon spectrum as shown Figure 8 As shown, the spectral data is as follows:

[0126] 13 C NMR (101MHz, Chloroform-d) δ155.27,75.26,74.06,66.73,61.43,27.44,24.87,1.16.

[0127] Example 11

[0128] The difference from Example 2 is that in step (2), epoxide styrene oxide (0.28 ml, 2.5 mmol, 1.0 equiv) was replaced with epoxide allyl glycidyl ether (0.30 ml, 2.5 mmol, 1.0 equiv). Otherwise, it was the same as Example 2, and a yellow solid 4-[(2-propenyloxy)methyl]-1,3-dioxolane-2-one was obtained. After drying to constant weight, the conversion rate was 93% and the selectivity was 99%.

[0129] The proton NMR spectrum of the product is as follows Figure 9 As shown (1H NMR spectrum, 400Hz, CDCl3).

[0130] The spectral data is as follows:

[0131] 1 H NMR(400MHz,Chloroform-d)δ5.89–5.75(m,1H),5.25–5.11(m,2H),4.79(ddt,J=9.1,6.5,3.5Hz,1H),4.46(t,J=8.3H z,1H),4.33(ddt,J=7.1,6.0,1.3Hz,1H),3.99(dq,J=5.9,1.4Hz,2H),3.65(dd,J=11.2,3.5Hz,1H),3.60–3.52(m,1H).

[0132] Carbon spectrum as shown Figure 10 As shown, the spectral data is as follows:

[0133] 13 C NMR (101MHz, Chloroform-d) δ 155.06, 133.71, 117.65, 75.19, 72.41, 68.83, 66.21.

[0134] Example 12

[0135] The difference from Example 2 is that in step (2), epoxide styrene oxide (0.28 ml, 2.5 mmol, 1.0 equiv) was replaced with epoxide phenyl glycidyl ether (0.34 ml, 2.5 mmol, 1.0 equiv). Otherwise, it was the same as Example 2, and a yellow solid 4-(phenoxymethyl)-1,3-dioxolane-2-one was obtained. After drying to constant weight, the conversion rate was 99% and the selectivity was 98%.

[0136] The proton NMR spectrum of the product is as follows Figure 11 As shown (1H NMR spectrum, 400Hz, CDCl3).

[0137] The spectral data is as follows:

[0138] 1 H NMR(400MHz,Chloroform-d)δ7.35–7.27(m,2H),7.02(tt,J=7.4,1.1Hz,1H),6.94–6.87(m,2H),5.03(dddd,J=8.1,5.9,4.4 ,3.6Hz,1H),4.62(t,J=8.4Hz,1H),4.54(dd,J=8.5,5.9Hz,1H),4.24(dd,J=10.5,4.4Hz,1H),4.16(dd,J=10.6,3.6Hz,1H).

[0139] Carbon spectrum as shown Figure 12 As shown, the spectral data is as follows:

[0140] 13 C NMR (101MHz, Chloroform-d) δ157.88,129.85,122.18,114.75,74.18,67.01,66.41.

[0141] Example 13

[0142] The difference from Example 2 is that in step (2), the epoxide styrene oxide (0.28 ml, 2.5 mmol, 1.0 equiv) was replaced with the epoxide 1,2-epoxyhexane (0.31 ml, 2.5 mmol, 1.0 equiv). Otherwise, it was the same as Example 2, and a yellow solid 4-butyl-1,3-dioxolan-2-one was obtained. After drying to constant weight, the conversion rate was 98% and the selectivity was 87%.

[0143] The proton NMR spectrum of the product is as follows Figure 13 As shown (1H NMR spectrum, 400Hz, CDCl3).

[0144] The spectral data is as follows:

[0145] 1 H NMR(400MHz,Chloroform-d)δ4.69(qd,J=7.5,5.4Hz,1H),4.55–4.49(m,1H),4.05(dd,J=8.4 ,7.2Hz,1H),1.82–1.74(m,1H),1.71–1.62(m,1H),1.45–1.29(m,4H),0.90(t,J=7.0Hz,3H).

[0146] Carbon spectrum as shown Figure 14 As shown, the spectral data is as follows:

[0147] 13 C NMR (101MHz, Chloroform-d) δ155.21,77.34,77.16,69.48,33.59,26.47,22.29,13.85.

[0148] Example 14

[0149] The difference from Example 2 is that in step (2), the epoxide styrene oxide (0.28 ml, 2.5 mmol, 1.0 equiv) was replaced with the epoxide (methoxymethyl) ethylene oxide (0.26 ml, 2.5 mmol, 1.0 equiv). Otherwise, it was the same as Example 2, and a yellow solid 4-(methoxymethyl)-1,3-dioxolan-2-one was obtained. After drying to constant weight, the conversion rate was 98% and the selectivity was 86%.

[0150] The proton NMR spectrum of the product is as follows Figure 15 As shown (1H NMR spectrum, 400Hz, CDCl3).

[0151] The spectral data is as follows:

[0152] 1 H NMR(400MHz,Chloroform-d)δ4.79(ddt,J=8.4,6.1,3.7Hz,1H),4.47(t,J=8.4Hz,1H),4.34(d d, J=8.4, 6.1Hz, 1H), 3.62 (dd, J=11.1, 3.6Hz, 1H), 3.53 (dd, J=11.1, 3.8Hz, 1H), 3.39 (s, 3H).

[0153] Carbon spectrum as shown Figure 16 As shown, the spectral data is as follows:

[0154] 13 C NMR (101MHz, Chloroform-d) δ155.06,75.13,71.52,68.64,66.24,59.68,1.07.

[0155] Example 15

[0156] The difference from Example 2 is that in step (2), the epoxide styrene oxide (0.28 ml, 2.5 mmol, 1.0 equiv) was replaced with the epoxide 2-tolylglycidyl ether (0.42 ml, 2.5 mmol, 1.0 equiv). Otherwise, the same as in Example 2 was obtained, yielding a yellow solid 4-((o-tolyloxy)methyl)-1,3-dioxolan-2-one, which was dried to constant weight. The conversion rate was 94%, and the selectivity was 99%.

[0157] The proton NMR spectrum of the product is as follows Figure 17 As shown (1H NMR spectrum, 400Hz, CDCl3).

[0158] The spectral data is as follows:

[0159] 1 H NMR(400MHz,Chloroform-d)δ7.16(tt,J=5.9,4.6,2.1Hz,2H),6.93(td,J=7.4,1.0Hz,1H),6.81–6.75(m,1H),5.05(d dt,J=8.6,5.5,3.3Hz,1H),4.65–4.56(m,2H),4.26(dd,J=10.6,3.5Hz,1H),4.13(dd,J=10.6,3.1Hz,1H),2.22(s,3H).

[0160] Carbon spectrum as shown Figure 18 As shown, the spectral data is as follows:

[0161] 13 C NMR (101MHz, Chloroform-d) δ155.86,154.90,131.21,127.21,127.00,121.78,110.92,74.33,67.11,66.36,16.10.

[0162] Example 16

[0163] The difference from Example 2 is that in step (2), the epoxide styrene oxide (0.28 ml, 2.5 mmol, 1.0 equiv) was replaced with the epoxide 1,2-epoxy-5-hexene (0.29 ml, 2.5 mmol, 1.0 equiv). Otherwise, it was the same as Example 2, and a yellow solid 4-(but-3-en-1-yl)-1,3-dioxolan-2-one was obtained. After drying to constant weight, the conversion rate was 94% and the selectivity was 90%.

[0164] The proton NMR spectrum of the product is as follows Figure 19As shown (1H NMR spectrum, 400Hz, CDCl3).

[0165] The spectral data is as follows:

[0166] 1 H NMR(400MHz,Chloroform-d)δ5.78(ddt,J=16.9,10.1,6.6Hz,1H),5.11–4.99(m,2H),4.72(qd,J=7.6,5.1Hz,1 H), 4.53 (t, J = 8.1Hz, 1H), 4.08 (dd, J = 8.4, 7.2Hz, 1H), 2.28–2.13 (m, 2H), 1.96–1.87 (m, 1H), 1.79–1.70 (m, 1H).

[0167] Carbon spectrum as shown Figure 20 As shown,

[0168] The spectral data is as follows: 13 C NMR (101MHz, Chloroform-d) δ155.07,136.17,116.56,76.43,69.44,63.81,33.18,28.77,1.12.

[0169] Example 17

[0170] Epichlorohydrin (0.78 ml, 10 mmol, 1.0 equiv) and ion-pair catalyst OAP-POSS-CF3SO3 (0.060 g, 0.020 mmol, 0.002 equiv) were added to a stainless steel pressure reactor. The stainless steel pressure reactor was sealed, and the air in the reactor was replaced with CO2 three times. Then, CO2 was introduced into the reactor until the initial pressure reached 1 MPa, and the temperature was raised to 120 °C. The reaction time was 6 h. After the reaction was completed, the stainless steel pressure reactor was cooled to 0 °C with an ice-water mixture to release the residual gas. The catalyst was obtained by filtration, washed three times with ethyl acetate, and dried to obtain a pure catalyst. The product conversion rate was 98%, and the selectivity was 99%.

[0171] The recovered catalyst was added back into the epichlorohydrin epoxide (0.78 ml, 10 mmol, 1.0 equiv) into a stainless steel pressure reactor. The stainless steel pressure reactor was sealed, and the air in the reactor was replaced with CO2 three times. Then, CO2 was introduced into the reactor until the initial pressure was 1 MPa, the temperature was raised to 120 °C, and the reaction time was 6 h. After seven cycles of this reaction, the catalyst OAP-POSS-CF3SO3 was recovered.

[0172] The hydrogen spectrum of the recovered catalyst is as follows: Figure 26 As shown (1H NMR spectrum, 400Hz, TFAA-d).

[0173] The spectral data is as follows:

[0174] 1 H NMR(400MHz,TFAA-d)δ9.09(d,J=17.8Hz,16H),8.42(d,J=7.3Hz,8H),7.67–7.26(m,8H),4.3 3(d,J=24.1Hz,16H),3.71(tq,J=8.6,5.6Hz,64H),2.41(h,J=7.7,6.0Hz,48H),1.23(s,16H).

[0175] Figure 27 The chemical structural formula of the functional cage-type ion-pair catalyst in Embodiment 8 of the present invention is shown.

[0176] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for catalytic fixation of carbon dioxide using a halogen-free octagonal cage-type ion-pair catalyst, characterized in that: This includes passing carbon dioxide through an octagonal cage-type ion-pair catalyst with the chemical structure shown in formula (I), an epoxide shown in formula (II), and carbon dioxide under solvent-free conditions to obtain a cyclic carbonate, and the catalyst can be recycled and reused in one step. HBD is selected from conjugate acids of organic bases containing N atoms; wherein the organic base is a C1-C4 alkyl-substituted quaternary ammonium base compound, a C1-C4 alkyl-substituted guanidine or an unsubstituted guanidine, or an imidazopyridine compound; R1 and R2 are selected from hydrogen, n-butyl, halogen-substituted alkyl, phenyl, benzyl, R3-O-CH2-, wherein R3 is selected from phenyl, phenyl linked by 1-3 carbon atoms, phenyl substituted by alkyl of 1-3 carbon atoms, halogen-substituted phenyl, allyl, or branched or straight-chain alkyl of 1-4 carbon atoms, wherein R1 and R2 have the same or different structures.

2. The method as described in claim 1, characterized in that: C1-C4 alkyl-substituted quaternary ammonium bases are selected from tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, and tetraethylammonium hydroxide; The amidine organic bases are selected from 1,8-diazobisspirocyclic [5.4.0]undec-7-ene; The alkyl-substituted or unsubstituted guanidine organic bases are selected from tetramethylguanidine, guanidine, and 1,1-dimethylguanidine; The bicyclic guanidine organic base is selected from 1,5,7-triazidobicyclo(4.4.0)dec-5-ene and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene; The aminopyridine compound is selected from 4-dimethylaminopyridine.

3. The method as described in claim 1, characterized in that: The molar ratio of the epoxide shown in formula (II) to the halogen-free catalyst shown in formula (I) is 100:0.15 to 0.

28.

4. The method as described in claim 1, characterized in that: The reaction temperature is 100–120℃, the reaction time is 6–24 h, and the initial pressure of carbon dioxide is 1–2 MPa.

5. The method as described in claim 1, characterized in that: Recovery involves lowering the reaction solution to room temperature, allowing the catalyst to flocculate and precipitate naturally, or adding ethyl acetate, filtering, and then washing and drying with ethyl acetate.

6. A method for preparing an octafunctional cage-type ion-pair catalyst, characterized in that: The method includes combining an imine-linked modified polyhedral oligomeric silsesquioxane as shown in formula (Ⅲ) with an organic base, neutralizing the mixture in the organic solvent methanol, and reacting it at room temperature.

7. The preparation method according to claim 6, characterized in that: The molar ratio of the polyhedral oligomeric silsesquioxane modified with imine bonds to the organic base is 1 to 10:

1.

8. The preparation method according to claim 6, characterized in that: The acid-base neutralization reaction in the organic solvent methanol is carried out at a temperature of 0–25°C and a reaction time of 6–24 h at room temperature.

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