Bisindole quaternary ammonium salt, method of preparation and use thereof for catalytic preparation of five-membered ring carbonates

Abstract

The present application relates to a kind of containing double indole quaternary ammonium salt, preparation method and its application in catalytic preparation of five-membered ring carbonate, the structure of containing double indole quaternary ammonium salt in containing double indole quaternary ammonium salt structure is at the end of containing double indole quaternary ammonium salt, containing alkyl chain hydrocarbon structure is connected on the nitrogen atom of indole ring of containing double indole quaternary ammonium salt;By two end halogen alkyl and indole reaction, the compound with two indole groups in end position is generated in medium chain hydrocarbon, further reaction with halogenated hydrocarbon is generated containing double indole quaternary ammonium salt;Under the condition of containing double indole quaternary ammonium salt as single catalyst, carbon dioxide and epoxy compound are reacted to obtain five-membered ring carbonate.The five-membered ring carbonate is prepared by catalysis using the present application, other cocatalyst is not needed, with the advantages of high efficiency, low cost, easy separation, catalyst raw material is easy to obtain, preparation method is simple, and catalytic efficiency is high.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of catalyst application, and particularly relates to a kind of double indole quaternary ammonium salt, a preparation method and application thereof in catalytic preparation of five-membered ring carbonates. BACKGROUND

[0002] For a long time, many researchers have been working hard for the resource utilization of CO2.According to the existing technology, the synthesis of cyclic carbonates from CO2 and epoxide compounds (as shown in Scheme 1) is one of the most typical successful examples of CO2 resource utilization. Cyclic carbonates are important industrial raw materials, which can be used as battery electrolyte, polar solvent and chemical intermediates, etc.

[0003]

[0004] Generally, the catalysts for the synthesis of five-membered ring carbonates from CO2 and epoxide compounds mainly include alkali metal and alkali metal halide catalysts, such as LiBr (Tetrahedron, 2005, 61, 1835); quaternary ammonium salt and quaternary phosphonium salt catalysts, such as molten tetrabutylammonium bromide (Organic Letters, 2002, 4(15): 2561-2563.); ionic liquid catalysts, such as 1-alkyl-3-methylimidazolium salt ([C n -min]X) (Chemical Communications, 2003, 39(7): 896-897.); metal complex catalysts, such as Salen ligand (Journal of American Chemical Society, 2001, 123(46): 11498-11499.), etc. Although the above catalysts show relatively high catalytic activity, there are still some problems. On the one hand, the above catalysts need to add other cocatalysts to participate in the reaction, and on the other hand, there are still some problems in the process of scale-up preparation, such as high synthesis cost, complex process, low scale-up catalytic efficiency, etc., which seriously restrict the industrialization process. Therefore, it is particularly important to select a new type of catalyst and reaction system with no solvent, high efficiency and low cost. SUMMARY

[0005] In order to overcome the deficiencies in the prior art, the present application provides a kind of double indole quaternary ammonium salt, a preparation method and application thereof in catalytic preparation of five-membered ring carbonates. When the double indole quaternary ammonium salt is used to catalyze the preparation of five-membered ring carbonates, it not only has the advantages of high efficiency and low cost, but also does not need to add other cocatalysts.

[0006] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0007] A kind of double indole quaternary ammonium salt, the structural formula of the double indole quaternary ammonium salt is as shown in (I) :

[0008]

[0009] Wherein R1, R2 are CH3, CH3CH2, CH3CH2CH2, (CH3)2CH, CH3CH2CH2CH2, (CH3)3C group one of, R1, R2 can be same, also can be different;N indicates the number of identical unit carbon, n=1~12;X1, X2 respectively indicate one of fluorine, chlorine, bromine, iodine, X1, X2 can be same, also can be different.

[0010] The structure of the double indole quaternary ammonium salt in the double indole quaternary ammonium salt is at the end of the double indole quaternary ammonium salt, and the alkyl chain structure is connected to the nitrogen atom on the indole ring of the double indole quaternary ammonium salt.

[0011] The structural formula of the double indole quaternary ammonium salt is one of (I-a), (I-b), (I-c), (I-d), (I-e) :

[0012]

[0013] The application also provides a preparation method of the above-mentioned double indole quaternary ammonium salt, wherein an indole derivative and dry acetonitrile are added to a reaction bottle, haloalkane is added dropwise, after the dropwise addition is completed, the reaction mixture is raised to reflux, after the reaction is completed, the solvent is rotary dried, and the product is recrystallized by ethanol to obtain the double indole quaternary ammonium salt.

[0014] The indole derivative is one or a combination of two of compounds with structural formula (II) or structural formula (II) :

[0015]

[0016] The haloalkane is one of 1,2-dibromoethane, 1,3-dichloropropane, 1-bromo-3-chloropropane and 1,5-diiodopentane.

[0017] The compound with two indole groups at the end of the medium-chain alkyl is generated by reacting the haloalkyl at both ends with the indole derivative, and the double indole quaternary ammonium salt is further generated by reacting the compound with haloalkane.

[0018] Preferably, the molar ratio of the indole derivative to haloalkane is 1-3:1.

[0019] In addition, the application also provides the application of the above-mentioned double indole quaternary ammonium salt in catalytic preparation of five-membered ring carbonates, and under the condition that the double indole quaternary ammonium salt is used as a single catalyst, carbon dioxide and an epoxide compound are reacted to prepare a five-membered ring carbonate.

[0020] As a preference, the amount of the bis-indole quaternary ammonium salt is 0.01-10% of the mass of the epoxide compound; more preferably, the amount of the bis-indole quaternary ammonium salt is 0.5-2% of the mass of the epoxide compound.

[0021] As a preference, the reaction temperature is 60-200℃, the reaction pressure is 1-30 MPa, and the reaction time is 1-72 h; more preferably, the reaction temperature is 100-150℃, the reaction pressure is 10-20 MPa, and the reaction time is 6-10 h.

[0022] As a preference, the bis-indole quaternary ammonium salt is one of 1,1'-(ethane-1,2-diyl)bis(1-methyl-1H-indol-1-bromide quaternary ammonium salt), 1,1'-(propane-1,3-diyl)bis(1-ethyl-1H-indol-1-chloride quaternary ammonium salt), 1-ethyl-1-(3-(1-methyl-1H-indol-1-bromide quaternary ammonium salt-1-yl)propyl)-1H-indol-1-chloride quaternary ammonium salt, 1,1'-(pentane-1,5-diyl)bis(1-methyl-1H-indol-1-iodide quaternary ammonium salt), and 1-butyl-1-(5-(1-methyl-1H-indol-1-quaternary ammonium salt-1-yl)pentyl)-1H-indol-1-iodide quaternary ammonium salt.

[0023] As a preference, the epoxide compound is one of oxirane, propylene oxide, epichlorohydrin, di-4-epoxycyclohexane, 2,3-epoxybutane, 2-phenylpropylene oxide, epoxidized soybean oil, and 1,4-butanediol diglycidyl ether.

[0024] The reaction mechanism of the present application for catalyzing the epoxide compound to prepare a five-membered ring carbonate product with the bis-indole quaternary ammonium salt is as follows (formula a):

[0025]

[0026] Compared with the prior art, the present application has the following advantages:

[0027] The present application has the advantages of high efficiency, low cost, easy separation, easy availability of the catalyst raw material, simple preparation method, and high catalytic efficiency. DETAILED DESCRIPTION

[0028] The present application is further described below in conjunction with specific examples, but the scope of the present application is not limited thereto. Any simple change or replacement based on the essential spirit of the present application should be within the scope of the present application.

[0029] The experimental methods described in the examples are all conventional methods unless otherwise specified; the percentages involved are all mass percentages unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0030] Example 1

[0031] Preparation of catalyst 1,1'-(propane-1,3-diyl)bis(1-ethyl-1H-indol-1-ium chloride)

[0032] In a reaction flask, 1-ethyl-1H-indole (29.4 g, 50.0 mmol) and 50 mL of dry acetonitrile were added, and 1,3-dichloropropane (5.65 g, 25.0 mmol) was added dropwise. After the dropwise addition was completed, the reaction mixture was brought to reflux and reacted for 6 h. After the reaction was completed, the solvent was evaporated, and the product was recrystallized from ethanol to obtain 1,1'-(propane-1,3-diyl)bis(1-ethyl-1H-indol-1-ium chloride) 17.5 g, with a yield of 87.0% and a purity of 98.3%.

[0033] The catalyst is 1,1'-(propane-1,3-diyl)bis(1-ethyl-1H-indol-1-ium chloride) with the following structure:

[0034]

[0035] Its nuclear magnetic resonance and mass spectrometry data are as follows:

[0036] 1 H NMR (400 MHz, CDCl3): δ 7.42-7.68 (4H, m), 6.88 (1H, d), 5.29 (1H, d), 3.34 (2H, t), 3.04 (2H, t), 2.77 (1H, m), 1.57 (3H, t); 13 C NMR (100 MHz, CDCl3): δ 139.7, 135.9, 134.4, 129.2, 126.6, 124.1, 119.1, 61.5, 56.2, 17.1, 6.8. MS: m / z [M]+332.5, theoretical value: 332.5.

[0037] Catalytic preparation of five-membered ring carbonates

[0038]

[0039] Put 0.1 g of catalyst 1,1'-(propane-1,3-diyl)bis(1-ethyl-1H-indol-1-ium chloride) into a stainless steel autoclave, back and forth with nitrogen / carbon dioxide for three times, then add 1,4-butanediol diglycidyl ether 100 g into the reactor, the system pressure is maintained at 2 MPa, open the stirring. The reactor temperature is raised to 100℃, and keep stirring for 5 h, stop the reaction, cool to room temperature. The product 142.42 g is collected, the yield is 99.3%, the purity is 98.9%. The product is characterized by nuclear magnetic resonance data: 1 H NMR (400 MHz, CDCl3): δ 4.81~4.79 (2H, m), 4.50~4.37 (4H, m), 3.70~3.56 (4H, m), 3.52 (4H, m), 1.65 (4H, m); 13C NMR (100 MHz, CDCl3): δ 155.3, 79.48, 75.39, 71.50, 70.46, 66.28, 43.54, 23.04, 7.65.

[0040] Example 2

[0041] Catalytic preparation of five-membered ring carbonate

[0042]

[0043] Put 0.2 g of catalyst 1,1'-(propane-1,3-diyl)bis(1-ethyl-1H-indol-1-ium chloride) into a stainless steel autoclave, back and forth with nitrogen / carbon dioxide for three times, then add 1,4-butanediol diglycidyl ether 100 g into the reactor, the system pressure is maintained at 2 MPa, open the stirring. The reactor temperature is raised to 100℃, and keep stirring for 5 h, stop the reaction, cool to room temperature. The product 142.42 g is collected, the yield is 99.3%, the purity is 98.9%. The product is characterized by nuclear magnetic resonance data: 1 H NMR (DMSO-d6, 300 MHz), δ 4.49 (s, 4H); 13 C NMR (100 MHz, CDCl3): δ 64.6, 155.5.

[0044] Example 3

[0045] Preparation of catalyst 1-butyl-1-(5-(1-methyl-1H-indol-1-ium-1-yl)pentyl)-1H-indol-1-ium iodide

[0046] In a reaction flask was added 1-butyl-1H-indole (4.33 g, 25.0 mmol), 1-methyl-1H-indole (3.28 g, 25.0 mmol) and 50 mL of dry acetonitrile, 1,5-diiodopentane (8.07 g, 25.0 mmol) was added dropwise, after the dropwise addition was completed, the reaction mixture was brought to reflux and reacted for 6 h. After the reaction was completed, the solvent was evaporated, and the product was recrystallized from ethanol to obtain 1-butyl-1-(5-(1-methyl-1H-indol-1-ium-1-yl)pentyl)-1H-indol-1-ium iodide 4.71 g, yield 30.0%, purity 98.5%.

[0047] The catalyst is 1-butyl-1-(5-(1-methyl-1H-indol-1-ium-1-yl)pentyl)-1H-indol-1-ium iodide, the structure is as follows:

[0048]

[0049] Its nuclear magnetic resonance and mass spectrometry data are as follows:

[0050] 1 H NMR (400 MHz, CDCl3): δ 7.50-7.63 (4H, m), 7.34-7.47 (4H, m), 6.95-6.93 (2H, m), 5.31-5.28 (2H, m), 3.36 (2H, t), 3.34 (2H, t), 3.24 (2H, t), 3.16 (3H, s), 1.32-1.40 (4H, m), 1.01 (3H, t); 13 C NMR (100 MHz, CDCl3): δ 143.3, 142.7, 140.3, 135.2, 134.0, 132.4, 130.1, 129.7, 128.9, 126.0, 124.8, 122.5, 59.2, 54.3, 40.4, 39.4, 28.6, 24.7, 23.2, 16.2, 13.1. MS: m / z [M] + 628.4, Theoretical value: 628.4.

[0051] Catalytic preparation of five-membered ring carbonates

[0052]

[0053] Put 2.0 g of catalyst 1-butyl-1-(5-(1-methyl-1H-indol-1-ium-1-yl)pentyl)-1H-indol-1-ium iodide into a stainless steel autoclave, back and forth replace three times with nitrogen / carbon dioxide, then add 100 g of 2-phenyl glycidol to the reactor, maintain the system pressure at 13 MPa, open the stirring. The reactor temperature is raised to 110°C, and keep stirring for 10 h, stop the reaction, cool to room temperature. The product 4-methyl-4-phenyl-1,3-dioxolan-2-one 130.8 g is collected, yield 98.5%, purity 99.1%. The product is characterized by NMR data: 1 H NMR (400 MHz, CDCl3) δ 7.43-7.39 (m, 2H), 7.37-7.33 (m, 3H), 4.48 (s, 2H), 1.83 (s, 3H); 13 C NMR (100 MHz, CDCl3) δ 154.3, 141.0, 128.9, 128.5, 123.8, 84.1, 76.2, 27.2.

[0054] Example 4

[0055] Preparation of catalyst 1,1'-(ethane-1,2-diyl)bis(1-methyl-1H-indol-1-ium bromide)

[0056] In the reaction bottle, add 1-methyl-1H-indole (13.1 g, 50.0 mmol) and 50 mL of dry acetonitrile, drop 1,2-dibromoethane (4.7 g, 25.0 mmol), after dropping, the reaction mixture is raised to reflux for 6 h. After the reaction is completed, the solvent is dried, and the product is recrystallized with ethanol to obtain 1,1'-(ethane-1,2-diyl)bis(1-methyl-1H-indol-1-ium bromide) 9.6 g, yield 85.1%, purity 98.6%.

[0057] The catalyst is 1,1'-(ethane-1,2-diyl)bis(1-methyl-1H-indol-1-ium bromide) with the following structure:

[0058]

[0059] Its NMR and mass spectral data:

[0060] 1 H NMR (400 MHz, CDCl3): δ 7.37-7.62 (4H, m), 6.86 (1H, d), 5.31 (1H, d), 4.02 (2H, t), 2.93 (3H, s); 13C NMR (100 MHz, CDC13): δ 140.2, 135.9, 135.2, 134.0, 129.5, 126.0, 124.3, 118.7, 61.3, 45.1. MS: m / z [M]+450.2, calcd 450.2.

[0061]

[0062] A 0.3 g of catalyst 1,1 '-(ethane-1,2-diyl)bis(1 -methyl-1 H-indol-1 -bromide quaternary ammonium salt) was put into a stainless steel autoclave, back and forth replaced three times with nitrogen / carbon dioxide, then 100 g of epoxidized soybean oil (ESBO) was added into the reactor, the system pressure was maintained at 3 MPa, and the stirring was started. The reactor temperature was raised to 120 °C, and the stirring was kept for 6 h, the reaction was stopped, and the reactor was cooled to room temperature. The product, five-membered ring carbonate CSBO, was collected as 116.61 g with a yield of 98.7%. The product IR spectrum showed that the CO stretching vibration peak in CSBO appeared at 1812 cm -1 -1. The chemical shift of the epoxy signal in the raw material and product NMR spectra was smaller at δ 2.20-3.15, while the signal of the cyclic carbonate was stronger at δ 4.15-4.20.

[0063] Example 5

[0064] Preparation of catalyst 1 -ethyl-1 -(3-(1 -methyl-1 H-indol-1 -bromide quaternary ammonium salt-1 -yl)propyl)-1 H-indol-1 -bromide quaternary ammonium salt

[0065] A reaction bottle was charged with 1 -ethyl-1 H-indole (7.26 g, 50.0 mmol), 1 -methyl-1 H-indole (6.56 g, 50.0 mmol) and 50 mL of dry acetonitrile, and 1 -bromo-3-chloropropane (7.87 g, 50.0 mmol) was added dropwise. After the dropwise addition was completed, the reaction mixture was raised to reflux and reacted for 6 h. After the reaction was completed, the solvent was evaporated, and the product was recrystallized from ethanol to obtain 1 -ethyl-1 -(3-(1 -methyl-1 H-indol-1 -bromide quaternary ammonium salt-1 -yl)propyl)-1 H-indol-1 -bromide quaternary ammonium salt 6.94 g with a yield of 32.0% and a purity of 98.3%.

[0066] The catalyst was 1 -ethyl-1 -(3-(1 -methyl-1 H-indol-1 -bromide quaternary ammonium salt-1 -yl)propyl)-1 H-indol-1 -bromide quaternary ammonium salt, which had the following structure:

[0067]

[0068] Its NMR and mass spectral data were as follows:

[0069] 1H NMR (400 MHz, CDC13): δ 7.52 ~ 7.68 (4H, m), 7.32 ~ 7.48 (4H, m), 6.94 (1H, d), 6.89 (1H, d), 5.31 ~ 5.28 (2H, d), 3.38 (2H, t), 3.35 (2H, t), 3.21 (2H, q), 3.18 (3H, s), 2.83 (2H, m), 1.57 (3H, t); 13 CNMR (100 MHz, CDC13): δ 141.8, 140.2, 135.6, 134.0, 130.5, 129.7, 128.8, 128.7, 128.6, 124.8, 122.5, 121.3, 121.0, 119.5, 118.6, 61.3, 55.7, 39.4, 19.1, 6.2. MS: m / z [M] + 433.8, Theoretical value: 433.8.

[0070] Catalytic preparation of five-membered ring carbonates

[0071] 0.1 g of catalyst 1-ethyl-1-(3-(1-methyl-1H-indol-1-ium-1-yl)propyl)-1H-indol-1-ium chloride was placed in a stainless steel autoclave, and was back and forth replaced with nitrogen / carbon dioxide for three times, then di-4-epoxycyclohexane 100 g was added into the reactor, the system pressure was maintained at 20 MPa, and the stirring was started. The reactor temperature was raised to 100 °C, and the stirring was maintained for 9 h, then the reaction was stopped, and the reactor was cooled to room temperature. The product 142.7 g was collected, the yield was 98.5%, and the purity was 99.1%.

[0072] Example 6

[0073] Preparation of catalyst 1,1'-(pentane-1,5-diyl)bis(1-methyl-1H-indol-1-ium iodide)

[0074] 1-methyl-1H-indole (6.56 g, 50.0 mmol) and 50 mL dry acetonitrile were added into a reaction bottle, and 1,5-diiodopentane (8.07 g, 25.0 mmol) was added dropwise, after the dropping was completed, the reaction mixture was raised to reflux for 6 h. After the reaction was completed, the solvent was dried, and the product was recrystallized with ethanol to obtain 1,1'-(pentane-1,5-diyl)bis(1-methyl-1H-indol-1-ium iodide) 11.43 g, the yield was 78.0%, and the purity was 98.7%.

[0075] The catalyst is 1,1'-(pentane-1,5-diyl)bis(1-methyl-1H-indol-1-ium iodide), and the structure is as follows:

[0076]

[0077] Its NMR and mass spectral data:

[0078] 1 H NMR (400 MHz, CDC13): δ 7.40 ~ 7.65 (4H, m), 6.83 (1H, d), 5.34 (1H, d), 3.36 (3H, s), 3.30 (2H, t), 2.12 (2H, m), 1.29 (1H, m); 13 C NMR (100 MHz, CDC13): δ 143.4, 142.6, 132.7, 130.5, 129.1, 124.4, 119.3, 59.5, 40.2, 24.7, 22. MS: m / z [M] + 586.3, Theoretical value: 586.3.

[0079] Catalytic preparation of five-membered ring carbonates

[0080] Put 1.0 g of catalyst 1,1'-(pentane-1,5-diyl) bis(1-methyl-1H-indol-1-ium iodide) into a stainless steel autoclave, back and forth with nitrogen / carbon dioxide for three times, then 2,3-epoxybutane 100 g is added to the reactor, the system pressure is maintained at 15 MPa, and the stirring is started. The temperature of the reactor is raised to 150°C, and the stirring is maintained for 6 h, the reaction is stopped, and the temperature is cooled to room temperature. The product 159.6 g is collected, the yield is 99.1%, and the purity is 99.2%.

[0081] Example 7

[0082] Put 0.1 g of catalyst 1,1'-(ethane-1,2-diyl) bis(1-methyl-1H-indol-1-ium bromide) into a stainless steel autoclave, back and forth with nitrogen / carbon dioxide for three times, then propylene oxide 20 g is added to the reactor, the system pressure is maintained at 10 MPa, and the stirring is started. The temperature of the reactor is raised to 120°C, and the stirring is maintained for 8 h, the reaction is stopped, and the temperature is cooled to room temperature. The product 17.26 g is collected, the yield is 98.2%, and the purity is 99.2%.

[0083] Example 8

[0084] Put 0.5 g of catalyst 1,1'-(propane-1,3-diyl) bis(1-ethyl-1H-indol-1-ium chloride) into a stainless steel autoclave, back and forth with nitrogen / carbon dioxide for three times, then epichlorohydrin 100 g is added to the reactor, the system pressure is maintained at 10 MPa, and the stirring is started. The temperature of the reactor is raised to 120°C, and the stirring is maintained for 8 h, the reaction is stopped, and the temperature is cooled to room temperature. The product 15.3 g is collected, the yield is 98.1%, and the purity is 98.7%.

[0085] Finally, it should be noted that the above examples are only used to illustrate but not to limit the technical solutions of the present application. Although the present application is described in detail with reference to the above examples, those skilled in the art should understand that the present application can still be modified or equivalently replaced without departing from the spirit and scope of the present application, and any modification or partial replacement should be covered in the scope of claims of the present application.

Claims

1. A bisindole quaternary ammonium salt, characterized in that: The structure of the double indole quaternary ammonium salt is shown as (I): ； Wherein R1, R2 are one of CH3, CH3CH2, CH3CH2CH2, (CH3)2CH, CH3CH2CH2CH2, (CH3)3C groups; n represents the number of the same unit carbon, n=1~12; X1, X2 respectively represent one of fluorine, chlorine, bromine, iodine.

2. The bisindole quaternary ammonium salt of claim 1, wherein: The structure of the double indole quaternary ammonium salt is one of (I-a), (I-b), (I-c), (I-d), (I-e): ； ； ； ； 。 3. A process for the preparation of a bisindole quaternary ammonium salt according to claim 1, characterized in that: In the reaction bottle, add indole derivatives and dry acetonitrile, drop halogenated alkane, drop, the reaction mixture is raised to reflux reaction; reaction is completed, spin dry solvent, the product is recrystallized by ethanol to obtain; Wherein, the indole derivative is one or two combinations of compounds with structural formula (II) or structural formula (III): 。 4. The method of claim 3, wherein the bisindole quaternary ammonium salt is prepared by the reaction of a bisindole with a quaternary ammonium salt. The halogenated alkane is one of 1,2-dibromoethane, 1,3-dichloropropane, 1-bromo-3-chloropropane, 1,5-diiodopentane.

5. The method of claim 3, wherein the bisindole quaternary ammonium salt is prepared by the reaction of a bisindole with a quaternary ammonium salt. The molar ratio of indole derivatives to halogenated alkane is 1~3:

1.

6. Use of a bisindole quaternary ammonium salt catalyst according to claim 1 for the catalytic preparation of a five-membered ring carbonate, characterized by: Under the condition of using double indole quaternary ammonium salt as single catalyst, carbon dioxide and epoxy compound are reacted to prepare five-membered ring carbonate.

7. Use of a bisindole quaternary ammonium salt catalyst according to claim 6 for the preparation of five-membered ring carbonates, characterized in that: The amount of double indole quaternary ammonium salt is 0.01~10% of the mass of epoxy compound.

8. Use of a bisindole quaternary ammonium salt catalyst according to claim 6 for the preparation of five-membered ring carbonates, characterized in that: The reaction temperature is 60~200 DEG C, the reaction pressure is 1~30 MPa, and the reaction time is 1~72 h.

9. Use of a bisindole quaternary ammonium salt catalyst according to claim 6 for the preparation of five-membered ring carbonates, characterized in that: The double indole quaternary ammonium salt is one of 1,1'-(ethane-1,2-diyl) bis(1-methyl-1H-indol-1-bromide quaternary ammonium salt), 1,1'-(propane-1,3-diyl) bis(1-ethyl-1H-indol-1-chloride quaternary ammonium salt), 1-ethyl-1-(3-(1-methyl-1H-indol-1-bromide quaternary ammonium salt-1-yl) propyl)-1H-indol-1-chloride quaternary ammonium salt, 1,1'-(pentane-1,5-diyl) bis(1-methyl-1H-indol-1-iodide quaternary ammonium salt), 1-butyl-1-(5-(1-methyl-1H-indol-1-quaternary ammonium salt-1-yl) pentyl)-1H-indol-1-iodide quaternary ammonium salt.

10. Use of a bisindole quaternary ammonium salt catalyst according to claim 6 for the preparation of five-membered ring carbonates, characterized in that: The epoxy compound is one of oxirane, propylene oxide, epichlorohydrin, di-4-epoxycyclohexane, 2,3-epoxybutane, 2-phenyl propylene oxide, epoxidized soybean oil, 1,4-butanediol diglycidyl ether.

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