A heterogeneous catalyst, its preparation method and use thereof

Abstract

The application discloses a kind of heterogeneous catalyst and its preparation method and application, chitosan and aldehyde are stirred in ethanol solution, after cooling, reduced pressure suction filtration, and chitosan schiff base ligand is obtained by drying;Chitosan schiff base ligand is dispersed with coordination metal ion in anhydrous ethanol and stirred, the mixture is suction filtered, and catalyst is obtained;Catalyst is stirred with Lewis acid or counterion in dichloromethane solution, and heterogeneous catalyst is obtained.The catalyst obtained by the application can improve the stability and recyclability of the catalyst while maintaining catalytic activity.The catalyst obtained by this method can effectively solve the problems of low metal loading, poor catalyst stability and recyclability in the chiral resolution of epichlorohydrin under mild conditions.

Description

Technical Field

[0001] This invention belongs to the field of organic chemical synthesis and catalysis technology, specifically relating to a heterogeneous catalyst, its preparation method, and its application. Background Technology

[0002] Epichlorohydrin is an important organic synthesis intermediate with wide applications in pharmaceuticals, pesticides, and chemicals. Because the two enantiomers of epichlorohydrin differ significantly in pharmacological effects and biological activities, developing an efficient and environmentally friendly chiral resolution technique is crucial for the synthesis of chiral epichlorohydrin.

[0003] Currently, the main method for synthesizing chiral epichlorohydrin is through the hydrolytic kinetic resolution of racemic epichlorohydrin using Salen metal catalysts. To address the problems of poor stability, difficult recovery, high cost, and environmental pollution associated with traditional chiral epichlorohydrin resolution methods, researchers have recently developed a series of chitosan-Schiff base catalysts and their preparation methods, such as direct adsorption loading and cross-linked chitosan loading, primarily for catalyzing olefin polymerization reactions. However, these catalysts suffer from low metal loading, poor stability, and poor recyclability, which limits their industrial application to some extent.

[0004] With industrial development and increasing environmental awareness, the demand for efficient and environmentally friendly catalytic technologies is growing. Chitosan, a natural polysaccharide, contains a large number of -OH and -NH2 groups in its molecule, making it easy to coordinate with metal ions or undergo surface modification. Furthermore, it possesses good biocompatibility, biodegradability, and abundant active groups, making it an ideal catalyst support. Therefore, developing a novel CS-Schiff base-based heterogeneous metal catalyst to address the aforementioned issues has significant scientific and practical value. 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] One objective of this invention is to provide a method for preparing a heterogeneous catalyst by first forming a chitosan-Schiff base ligand with an aldehyde, and then coordinating it with metal ions to achieve metal immobilization. This catalyst can maintain catalytic activity while improving its stability and recyclability, and also reducing its environmental impact. This method provides a new and effective solution for chiral resolution.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a heterogeneous catalyst, comprising, including,

[0009] A certain amount of chitosan and aldehyde were stirred and refluxed in an ethanol solution for 5-12 hours. After cooling, the mixture was filtered under reduced pressure. The filter cake was washed with dichloromethane and methanol, respectively, and dried to obtain chitosan Schiff base ligand.

[0010] Chitosan Schiff base ligands and coordinating metal ions were dispersed in anhydrous ethanol and stirred under reflux for 5-10 hours. The mixture was then filtered to obtain the catalyst.

[0011] The catalyst was reacted with Lewis acid or counterion in dichloromethane solution by stirring for 4-6 hours. After the reaction was completed, the mixture was filtered to obtain a heterogeneous catalyst.

[0012] In a preferred embodiment of the preparation method of the heterogeneous catalyst of the present invention, the degree of deacetylation of the chitosan is ≥90%; and the mass ratio of the aldehyde to the chitosan is 1:2~5.

[0013] In a preferred embodiment of the preparation method of the heterogeneous catalyst of the present invention, the coordinating metal ion includes one of cobalt acetate, cobalt acetate tetrahydrate, aluminum acetate, iron acetate, zinc acetate, manganese acetate, nickel acetate, etc.; the molar ratio of the chitosan Schiff base ligand to the coordinating metal ion is 1:0.1~1.

[0014] In a preferred embodiment of the method for preparing the heterogeneous catalyst of the present invention, the Lewis acid includes one of FeCl3, AlCl3, ZnCl2, NiCl2, MnCl2, CrCl3, and TiCl4.

[0015] The molar ratio of the catalyst to the metal ions in the Lewis acid is 1:0.001~1.

[0016] In a preferred embodiment of the method for preparing the heterogeneous catalyst of the present invention, the counterions include OTf, OTs, BF3, OAc, etc. One of CF3SO3;

[0017] The molar ratio of the catalyst to the counter ion is 1:1 to 2.5.

[0018] Another object of the present invention is to provide a heterogeneous catalyst obtained by the preparation method described in any of the preceding claims. This catalyst can improve catalyst stability and recyclability while maintaining catalytic activity. The catalyst obtained by this method can be used for the chiral resolution of epichlorohydrin under mild conditions, effectively solving problems such as low metal loading, poor catalyst stability, and poor recyclability.

[0019] Another object of the present invention is to provide a method for the chiral resolution of epichlorohydrin using heterogeneous catalysts as described above, comprising,

[0020] Epichlorohydrin, a heterogeneous catalyst, and a solvent were mixed and chiral separation was performed at room temperature and pressure.

[0021] The reaction process is as follows:

[0022] .

[0023] As a preferred embodiment of the method for chiral resolution of epichlorohydrin using the heterogeneous catalyst of the present invention, the product is separated by vacuum distillation after the reaction is completed, and the heterogeneous catalyst is recovered.

[0024] The recovered heterogeneous catalyst does not require activation and can be used directly in subsequent reactions.

[0025] As a preferred embodiment of the method for chiral resolution of epichlorohydrin using the heterogeneous catalyst of the present invention, wherein the molar ratio of epichlorohydrin to the heterogeneous catalyst is 10000~1000000:1.

[0026] As a preferred embodiment of the method for chiral resolution of epichlorohydrin using heterogeneous catalyst of the present invention, wherein the solvent is one or two of water and tetrahydrofuran;

[0027] The chiral separation is performed at a reaction temperature of 25-30°C for 6-50 hours.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention achieves metal immobilization by first forming a chitosan-Schiff base ligand with an aldehyde and then coordinating it with metal ions. This catalyst maintains catalytic activity while improving its stability and recyclability. The catalyst obtained through this method, used for the chiral resolution of epichlorohydrin under mild conditions, effectively solves problems such as low metal loading, poor catalyst stability, and poor recyclability. 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 The infrared spectrum of the chitosan Schiff base ligand prepared in Example 1 of this invention;

[0032] Figure 2 The image shows the infrared spectrum of the solid CS-Schiff bimetallic heterogeneous catalyst prepared in Example 1 of this invention. Detailed Implementation

[0033] 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.

[0034] 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.

[0035] 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.

[0036] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0037] Example 1

[0038] Preparation of catalyst A1:

[0039] (1) Chitosan (1g) and phthalaldehyde (1.50ml) were added to a 50ml three-necked flask and stirred and refluxed in 20ml ethanol solution for 8h. After the solution was cooled, the filter cake was obtained by suction filtration. The filter cake was washed with dichloromethane and methanol respectively, and dried to obtain 1.20g of yellow ligand (L1).

[0040] (2) Add L1 ligand and cobalt acetate tetrahydrate (1.50 g) to a 50 ml three-necked flask, and stir and reflux in 3 ml anhydrous ethanol for 8 h. Filter the mixture to obtain a brown catalyst (a1);

[0041] The prepared catalyst (a1) was reacted with AlCl3 in dichloromethane and stirred for 4 h. After the reaction was completed, the mixture was filtered to obtain the solid CS-Schiff bimetallic heterogeneous catalyst A1. Yield: 75%.

[0042] Figure 1 The infrared spectrum of the prepared chitosan Schiff base ligand L1; from Figure 1 The characteristic absorption peaks of chitosan Schiff base ligands can be seen in the data, indicating the formation of chitosan Schiff base ligand products. Figure 2 The infrared spectrum of the prepared solid CS-Schiff bimetallic heterogeneous catalyst A1; from Figure 2 It can be seen that the characteristic absorption peaks of the CS-Schiff bimetallic heterogeneous catalyst were generated, that is, the product of the CS-Schiff bimetallic heterogeneous catalyst was generated.

[0043] Applications of catalyst A1:

[0044] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), catalyst A1 (88 mg), and distilled water (1 ml) were added separately. The mixture was stirred at room temperature and pressure for 24 h to achieve chiral resolution. After the reaction was complete, the products were separated by vacuum distillation, and the catalyst was filtered for recovery. The chiral resolution effect of catalyst A1 in epichlorohydrin is shown in Table 1.

[0045] Table 1. Chiral resolution effect of catalyst A1 in epichlorohydrin

[0046] A1 67.3 48.9

[0047] Example 2

[0048] In Example 2, based on Example 1, o-phthalaldehyde was replaced with isophthalaldehyde and 4-tert-butyl-2,6-dicarboxyphenol, respectively, while other conditions remained the same as in Example 1, resulting in catalysts B1 and C1.

[0049] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), catalyst B1 or C1 (88 mg), and distilled water (1 ml) were added separately. The mixture was stirred at room temperature and pressure for 24 h to achieve chiral resolution. After the reaction was complete, the product was separated by vacuum distillation, and the catalyst was filtered for recovery. The effects of different catalyst structures on the chiral resolution of epichlorohydrin are shown in Table 2.

[0050] Table 2. Effect of catalysts with different structures on the chiral resolution of epichlorohydrin

[0051] A1 67.3 48.9 B1 36.2 27.8 C1 42.9 25.6

[0052] Table 2 shows that catalyst A1 exhibits the best resolution effect in the epichlorohydrin resolution. This may be because catalyst A1 is synthesized from phthalaldehyde and chitosan. Phthalate, with its two aldehyde groups in the ortho position, can better bind to the amino groups of chitosan, forming a stable intermediate. This improves the stability of the ligand, which is beneficial for the chiral resolution of epichlorohydrin, thus enhancing the selectivity of the reaction.

[0053] Example 3

[0054] In Example 3, based on Example 1, cobalt acetate tetrahydrate was replaced with aluminum acetate, ferric acetate, and manganese acetate, respectively, while other conditions remained the same as in Example 1, resulting in catalysts D1, E1, and F1.

[0055] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), catalyst D1 or E1, F1 (88 mg), and distilled water (1 ml) were added separately. The mixture was stirred at room temperature and pressure for 24 h to achieve chiral resolution. After the reaction was complete, the products were separated by vacuum distillation, and the catalyst was filtered for recovery. The effects of different metal catalysts on the chiral resolution of epichlorohydrin are shown in Table 3.

[0056] Table 3. Effects of Salen's different metal catalysts on the chiral resolution of epichlorohydrin

[0057] A1 67.3 48.9 D1 53.2 38.7 E1 42.7 27.9 F1 34.1 19.6

[0058] As shown in Table 3, the catalyst containing cobalt metal has the best resolution effect. This may be because the special structure of cobalt can form a stable chelate ring with Salen ligand, which is conducive to the formation of a stable intermediate, thereby promoting the resolution of epichlorohydrin.

[0059] Example 4

[0060] In Example 4, AlCl3 was replaced with FeCl3, ZnCl2, and SnCl4 respectively, while other conditions remained the same as in Example 1, resulting in catalysts H1, I1, and J1 respectively.

[0061] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), catalyst H1, I1 or J1 (88 mg), and distilled water (1 ml) were added separately. The mixture was stirred at room temperature and pressure for 24 h to achieve chiral resolution. After the reaction was complete, the product was separated by vacuum distillation, and the catalyst was filtered for recovery. The effects of different Lewis acids on the chiral resolution of epichlorohydrin are shown in Table 4.

[0062] Table 4. Effects of different Lewis acids on the chiral resolution of epichlorohydrin

[0063] A1 67.3 48.9 H1 49.8 31.2 I1 37.6 21.6 J1 45.7 27.5

[0064] Table 4 shows that the bimetallic catalyst synthesized from AlCl3 and chitosan exhibits the best performance in chiral resolution. This may be because the addition of AlCl3 helps improve the catalyst's stability, thereby enhancing the reaction's selectivity.

[0065] Example 5

[0066] This Example 5 is based on Example 1, with the catalyst preparation conditions remaining the same as in Example 1.

[0067] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), different amounts of catalyst, and 1 ml of distilled water were added separately. The mixture was stirred for 24 h at room temperature and pressure to achieve chiral resolution. After the reaction was complete, the products were separated by vacuum distillation, and the catalyst was filtered for recovery. The effect of different catalyst amounts on the chiral resolution of epichlorohydrin is shown in Table 5.

[0068] Table 5. Effect of different catalyst dosages on the chiral resolution of epichlorohydrin

[0069] 1 65 53.7 29.6 2 88 67.3 48.9 3 120 42.6 23.8

[0070] Table 5 shows that the catalytic effect is optimal when the catalyst dosage reaches 88 mg. Beyond this dosage, the catalytic effect decreases. This indicates that under certain reaction conditions, increasing the catalyst dosage can accelerate the reaction rate and improve selectivity and conversion. However, exceeding a certain catalyst dosage leads to a decrease in reaction rate, an increase in byproducts, and consequently affects selectivity.

[0071] Example 6

[0072] This Example 6 is based on Example 1, with the catalyst preparation conditions remaining the same as in Example 1.

[0073] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), catalyst A1 (88 mg), and distilled water (1 ml) were added separately. The mixtures were reacted at different temperatures and stirred for 24 h to achieve chiral resolution. After the reaction, the products were separated by vacuum distillation, and the catalyst was filtered for recovery. The effect of different reaction temperatures on the chiral resolution of epichlorohydrin is shown in Table 6.

[0074] Table 6. Effect of different reaction temperatures on the chiral resolution of epichlorohydrin

[0075] 1 5 56.7 38.6 2 25 67.3 51.9 3 40 35.3 20.6

[0076] As shown in Table 6, the catalyst exhibits the best resolution effect in epichlorohydrin at room temperature. This may be because the active sites of the catalyst can form a stable transition state with epichlorohydrin at room temperature, which improves the catalyst's stability and thus results in the best resolution effect.

[0077] Example 7

[0078] In Example 7, based on Example 1, the catalyst from the first reaction was directly filtered and recycled. Other conditions remained the same as in Example 1, and the recovered catalysts a, b, c, and d were obtained respectively.

[0079] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), recovered catalyst (88 mg), and distilled water (1 ml) were added separately. The mixture was stirred at room temperature and pressure for 24 h to achieve chiral resolution. After the reaction, the product was separated by vacuum distillation, and the catalyst was recovered and used in the next round of epichlorohydrin chiral resolution experiments. The first recovered catalyst was named catalyst a, the second recovered catalyst was named catalyst b, and so on. The effect of the recovered catalyst on the chiral resolution of epichlorohydrin is shown in Table 7.

[0080] Table 7. Effect of catalyst recovery on chiral resolution of epichlorohydrin

[0081] A1 67.3 51.9 a 59.8 45.6 b 51.5 38.9 c 32.7 19.7 d 27.8 12.6

[0082] As shown in Table 7, the recovered catalyst still retains activity and selectivity after four cycles, indicating that the catalyst can be recycled and reused.

[0083] Example 8

[0084] Preparation of catalyst A2:

[0085] (1) Chitosan (1g) and phthalaldehyde (1.50g) were added to a 50ml three-necked flask and stirred and refluxed in 20ml ethanol solution for 8h. After the solution was cooled, the filter cake was obtained by suction filtration. The filter cake was washed with dichloromethane and methanol respectively, and dried to obtain 1.20g of yellow ligand (L1).

[0086] (2) L1 ligand and cobalt acetate tetrahydrate (1.50 g) were added to a 50 ml three-necked flask and stirred under reflux in 3 ml anhydrous ethanol for 8 h. The mixture was then filtered to obtain a brown catalyst (a2). The prepared catalyst (a2) was reacted with trifluoromethanesulfonic acid in dichloromethane and stirred for 4 h. After the reaction was completed, the mixture was filtered to obtain solid CS-Schiff alkali metal catalyst A2. Yield: 75%.

[0087] Applications of catalyst A2:

[0088] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), catalyst A2 (88 mg), and distilled water (1 ml) were added separately. The mixture was stirred at room temperature and pressure for 36 h to achieve chiral resolution. After the reaction was complete, the products were separated by vacuum distillation, and the catalyst was filtered for recovery. The chiral resolution effect of catalyst A2 in epichlorohydrin is shown in Table 8.

[0089] Table 8. Chiral resolution effect of catalyst A2 in epichlorohydrin

[0090] A2 60.0 48.5

[0091] Example 9

[0092] In Example 9, based on Example 8, o-phthalaldehyde was replaced with isophthalaldehyde and 4-tert-butyl-2,6-dicarboxyphenol, respectively, while other conditions remained the same as in Example 8, resulting in catalysts B2 and C2.

[0093] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), catalyst B2 or C2 (88 mg), and distilled water (1 ml) were added separately. The mixture was stirred at room temperature and pressure for 36 h to achieve chiral resolution. After the reaction, the product was separated by vacuum distillation, and the catalyst was filtered for recovery. The effects of different catalyst structures on the chiral resolution of epichlorohydrin are shown in Table 9.

[0094] Table 9. Effects of catalysts with different structures on the chiral resolution of epichlorohydrin

[0095] A2 60.0 48.5 B2 38.5 27.3 C2 47.8 32.4

[0096] As shown in Table 9, catalyst A2 exhibits the best resolution effect in the resolution of epichlorohydrin. The main reason for this difference lies in the structural differences among the three catalysts, which lead to different results. Catalyst A2, with its two aldehyde groups in the ortho position, can better bind with the amino group of chitosan to form a stable intermediate, thereby improving the stability of the ligand and facilitating the chiral resolution of epichlorohydrin, thus enhancing the selectivity of the reaction.

[0097] Example 10

[0098] In Example 10, cobalt acetate tetrahydrate was replaced with aluminum acetate, ferric acetate, and manganese acetate, respectively, while other conditions remained the same as in Example 8, resulting in catalysts D2, E2, and F2.

[0099] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), catalyst D2 or E2, F2 (88 mg), and distilled water (1 ml) were added separately. The mixture was stirred at room temperature and pressure for 36 h to achieve chiral resolution. After the reaction, the products were separated by vacuum distillation, and the catalyst was filtered for recovery. The effects of different Salen metal catalysts on the chiral resolution of epichlorohydrin are shown in Table 10.

[0100] Table 10. Effects of Salen's different metal catalysts on the chiral resolution of epichlorohydrin

[0101] A2 60.0 48.5 D2 49.2 34.8 E2 31.7 18.1 F2 40.3 25.7

[0102] As shown in Table 10, the catalyst containing cobalt metal has the best resolution effect. This is mainly because the special structure of cobalt can form a stable chelate ring with Salen ligand, which helps to improve the stability of the catalyst and thus improve the selectivity of the reaction.

[0103] Example 11

[0104] In Example 11, based on Example 8, trifluoromethanesulfonic acid was replaced with glacial acetic acid and p-toluenesulfonic acid, respectively, while other conditions remained the same as in Example 8, resulting in catalysts H2 and I2.

[0105] In a 5 ml round-bottom flask, epichlorohydrin (1 ml), catalyst H2 or I2 (88 mg), and distilled water (1 ml) were added separately. The mixture was stirred at room temperature and pressure for 36 h to achieve chiral resolution. After the reaction, the product was separated by vacuum distillation, and the catalyst was filtered for recovery. The effects of different counterions on the chiral resolution of epichlorohydrin are shown in Table 11.

[0106] Table 11. Effects of different counterions on the chiral resolution of epichlorohydrin

[0107] A2 60.0 48.5 H2 38.6 26.8 I2 54.8 36.9

[0108] As shown in Table 11, the catalyst containing the OTf structure has the best resolution effect, which may be because OTf, as a strong electron-withdrawing group, can significantly reduce the electron cloud density of cobalt and improve its selectivity.

[0109] 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 claims of the present invention.

Claims

1. A method for preparing a heterogeneous catalyst, characterized in that: include, Chitosan and aldehyde were stirred and refluxed in an ethanol solution for 5-12 hours. After cooling, the mixture was filtered under reduced pressure. The filter cake was washed with dichloromethane and methanol, respectively, and dried to obtain chitosan Schiff base ligands. Chitosan Schiff base ligands and coordinating metal ions were dispersed in anhydrous ethanol and stirred under reflux for 5-10 hours. The mixture was then filtered to obtain the catalyst. The catalyst was reacted with Lewis acid or counterion in dichloromethane solution by stirring for 4-6 hours. After the reaction was completed, the mixture was filtered to obtain a heterogeneous catalyst.

2. The method for preparing the heterogeneous catalyst as described in claim 1, characterized in that: The degree of deacetylation of the chitosan is ≥90%; the mass ratio of the aldehyde to chitosan is 1:2~5.

3. The method for preparing the heterogeneous catalyst as described in claim 1, characterized in that: The coordinating metal ion includes one of cobalt acetate, cobalt acetate tetrahydrate, aluminum acetate, ferric acetate, zinc acetate, manganese acetate, nickel acetate, etc.; the molar ratio of the chitosan Schiff base ligand to the coordinating metal ion is 1:0.1~1.

4. The method for preparing the heterogeneous catalyst as described in claim 1, characterized in that: The Lewis acid includes one of FeCl3, AlCl3, ZnCl2, NiCl2, MnCl2, CrCl3, and TiCl4; The molar ratio of the catalyst to the metal ions in the Lewis acid is 1:0.001~1.

5. The method for preparing the heterogeneous catalyst as described in claim 1, characterized in that: The counterions include OTf, OTs, BF3, and OAc. One of CF3SO3; The molar ratio of the catalyst to the counter ion is 1:1 to 2.

5.

6. The heterogeneous catalyst obtained by the preparation method according to any one of claims 1 to 5.

7. The method for chiral resolution of epichlorohydrin using the heterogeneous catalyst as described in claim 6, characterized in that: include, Epichlorohydrin, a heterogeneous catalyst, and a solvent were mixed and chiral separation was performed at room temperature and pressure.

8. The method for chiral resolution of epichlorohydrin using the heterogeneous catalyst as described in claim 7, characterized in that: After the reaction was completed, the products were separated by vacuum distillation, and the heterogeneous catalyst was recovered. The recovered heterogeneous catalyst does not require activation and can be used directly in subsequent reactions.

9. The method for chiral resolution of epichlorohydrin using the heterogeneous catalyst as described in claim 7, characterized in that: The molar ratio of epichlorohydrin to the heterogeneous catalyst shown is 10,000 to 1,000,000:

1.

10. The method for chiral resolution of epichlorohydrin using the heterogeneous catalyst as described in claim 7, characterized in that: The solvent is one or both of water and tetrahydrofuran; The chiral separation is performed at a reaction temperature of 25-30°C for 6-50 hours.

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