Organic polymer containing chiral bisoxazoline ligand as well as preparation method and application of organic polymer
By copolymerizing chiral bisoxazoline ligand with divinylbenzene and styrene, a stable organic polymer is formed, which solves the problem of high recycling costs, improves catalytic activity and stability, and realizes easy recycling and recycling of materials.
Patent Information
- Application Number
- CN202510106087.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-06-10
AI Technical Summary
The existing chiral bisoxazoline ligands are costly and difficult to recover in catalytic reactions, and the research on polymerization with polystyrene is extremely limited.
By copolymerizing chiral bisoxazoline ligand with divinylbenzene and styrene, an organic polymer with large specific surface area, developed pores and stable molecular framework is formed, which solves the problem of high recycling costs and improves catalytic activity and stability.
The stability and catalytic performance of chiral bisoxazoline ligands are improved, while making polymer materials easy to be separated and recovered from the solvent system and easy to be recycled.
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Figure CN120118231A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of polymer functional materials, and particularly relates to an organic polymer containing a chiral bisoxazoline ligand, a preparation method thereof, and an application thereof. Background Art
[0002] Chirality is closely related to asymmetry and is a basic characteristic of natural biological systems and organisms. For example, proteins, nucleic acids, and carbohydrates are all composed of chiral structural units, and most endogenous bioactive substances (such as hormones and neurotransmitters) usually have chirality. Chiral compounds can be obtained through asymmetric catalysis, in which chiral ligands play a crucial role in asymmetric catalytic reactions. Bisoxazoline ligands are one of the powerful and widely used chiral ligands, and are widely used in asymmetric catalytic reactions such as Aldol reactions, Diels-Alder reactions, Friedel-Crafts reactions, etc. Although bisoxazoline ligands have great potential in asymmetric catalysis, their relatively high cost and poor recyclability limit their practical applications.
[0003] The heterogenization of chiral bisoxazoline ligands has become a research hotspot in recent years. Mainly, the ligands are immobilized on silica, fluorinated alkyl chains, and polymer polymers, and are mainly connected to the carrier through substituents on the methylene bridge of the ligand. Polystyrene carriers have attracted wide attention in the heterogenization of homogeneous catalysts due to their advantages such as simple preparation, fast mass transfer process, and high stability. However, the current research on the polymerization of bisoxazoline ligands and polystyrene is extremely limited. The bisoxazoline ligand L1 substituted by an indene skeleton at the C4 and C5 positions of the bisoxazoline ring has large steric hindrance and good stereochemical control, and has been widely used in a series of asymmetric catalytic reactions. However, there is no report on the related research of the heterogenization of L1 at present.
[0004] Summary of the Invention
[0005] The technical problem solved by the present invention is to provide a preparation method of a chiral bisoxazoline ligand polymer with different vinyl modification positions, which solves the problems of high recovery cost and difficulty in recovery while ensuring the catalytic activity of the ligand.
[0006] The specific solution provided by the present invention is as follows:
[0007] The present invention provides a preparation method of an organic polymer containing a chiral bisoxazoline ligand, comprising the following steps:
[0008] A chiral bisoxazoline ligand monomer, divinylbenzene, styrene and a polymerization initiator are added to a pore-forming solvent, and a polymerization reaction is carried out at a temperature of 40-140 °C. After the reaction is completed, the pore-forming solvent is removed to obtain the organic polymer;
[0009] The chiral bisoxazoline ligand monomer is a vinyl-modified indene skeleton-substituted bisoxazoline ligand, and the structural formula is one of Formula I, Formula II, and Formula III;
[0010]
[0011] Among them, n = 1 or 2 in Formula I, and the vinyl position in Formula II is ortho, meta or para.
[0012] Based on the method of the present invention, copolymerization of the modified chiral bisoxazoline ligand, divinylbenzene, and styrene gives an organic polymer containing a chiral bisoxazoline ligand with a large specific surface area, developed pores, a stable molecular skeleton, and high thermal stability. Its adjustable olefin modification position and developed pore structure enable the transition metal to smoothly complex with the chiral bisoxazoline ligand and are not easily dissociated from the ligand, improving the stability of the catalyst; its stable skeleton structure makes the chiral bisoxazoline ligand structure in it more stable. When used as a ligand in a catalytic reaction, it is beneficial to maintain its chiral structure and is not easily racemized, thus having high catalytic performance; moreover, the chiral bisoxazoline ligand - p-divinylbenzene - styrene three-fragment polymer material obtained based on the method of the present invention is easy to separate and recover from the solvent system, facilitating recycling.
[0013] Preferably, the molar ratio of the chiral bisoxazoline ligand monomer, divinylbenzene, styrene, and the polymerization initiator is 1:(1 - 2):(88 - 90):(1 - 1.5).
[0014] Preferably, the pore-forming solvent is selected from one or more of water, tetrahydrofuran, toluene, ethyl acetate, chlorobenzene, N-methylpyrrolidone, N,N-dimethylformamide, and n-octanol.
[0015] More preferably, the pore-forming solvent is a mixed solution of N,N-dimethylformamide and n-octanol, and the volume ratio of N,N-dimethylformamide to n-octanol in the mixed solution is 1:(3 - 6).
[0016] Preferably, the polymerization initiator is azobisisobutyronitrile.
[0017] Preferably, the reaction time of the polymerization reaction is 18 - 30 h.
[0018] Preferably, the chiral bisoxazoline ligand monomer is selected from one of the following structures:
[0019]
[0020] The present invention also provides an organic polymer containing a chiral bisoxazoline ligand prepared by the above preparation method.
[0021] The present invention also provides the use of the above organic polymer containing a chiral bisoxazoline ligand in a photo / copper-catalyzed asymmetric cyanation reaction.
[0022] Further, the cyanation reaction is a reaction between propargyl ester and trimethylsilyl cyanide. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 1H NMR spectrum of chiral bisoxazoline ligand monomer M6; 1
[0024] Figure 2 13C NMR spectrum of chiral bisoxazoline ligand monomer M6; 13
[0025] Figure 3 13C MAS NMR spectrum of polymer P6; 13
[0026] Figure 4 SEM image of polymer P6;
[0027] Figure 5 TEM surface scan image of polymer P6;
[0028] Figure 6 Thermogravimetric curve of polymer P6;
[0029] Figure 7 Nitrogen adsorption-desorption isotherm curve of polymer P6;
[0030] Figure 8 Pore size distribution curve of polymer P6. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0031] To enable those skilled in the art to more clearly understand the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following further details the specific embodiments, structures, features and effects of the present invention in conjunction with the accompanying drawings and preferred embodiments. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention. In the embodiments of the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art; if not specifically specified, the technical means used are conventional means well known to those skilled in the art.
[0032] A preparation method of an organic polymer containing a chiral bisoxazoline ligand provided by an embodiment of the present invention includes the following steps:
[0033] The chiral bisoxazoline ligand monomer, divinylbenzene, styrene and polymerization initiator are added to a pore-forming solvent, and a polymerization reaction is carried out at a temperature of 40 to 140 °C. After the reaction is completed, the pore-forming solvent is removed to obtain the organic polymer;
[0034] The chiral bisoxazoline ligand monomer is a vinyl-modified indene skeleton-substituted bisoxazoline ligand, and the structural formula is one of Formula I, Formula II, and Formula III;
[0035]
[0036] Among them, in Formula I, n = 1 or 2, and in Formula II, the vinyl position is ortho, meta or para.
[0037] Based on the method of the embodiments of the present invention, copolymerization of the chiral bisoxazoline ligand, divinylbenzene and styrene can obtain an organic polymer containing a chiral bisoxazoline ligand with a large specific surface area, developed pores and a stable molecular skeleton.
[0038] In a preferred embodiment, the molar ratio of the chiral bisoxazoline ligand monomer, divinylbenzene, styrene and polymerization initiator is 1:(1 - 2):(88 - 90):(1 - 1.5).
[0039] The chiral bisoxazoline ligand monomer and styrene are used as the main monomer raw materials, supplemented with an appropriate amount of divinylbenzene crosslinking agent, and a polymer with stable performance and high catalytic activity can be obtained.
[0040] In a preferred embodiment, the divinylbenzene is p-divinylbenzene.
[0041] In a preferred embodiment, the pore-forming solvent is selected from one or more of water, tetrahydrofuran, toluene, ethyl acetate, chlorobenzene, N-methylpyrrolidone, N,N-dimethylformamide, and n-octanol.
[0042] In a preferred embodiment, the pore-forming solvent is a mixed solution of N,N-dimethylformamide and n-octanol, and the volume ratio of N,N-dimethylformamide to n-octanol is 1:(3 - 6). At this solvent ratio, after the pore-forming solvent is removed, a porous polymer with uniform pore size and high porosity can be formed.
[0043] In a preferred embodiment, the polymerization initiator is azobisisobutyronitrile.
[0044] In a preferred embodiment, the reaction time of the polymerization reaction is 18 - 30 h.
[0045] In a preferred embodiment, the chiral bisoxazoline ligand monomer is selected from one of the following structures:
[0046]
[0047] Specifically, the preparation methods of chiral bisoxazoline ligand monomers M1 to M6 are as follows:
[0048]
[0049] Preparation of chiral bisoxazoline ligand monomer M1: Dissolve 0.2 mmol of precursor compound 1 in 6 mL of tetrahydrofuran solution, add 0.8 mmol of sodium hydride and 0.4 mmol of p-vinylbenzyl chloride at 0 °C, and react at room temperature for 12 h to obtain chiral bisoxazoline ligand monomer M1.
[0050] Preparation of chiral bisoxazoline ligand monomer M2: Dissolve 0.2 mmol of precursor compound 1 in 6 mL of tetrahydrofuran solution, add 0.8 mmol of sodium hydride and 0.4 mmol of biphenylylvinylbenzyl chloride at 0 °C, and react at room temperature for 12 h to obtain chiral bisoxazoline ligand monomer M2.
[0051]
[0052] Preparation of chiral bisoxazoline ligand monomer M3: Dissolve 0.2 mmol of precursor compound 2 in 6 mL of tetrahydrofuran solution, add 0.4 mmol of sodium hydride and 0.4 mmol of o-vinylbenzyl chloride at 0 °C, and react at room temperature for 12 h to obtain chiral bisoxazoline ligand monomer M3.
[0053] Preparation of chiral bisoxazoline ligand monomer M4: Dissolve 0.2 mmol of precursor compound 2 in 6 mL of tetrahydrofuran solution, add 0.4 mmol of sodium hydride and 0.4 mmol of m-vinylbenzyl chloride at 0 °C, and react at room temperature for 12 h to obtain chiral bisoxazoline ligand monomer M4.
[0054] Preparation of chiral bisoxazoline ligand monomer M5: Dissolve 0.2 mmol of precursor compound 2 in 6 mL of tetrahydrofuran solution, add 0.4 mmol of sodium hydride and 0.4 mmol of p-vinylbenzyl chloride at 0 °C, and react at room temperature for 12 h to obtain chiral bisoxazoline ligand monomer M5.
[0055]
[0056] Preparation of chiral bisoxazoline ligand monomer M6: Dissolve 0.2 mmol of precursor compound 3 in 6 mL of tetrahydrofuran solution, add 0.4 mmol of sodium hydride and 0.4 mmol of 1,2-dibromoethane at 0 °C, and react at room temperature for 12 h to obtain chiral bisoxazoline ligand monomer M6. From Figure 1 and Figure 2 the NMR results, it can be determined that the synthesized structure is that of monomer M6.
[0057] Example 1
[0058]
[0059] Preparation of Polymer P1: 0.1 mmol (56.5 mg) of ligand monomer M1, 0.1 mmol (13 mg) of p-divinylbenzene, 930 mg of styrene and 15 mg of azobisisobutyronitrile were dissolved in 6 mL of a mixed solvent with a volume ratio of 5:1 of n-octanol to N,N-dimethylformamide. The mixture was stirred and heated to 70 °C and reacted for 24 h. The solvent was removed by distillation and dried in vacuo at 60 °C for 12 h to obtain white polymer P1.
[0060] Example 2
[0061]
[0062] Preparation of Polymer P2: 0.1 mmol (71.4 mg) of ligand monomer M2, 0.1 mmol (13 mg) of p-divinylbenzene, 916 mg of styrene and 15 mg of azobisisobutyronitrile were dissolved in 6 mL of a mixed solvent with a volume ratio of 5:1 of n-octanol to N,N-dimethylformamide. The mixture was stirred and heated to 70 °C and reacted for 24 h. The solvent was removed by distillation and dried in vacuo at 60 °C for 12 h to obtain white polymer P2.
[0063] Example 3
[0064]
[0065] Preparation of Polymer P3: 0.1 mmol (46 mg) of ligand monomer M3, 0.1 mmol (13 mg) of p-divinylbenzene, 941 mg of styrene and 15 mg of azobisisobutyronitrile were dissolved in 6 mL of a mixed solvent with a volume ratio of 5:1 of n-octanol to N,N-dimethylformamide. The mixture was stirred and heated to 70 °C and reacted for 24 h. The solvent was removed by distillation and dried in vacuo at 60 °C for 12 h to obtain white polymer P3.
[0066] Example 4
[0067]
[0068] Preparation of Polymer P4: 0.1 mmol (46 mg) of ligand monomer M4, 0.1 mmol (13 mg) of p-divinylbenzene, 941 mg of styrene and 15 mg of azobisisobutyronitrile were dissolved in 6 mL of a mixed solvent with a volume ratio of 5:1 of n-octanol to N,N-dimethylformamide. The mixture was stirred and heated to 70 °C and reacted for 24 h. The solvent was removed by distillation and dried in vacuo at 60 °C for 12 h to obtain white polymer P4.
[0069] Example 5
[0070]
[0071] Preparation of Polymer P5: 0.1 mmol (46 mg) of ligand monomer M5, 0.1 mmol (13 mg) of p-divinylbenzene, 941 mg of styrene, and 15 mg of azobisisobutyronitrile were dissolved in 6 mL of a mixed solvent with a volume ratio of 5:1 of n-octanol to N,N-dimethylformamide. The mixture was stirred and heated to 70 °C and reacted for 24 h. The solvent was removed by distillation, and the residue was dried in vacuo at 60 °C for 12 h to obtain white polymer P5.
[0072] Example 6
[0073]
[0074] Preparation of Polymer P6: 0.1 mmol (56 mg) of ligand monomer M6, 0.1 mmol (13 mg) of p-divinylbenzene, 931 mg of styrene, and 15 mg of azobisisobutyronitrile were dissolved in 6 mL of a mixed solvent with a volume ratio of 5:1 of n-octanol to N,N-dimethylformamide. The mixture was stirred and heated to 70 °C and reacted for 24 h. The solvent was removed by distillation, and the residue was dried in vacuo at 60 °C for 12 h to obtain white polymer P6.
[0075] Figure 3 For polymer P6 13 C MAS NMR spectrum. Among them, the resonance peaks at 143 and 126 ppm correspond to the carbons in the benzene ring, and the resonance peak at 38 ppm has a weak peak intensity and is related to the carbon in the alkyl linker generated by vinyl polymerization. This result indicates that the degree of ternary polymerization of the bisoxazoline ligand with p-divinylbenzene and styrene is very high.
[0076] Figure 4 SEM image of polymer P6. It can be seen that the polymer is composed of micron-sized blocks with irregular shapes, forming pores.
[0077] Figure 5 For the TEM surface scan of polymer P6. From Figure 5 it can be seen that carbon, nitrogen, and oxygen are evenly distributed on the polymer particles. This result shows that the bisoxazoline ligand is successfully fixed on the polystyrene chain. And each ligand monomer is evenly dispersed, rather than aggregating within the polymer backbone.
[0078] Figure 6 Thermogravimetric diagram of polymer P6. Thermogravimetric analysis shows that the polymer can be stable up to 400 °C with a small mass loss.
[0079] Figure 7 For the nitrogen adsorption-desorption isotherm of polymer P6. In the figure, at P / P 0 <0.01 and 0.90 < P / P 0<1.0 Region has two steep slopes, indicating the presence of micropores within the polymer structure. Meanwhile, P6 has a relatively high specific surface area (401.18 m 2 g -1 ).
[0080] Figure 8 Figure 0000204 is the pore size distribution diagram of polymer P6. The results show that the average pore size of this polymer is 4.0326 nm. This porous structure with a high surface area is conducive to the ligands on the polystyrene chain approaching the copper salt and the substrate, thereby improving the catalytic efficiency of the asymmetric cyanation reaction.
[0081] To further illustrate the catalytic effect of the above polymerization method, a series of comparative polymers were prepared by the method of not adding styrene.
[0082] Comparative Example 1
[0083]
[0084] Preparation of polymer P1-D: Dissolve 0.1 mmol (56.5 mg) of ligand monomer M1, 944 mg of p-divinylbenzene, and 25 mg of azobisisobutyronitrile in 10 mL of tetrahydrofuran. Stir and heat to 100 °C and react for 24 h. Distill off the solvent and dry in vacuo at 60 °C for 12 h to obtain white polymer P1-D.
[0085] Comparative Example 2
[0086]
[0087] Preparation of polymer P2-D: Dissolve 0.1 mmol (71.4 mg) of ligand monomer M2, 929 mg of p-divinylbenzene, and 25 mg of azobisisobutyronitrile in 10 mL of tetrahydrofuran. Stir and heat to 100 °C and react for 24 h. Distill off the solvent and dry in vacuo at 60 °C for 12 h to obtain white polymer P2-D.
[0088] Comparative Example 3
[0089]
[0090] Preparation of polymer P3-D: Dissolve 0.1 mmol (46 mg) of ligand monomer M3, 954 mg of p-divinylbenzene, and 25 mg of azobisisobutyronitrile in 10 mL of tetrahydrofuran. Stir and heat to 100 °C and react for 24 h. Distill off the solvent and dry in vacuo at 60 °C for 12 h to obtain white polymer P3-D.
[0091] Comparative Example 4
[0092]
[0093] Preparation of Polymer P4-D: Dissolve 0.1 mmol (46 mg) of ligand monomer M4, 954 mg of p-divinylbenzene, and 25 mg of azobisisobutyronitrile in 10 mL of tetrahydrofuran. Stir and heat to 100 °C, react for 24 h, distill off the solvent, and dry in vacuo at 60 °C for 12 h to obtain white polymer P4-D.
[0094] Comparative Example 5
[0095]
[0096] Preparation of Polymer P5-D: Dissolve 0.1 mmol (46 mg) of ligand monomer M5, 954 mg of p-divinylbenzene, and 25 mg of azobisisobutyronitrile in 10 mL of tetrahydrofuran. Stir and heat to 100 °C, react for 24 h, distill off the solvent, and dry in vacuo at 60 °C for 12 h to obtain white polymer P5-D.
[0097] Comparative Example 6
[0098]
[0099] Preparation of Polymer P6-D: Dissolve 0.1 mmol (56 mg) of ligand monomer M6, 944 mg of p-divinylbenzene, and 25 mg of azobisisobutyronitrile in 10 mL of tetrahydrofuran. Stir and heat to 100 °C, react for 24 h, distill off the solvent, and dry in vacuo at 60 °C for 12 h to obtain white polymer P6-D.
[0100] Example 7
[0101] In this example, the heterogeneous organic ligand polymers provided in Examples 1-6 and Comparative Examples 1-6 were in-situ coordinated with metallic copper and then applied to the reaction of propargyl esters and trimethylsilyl cyanide under photo / Cu catalysis. The specific experimental procedure was as follows: In a 10 mL Schlenk tube filled with dry argon, place copper(II) tetraacetonitrile tetrafluoroborate (0.005 mmol) and chiral bisoxazoline ligand polymer (3 mol%) in 1.0 mL of tetrahydrofuran. After stirring at room temperature for 30 min, an in-situ complex of the ligand polymer and Cu was formed. Then add propargyl ester (0.2 mmol), N-phenylphenazine (0.01 mmol), and anhydrous tetrahydrofuran (1.0 mL), and remove the oxygen in the reaction system under liquid nitrogen conditions. Finally, add trimethylsilyl cyanide (75 μL) to the reaction system and react under irradiation with a 2 × 3 W purple lamp for 24 hours.
[0102]
[0103] In the reaction of propargyl esters and trimethylsilyl cyanide under photo / Cu catalysis, different products participated in the reaction as ligands, and the corresponding yields and enantioselectivities are shown in Table 1.
[0104] Table 1 Yields and enantioselectivities corresponding to ligands in the reaction of propargyl esters with trimethylsilyl cyanide under photo / copper catalysis
[0105]
[0106] The above experiments show that the catalytic performance of the polymer material obtained by copolymerizing divinylbenzene and chiral bisoxazoline ligand molecules is generally inferior to that of the three-fragment polymer material formed by copolymerizing divinylbenzene, styrene and chiral bisoxazoline ligand molecules. Based on the method of the present invention, the structure of the chiral bisoxazoline ligand can be made more stable, less prone to racemization, and can better ensure the smooth complexation of the transition metal with the chiral bisoxazoline ligand, thus ensuring the catalytic activity of the catalyst and obtaining a higher catalytic yield. As can be seen from the table, the optimal polymer ligand is P6 modified with vinyl on the indene skeleton, and the yield of its photo / copper-catalyzed cyanation reaction is 71%, and the corresponding enantioselectivity can be as high as 91%. In heterogeneous materials with polymers as carriers, flexible polystyrene chains usually bring steric hindrance effects, thus reducing the catalytic reaction efficiency. Compared with other polymers P1-P5 modified on the methylene bridge, in the polymer P6 modified on the indene skeleton, the nitrogen atom of the oxazoline ring is farther away from the polystyrene skeleton. Therefore, this structure creates a necessary three-dimensional environment for copper coordination and ensures effective contact with substrate molecules, so that the ligand polymer has excellent catalytic performance.
[0107] Example 8
[0108] Recovery experiment of polymer P6 in photo / copper-catalyzed cyanation reaction. In the reaction of propargyl esters with trimethylsilyl cyanide under photo / copper catalysis, using polymer P6 as the ligand, a recovery experiment was carried out, and the yield and enantioselectivity results are shown in Table 2.
[0109] Table 2 Recycling times of ligand polymer P6 and its corresponding yields and enantioselectivities
[0110]
[0111]
[0112] Based on the polymer P6 of the present invention, after being recycled 5 times, its yield and enantioselectivity can still be well maintained. The three-fragment porous polymer material prepared by the method of the present invention has a stable skeleton structure, making the structure of the chiral bisoxazoline ligand more stable, thus ensuring the stability of the catalytic activity of the catalyst and increasing the number of recycling times.
[0113] The above are only the preferred embodiments of the present invention and do not impose any formal restrictions on the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications using the disclosed technical content to obtain equivalent embodiments with equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A method for preparing an organic polymer containing a chiral bisoxazoline ligand, characterized in that: The steps include: Adding a chiral bis-oxazoline ligand monomer, divinylbenzene, styrene and a polymerization initiator into a porogenic solvent, performing a polymerization reaction at a temperature of 40 to 140° C., and removing the porogenic solvent after the reaction is completed to obtain the organic polymer; The chiral bisoxazoline ligand monomer is a vinyl-modified indene skeleton-substituted bisoxazoline ligand, and the structural formula is one of Formula I, Formula II, and Formula III; Wherein, in formula I, n=1 or 2, and in formula II, the vinyl group is located at the ortho, meta or para position.
2. The method for preparing an organic polymer containing a chiral bisoxazoline ligand according to claim 1, wherein: The molar ratio of the chiral bis-oxazoline ligand monomer, divinylbenzene, styrene and polymerization initiator is 1:(1-2):(88-90):(1-1.5).
3. The method for preparing an organic polymer containing a chiral bisoxazoline ligand according to claim 1, wherein: The porogenic solvent is selected from one or more of water, tetrahydrofuran, toluene, ethyl acetate, chlorobenzene, N-methylpyrrolidone, N,N-dimethylformamide, and n-octanol.
4. The method for preparing an organic polymer containing a chiral bisoxazoline ligand according to claim 1, characterized in that: The porogenic solvent is a mixed solution of N,N-dimethylformamide and n-octanol, and the volume ratio of N,N-dimethylformamide to n-octanol in the mixed solution is 1:(3-6).
5. The method for preparing an organic polymer containing a chiral bisoxazoline ligand according to claim 1, characterized in that: The polymerization initiator is azobisisobutyronitrile.
6. The method for preparing an organic polymer containing a chiral bisoxazoline ligand according to claim 1, characterized in that: The reaction time of the polymerization reaction is 18 to 30 hours.
7. The method for preparing an organic polymer containing a chiral bisoxazoline ligand according to claim 1, characterized in that: The chiral bisoxazoline ligand monomer is selected from one of the following structures:
8. An organic polymer containing a chiral bisoxazoline ligand prepared by the preparation method according to any one of claims 1 to 7.
9. Use of the organic polymer containing chiral bis-oxazoline ligands as claimed in claim 8 in a light / copper catalyzed asymmetric cyanation reaction.
10. The use according to claim 9, characterized in that: The cyanation reaction is a reaction of propargyl ester and trimethylsilyl cyanide.