Chitosan-copper MOF material, use thereof, and methods for preparing β-boronimine compound and hydroxyl compound

Abstract

The present application belongs to the technical field of organic synthesis. Particularly disclosed is a method for preparing a β-boronimine compound under the catalysis of a chitosan-copper MOF material. The method specifically comprises the following steps: 1) adding an α-propylene imine compound I, bis(pinacolato)diboron and the chitosan-copper MOF material to water, and reacting same under mixing and stirring at room temperature; and 2) after the reaction is finished, performing filtration, separating a filtrate, and purifying same to obtain a β-boronimine compound II, and washing and drying a precipitate to recover the catalytic material for use in the next cycle. Compared with other porous materials, the metal organic framework material has the advantages of high porosity, large specific surface area, various structures, designability and the like, and therefore is widely applied to the fields of catalysis, organic synthesis and medicine preparation.

Description

Chitosan copper MOF material and its application, preparation method of β-boron imine compound and hydroxyl compound

[0001] This application claims priority to a Chinese patent application filed with the Patent Office of China on October 30, 2023, with application number CN202311416875.5 and invention name “A method for preparing β-boron imine compounds catalyzed by chitosan copper MOF material”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of organic synthesis, and specifically to a method for preparing β-boron imine compounds from chitosan copper MOF materials. Background Art

[0003] Metal-organic frameworks (MOFs), composed of extended metal ion / inorganic clusters bridged by organic linkers, have emerged as a molecularly programmable toolbox in chemistry and materials science. The high surface area, presence of reactive metals, defective ligands, and possible framework functionalization of these frameworks have led to diverse applications in heterogeneous catalysis. MOFs are suitable for applications in a variety of fields, including gas adsorption and separation, biomedicine, sensing, and catalysis. Specifically, catalysis can involve thermocatalysis (e.g., hydrogenation, hydroboration, oxidation, acetalization, and cycloaddition), electrocatalysis (e.g., ORR, HER, and CO2 reduction), and photocatalysis (e.g., hydrogen evolution, water oxidation, CO2 reduction, and amine oxidation).

[0004] Chitosan is the second largest renewable resource in nature. It is cheap, easy to obtain, green and environmentally friendly, and has strong metal chelating ability. The hydroxyl and amino groups in the molecular structure of natural polymer chitosan can coordinate with transition metal ions and have strong chelating ability. It can chelate with heavy metal ions Pb 2+ 、Zn 2+ 、Hg + Forming chelates, such as with Hg + Forming a stable -N-Hg-O-inner salt structure, such as Cu 2+ It is a four-coordinated metal ion, coordinated by heteroatoms, Cu 2+ It can form complexes with special structures with polymer groups.

[0005] MOFs chitosan can improve chitosan's physical and chemical properties and enhance its mechanical properties while retaining its advantages such as low cost, easy availability, and environmental friendliness. As a biomass-based functional material carrier, MOFs chitosan can overcome the shortcomings of traditional catalysts, such as difficulty in recycling, environmental pollution, and resource waste.

[0006] Existing methods for preparing β-boronimines primarily rely on homogeneous catalytic systems, which can result in residual metal particles in the product, making it difficult to separate. Therefore, there is a need for a method to prepare β-boronimines that can be synthesized under mild conditions and that allows for catalyst recycling, thus avoiding catalyst residue in the product.

[0007] Summary of the Invention

[0008] The purpose of this application is to address the deficiencies of the above-mentioned background technology and provide a method for catalyzing the preparation of β-boron imine compounds using chitosan copper MOF (CS@CuMOF) functional materials, which can achieve synthesis under mild conditions, realize catalyst recycling, and avoid catalyst residues in the product.

[0009] The technical solution of this application is:

[0010] A method for preparing a β-boron imine compound by catalysis using a chitosan copper MOF (CS@Cu MOF) functional material comprises the following steps:

[0011] 1) Adding an α-propenylquinoline compound I, pinacol biborate, and a CS@Cu MOF material to a mixed solvent of methanol and water, and stirring the mixture at room temperature for 8 to 16 hours, wherein the molar ratio of the α-propenylquinoline compound I, pinacol biborate, and the copper contained in the CS@Cu MOF material is 1:(1 to 2):(0.01 to 0.05), and the chemical reaction equation is as follows:

[0012] Wherein, R is one of phenyl, m-chlorophenyl, o-bromophenyl, m-methoxyphenyl, p-tert-butylphenyl and naphthyl;

[0013] 2) After the reaction is completed, the reaction is filtered, and the obtained filtrate is separated and purified to obtain β-boron imine compound II. The precipitate is washed and dried to obtain the recovered CS@CuMOF material for the next recycling.

[0014] Preferably, in step 1), the copper content in the CS@CuMOF material is 1.2 to 3.8 mmol / g.

[0015] Preferably, in step 1), the molar ratio of the α-propenylquinoline compound I, the bipyraclostrobin and the copper contained in the CS@CuMOF material is 1:2:0.0167-0.025.

[0016] Preferably, in step 1), the ratio of copper contained in CS@CuMOF to methanol and water is 0.005 mmol:1.2-1.8 mL:0.2-0.8 mL.

[0017] Preferably, in step 1), the mixture is stirred and reacted at room temperature for 12 h.

[0018] Preferably, in step 2), the separation and purification of the obtained filtrate to obtain the β-boron imine compound II specifically comprises: extracting the filtrate with ethyl acetate to obtain an organic phase containing the product, and then drying it with anhydrous Na2SO4, filtering, rotary evaporation, and column chromatography to obtain the β-boron imine compound II; washing and drying the precipitate to obtain the recovered CS@Cu MOF material specifically comprises: repeatedly washing with water and ethanol alternately, and drying in an oven at 50°C for 12 hours.

[0019] Preferably, in step 1), the CS@CuMOF material is prepared by a method comprising the following steps:

[0020] a. The chitosan powder was dissolved in an aqueous acetic acid solution to obtain an acidic chitosan solution, the metal precursor Cu(NO3)2·3H2O was added, and the mixture was stirred at room temperature to obtain a uniform solution;

[0021] b. The mixture was added dropwise to a NaOH solution to obtain porous chitosan gel beads. After 5 to 6 hours, the beads were filtered and washed;

[0022] c. The washed beads were placed in an alcohol solution containing dimethylimidazole, soaked at 40-45°C for 24-48 hours, and vacuum dried to obtain the chitosan copper MOF catalytic material CS@CuMOF.

[0023] Furthermore, in step a, the concentration of the acetic acid aqueous solution is 1wt% to 2wt%, each 1g of chitosan powder is dissolved in 15 to 40mL of acetic acid aqueous solution, and the molar ratio of Cu(NO3)2·3H2O to amino group-NH2 in the chitosan powder is 1.9 to 4:1.

[0024] Furthermore, in step b, the concentration of the NaOH solution is 3-4 mol / L.

[0025] Furthermore, in step b, the washing comprises: first washing with distilled water until the aqueous phase is neutral, then immersing in ethanol / water aqueous solutions formed by mixing ethanol / water at a volume ratio of 10 / 90, 30 / 70, 50 / 50, 70 / 30, and 90 / 10 in sequence, the immersion time for each volume ratio of ethanol aqueous solution being 15 to 20 minutes, and finally immersing in anhydrous ethanol for 15 to 20 minutes. Specifically, that is, first washing with distilled water until the aqueous phase is neutral, then immersing in a solution formed by ethanol / water at a volume ratio of 10 / 90 for 15 to 20 minutes, in a solution formed by ethanol / water at a volume ratio of 30 / 70 for 15 to 20 minutes, in a solution formed by ethanol / water at a volume ratio of 50 / 50 for 15 to 20 minutes, in a solution formed by ethanol / water at a volume ratio of 70 / 30 for 15 to 20 minutes, in a solution formed by ethanol / water at a volume ratio of 90 / 10 for 15 to 20 minutes, and finally immersing in anhydrous ethanol for 15 to 20 minutes.

[0026] Furthermore, in step c, the concentration of dimethylimidazole in the alcoholic solution containing dimethylimidazole is 0.16 to 0.26 g / L, wherein the alcohol is ethanol, and the vacuum drying is performed at 50 to 60° C. for 12 to 16 hours. The amount of the alcoholic solution containing dimethylimidazole used is 30 to 150 mL of the alcoholic solution containing dimethylimidazole for every 1 g of chitosan powder in step a.

[0027] In this application, the boron addition product II is further converted into the corresponding hydroxyl compound III by oxidation to prevent partial decomposition of the sample during PTLC separation or storage. At the same time, literature has shown that the conversion of -B to -OH does not change the yield calculation and other related data. This is a common operation in the field. The reaction formula is as follows:

[0028] During the preparation of the CS@Cu MOF catalytic material of the present application, Cu(NO3)2·3H2O provides sufficient copper ions to chitosan, enabling it to adsorb copper ions through its own adsorption capacity.

[0029] In the present application, in the natural polymer coordinated Cu (II) chitosan, the amino group of chitosan is coordinated with Cu through the interaction of -NH2 and Lewis acidic metal ions. The resulting uniform Cu (II) chitosan solution is added to a NaOH bath, which causes the entire material to spontaneously solidify and form three-dimensional, self-supporting porous microspheres with excellent specific surface area. This heterogeneous catalyst material is easy to separate and recycle and can be used repeatedly. At the same time, in terms of the selection of catalytic metal ions, compared with high-priced and highly polluting metals such as palladium, rhodium, and nickel, copper is a transition metal that is inexpensive, abundant in resources, and widely used. Therefore, this method is green, environmentally friendly, low-cost, and recyclable, providing an effective idea for constructing a new class of chiral CB bond compounds, and has low economic and high-yield industrial value.

[0030] The beneficial effects of this application are:

[0031] 1. This application provides a method for preparing a chitosan copper MOF material, which has the advantages of high activity, high selectivity, recyclability, and low catalytic dosage.

[0032] 2. The catalytic material successfully achieved the boron addition reaction of α-propenylquinoline compounds. This synthesis method was carried out at room temperature in a mixed solvent of methanol / water = 4:1 (v / v). It has the advantages of low cost, low pollution, simple components, easy operation, and a wide substrate range. The yield of the boron addition product can be as high as 98%, and the yield of the boron addition product can still reach 94% after five cycles of catalytic use.

[0033] 3. This invention applies green and recyclable heterogeneous catalysts to organoboron addition reactions, expanding the synthetic method for constructing CB bonds.

[0034] 4. Chitosan copper MOF materials can also be used in microreactors and mobile phases to improve production safety and economic benefits. They are not limited to the construction of boron compounds and can be expanded to the efficient synthesis of green drugs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is the SEM spectrum (1 mm) of the CS@CuMOF material in Example 1;

[0036] Figure 2 is the SEM spectrum (2 μm) of the CS@CuMOF material in Example 1;

[0037] FIG3 is a TEM spectrum of the CS@CuMOF material in Example 1;

[0038] FIG4 is a distribution diagram of Cu in the CS@CuMOF material in Example 1;

[0039] FIG5 is an infrared spectrum of the CS@CuMOF material in Example 1;

[0040] FIG6 is a hydrogen NMR spectrum of the target product in Example 2;

[0041] FIG7 is a carbon NMR spectrum of the target product in Example 2;

[0042] FIG8 is a carbon NMR spectrum of the target product in Example 2;

[0043] FIG9 is a hydrogen NMR spectrum of the target product in Example 3;

[0044] FIG10 is a carbon NMR spectrum of the target product in Example 3;

[0045] FIG11 is a hydrogen NMR spectrum of the target product in Example 4;

[0046] FIG12 is a carbon NMR spectrum of the target product in Example 4;

[0047] FIG13 is a hydrogen NMR spectrum of the target product in Example 5;

[0048] FIG14 is a carbon NMR spectrum of the target product in Example 5;

[0049] FIG15 is a hydrogen NMR spectrum of the target product in Example 6;

[0050] Figure 16 is the NMR carbon spectrum of the target product in Example 6. DETAILED DESCRIPTION

[0051] The following specific examples further illustrate this application in detail. The drugs used in the examples of this application are all commercially available products unless otherwise specified, and the methods used are all conventional methods in the art unless otherwise specified. The viscosity of the chitosan powder used in this application is 100-200 Pa·s, and each 1g of chitosan contains approximately 6.2mmol -NH2.

[0052] Example 1

[0053] The specific preparation method of CS@CuMOF material is as follows:

[0054] a. Dissolve 2 g of chitosan powder in 50 mL of 1 wt% aqueous acetic acid solution and stir for 24 hours to obtain a chitosan acid solution. Add the metal precursor Cu(NO3)2·3H2O (5.7 g) to the chitosan acid solution and stir at room temperature for an additional 2 hours until the mixture is completely homogenized.

[0055] b. Use a syringe to dropwise add the mixture into a 100 mL, 3 mol / L NaOH solution to gel the chitosan into porous beads. After 5 hours in the NaOH solution, filter the beads and wash them extensively with distilled water until the aqueous phase is nearly neutral. Dehydrate the beads by immersing them in aqueous ethanol solutions (ethanol / water) at volume ratios of 10 / 90, 30 / 70, 50 / 50, 70 / 30, and 90 / 10, sequentially for 15 minutes. Finally, dehydrate and wash them by immersing them in anhydrous ethanol for 15 minutes.

[0056] c. The washed beads were placed in 100 mL of 0.16 g / L dimethylimidazole ethanol solution, soaked at 40 ° C for 24 hours, and then vacuum-dried at 50 ° C for 12 hours to obtain chitosan copper MOF material (CS@CuMOF).

[0057] The CS@CuMOF obtained in this example was tested by inductively coupled plasma spectrometer ICP, and the copper content was 1.87 mmol / g.

[0058] The SEM spectra of CS@CuMOF obtained in this example are shown in Figures 1 and 2. From Figure 1, it can be seen that the sample is a regular sphere, and from Figure 2, it can be seen that the material is evenly distributed on the spherical sample;

[0059] The TEM spectrum of CS@CuMOF obtained in this example is shown in FIG3 , from which it can be seen that the sample is prepared uniformly without obvious particle aggregation;

[0060] The distribution diagram of Cu in the CS@Cu MOF obtained in this example is shown in FIG4 , from which it can be seen that the Cu element is distributed very evenly and at the nanometer level;

[0061] The infrared spectrum of CS@CuMOF obtained in this example is shown in FIG5 . It can be seen from FIG5 that the bonding structure of the chitosan skeleton is not damaged and Cu-O bonds are generated.

[0062] Example 2

[0063] This embodiment provides a method for applying a CS@Cu MOF material in the boron addition reaction of an α-propylene imine compound, comprising the following steps:

[0064] 1) α-Propylene quinoline compound I-1, bipyraclostrobin reagent and CS@CuMOF material (prepared in Example 1) were added to a methanol / water = 4:1 (v / v) mixed solvent (2 mL), wherein α-Propylene quinoline compound I-1 was 0.2 mmol, bipyraclostrobin reagent was 0.4 mmol, and CS@Cu MOF material loaded copper was 0.005 mmol. The mixture was stirred at room temperature for 12 h. In this example, α-Propylene quinoline compound I-1 (R is phenyl) was reacted as follows:

[0065] 2) After the reaction, the resulting mixture is centrifuged and filtered. The resulting liquid phase is extracted with ethyl acetate, dried over anhydrous sodium sulfate, and rotary evaporated to obtain a crude boron compound. The crude product is then purified by column chromatography to yield β-boronitrile compound II-1 (R is phenyl). The precipitate is alternately washed with water and ethanol and dried in an oven at 50°C for 12 hours to obtain the recovered CS@CuMOF material.

[0066] The product II-1 was then further converted to the corresponding hydroxy compound III-1 via oxidation to determine yield. The boron addition product II-1 obtained in step 2) was transferred entirely to a reaction flask. A magnetic stirrer, sodium borate tetrahydrate (244 mg), THF (3 mL), and H₂O (2 mL) were added sequentially and reacted at room temperature for 4 h. Extraction was performed with ethyl acetate, and the organic phase was separated and dried over anhydrous Na₂SO₄. The solvent was removed by rotary evaporation, and purification was performed by column chromatography to yield hydroxy compound III-1 (R is phenyl).

[0067] CS@CuMOF material was used in this reaction for the first time, and the yield of the target product III-1 was 98%.

[0068] After the CS@CuMOF material was used for catalysis five times, it was applied to the boron addition reaction of the α-propenylquinoline compound for the sixth time, and the yield of the obtained product III-1 was 94%.

[0069] The H-NMR spectrum and C-NMR spectrum of the target product are shown in Figures 6, 7, and 8. The concentration of the target product in Figure 7 is 5 mg / mL, and the concentration of the target product in Figure 8 is 25 mg / mL.

[0070] The results of this example show that when the CS@Cu MOF material provided in Example 1 of the present application participates in the boron addition reaction, the conversion rate of N,2-diphenylpropyleneimine is high, and the yield of the boron addition product reaches 98%.

[0071] Example 3

[0072] This embodiment provides a method for applying a CS@Cu MOF material in the boron addition reaction of an α-propylene imine compound, comprising the following steps:

[0073] 1) α-Propylene quinoline compound I-2, bipyraclostrobin reagent and CS@Cu MOF material (prepared in Example 1) were added to a methanol / water = 4:1 (v / v) mixed solvent (2 mL), wherein α-Propylene quinoline compound I-2 was 0.2 mmol, bipyraclostrobin reagent was 0.4 mmol, and CS@CuMOF material loaded copper was 0.005 mmol. The mixture was stirred at room temperature for 12 hours. In this example, α-Propylene quinoline compound I-2 (R is m-chlorophenyl) was prepared, and the reaction formula is as follows:

[0074] 2) After the reaction, the resulting mixture is centrifuged and filtered. The resulting liquid phase is extracted with ethyl acetate, dried over anhydrous sodium sulfate, and rotary evaporated to obtain a crude boron compound. The crude boron compound is then purified by column chromatography to yield β-boronitrile compound II-2 (R is m-chlorophenyl). The precipitate is alternately washed with water and ethanol and dried in an oven at 50°C for 12 hours to obtain the recovered CS@CuMOF material.

[0075] The product II-2 was then further converted to the corresponding hydroxy compound III-2 via oxidation to determine yield. The boron addition product II-2 obtained in step 2) was transferred entirely to a reaction flask. A magnetic stirrer, sodium borate tetrahydrate (244 mg), THF (3 mL), and H₂O (2 mL) were added sequentially and reacted at room temperature for 4 hours. Extraction was performed with ethyl acetate, and the organic phase was separated and dried over anhydrous Na₂SO₄. The solvent was removed by rotary evaporation, and purification was performed by column chromatography to yield hydroxy compound III-2 (R is m-chlorophenyl).

[0076] CS@CuMOF material was used in the reaction, and the yield of the target product was 96%.

[0077] The H-NMR spectrum and C-NMR spectrum of the target product are shown in Figures 9 and 10.

[0078] The results of this example show that when the CS@Cu MOF material provided in Example 1 of the present application participates in the boron addition reaction, the conversion rate of E,(3-chloro)-2-diphenylpropyleneimine is high, and the yield of the boron addition product reaches 96%.

[0079] Example 4

[0080] This embodiment provides a method for applying a CS@Cu MOF material in the boron addition reaction of an α-propylene imine compound, comprising the following steps:

[0081] 1) α-propenylquinoline compound I-3, biboronic acid pinacol ester reagent and CS@Cu MOF material (prepared in Example 1) were added to a methanol / water = 4:1 (v / v) mixed solvent (2 mL), wherein α-propenylquinoline compound I-3 was 0.2 mmol, biboronic acid pinacol ester was 0.4 mmol, and CS@CuMOF material loaded copper was 0.005 mmol. The mixture was stirred at room temperature for 12 hours. In this example, α-propenylquinoline compound I-3 (R is o-bromophenyl) is prepared, and the reaction formula is as follows:

[0082] 2) After the reaction, the resulting mixture is centrifuged and filtered. The resulting liquid phase is extracted with ethyl acetate, dried over anhydrous sodium sulfate, and rotary evaporated to obtain a crude boronate product. The crude product is then purified by column chromatography to yield β-boronimine compound II-3 (R is o-bromophenyl). The precipitate is alternately washed with water and ethanol and dried in an oven at 50°C for 12 hours to obtain the recovered CS@CuMOF material.

[0083] The product II-3 was then further converted to the corresponding hydroxy compound III-3 via oxidation to determine the yield. The boron addition product II-3 obtained in step 2) was transferred entirely to a reaction flask. A magnetic stirrer, sodium borate tetrahydrate (244 mg), THF (3 mL), and H₂O (2 mL) were added sequentially and reacted at room temperature for 4 hours. Extraction was performed with ethyl acetate, and the organic phase was separated and dried over anhydrous Na₂SO₄. The solvent was removed by rotary evaporation, and purification was performed by column chromatography to yield hydroxy compound III-3 (R is o-bromophenyl).

[0084] CS@CuMOF material was used in the reaction, and the yield of the target product was 95%.

[0085] The H-NMR spectrum and C-NMR spectrum of the target product are shown in Figures 11 and 12.

[0086] The results of this example show that when the CS@Cu MOF material provided in Example 1 of the present application participates in the boron addition reaction, the conversion rate of E,(2-bromo)-2-diphenylpropyleneimine is high, and the yield of the boron addition product reaches 95%.

[0087] Example 5

[0088] This embodiment provides a method for applying a CS@Cu MOF material in the boron addition reaction of an α-propylene imine compound, comprising the following steps:

[0089] 1) α-propenylquinoline compound I-4, bipyraclostrobin reagent and CS@Cu MOF material (prepared in Example 1) were added to a methanol / water = 4:1 (v / v) mixed solvent (2 mL), wherein α-propenylquinoline compound I-4 was 0.2 mmol, bipyraclostrobin reagent was 0.4 mmol, and CS@CuMOF material loaded copper was 0.005 mmol. The mixture was stirred at room temperature for 12 h. In this example, α-propenylquinoline compound I-4 (R is m-methoxyphenyl) was prepared, and the reaction formula is as follows:

[0090] 2) After the reaction, the resulting mixture is centrifuged and filtered. The resulting liquid phase is extracted with ethyl acetate, dried over anhydrous Na2SO4, and rotary evaporated to obtain a crude boron compound. The crude boron compound is then purified by column chromatography to yield β-boronimine compound II-4 (R is m-methoxyphenyl). The precipitate is alternately washed with water and ethanol and dried in an oven at 50°C for 12 hours to obtain the recovered CS@CuMOF material.

[0091] The product II-4 was then further converted to the corresponding hydroxy compound III-4 via oxidation to determine yield. The boron addition product II-4 obtained in step 2) was transferred entirely to a reaction flask. A magnetic stirrer was added, followed by sodium borate tetrahydrate (244 mg), THF (3 mL), and H₂O (2 mL). The mixture was reacted at room temperature for 4 h. Extraction was performed with ethyl acetate, and the organic phase was separated and dried over anhydrous Na₂SO₄. The solvent was removed by rotary evaporation, and purification was performed by column chromatography to yield hydroxy compound III-4 (R is m-methoxyphenyl).

[0092] CS@CuMOF material was used in the reaction, and the yield of the target product was 93%.

[0093] The H-NMR spectrum and C-NMR spectrum of the target product are shown in Figures 13 and 14.

[0094] The results of this example show that when the CS@Cu MOF material provided in Example 1 of the present application participates in the boron addition reaction, the conversion rate of E,(3-methoxy)-2-phenylpropyleneimine is high, and the yield of the chiral boron addition product reaches 93%.

[0095] Example 6

[0096] This embodiment provides a method for applying a CS@Cu MOF material in the boron addition reaction of an α-propylene imine compound, comprising the following steps:

[0097] 1) α-propenylquinoline compound I-6, biboronic acid pinacol ester reagent and CS@Cu MOF material (prepared in Example 1) were added to a methanol / water = 4:1 (v / v) mixed solvent (2 mL), wherein α-propenylquinoline compound I-6 was 0.2 mmol, biboronic acid pinacol ester was 0.4 mmol, and CS@CuMOF material loaded copper was 0.005 mmol. The mixture was stirred at room temperature for 12 hours. In this example, α-propenylquinoline compound I-6 (R is naphthyl) has the following reaction formula:

[0098] 2) After the reaction, the resulting mixture is centrifuged and filtered. The resulting liquid phase is extracted with ethyl acetate, dried over anhydrous sodium sulfate, and rotary evaporated to obtain a crude boronate product. The crude product is then purified by column chromatography to yield β-boronimine compound II-6 (R is naphthyl). The precipitate is alternately washed with water and ethanol and dried in an oven at 50°C for 12 hours to obtain the recovered CS@CuMOF material.

[0099] The product II-6 was then further converted to the corresponding hydroxy compound III-6 via oxidation to determine yield. The boron addition product II-6 obtained in step 2) was transferred entirely to a reaction flask. A magnetic stirrer, sodium borate tetrahydrate (244 mg), THF (3 mL), and H₂O (2 mL) were added sequentially and reacted at room temperature for 4 h. Extraction was performed with ethyl acetate, and the organic phase was separated and dried over anhydrous Na₂SO₄. The solvent was removed by rotary evaporation, and purification was performed by column chromatography to yield hydroxy compound III-6 (R is naphthyl).

[0100] CS@CuMOF material was used in the reaction, and the yield of the target product was 94%.

[0101] The H-NMR spectrum and C-NMR spectrum of the target product are shown in Figures 15 and 16.

[0102] The results of this example show that when the CS@Cu MOF material provided in Example 1 of the present application participates in the boron addition reaction, the conversion rate of E,2-(2-(naphthalen-2-yl)vinyl)quinoline is high, and the yield of the chiral boron addition product reaches 94%.

[0103] Although the above embodiments provide a detailed description of the present application, they are only part of the embodiments of the present application, not all of the embodiments. People can also obtain other embodiments based on the embodiments of the present application without creative work, and these embodiments all fall within the scope of protection of the present application.

Claims

1. A chitosan copper MOF material is prepared by a method comprising the following steps: a. dissolving chitosan powder in an aqueous acetic acid solution to obtain a chitosan acidic solution, adding a metal precursor Cu(NO3)2·3H2O, and stirring at room temperature to obtain a mixed solution; b. adding the mixture dropwise to a NaOH solution to gel the chitosan to obtain porous beads, and filtering and washing the beads after 5 to 6 hours; c. The washed beads were placed in an alcohol solution containing dimethylimidazole, immersed at 40-45° C. for 24-48 hours, and vacuum dried to obtain the chitosan copper MOF catalytic material CS@Cu MOF.

2. The chitosan copper MOF material according to claim 1, characterized in that: In step a, the concentration of the acetic acid aqueous solution is 1wt% to 2wt%, each 1g of chitosan powder is dissolved in 15 to 40mL of acetic acid aqueous solution, and the molar ratio of the Cu(NO3)2·3H2O to -NH2 in the chitosan powder is 1.9 to 4:

1.

3. The chitosan copper MOF material according to claim 1, characterized in that: In step b, the concentration of the NaOH solution is 3-4 mol / L.

4. The chitosan copper MOF material according to claim 1, characterized in that In step b, the washing includes: first washing with distilled water until the water phase is neutral, then immersing in ethanol aqueous solutions formed by mixing ethanol / water in volume ratios of 10 / 90, 30 / 70, 50 / 50, 70 / 30, and 90 / 10 in sequence, the immersion time for each volume ratio of ethanol aqueous solution is 15 to 20 minutes, and finally immersing in anhydrous ethanol for 15 to 20 minutes.

5. The chitosan copper MOF material according to claim 1, characterized in that: In step c, the concentration of dimethylimidazole in the alcohol solution containing dimethylimidazole is 0.16-0.26 g / L, wherein the alcohol is ethanol, and the vacuum drying is performed at 50-60° C. for 12-16 hours under vacuum conditions.

6. The chitosan copper MOF material according to claim 1, characterized in that: The copper content in CS@Cu MOF material is 1.2~3.8mmol / g.

7. Use of the chitosan copper MOF material according to any one of claims 1 to 6 as a heterogeneous catalyst in the preparation of CB bond-containing products or hydroxyl compounds.

8. Use of the chitosan copper MOF material according to any one of claims 1 to 6 in a microreactor and a mobile phase.

9. Use of the chitosan copper MOF material according to any one of claims 1 to 6 in the synthesis of green drugs.

10. A method for preparing a β-boryl imine compound, characterized in that: The following steps are involved: 1) Adding α-propylene quinoline compound I, bipyraclostrobin and CS@Cu MOF material into a mixed solvent formed by methanol and water, mixing and stirring at room temperature for 8 to 16 hours, wherein the molar ratio of α-propylene quinoline compound I, bipyraclostrobin and copper contained in CS@Cu MOF material is 1:(1 to 2):(0.01 to 0.05), and the chemical reaction equation is as follows: Wherein, R is one of phenyl, m-chlorophenyl, o-bromophenyl, m-methoxyphenyl, p-tert-butylphenyl and naphthyl; 2) After the reaction is completed, the reaction is filtered, and the obtained filtrate is separated and purified to obtain the β-boryl imine compound II. The precipitate is washed and dried to obtain the recovered CS@Cu MOF material for the next recycling; The CS@Cu MOF material is the chitosan copper MOF material according to any one of claims 1 to 6.

11. The preparation method according to claim 10, characterized in that: In step 1), the molar ratio of the α-propylene quinoline compound I, the biphenyl borate and the copper contained in the CS@Cu MOF material is 1:2:0.0167-0.

025.

12. The preparation method according to claim 10, characterized in that: In step 1), the ratio of copper contained in CS@Cu MOF to methanol and water is 0.005mmol:1.2-1.8mL:0.2-0.8mL.

13. The preparation method according to claim 10, characterized in that: In step 2), the filtrate is separated and purified to obtain the β-boryl imine compound II, specifically comprising: extracting the filtrate with ethyl acetate to obtain an organic phase containing the product, and the organic phase is dried over anhydrous Na2SO4, filtered, rotary evaporated, and purified by column chromatography to obtain the β-boryl imine compound II; The washing and drying of the precipitate specifically includes: washing with water and ethanol repeatedly and alternately, and drying in an oven at 50° C. for 12 hours.

14. A method for preparing a hydroxy compound, characterized in that: The method comprises the following steps: oxidizing the beta-boryl imine compound prepared by the preparation method according to any one of claims 10 to 13 to obtain a hydroxy compound.

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