Catalytic synthesis method of asymmetric chiral boron compound

Abstract

The invention provides a catalytic synthesis method of an asymmetric chiral boron compound, and belongs to the technical field of asymmetric chiral boron compound synthesis. The catalytic synthesis method comprises the following steps: mixing an alpha, beta-unsaturated ketone compound, bis (pinacolato) diboron, a catalyst, a chiral ligand and a solvent, carrying out a reaction at room temperature for 6-24 h, and after the reaction is finished, carrying out post-treatment on the obtained mixed system to obtain the asymmetric chiral boron compound product. According to the method, the copper oxide nanosheet is used as the catalyst, when the synthesis of the chiral boron compound is catalyzed, the catalytic efficiency is high, the enantioselectivity is good, the method can be used for the chiral boron addition reaction of alpha, beta-unsaturated ketone compounds containing different substituent groups, and the substrate application range is wide; and the catalytic synthesis method can be carried out at room temperature, is mild in reaction condition, simple and easy to operate, avoids the use of alkali, is green and environment-friendly, and has potential industrial application value.

Description

Technical Field

[0001] The invention relates to the technical field of synthesis of asymmetric chiral boron compounds, and in particular to a catalytic synthesis method of an asymmetric chiral boron compound. Background Art

[0002] Chiral organoboron compounds are commonly found in bioactive compounds and can be used as chiral intermediates in the synthesis of important organic molecules. Many bioactive drugs such as bortezomib and delanzomib contain functional boron groups. In addition, enantiomer-rich β-chiral boron derivatives have been widely used in chemical bond transformations. The addition of transition metal-catalyzed diboron reagents (B2pin2) to CC multiple bonds is a key step in the synthesis of chiral organoboron compounds. Chiral boron compounds are important intermediates for the synthesis of chiral drugs. Their chiral CB bonds can undergo a series of transformations through oxidation reactions, Suzuki-Miyaura coupling reactions, Petasis reactions, etc. to obtain chiral CO bonds, chiral CN bonds, and chiral CC bonds.

[0003] At present, the catalytic activity and enantioselectivity of the transition metal-catalyzed addition reaction of diboron reagents (B2pin2) on CC multiple bonds to synthesize chiral organoboron compounds need to be improved. Therefore, it is urgent to develop a catalytic synthesis method for asymmetric chiral boron compounds to improve the yield and enantioselectivity of asymmetric chiral boron compounds. Summary of the invention

[0004] In view of the technical problems existing in the background technology, the present invention provides a catalytic synthesis method for asymmetric chiral boron compounds, aiming to solve the technical problems of low catalytic activity and enantioselectivity in the synthesis of chiral organic boron compounds by the addition reaction of existing transition metal-catalyzed diboron reagents (B2pin2) on CC multiple bonds.

[0005] In a first aspect, the present invention provides a catalytic synthesis method of an asymmetric chiral boron compound, comprising the following steps: An α,β-unsaturated ketone compound, biboric acid pinacol ester, a catalyst, a chiral ligand and a solvent are mixed and reacted at room temperature for 6 to 24 hours. After the reaction, the obtained mixed system is post-treated to obtain an asymmetric chiral boron compound product; Among them, the structural formula of the α,β-unsaturated ketone compound is: ; Wherein, R1 is phenyl, substituted phenyl or naphthyl, and R2 is phenyl or substituted phenyl; The catalyst is copper oxide nanosheets; the copper oxide nanosheets have a length of 500-3500 nm, a width of 100-1400 nm, and a thickness of 20-40 nm.

[0006] Preferably, the method for preparing copper oxide nanosheets comprises the following steps: uniformly mixing a copper salt solution and a NaOH solution, heating to 80° C. to 110° C. for reaction for 10 h to 15 h, filtering, washing and drying to obtain copper oxide nanosheets.

[0007] Preferably, the copper salt includes one or more of copper chloride, copper sulfate, and copper acetate; the concentration of the copper salt solution is 0.1-0.3 mol / L, more preferably 0.15 mol / L; the volume ratio of the copper salt solution to the NaOH solution is 1:(2-4), more preferably 1:3.

[0008] In the present invention, the copper salt solution and the NaOH solution are mixed evenly, heated to 80°C~110°C and reacted for 10h~15h. Specifically, the mixed solution is placed in a PTFE-lined autoclave and sealed for heating reaction; the heating temperature is preferably 80°C~110°C, more preferably 100°C; the heating time is preferably 10h~15h, more preferably 12h.

[0009] In the present invention, washing specifically includes: washing the filtered solid product by centrifugation using water and ethanol.

[0010] Preferably, the drying temperature is 50°C to 80°C, more preferably 60°C; the drying time is 10h to 15h, more preferably 12h.

[0011] In the present invention, when R1 in the structural formula of the α,β-unsaturated ketone compound is a substituted phenyl group, the substituted phenyl group is preferably one of p-methylphenyl, o-methylphenyl, p-chlorophenyl, o-chlorophenyl, m-chlorophenyl or p-bromophenyl; when R2 in the structural formula of the α,β-unsaturated ketone compound is a substituted phenyl group, the substituted phenyl group is preferably one of p-methoxyphenyl, p-chlorophenyl, o-chlorophenyl, m-chlorophenyl or p-bromophenyl.

[0012] Preferably, the chiral ligand has the structural formula: .

[0013] Preferably, the molar ratio of the α,β-unsaturated ketone compound, the biphenyl pinacol borate, the catalytic material and the chiral ligand is 1:1.2:0.01~0.05:0.01~0.06, more preferably 1:1.2:0.015:0.02.

[0014] Preferably, the ratio of copper oxide nanosheets to solvent is 10-40 mg:10 mL, more preferably 20 mg:10 mL.

[0015] Preferably, the solvent is a mixture of toluene and water; the volume ratio of toluene to water is 7-11:1, more preferably 9:1.

[0016] In the present invention, the asymmetric chiral boron addition reaction is preferably carried out under stirring conditions, and the present invention has no special requirements on the stirring speed.

[0017] Preferably, the post-treatment comprises the following steps: solid-liquid separation of the obtained mixed system to obtain a solid phase and a liquid phase, extraction of the liquid phase to obtain an organic phase, drying the organic phase with a desiccant, and removing the solvent to obtain an asymmetric chiral boron compound.

[0018] Preferably, the solid-liquid separation method includes centrifugation and filtration; the reagent used for extraction includes ethyl acetate, the desiccant includes Na2SO4, and the solvent removal method includes rotary evaporation.

[0019] In the present invention, for chirality testing, the asymmetric chiral boron compound obtained by the above preparation method is oxidized to a stable asymmetric chiral hydroxyl compound, and the specific steps are as follows: the asymmetric chiral boron compound, sodium borate tetrahydrate, tetrahydrofuran and water are mixed for oxidation reaction, and the chiral hydroxyl compound is obtained by extraction, drying, rotary evaporation and thin layer chromatography; wherein the eluent for thin layer chromatography is preferably a mixture of ethyl acetate and petroleum ether, and the volume ratio of ethyl acetate and petroleum ether in the mixture is preferably 1:4~9, more preferably 1:5; the amount ratio of the asymmetric chiral boron compound, sodium borate tetrahydrate, tetrahydrofuran and water is preferably 50mg-90mg:220mg-250mg:1mL-5mL:1mL-5mL; the temperature of the oxidation reaction is preferably room temperature, and the time is preferably 2~6 h, more preferably 4 h.

[0020] The technical solution of the present invention is based on the unique performance advantages of copper oxide nanosheets. CuO nanosheets have a large specific surface area and many exposed active sites due to their unique two-dimensional structure, which can effectively improve the catalytic efficiency. The specific reaction process is as follows: copper oxide nanosheets react with B2(pin)2 in a toluene-water mixture to form a copper-boron-based complex, which is then conjugated with an α, β-unsaturated receptor to generate an organic copper species. Then, water protonates this complex to produce a final product and allows the copper oxide nanosheet catalyst to be regenerated for subsequent reactions. Throughout the process, water acts as a proton source. The chiral Bolm-copper oxide complex asymmetrically promotes the formation of boron conjugates, thereby controlling the enantioselective formation of chiral products.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The invention provides a catalytic synthesis method for an asymmetric chiral boron compound. A copper oxide nanosheet prepared by a hydrothermal method is used as a catalyst. When catalyzing the synthesis of the chiral boron compound, a mixed solvent of toluene and water can be used, and the use of alkali is avoided. The method is green and environmentally friendly, and has potential industrial application value. The copper oxide nanosheet has high catalytic efficiency and good enantioselectivity, and can be used for the chiral boron addition reaction of α, β-unsaturated ketone compounds containing different substituent groups, and the substrate has a wide range of application. In addition, the catalytic synthesis method for the asymmetric chiral boron compound provided by the invention can be carried out at room temperature, the reaction conditions are mild, the operation is simple and easy, and the method has a wide range of application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The XRD spectrum of the copper oxide nanosheets prepared by the present invention; Figure 2 This is a SEM spectrum of the copper oxide nanosheets prepared in the present invention; Figure 3 is a size distribution diagram of the copper oxide nanosheets prepared by the present invention; wherein Figure 3 (a) is the length size distribution diagram, Figure 3 (b) is the width size distribution diagram; Figure 4 This is the H NMR spectrum of the target product of Example 1; Figure 5 The NMR carbon spectrum of the target product of Example 1; Figure 6 This is the HPLC spectrum of the racemate of the target product in Example 1; Figure 7 HPLC spectrum of the target product of Example 1; Figure 8 This is the H NMR spectrum of the target product of Example 2; Fig. 9 The NMR carbon spectrum of the target product of Example 2; Fig.10 This is the HPLC spectrum of the racemate of the target product in Example 2; Fig.11 HPLC spectrum of the target product of Example 2; Fig.12 The H NMR spectrum of the target product of Example 3; Fig.13 The NMR carbon spectrum of the target product of Example 3; Fig.14 This is the HPLC spectrum of the racemate of the target product in Example 3; Fig.15 The HPLC spectrum of the target product of Example 3 is shown in FIG. DETAILED DESCRIPTION

[0023] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0024] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0025] The preparation method of the copper oxide nanosheet catalyst used in each embodiment of the present invention is as follows: A 0.15 mol / L CuCl2 solution and a 4.5 mol / L NaOH solution were mixed in a volume ratio of 1:3, and the mixed solution was placed in a PTFE-lined autoclave, sealed and heated at 100°C for 12 h. After the reaction was completed, a solid product was obtained by filtration. The solid product was washed three times by centrifugation with water and ethanol, and dried in a vacuum drying oven at 60°C for 12 h to obtain copper oxide nanosheets.

[0026] Figure 1 This is the X-ray diffraction (XRD) spectrum of copper oxide nanosheets. Its diffraction peaks correspond one-to-one with the peaks of standard card CuO PDF#48-1548, which verifies that the crystal structure of the obtained material is copper oxide; Figure 2 is the SEM spectrum of copper oxide nanosheets. Figure 2 It can be seen that the copper oxide nanomaterial obtained by the present invention has a flaky structure. Figure 3 is the size distribution diagram of copper oxide nanosheets, where Figure 3 (a) is the length size distribution diagram, Figure 3 (b) is the width size distribution diagram. The length of copper oxide nanosheets is 500~3500nm, the width is 100~1400nm, the average length is 1679.4±498.4nm, and the average width is 873.6±252.1nm. Figure 2 It can be seen that the thickness of copper oxide nanosheets is about 20~40nm.

[0027] Example 1 This embodiment uses the prepared copper oxide nanosheets as a catalyst to catalyze the chiral boron addition reaction of α,β-unsaturated ketone compounds (chalcone), including the following steps: Step (1): Add chalcone, bipyrin (B2pin2), copper oxide nanosheets, and Bolm chiral ligands into a mixed solvent of toluene / deionized water = 9:1 (v / v), and stir at room temperature for 12 h, wherein the molar ratio of chalcone, bipyrin (B2pin2), copper oxide nanosheets, and Bolm ligands is 1:1.2:0.015:0.02, and the molar ratio of copper oxide nanosheets to solvent is 20 mg:10 mL. The chemical reaction equation is as follows: ; Among them, the structural formula of Bolm chiral ligand is: ; Step (2): after the reaction in step (1) is completed, the obtained mixed system is centrifuged and filtered, the obtained liquid phase is extracted with ethyl acetate, the extracted organic phase is dried over anhydrous sodium sulfate, and then the organic solvent is removed by rotary evaporation to obtain a boride product; Since the prepared chiral boron compound is easy to deteriorate when using liquid chromatography detection, in order to facilitate subsequent chiral testing, it is oxidized to a stable hydroxyl compound (target product). The specific steps are as follows: The boride product (69 mg) was transferred to a reaction bottle, and a magnetic stirrer, sodium borate tetrahydrate (244 mg), tetrahydrofuran (3 mL), and deionized water (2 mL) were added in sequence to react at room temperature for 4 h, followed by extraction with ethyl acetate, drying with anhydrous sodium sulfate, rotary evaporation, and thin layer chromatography to obtain a chiral hydroxy compound, wherein the eluent for thin layer chromatography purification was a mixture of ethyl acetate and petroleum ether, and the volume ratio of ethyl acetate to petroleum ether in the mixture was 1:5. The chemical reaction equation is as follows: .

[0028] In this example, Bolm ligand was not used, and a non-chiral racemic sample was prepared by the same method as above, and the peak times of the two enantiomers under the same conditions were determined. The H NMR spectrum, C NMR spectrum and HPLC spectrum of the target product are shown in Figures 4 to 7 As shown, Figure 4 The H NMR spectrum of the synthesized target product is Figure 5 The NMR carbon spectrum of the target product synthesized is Figure 6 The HPLC spectrum of the synthetic target product racemate is shown in Figure 2. Figure 7 The HPLC spectrum of the synthesized target product is as follows: 1H NMR (400 MHz, Chloroform-d) δ = 8.05 - 7.89 (m, 2H), 7.62 - 7.57(m, 1H), 7.51-7.42 (m, 4H), 7.42 - 7.35 (m, 2H), 7.34 - 7.28 (m, 1H), 5.36(t, J = 6.1 Hz, 1H), 3.43 - 3.33 (m, 2H); 13 C NMR (101 MHz, Chloroform-d) δ = 200.20, 142.95, 136.57, 133.67,128.72, 128.59, 128.17, 127.70, 125.77, 70.06, 47.41; HPLC (Dialcel Chiralcel OD-H, nhexane / iPrOH = 90 / 10, flow rate 1.0mL / min); tR = 12.4 min (S, minor), tR =13.4 min (R, major).

[0029] In the chiral boron addition reaction of chalcone catalyzed by copper oxide nanosheets, the yield and enantioselectivity of the product (chiral boron-based compounds) were 92% and 97%, respectively.

[0030] Example 2 This embodiment uses the prepared copper oxide nanosheets as a catalyst to catalyze the chiral boron addition reaction of an α,β-unsaturated ketone compound (3-naphthyl-1-phenylpropyl-2-en-1-one), comprising the following steps: Step (1): Add 3-naphthyl-1-phenylpropyl-2-en-1-one, bipyraclostrobin, copper oxide nanosheets, and Bolm ligand into a mixed solvent of 2 mL toluene / distilled water = 9:1 (v / v), and stir at room temperature for 12 h, wherein the molar ratio of 3-naphthyl-1-phenylpropyl-2-en-1-one, bipyraclostrobin, copper oxide nanosheets, and Bolm ligand is 1:1.2:0.015:0.02, and the molar ratio of copper oxide nanosheets to solvent is 20 mg:10 mL; the chemical reaction equation is as follows: ; Among them, the structural formula of Bolm chiral ligand is: ; Step (2): after the reaction in step (1) is completed, the obtained mixed system is centrifuged and filtered, the obtained liquid phase is extracted with ethyl acetate, the extracted organic phase is dried over anhydrous sodium sulfate, and then the organic solvent is removed by rotary evaporation to obtain a boride product; Since the prepared chiral boron compound is easy to deteriorate when using liquid chromatography detection, in order to facilitate subsequent chiral testing, it is oxidized to a stable hydroxyl compound (target product). The specific steps are as follows: The crude boride product (75 mg) was transferred to a reaction bottle, and a magnetic stirrer, sodium borate tetrahydrate (244 mg), tetrahydrofuran (3 mL), and deionized water (2 mL) were added in sequence to react at room temperature for 4 h, followed by extraction with ethyl acetate, drying with anhydrous sodium sulfate, rotary evaporation, and thin layer chromatography to obtain a chiral hydroxy compound, wherein the eluent for thin layer chromatography purification was a mixture of ethyl acetate and petroleum ether, and the volume ratio of ethyl acetate to petroleum ether in the mixture was 1:5. The chemical reaction equation is as follows:

[0031] In this example, Bolm ligand was not used, and a non-chiral racemic sample was prepared by the same method as above, and the peak times of the two enantiomers under the same conditions were determined. The H NMR spectrum, C NMR spectrum and HPLC spectrum of the target product are shown in Figures 8 to 11 As shown, Figure 8 The H NMR spectrum of the synthesized target product is Fig. 9 The NMR carbon spectrum of the target product synthesized is Fig.10 The HPLC spectrum of the synthetic target product racemate is shown in Figure 2. Fig.11 The HPLC spectrum of the synthesized target product is as follows: 1 H NMR (400 MHz, Chloroform-d) δ = 8.10 - 8.02 (m, 1H), 8.00 - 7.94(m, 2H), 7.92 - 7.89 (m, 1H), 7.85 - 7.77 (m, 2H), 7.60 - 7.45 (m, 6H), 6.16(dd, J = 9.3, 2.5 Hz, 1H), 3.63 - 3.37 (m, 2H); 13C NMR (101 MHz, Chloroform-d) δ = 200.33, 138.54, 136.57, 133.82,133.71, 129.95, 129.09, 128.74, 128.24, 128.10, 126.28, 125.68, 125.60,123.20, 122.85, 66.86, 46.85; HPLC (Dialcel Chiralcel OD-H, nhexane / iPrOH = 95 / 5, flow rate 1.0 mL / min); tR = 12.4 min (S, minor), tR = 33.7 min (R, major).

[0032] In the chiral boron addition reaction of 3-naphthyl-1-phenylpropyl-2-en-1-one catalyzed by copper oxide nanosheets, the yield and enantioselectivity of the product (chiral boron-based compounds) were 91% and 98%, respectively.

[0033] Example 3 This embodiment uses the prepared copper oxide nanosheets as a catalyst to catalyze the chiral boron addition reaction of an α,β-unsaturated ketone compound (1-(4-bromophenyl)-3-(4-chlorophenyl)prop-2-en-1-one), comprising the following steps: Step (1): 1-(4-bromophenyl)-3-(4-chlorophenyl)prop-2-en-1-one, bipyraclostrobin, copper oxide nanosheets, and Bolm ligands are added to a mixed solvent of 2 mL toluene / distilled water = 9:1 (v / v), and mixed and stirred at room temperature for 12 h. The molar ratio of 1-(4-bromophenyl)-3-(4-chlorophenyl)prop-2-en-1-one, bipyraclostrobin, copper oxide nanosheets, and Bolm ligands is 1:1.2:0.015:0.02, and the molar ratio of copper oxide nanosheets to solvent is 20 mg:10 mL. The chemical reaction equation is as follows: ; Among them, the structural formula of Bolm chiral ligand is: ; Step (2): after the reaction in step (1) is completed, the obtained mixed system is centrifuged and filtered, the obtained liquid phase is extracted with ethyl acetate, the extracted organic phase is dried over anhydrous sodium sulfate, and then the organic solvent is removed by rotary evaporation to obtain a boride product; Since the prepared chiral boron compound is easy to deteriorate when using liquid chromatography detection, in order to facilitate subsequent chiral testing, it is oxidized to a stable hydroxyl compound (target product). The specific steps are as follows: The crude boride product (81 mg) was transferred to a reaction bottle, and a magnetic stirrer, sodium borate tetrahydrate (244 mg), tetrahydrofuran (3 mL), and deionized water (2 mL) were added in sequence to react at room temperature for 4 h, followed by extraction with ethyl acetate, drying with anhydrous sodium sulfate, rotary evaporation, and thin layer chromatography to obtain a chiral hydroxy compound, wherein the eluent for thin layer chromatography purification was a mixture of ethyl acetate and petroleum ether, and the volume ratio of ethyl acetate to petroleum ether in the mixture was 1:5. The chemical reaction equation is as follows:

[0034] In this example, Bolm ligand was not used, and a non-chiral racemic sample was prepared by the same method as above, and the peak times of the two enantiomers under the same conditions were determined. The H NMR spectrum, C NMR spectrum and HPLC spectrum of the target product are shown in Figures 12 to 15 As shown, Fig.12 The H NMR spectrum of the synthesized target product is Fig.13 The NMR carbon spectrum of the target product synthesized is Fig.14 The HPLC spectrum of the synthetic target product racemate is shown in Figure 2. Fig.15 The HPLC spectrum of the synthesized target product is as follows: 1 H NMR (400 MHz, Chloroform-d) δ = 7.84 - 7.75 (m, 2H), 7.69 - 7.60(m, 2H), 7.35 (d, J = 2.9 Hz, 4H), 5.32 (dd, J = 7.7, 4.4 Hz, 1H), 3.96 (dd,J = 7.6, 5.5 Hz, 1H), 3.35 - 3.19 (m, 2H); 13 C NMR (101 MHz, Chloroform-d) δ = 198.77, 141.30, 135.15, 133.44,132.10, 129.64, 129.09, 128.74, 127.14, 69.34, 47.28; HPLC (Dialcel Chiralcel OD-H, nhexane / iPrOH = 90 / 10, flow rate 1.0mL / min); tR = 14.4 min (S, minor), tR = 16.2 min (R, major).

[0035] In the chiral boron addition reaction of 1-(4-bromophenyl)-3-(4-chlorophenyl)prop-2-en-1-one catalyzed by copper oxide nanosheets, the yield and enantioselectivity of the product (chiral boron-based compounds) were 84% and 95%, respectively.

[0036] It should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, without departing from the scope of the main purpose of the present invention, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A catalytic synthesis method of an asymmetric chiral boron compound, characterized in that: The following steps are involved: An α,β-unsaturated ketone compound, biboric acid pinacol ester, a catalyst, a chiral ligand and a solvent are mixed and reacted at room temperature for 6 to 24 hours. After the reaction, the obtained mixed system is post-treated to obtain an asymmetric chiral boron compound product; Wherein, the structural formula of the α,β-unsaturated ketone compound is: ； Wherein, R1 is phenyl, substituted phenyl or naphthyl, and R2 is phenyl or substituted phenyl; The catalyst is a copper oxide nanosheet, and the copper oxide nanosheet has a length of 500-3500nm, a width of 100-1400nm, and a thickness of 20-40nm.

2. The catalytic synthesis method of an asymmetric chiral boron compound according to claim 1, characterized in that: The method for preparing the copper oxide nanosheets comprises the following steps: uniformly mixing a copper salt solution and a NaOH solution, heating to 80° C. to 110° C. for reaction for 10 h to 15 h, filtering, washing and drying to obtain the copper oxide nanosheets.

3. The catalytic synthesis method of an asymmetric chiral boron compound according to claim 2, characterized in that: The copper salt includes one or more of copper chloride, copper sulfate, and copper acetate; the concentration of the copper salt solution is 0.1-0.3 mol / L; the volume ratio of the copper salt solution to the NaOH solution is 1:(2-4).

4. The catalytic synthesis method of an asymmetric chiral boron compound according to claim 2, characterized in that: The drying temperature is 50° C. to 80° C., and the drying time is 10 h to 15 h.

5. The catalytic synthesis method of an asymmetric chiral boron compound according to claim 1, characterized in that: The structural formula of the chiral ligand is: 。 6. The catalytic synthesis method of an asymmetric chiral boron compound according to claim 1, characterized in that: The molar ratio of the α,β-unsaturated ketone compound, the biboric acid pinacol ester, the catalytic material and the chiral ligand is 1:1.2:0.01-0.05:0.01-0.

06.

7. The catalytic synthesis method of an asymmetric chiral boron compound according to claim 6, characterized in that: The molar ratio of the α,β-unsaturated ketone compound, the biphenyl borate, the catalytic material and the chiral ligand is 1:1.2:0.015:0.

02.

8. The catalytic synthesis method of an asymmetric chiral boron compound according to claim 1, characterized in that: The usage ratio of the copper oxide nanosheets to the solvent is 10-40 mg:10 mL.

9. The catalytic synthesis method of an asymmetric chiral boron compound according to claim 1, characterized in that: The solvent is a mixture of toluene and water; the volume ratio of toluene to water is 7-11:

1.

10. The catalytic synthesis method of an asymmetric chiral boron compound according to claim 1, characterized in that: The post-treatment comprises the following steps: separating the obtained mixed system into solid and liquid to obtain a solid phase and a liquid phase, extracting the liquid phase to obtain an organic phase, drying the organic phase with a desiccant, and removing the solvent to obtain an asymmetric chiral boron compound.

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