Method for catalyzing hydroboration reaction of alkyne and B2Pin2 by heterogeneous catalyst
By preparing the heterogeneous catalyst OH-HKUST-1 under additive-free conditions, the problem of high temperature and high pressure and transition metal catalysts required for hydroborogenesis of alkynes and B2Pin2 in the prior art is solved, and efficient catalyzing of alkynes and alkynes at room temperature is achieved. The hydroborohydrogenation reaction of B2Pin2 is highly selective and low cost, and is suitable for green industrial production.
Patent Information
- Application Number
- CN202411148579.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2024-12-24
AI Technical Summary
The existing methods of catalyzing the hydrotranization of alkynes with B2Pin2 boromolysis require high temperature and high pressure, long-term and transition metal catalysts, resulting in high costs, insufficient environmental pollution and atomic economy, and the synthesis of MOFs is complex, affecting catalytic activity.
Using heterogeneous catalysts without additives, the heterogeneous catalyst was used to stir copper nitrate trihydrate, tribene tricyclic acid and 5-hydroxy isophthalic acid in anhydrous methanol, and the reaction was made in hydrothermal reaction vessel. The phase catalyst OH-HKUST-1 is used to catalyze the borohydrogenation reaction of alkynes and B2Pin2 at room temperature to achieve high selectivity and high conversion.
It has achieved efficient catalyzing of borohydrogenation reaction between alkynes and B2Pin2 at room temperature, with high conversion and selectivity, easy to prepare and low cost, suitable for green industrial production, and easy to recover the catalyst.
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Figure CN119176826A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a preparation method of a heterogeneous catalyst and a method for catalyzing the hydroboration reaction of alkynes and B2Pin2 without additives. Background Art
[0002] Vinyl boronates are a class of widely used intermediates in pharmaceutical and synthetic chemistry. They have good reactivity and stability, are easy to store and have low toxicity. They can be widely involved in certain cross-coupling reactions to construct new carbon-carbon bonds. In this field, although noble transition metals have played an important role, their high cost, low abundance and environmental pollution issues have promoted the use of more earth-abundant and sustainable alkali metal catalysts.
[0003] At present, the hydroboration reaction of alkynes with pinacol diboron (B2Pin2) is an effective method for synthesizing vinyl borate esters, which usually requires the use of transition metal catalysts, especially copper-based catalysts. However, this method has some limitations, such as the need to use bases that are sensitive to moisture and air, such as sodium tert-butoxide or potassium tert-butoxide, and the production of boron-containing byproducts, resulting in insufficient atom economy. Under these conditions, metal-organic framework compounds came into being. As a new type of inorganic material, metal-organic framework compounds have particularly high porosity and surface area, and the framework structure of the material is diverse and easy to control. These characteristics make it have broad application prospects in optics, sensing, medicine, magnetism, gas adsorption and separation, catalysis, etc. However, for the catalytic hydroboration reaction of alkynes with B2Pin2, MOFs also show the disadvantages of requiring a long time and high temperature to achieve high selectivity and high conversion rate.
[0004] The synthesis of MOFs depends on many factors, reaction time and temperature, the solvent used, the nature of the metal ions and organic ligands, the size of the nodes and their structural characteristics, the presence of counterions and the kinetics of crystallization, all of which affect nucleation and crystal growth. In most cases, the synthesis of MOFs is carried out in the liquid phase through a mixed solution of ligands and metal salts. The choice of solvent should pay attention to its reactivity, solubility and redox potential. The solvent also plays an important role in determining the thermodynamics and activation energy of each reaction. In most cases, the classical method for the synthesis of MOFs is solvothermal or hydrothermal conditions at high temperature and pressure. Therefore, it is necessary to explore the catalytic activity of MOFs synthesized under different reaction conditions. Summary of the invention
[0005] The invention provides a method for catalyzing the hydroboration reaction of alkynes and B2Pin2 using a heterogeneous catalyst. The method comprises the following steps: adding a heterogeneous catalyst, B2Pin2, alkynes and a solvent to a reactor in sequence without any additives, and reacting the mixture under stirring in a nitrogen atmosphere at room temperature to obtain an (E)-vinyl borate product. The heterogeneous catalyst comprises: adding copper nitrate trihydrate, trimesic acid and 5-hydroxyisophthalic acid to a mixed solvent in sequence under stirring, and transferring the mixture to a hydrothermal reactor after stirring. The mixture reacts at 120° C., and naturally cools to room temperature after the reaction is completed. The product is obtained by solid-liquid separation, solid washing and vacuum drying.
[0006] The solvent is anhydrous methanol, the molar ratio of alkyne to B2Pin2 is 1:4, and the amount of heterogeneous catalyst added is 3% of the molar amount of alkyne.
[0007] The molar ratio of copper nitrate trihydrate: trimesic acid and 5-hydroxyisophthalic acid is 3:2, and the added amount of 5-hydroxyisophthalic acid is 10-20% of the total molar amount of trimesic acid and 5-hydroxyisophthalic acid; the mixed solvent is prepared by mixing anhydrous ethanol and deionized water in a volume ratio of 1:1.
[0008] The alkyne is selected from phenylacetylene, 4-ethynylbiphenyl, 4-methoxyphenylacetylene, 3-ethynylthiophene, 3-chloro-1-ethynylbenzene, 2-ethynylnaphthalene, and 4-ethynyltoluene.
[0009]
[0010] Compared with the prior art, the present invention has the following advantages:
[0011] (1) The heterogeneous catalyst of the present invention is used for the hydroboration reaction of alkynes and B2Pin2 without additives, and it catalyzes the hydroboration reaction at room temperature and exhibits extremely high conversion rate and selectivity;
[0012] (2) The heterogeneous catalyst preparation method of the present invention is simple, easy to operate, low in cost, high in catalytic efficiency, excellent in selectivity, and easy to recover the catalyst, thus easily achieving the requirements of green industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 is the XRD pattern of the heterogeneous catalyst synthesized in different preparation ratios in Example 1;
[0014] Figure 2 It is a (E)-vinyl borate ester prepared from phenylacetylene as an alkyne. 1 H NMR spectra;
[0015] Figure 3 It is a (E)-vinyl borate ester prepared from phenylacetylene as an alkyne. 13 C NMR spectra;
[0016] Figure 4 It is a (E)-vinyl borate ester prepared from 4-ethynylbiphenyl 1 H NMR spectra;
[0017] Figure 5 It is a (E)-vinyl borate ester prepared from 4-ethynylbiphenyl 13 C NMR spectra;
[0018] Figure 6 It is a (E)-vinyl borate ester prepared from 4-methoxyphenylacetylene as alkyne. 1 H NMR spectra;
[0019] Figure 7 It is a (E)-vinyl borate ester prepared from 4-methoxyphenylacetylene as alkyne. 13 C NMR spectra;
[0020] Figure 8 It is a (E)-vinyl borate ester prepared from 3-ethynylthiophene as alkyne. 1 H NMR spectra;
[0021] Fig. 9 It is a (E)-vinyl borate ester prepared from 3-ethynylthiophene as alkyne. 13 C NMR spectra;
[0022] Fig.10 It is a (E)-vinyl borate ester prepared from 3-chloro-1-ethynylbenzene as alkyne. 1 H NMR spectra;
[0023] Fig.11 It is a (E)-vinyl borate ester prepared from 3-chloro-1-ethynylbenzene as alkyne. 13 C NMR spectra;
[0024] Fig.12 It is a (E)-vinyl borate ester prepared from 2-ethynylnaphthalene as an alkyne. 1 H NMR spectra;
[0025] Fig.13 It is a (E)-vinyl borate ester prepared from 2-ethynylnaphthalene as an alkyne. 13 C NMR spectra;
[0026] Fig.14 It is a (E)-vinyl borate ester prepared from 4-ethynyltoluene as alkyne. 1 H NMR spectra;
[0027] Fig.15 It is a (E)-vinyl borate ester prepared from 4-ethynyltoluene as alkyne. 13C NMR spectra;
[0028] Fig.16 It is the (E)-vinyl borate ester prepared from cyclopropylacetylene as alkyne. 1 H NMR spectra;
[0029] Fig.17 It is the (E)-vinyl borate ester prepared from cyclopropylacetylene as alkyne. 13 C NMR spectrum. DETAILED DESCRIPTION
[0030] The present invention is further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the contents described above. The methods in the embodiments are conventional methods unless otherwise specified, and the reagents used are conventional commercially available reagents or reagents prepared according to conventional methods unless otherwise specified;
[0031] Example 1: Preparation of heterogeneous catalyst
[0032] Under stirring conditions, copper nitrate trihydrate (3 mmol), trimesic acid (1.9 mmol), and 5-hydroxyisophthalic acid (0.1 mmol) were added to 24 mL of anhydrous ethanol-deionized water (volume ratio 1:1) mixed solvent in sequence, and after stirring evenly, the mixture was transferred to a 100 mL polytetrafluoroethylene-lined stainless steel hydrothermal reactor, and reacted in an oven at 120° C. for 24 h to produce crystals. After the reaction was completed, it was naturally cooled to room temperature, and centrifuged at 8000 r / min for 5 min to separate and obtain a solid. The solid was washed three times with anhydrous ethanol, and vacuum dried at 80° C. for 12 h to obtain a heterogeneous catalyst OH-HKUST-1-5%;
[0033] According to the above method, heterogeneous catalysts OH-HKUST-1-10%, OH-HKUST-1-15%, OH-HKUST-1-20%, OH-HKUST-1-25%, OH-HKUST-1-30% were prepared, and the addition amount of 5-hydroxyisophthalic acid was 10-30% of the total molar amount of trimesic acid and 5-hydroxyisophthalic acid; the XRD spectrum of the prepared heterogeneous catalyst is shown in Figure 1 , compared with the standard HKUST-1 simulation spectrum, dense peaks appear at smaller 2θ angles, which indicates that the material has many tiny pores or cavities.
[0034] Meanwhile, the HKUST-1 catalyst was prepared according to the above method, and 5-hydroxyisophthalic acid was not added during the preparation of the HKUST-1 catalyst.
[0035] Example 2: Preparation of (E)-vinyl borate by phenylacetylene and B2Pin2 catalyzed by the heterogeneous catalyst prepared in Example 1
[0036]
[0037] A heterogeneous catalyst (0.015 mmol), B2Pin2 (2 mmol), phenylacetylene (0.5 mmol), and anhydrous methanol (1 mL) were sequentially added to a 5 mL Shrek reaction tube equipped with a magnetic stirrer. The reaction tube was evacuated and filled with nitrogen gas having a volume concentration of 99.99% through a double-row tube, and the process was repeated three times. The reaction tube containing the reaction mixture was then subjected to magnetic stirring at 25° C. for 8 h. After the reaction, the solid catalyst was removed by filtration. The filtrate was purified by silica gel column chromatography (eluted with a mixture of petroleum ether and ethyl acetate in a volume ratio of 100:1). The eluate was collected and dried by rotary evaporation at 40° C. to obtain the (E)-vinyl borate product. 1 H NMR and 13 C NMR spectra Figure 2 , 3 , 1 H NMR (600MHz, CDCl3) δ7.49(d,J=7.0Hz,2H),7.40(d,J=18.4Hz,1H),7.34(t,J=7.5Hz,2H),7.29(t,J=7.3Hz,1H),6.18(d,J=18.4Hz,1H),1.32(s,12H). 13 C NMR (151MHz, CDCl3) δ149.64,137.51,129.04,128.70,127.18,116.39,83.48,24.93.
[0038] pass 1 H NMR analysis determined the product yield, and the results are shown in the following table:
[0039] catalyst Yield (%) Selectivity (%) OH-HKUST-1-5% 51％ 99.9％ OH-HKUST-1-10% 82％ 99.9％ OH-HKUST-1-15% 98％ 99.9％ OH-HKUST-1-20% 68％ 99.9％ OH-HKUST-1-25% 56％ 99.8％ OH-HKUST-1-30% 25％ 99.7％ HKUST-1 41％ 99.8％ .
[0040] Example 3: Preparation of (E)-vinyl borate ester by 4-ethynylbiphenyl and B2Pin2 catalyzed by heterogeneous catalyst OH-HKUST-1-15%
[0041]
[0042] The heterogeneous catalyst OH-HKUST-1-15% (0.015 mmol), B2Pin2 (2 mmol), 4-ethynylbiphenyl (0.5 mmol), and anhydrous methanol (1 mL) were added in sequence to a 5 mL Shrek reaction tube equipped with a magnetic stirrer. The reaction tube was evacuated and filled with nitrogen gas with a volume concentration of 99.99% through a double-row tube, and the reaction was repeated three times. The reaction tube containing the reaction mixture was then stirred magnetically at 25° C. for 8 h. After the reaction, the solid catalyst was removed by filtration. The filtrate was purified by silica gel column chromatography (eluted with a mixture of petroleum ether and ethyl acetate in a volume ratio of 100:1). The eluate was collected and dried by rotary evaporation at 40° C. to obtain the (E)-vinyl borate product. 1 H NMR analysis determined the product yield to be 97% with a selectivity of 99.9%.
[0043] (E)-vinyl borate 1 H NMR and 13 C NMR spectra Figure 4 , 5 ,1H NMR(600MHz, CDCl3)δ7.61(d,J=7.2Hz,2H),7.60-7.56(m,4H),7.46(d,J=3.1Hz,1H) ,7.44(d,J=7.7Hz,2H),7.35(t,J=7.4Hz,1H),6.22(d,J=18.4Hz,1H),1.33(s,12H). 13 C NMR (151MHz, CDCl3) δ149.13,141.71,140.65,136.54,128.93,127.65,127.59,127.40,127.11,116.47,83.51,24.95.
[0044] Example 4: Preparation of (E)-vinyl borate ester by 4-methoxyphenylacetylene and B2Pin2 catalyzed by heterogeneous catalyst OH-HKUST-1-15%
[0045]
[0046] The heterogeneous catalyst OH-HKUST-1-15% (0.015 mmol), B2Pin2 (2 mmol), 4-methoxyphenylacetylene (0.5 mmol), and anhydrous methanol (1 mL) were sequentially added to a 5 mL Shrek reaction tube equipped with a magnetic stirrer. The reaction tube was evacuated and filled with nitrogen gas with a volume concentration of 99.99% through a double-row tube, and the reaction was repeated three times. The reaction tube containing the reaction mixture was then subjected to magnetic stirring at 25° C. for 8 h. After the reaction, the solid catalyst was removed by filtration. The filtrate was purified by silica gel column chromatography (eluted with a mixture of petroleum ether and ethyl acetate in a volume ratio of 80:1). The eluate was collected and dried by rotary evaporation at 40° C. to obtain the (E)-vinyl borate product. 1 H NMR analysis determined the product yield to be 82% with a selectivity of 99.5%.
[0047] (E)-vinyl borate 1 H NMR and 13 C NMR spectra Figure 6 , 7 , 1 H NMR (600MHz, CDCl3) δ7.44(d,J=8.8Hz,2H),7.35(d,J=18.4Hz,1H),6.86(d,J=8.8Hz,2H),6.01(d,J=18.4Hz,1H),3.81(s,3H),1.31(s,12H). 13 C NMR (151MHz, CDCl3) δ160.38,149.19,130.44,128.60,114.06,113.52,83.35,55.40,24.93.
[0048] Example 5: Preparation of (E)-vinyl borate ester by 3-ethynylthiophene and B2Pin2 catalyzed by heterogeneous catalyst OH-HKUST-1-15%
[0049]
[0050] The heterogeneous catalyst OH-HKUST-1-15% (0.015 mmol), B2Pin2 (2 mmol), 3-ethynylthiophene (0.5 mmol), and anhydrous methanol (1 mL) were sequentially added to a 5 mL Shrek reaction tube equipped with a magnetic stirrer. The reaction tube was evacuated and filled with nitrogen gas with a volume concentration of 99.99% through a double-row tube, and the reaction was repeated three times. The reaction tube containing the reaction mixture was then stirred magnetically at 25° C. for 8 h. After the reaction, the solid catalyst was removed by filtration. The filtrate was purified by silica gel column chromatography (eluted with a mixture of petroleum ether and ethyl acetate in a volume ratio of 60:1). The eluate was collected and dried by rotary evaporation at 40° C. to obtain the (E)-vinyl borate product.1 H NMR analysis determined the product yield to be 99% with a selectivity of 99.9%.
[0051] (E)-vinyl borate 1 H NMR and 13 C NMR spectra Figure 8 , 9 , 1 H NMR (600MHz, CDCl3) δ7.39 (d, J = 18.3Hz, 1H), 7.32-7.29 (m, 2H), 7.28-7.25 (m, 1H), 5.95 (d, J = 18.3Hz, 1H), 1.31 (s, 12H). 13 C NMR (151MHz, CDCl3) δ143.27,141.27,126.26,125.08,125.06,116.25,83.41,24.90.
[0052] Example 6: Preparation of (E)-vinyl borate by 3-chloro-1-ethynylbenzene and B2Pin2 catalyzed by heterogeneous catalyst OH-HKUST-1-15%
[0053]
[0054] The heterogeneous catalyst OH-HKUST-1-15% (0.015 mmol), B2Pin2 (2 mmol), 3-chloro-1-ethynylbenzene (0.5 mmol), and anhydrous methanol (1 mL) were added in sequence to a 5 mL Shrek reaction tube equipped with a magnetic stirrer. The reaction tube was evacuated and filled with nitrogen gas with a volume concentration of 99.99% through a double-row tube, and the reaction was repeated three times. The reaction tube containing the reaction mixture was then stirred magnetically at 25° C. for 8 h. After the reaction, the solid catalyst was removed by filtration. The filtrate was purified by silica gel column chromatography (eluted with a mixture of petroleum ether and ethyl acetate in a volume ratio of 50:1). The eluate was collected and dried by rotary evaporation at 40° C. to obtain the (E)-vinyl borate product. 1 H NMR analysis determined the product yield to be 83% with a selectivity of 99.1%.
[0055] (E)-vinyl borate 1 H NMR and 13 C NMR spectra Fig.10 , 11 , 1H NMR (600MHz, CDCl3) δ7.43 (s, 1H), 7.33 (d, J = 4.4Hz, 1H), 7.30 (d, J = 18.4Hz, 1H), 7.24 (d, J = 4.3Hz, 2H), 6.15 (d, J = 18.4Hz, 1H), 1.29 (s, 12H). 13 C NMR (151MHz, CDCl3) δ147.95,139.39,134.65,129.93,128.88,127.04,125.32,118.24,83.62,24.91.
[0056] Example 7: Preparation of (E)-vinyl borate ester by 2-acetylenonaphthalene and B2Pin2 catalyzed by heterogeneous catalyst OH-HKUST-1-15%
[0057]
[0058] The heterogeneous catalyst OH-HKUST-1-15% (0.015 mmol), B2Pin2 (2 mmol), 2-ethynylnaphthalene (0.5 mmol), and anhydrous methanol (1 mL) were added in sequence to a 5 mL Shrek reaction tube equipped with a magnetic stirrer. The reaction tube was evacuated and filled with nitrogen gas with a volume concentration of 99.99% through a double-row tube, and the reaction was repeated three times. The reaction tube containing the reaction mixture was then stirred magnetically at 25° C. for 8 h. After the reaction, the solid catalyst was removed by filtration. The filtrate was purified by silica gel column chromatography (eluted with a mixture of petroleum ether and ethyl acetate in a volume ratio of 60:1). The eluate was collected and dried by rotary evaporation at 40° C. to obtain the (E)-vinyl borate product. 1 H NMR analysis determined the product yield to be 99% with a selectivity of 99.9%.
[0059] (E)-vinyl borate 1 H NMR and 13 C NMR spectra Fig.12 , 13 , 1 H NMR (600MHz, CDCl3) δ7.88-7.78(m,4H),7.71(dd,J=8.6,1.7Hz,1H),7.58(d,J=18.4Hz,1H),7.52-7.41(m,2H),6.31(d,J=18.4Hz,1H),1.34(s,12H). 13C NMR (151MHz, CDCl3) δ149.65,135.04,133.82,133.52,128.54,128.38,128.20,127.81,126.54,126.41,123.45,116.73,83.52,24.96.
[0060] Example 8: Preparation of (E)-vinyl borate by 4-ethynyltoluene and B2Pin2 catalyzed by heterogeneous catalyst OH-HKUST-1-15%
[0061]
[0062] The heterogeneous catalyst OH-HKUST-1-15% (0.015 mmol), B2Pin2 (2 mmol), 4-ethynyltoluene (0.5 mmol), and anhydrous methanol (1 mL) were added in sequence to a 5 mL Shrek reaction tube equipped with a magnetic stirrer. The reaction tube was evacuated and filled with nitrogen gas with a volume concentration of 99.99% through a double-row tube, and the reaction was repeated three times. The reaction tube containing the reaction mixture was then subjected to magnetic stirring at 25° C. for 8 h. After the reaction, the solid catalyst was removed by filtration. The filtrate was purified by silica gel column chromatography (eluted with a mixture of petroleum ether and ethyl acetate in a volume ratio of 100:1). The eluate was collected and dried by rotary evaporation at 40° C. to obtain the (E)-vinyl borate product. 1 H NMR analysis determined the product yield to be 80% with a selectivity of 99.4%.
[0063] (E)-vinyl borate 1 H NMR and 13 C NMR spectra Fig.14 , 15 , 1 H NMR (600MHz, CDCl3) δ7.39 (d, J = 8.0 Hz, 2H), 7.36 (s, 1H), 7.14 (d, J = 7.8 Hz, 2H), 6.12 (d, J = 18.5 Hz, 1H), 2.35 (s, 3H), 1.31 (s, 12H). 13 C NMR (151MHz, CDCl3) δ149.60,139.11,134.83,129.42,127.13,115.23,83.39,24.93,21.48.
[0064] Example 9: Preparation of (E)-vinyl borate by cyclopropylacetylene and B2Pin2 catalyzed by heterogeneous catalyst OH-HKUST-1-15%
[0065]
[0066] The heterogeneous catalyst OH-HKUST-1-15% (0.015 mmol), B2Pin2 (2 mmol), cyclopropylacetylene (0.5 mmol), and anhydrous methanol (1 mL) were added in sequence to a 5 mL Shrek reaction tube equipped with a magnetic stirrer. The reaction tube was evacuated and filled with nitrogen gas with a volume concentration of 99.99% through a double-row tube, and the reaction was repeated three times. The reaction tube containing the reaction mixture was then subjected to magnetic stirring at 25° C. for 8 h. After the reaction, the solid catalyst was removed by filtration. The filtrate was purified by silica gel column chromatography (eluted with a mixture of petroleum ether and ethyl acetate in a volume ratio of 80:1). The eluate was collected and dried by rotary evaporation at 40° C. to obtain the (E)-vinyl borate product. 1 H NMR analysis determined the product yield to be 54% with a selectivity of 99.2%.
[0067] (E)-vinyl borate 1 H NMR and 13 C NMR spectra Fig.16 , 17 , 1 H NMR(600MHz, CDCl3) δ6.04(dd,J=17.8,9.3Hz,1H),5.48(d,J=17.8Hz,1H),1.50(q t,J=8.6,4.6Hz,1H),1.23(s,12H),0.79(dd,J=8.0,2.4Hz,2H),0.58-0.45(m,2H). 13 C NMR (151MHz, CDCl3) δ158.77,115.10,83.02,24.85,17.18,8.01.
[0068] Example 10: Preparation of (E)-vinyl borate esters from different alkynes catalyzed by heterogeneous catalyst OH-HKUST-1-15%
[0069] The catalytic method of this embodiment is the same as that of embodiment 3, and the specific results are shown in the following table:
[0070]
[0071]
[0072] Example 11: Preparation of (E)-vinyl borate esters by phenylacetylene and B2Pin2 catalyzed by heterogeneous catalyst OH-HKUST-1-15% under different solvent conditions
[0073]
[0074] The method of this embodiment is the same as that of embodiment 2, except that anhydrous methanol is replaced with anhydrous ethanol, acetonitrile, isopropanol, heptane, and 1,4-dioxane;
[0075] The results showed that when the solvent was anhydrous ethanol, the yield of (E)-vinyl borate was 6%, when the solvent was 1,4-dioxane, the yield of (E)-vinyl borate was 2%, and when the solvents were acetonitrile, isopropanol, and heptane, respectively, (E)-vinyl borate could not be obtained.
[0076] Example 12: Preparation of (E)-vinyl borate ester by phenylacetylene and B2Pin2 catalyzed by heterogeneous catalysts prepared under different mixed solvent conditions
[0077]
[0078] The preparation method of the heterogeneous catalyst is the same as that of Example 1, except that the volume ratio of anhydrous ethanol to deionized water in the anhydrous ethanol-deionized water mixed solvent is 2:1 and 1:2, the mixed solvent is anhydrous ethanol:N,N-dimethylformamide=1:1, and the mixed solvent is deionized water:N,N-dimethylformamide=1:1; the catalytic reaction is the same as that of Example 2; the results show that the catalyst prepared when the mixed solvent is anhydrous ethanol-deionized water (2:1) catalyzes the reaction of phenylacetylene, and the yield of (E)-vinyl borate is The catalyst prepared when the mixed solvent was anhydrous ethanol-deionized water (1:2) catalyzed the reaction of phenylacetylene with a (E)-vinyl borate yield of 16%. The catalyst prepared when the mixed solvent was anhydrous ethanol-N,N-dimethylformamide (1:1) catalyzed the reaction of phenylacetylene with a (E)-vinyl borate yield of 15%. The catalyst prepared when the mixed solvent was deionized water-N,N-dimethylformamide (1:1) catalyzed the reaction of phenylacetylene with a (E)-vinyl borate yield of 13%.
Claims
1. A method for the hydroboration of alkynes with B2Pin2 using a heterogeneous catalyst, characterized in that: Under additive-free conditions, a heterogeneous catalyst, B2Pin2, alkyne and a solvent are sequentially added into a reactor, and the reaction is stirred at room temperature and in a nitrogen atmosphere to obtain an (E)-vinyl borate product.
2. The method according to claim 1, characterized in that: The solvent was anhydrous methanol.
3. The method according to claim 1, characterized in that: The molar ratio of alkyne to B2Pin2 was 1:
4.
4. The method according to claim 1, characterized in that: The heterogeneous catalyst is prepared by sequentially adding copper nitrate trihydrate, trimesic acid and 5-hydroxyisophthalic acid into a mixed solvent under stirring conditions, transferring the mixture into a hydrothermal reactor after stirring evenly, reacting at 120° C., naturally cooling to room temperature after the reaction is completed, separating the solid from the liquid, washing the solid, and vacuum drying.
5. The method according to claim 4, characterized in that: The molar ratio of copper nitrate trihydrate: trimesic acid and 5-hydroxyisophthalic acid is 3:2, and the added amount of 5-hydroxyisophthalic acid is 10-20% of the total molar amount of trimesic acid and 5-hydroxyisophthalic acid.
6. The method according to claim 4, characterized in that: The mixed solvent is prepared by mixing anhydrous ethanol and deionized water in a volume ratio of 1:1.