Copper-based high-entropy alloy material and preparation method and application thereof

Abstract

The invention provides a copper-based high-entropy alloy material and a preparation method and application thereof.The copper-based high-entropy alloy material comprises Cu, Lu, Yb, Tm, Er and Ho, CuLuYbTmErHo-LDHs (layered double hydroxides) are prepared from cheap metal nitrate and a sodium hydroxide solution through a coprecipitation method, the CuLuYbTmErHo-LDHs (layered double hydroxides) are dried and ground into powder, thermal reduction is conducted in the atmosphere of hydrogen and nitrogen, and the copper-based high-entropy alloy material is obtained. The copper-based high-entropy alloy material is obtained; the copper-based high-entropy alloy material provided by the invention is used as a catalyst for an alkyne hydroboration reaction, the catalytic reaction condition is mild, no additive is needed, the reaction universality is good, the reaction yield is relatively high, the atom economy is high, the substrate universality is wide, the catalyst is easy to recover, the activity is not obviously reduced after the catalyst is recycled for more than 6 times, and the method is suitable for industrial production. The method has a potential large-scale application prospect.

Description

Technical Field

[0001] The present invention relates to the field of high entropy alloy materials and functional material catalysis technology, in particular to a copper-based high entropy alloy material and a preparation method and application thereof. Background Art

[0002] In the booming development of modern science and technology, boron-containing organic compounds are like a shining star, firmly occupying a key position in the fields of organic chemistry, materials science and drug research and development, and can be regarded as the core force driving technological innovation. It has multiple excellent "halos": stable chemical properties, no fear of the test of time, and can be stored safely for a long time; low toxicity, like a gentle and harmless partner, reducing health and environmental risks; moderate reactivity, precise control of reaction rhythm; rich reaction types, it is a "creative treasure box" in the hands of chemists; strong functional group compatibility, helping to build complex organic structures.

[0003] Because of these characteristics, boron-containing organic compounds have become key intermediates, ingeniously performing the "unique skill" of converting carbon-boron bonds into carbon-carbon and carbon-heteroatom bonds, drawing many possible blueprints for the research and development of new drugs and high-end materials. However, the traditional method of preparing organic boron compounds has many drawbacks. The use of active metal reagents to react with boron-containing compounds has poor substrate universality, like a "picky" eater, with very few raw materials to choose from; the atomic economy is low, and a large amount of raw materials become "abandoned", causing serious waste, and it is difficult to adapt to industrial and scientific research needs.

[0004] In-depth research shows that the traditional synthesis path is stuck in a quagmire. The preparation requires the introduction of transition metals, strong acids and bases, and a large number of organic reagents, which has soaring costs and cumbersome operations; the reaction conditions are harsh, the equipment requirements are high, the process is time-consuming, and the efficiency is low; it also leads to high costs, many impurities, and environmental pollution, which is contrary to the concept of green chemistry. The development of new green synthesis technology has become an urgent need in the field of organic synthesis.

[0005] At the same time, high entropy alloys have emerged in the field of materials science. This new type of solid solution is formed by the fusion of five or more metals, and has outstanding advantages over traditional alloys. It is rich in elements, has flexible and adjustable composition, and has strong structural plasticity; the configuration entropy increases with the increase of elements, giving rise to new properties. With customizable composition, high entropy alloys can be transformed into efficient catalysts in extreme environments after the introduction of catalytically active metals, opening up a new path for multi-metal atom catalysis.

[0006] In the early research of hydroboration reaction, noble metal catalysts such as Rh, Ir, and Pd were mostly used. However, noble metals have high toxicity, low natural reserves, high costs, are prone to catalyst deactivation, and the post-treatment is rather cumbersome. In contrast, copper materials are environmentally friendly (compared with most 4d and 5d transition metals, Cu has lower toxicity), easy to operate, have abundant and inexpensive natural reserves, and copper exhibits catalytic activity and regioselectivity no weaker than noble metal catalysts. More importantly, the characteristics of high abundance, low price, and environmental friendliness of copper materials are more in line with the requirements of green chemistry and meet the sustainable development needs of industrial production. However, in the existing technology, the catalytic efficiency of copper in many reaction systems is lower than that of other noble metal catalysts. Therefore, the development of new, highly efficient, pollution-free, and recyclable copper-based catalysts is the research focus to promote technological development.

[0007] In view of the synthesis dilemma of boron-containing organic compounds and the great potential of high-entropy alloys, the present invention focuses on copper-based high-entropy alloy materials. After rigorous comparison of catalytic performance, the optimal doping scheme is determined, and a catalyst with simple preparation, recyclable, and reusable properties is successfully created, which can efficiently catalyze the hydroboration reaction of alkynes and expands the functional applications of high-entropy alloys. Summary of the Invention

[0008] The purpose of the present invention is to overcome the shortcomings and deficiencies of the existing technology, and to provide a copper-based high-entropy alloy material, its preparation method and application. This material can be used as a catalyst in the hydroboration reaction of alkynes, and the preparation method of this catalyst is simple, easy to recycle and reusable. The technical solutions adopted by the present invention are as follows:

[0009] In the first aspect, a copper-based high-entropy alloy material is provided, which includes Cu and rare earth metal elements Lu, Yb, Tm, Er, and Ho.

[0010] In the second aspect, a preparation method of the above copper-based high-entropy alloy material is provided. It is mainly prepared by coprecipitation method using aqueous nitrate solutions of Cu and rare earth metal elements Lu, Yb, Tm, Er, and Ho and sodium hydroxide solution to obtain layered double hydroxides of copper-based high-entropy alloy, namely CuLuYbTmErHo-LDHs; then the prepared CuLuYbTmErHo-LDHs are dried, ground, and thermally reduced in an atmosphere of hydrogen and nitrogen to obtain the copper-based high-entropy alloy material.

[0011] Preferably, in the above steps, during the mixing process of the aqueous nitrate solutions of Cu, Lu, Yb, Tm, Er, and Ho and the sodium hydroxide solution, the pH of the mixed solution is maintained at 8.5. After titration, the resulting liquid is stirred for another 10 - 14 hours. The obtained product CuLuYbTmErHo-LDHs is centrifugally washed alternately with ethanol and water, and then dried in an oven at 55 - 65 °C for 4 - 8 h, ground into a powder. The conditions for thermal reduction are as follows: in an atmosphere of hydrogen and nitrogen, thermal reduction is carried out in a tubular furnace at 290 - 310 °C for 2 - 4 hours.

[0012] In a third aspect, there is provided the use of the above copper-based high-entropy alloy material in the hydroboration reaction of alkynes. The specific steps include: adding B 2 pin 2 , the copper-based high-entropy alloy, a base, a ligand, and the base are successively added to a Schlenk reaction tube containing a magnetic stir bar. Anaerobic operation is carried out through a double manifold. The reaction tube is evacuated and filled with 99.99% (volume concentration) argon three times. Subsequently, in an argon atmosphere, an alkyne and acetonitrile are added. The reaction tube containing the reaction mixture is reacted at 60 °C under argon and magnetic stirring for 10 hours. After the reaction is completed, the solid catalyst is removed by centrifugation, and the supernatant is passed through silica gel column chromatography (petroleum ether: ethyl acetate volume ratio of 50:1 as the eluent) to obtain a pure (E)-vinyl borate product, and the product structure is determined by 1 1H NMR.

[0013] In the above hydroboration reaction method, a feasible implementation method is as follows: the addition amount of the copper-based high-entropy alloy material catalyst is 9 mg, the amount of the ligand 4,4'-di-tert-butyl-2,2'-dipyridine is 11.2 mg, the amount of the base K 2 CO 3 is 124.2 mg, and the amount of the solvent acetonitrile is 6 ml.

[0014] In the above reaction method, the raw material alkyne compounds are preferably phenylacetylene, 2-ethylacetylene toluene, 4-ethynylanisole, 1-ethynyl-3-fluorobenzene, 4-chlorophenylacetylene, 4-tert-butylphenylacetylene, 4-ethynyl-α,α,α-trifluorotoluene, methyl 3-ethynylbenzoate, diphenylacetylene, 2-ethynylnaphthalene, 6-ethynyl-4,4-dimethyldihydrobenzothiophene, 3-ethynylthiophene, etc.

[0015] In the above reaction method, the preferred catalytic reaction conditions are: in an argon atmosphere, reaction at 60 °C for 10 hours.

[0016] The reaction equation of the present invention is:

[0017]

[0018] The beneficial effects of the present invention are as follows:

[0019] The element combination of the copper-based high-entropy alloy material provided by the present invention is the optimal element doping scheme; in the preparation method provided by the present invention, the metal nitrates used are relatively cheap, the reaction conditions required for the catalytic reaction are mild, additives are not required, the reaction has good universality, the reaction yield is relatively high, the atom economy is high, and it has specific regioselectivity and stereoselectivity; the high-entropy alloy material provided by the present invention will be used in the hydroboration reaction of alkynes, and it shows extremely high conversion rate and selectivity in the catalytic hydroboration reaction.

[0020] In summary, the copper-based high-entropy alloy material provided by the present invention, as a catalyst, has low preparation cost, high catalytic efficiency, excellent selectivity, easy recovery of the catalyst, meets the requirements of green industrial production, and has potential for large-scale application prospects. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, obtaining other drawings based on these drawings still belongs to the scope of the present invention.

[0022] Figure 1 It is a transmission electron microscope image of the copper-based high-entropy alloy CuLuYbTmErHo material prepared in Example 1 of the present invention, and it is observed that the structure of this catalyst is honeycomb-like porous nanoparticles;

[0023] Figure 2 It is a partial enlarged transmission electron microscope image of the copper-based high-entropy alloy CuLuYbTmErHo material prepared in Example 1 of the present invention. At a resolution of 5 nm, the lattice fringes of Cu can be clearly observed, corresponding to the (111) crystal plane of Cu;

[0024] Figure 3 It is an element distribution map of the copper-based high-entropy alloy CuLuYbTmErHo material prepared in Example 1 of the present invention. Obvious rare earth bright spots can be found in the Mapping under dark field, indicating that the rare earth elements are successfully doped;

[0025] Figure 4 It is a cyclic yield diagram of the copper-based high-entropy alloy CuLuYbTmErHo material prepared in Example 1 of the present invention after different times of catalyzing the hydroboration reaction of 4-ethynylanisole under the conditions of Example 2. Detailed Description of the Embodiments

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with examples, comparative examples, and the accompanying drawings.

[0027] Example 1

[0028] The present invention provides a copper-based high-entropy alloy material, and its preparation method includes the following steps:

[0029] Step 1: Dissolve Cu(NO 3 ) 2 ·6H 2 O (16 mmol) and Lu(NO 3 ) 3 ·6H 2 O (1.07 mmol), Yb(NO 3 ) 3 ·5H 2 O (1.07 mmol), Tm(NO 3 ) 3 ·6H 2 O (1.07 mmol), Er(NO 3 ) 3 ·5H 2 O (1.07 mmol), Ho(NO 3 ) 3 ·5H 2 O (1.07 mmol) in 20 ml of deionized water to form solution A. Dissolve NaOH (34.2 mmol) in 20 ml of deionized water to form solution B.

[0030] Step 2: Under magnetic stirring (600 rpm), simultaneously drip the prepared solutions A and B into 40 ml of deionized water. During this process, maintain the pH of the mixed solution at 8.5. Use a pH indicator. After titration, stir the resulting liquid for another 12 hours.

[0031] Step 3: Wash the product (CuLuYbTmErHo-LDHs) 4 times by alternating centrifugation (10000 rpm) with ethanol and water, then dry it in an oven at 60 °C for 6 h, and grind it into a blue powder.

[0032] Step 4: Thermally reduce the prepared powder in a hydrogen / nitrogen (5% hydrogen) atmosphere in a tubular furnace at 300 °C for 3 hours to obtain CuLuYbTmErHo-300 °C.

[0033] Comparative Examples 1 - 5

[0034] (1) Tm(NO 3 )3·6H 2O (2.66 mmol) and Ho(NO 3 ) 3 ·5H 2 O (2.66 mmol) was dissolved in 20 ml of deionized water to form Solution A. According to the same operation method for preparing Solution B and Steps 2, 3, and 4 in Example 1 above, HoTm-300 °C was prepared.

[0035] (2) Cu(NO 3 ) 2 ·6H 2 O (16 mmol) and Tm(NO 3 ) 3 ·6H 2 O (5.33 mmol) were dissolved in 20 ml of deionized water to form Solution A. According to the subsequent reaction steps above, CuTm-300 °C was prepared.

[0036] (3) Cu(NO 3 ) 2 ·6H 2 O (16 mmol) and Tm(NO 3 ) 3 ·6H 2 O (2.66 mmol), Ho(NO 3 ) 3 ·5H 2 O (2.66 mmol) were dissolved in 20 ml of deionized water to form Solution A. According to the subsequent reaction steps above, CuHoTm-300 °C was prepared.

[0037] (4) Cu(NO 3 ) 2 ·6H 2 O (16 mmol) and Tm(NO 3 ) 3 ·6H 2 O (1.78 mmol), Ho(NO 3 ) 3 ·5H 2 O (1.78 mmol), Er(NO 3 ) 3 ·5H 2 O (1.78 mmol) were dissolved in 20 ml of deionized water to form Solution A. According to the subsequent reaction steps above, CuHoTmEr-300 °C was prepared.

[0038] (5) Cu(NO 3 ) 2 ·6H 2 O (16 mmol) and Tm(NO 3) 3 ·6H 2 O (1.33 mmol), Ho(NO 3 ) 3 ·5H 2 O (1.22 mmol), Er(NO 3 ) 3 ·5H 2 O (1.33 mmol), Lu(NO 3 ) 3 ·6H 2 O (1.33 mmol) was dissolved in 20 ml of deionized water to form solution A. According to the subsequent reaction steps described above, CuLuTmErHo-300 °C was prepared.

[0039] Test Example

[0040] 5 mg of the catalyst was used to catalyze the hydroboration reaction of 4-ethynylanisole respectively. The reaction process was as follows: It was carried out under an anhydrous inert argon atmosphere. In a 25 mL dry Schlenk tube, bis(pinacolato)diboron (0.6 mmol, 2.0 eq), CuLuYbTmErHo-300 °C (9 mg), 4,4'-di-tert-butyl-2,2'-bipyridine (0.042 mmol, 14 mol%), and potassium carbonate (0.9 mmol, 3.0 eq) were added in sequence. Then the reaction tube was purged with argon, and an alkyne (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were further added to the reaction tube. The resulting solution was stirred at 60 °C for 10 hours. After the reaction was completed, the solvent was evaporated under vacuum, and the crude product obtained was purified by silica gel chromatography using petroleum ether / ethyl acetate = 50 / 1 as the eluting solvent to obtain the pure product of the desired product.

[0041] Cu-300 °C was obtained by firing copper powder at 300 °C for 3 hours. The conversion rates of the catalytic reactions of each catalyst are shown in Table 1. It can be seen that the catalytic effect of CuLuYbTmErHo-300 °C is better than that of other catalysts, and it is the optimal element-doped copper-based high-entropy alloy material.

[0042] Table 1 Yields of the hydroboration reactions of alkynes catalyzed by each catalyst

[0043]

[0044] Examples 2 - 13 The reaction of copper-based high-entropy alloy catalyzing different alkynes with bis(pinacolato)diboron is as follows:

[0045] Examples 2-13 were all carried out under an anhydrous inert argon atmosphere. In a 25 mL dry Schlenk tube, bis(pinacolato)diboron (B 2 Pin 2, 0.6 mmol, 2.0 eq), CuLuYbTmErHo - 300 °C (9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq). Then the reaction tube was purged with argon, and alkyne (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were added to the reaction tube. The resulting solution was stirred at 60 °C for 10 hours. After the reaction was completed, the solvent was evaporated in vacuo, and the crude product obtained was purified by silica gel chromatography using petroleum ether / ethyl acetate = 50 / 1 as the eluent solvent to obtain the pure product of the desired product. (The yields shown in Examples 2 - 12 are all isolated yields).

[0046] Example 2

[0047] In a 25 mL reaction tube, B was added successively 2 Pin 2 (0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq). Then the reaction tube was purged with argon, and phenylacetylene (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were added to the reaction tube. Under an argon atmosphere, the reaction was carried out at 60 °C for 10 hours. After the reaction was completed, the solution was evaporated and concentrated, and 67.4 mg of the product was obtained by column chromatography separation, with a yield of 98%.

[0048] The product was characterized, and the results were as follows: 1 1H NMR (400 Mz, CDCl 3 ) δ: 7.56–7.49 (m, 2H, Ar-H), 7.44 (d, J = 18.4 Hz, 1H, CH=), 7.40–7.30 (m, 3H, Ar-H), 6.21 (d, J = 18.4 Hz, 1H, CH=), 1.35 (s, 12H, Bpin-CH 3 ).

[0049] The structural formula of the product is:

[0050]

[0051] Example 3

[0052] In a 25 mL reaction tube, B was added successively 2 Pin 2(0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq). Then the reaction tube was purged with argon, and 2-ethynyltoluene (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were added to the reaction tube. The reaction was carried out at 60 °C for 10 hours under an argon atmosphere. After the reaction was completed, the mixture was evaporated to dryness and concentrated, and the product was obtained by column chromatography separation, with a yield of 92% and a mass of 73.2 mg.

[0053] The product was characterized, and the results were as follows: 1 H NMR (400 Mz, CDCl 3 ) δ: 7.70 (d, J = 18.3 Hz, 1H, CH=), 7.64–7.57 (m, 1H, Ar-H), 7.28–7.15 (m, 3H, Ar-H), 6.18–6.09 (d, J = 18.4 Hz, 1H, CH=), 2.47 (s, 3H, CH 3 ), 1.37 (s, 12H, Bpin-CH 3 ).

[0054] The structural formula of the product is:

[0055]

[0056] Example 4

[0057] In a 25 mL reaction tube, B 2 Pin 2 (0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq) were added successively. Then the reaction tube was purged with argon, and 4-ethynylanisole (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were added to the reaction tube. The reaction was carried out at 60 °C for 10 hours under an argon atmosphere. After the reaction was completed, the mixture was evaporated to dryness and concentrated, and the product was obtained by column chromatography separation, with a yield of 94% and a mass of 73.5 mg.

[0058] The product was characterized, and the results were as follows: 1 H NMR (400 Mz, CDCl 3) δ: 7.46 (d, J = 8.8 Hz, 2H, Ar-H), 7.38 (d, J = 18.4 Hz, 1H, CH=), 6.89 (d, J = 8.4 Hz, 2H, Ar-H), 6.04 (d, J = 18.4 Hz, 1H, CH=), 3.84 (s, 3H, OCH 3 ), 1.34 (s, 12H, Bpin-CH 3 )。

[0059] The structural formula of the product is:

[0060]

[0061] Example 5

[0062] In a 25 mL reaction tube, B 2 Pin 2 (0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), and potassium carbonate (0.9 mmol, 3.0 eq) were added in sequence. Then the reaction tube was purged with argon, and 1-ethynyl-3-fluorobenzene (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were further added to the reaction tube. The reaction was carried out at 60 °C for 10 hours under an argon atmosphere. After the reaction was completed, it was evaporated to concentrate, and the product (59.7 mg) was obtained by column chromatography separation with a yield of 80%.

[0063] The product was characterized, and the results were as follows: 1 H NMR (400 Mz, CDCl 3 ) δ: 7.37 (d, J = 18.4 Hz, 1H, CH=), 7.34 - 7.29 (m, 1H, Ar-H), 7.29 - 7.26 (m, 1H, Ar-H), 7.23 - 7.18 (m, 1H, Ar-H), 7.05 - 6.97 (m, 1H, Ar-H), 6.19 (d, J = 18 Hz, 1H, CH=), 1.34 (s, 12H, Bpin-CH 3 )。

[0064] The structural formula of the product is:

[0065]

[0066] Example 6

[0067] In a 25 mL reaction tube, B 2 Pin 2(0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq). Then the reaction tube was purged with argon, and 4-chlorophenylacetylene (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were added to the reaction tube. The reaction was carried out at 60 °C for 10 hours under an argon atmosphere. After the reaction was completed, the mixture was evaporated to dryness and concentrated, and the product was obtained by column chromatography separation in a yield of 92% (73.2 mg).

[0068] The product was characterized, and the results were as follows: 1 H NMR (400 Mz, CDCl 3 ) δ: 7.48–7.41 (m, 2H, CH=), 7.40–7.30 (m, 3H, CH=), 6.17 (d, J = 18.4 Hz, 1H, CH=), 1.35 (s, 12H, Bpin-CH 3 ).

[0069] The structural formula of the product was:

[0070]

[0071] Example 7

[0072] In a 25 mL reaction tube, B 2 Pin 2 (0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq) were added successively. Then the reaction tube was purged with argon, and 4-tert-butylphenylacetylene (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were added to the reaction tube. The reaction was carried out at 60 °C for 10 hours under an argon atmosphere. After the reaction was completed, the mixture was evaporated to dryness and concentrated, and the product was obtained by column chromatography separation in a yield of 85% (76.2 mg).

[0073] The product was characterized, and the results were as follows: 1 H NMR (400 Mz, CDCl 3 ) δ: 7.48–7.35 (m, 5H, VinylH + ArH), 6.14 (d, J = 18.4, 1H, CH=), 1.34 (s, 21H, CH).

[0074] The structural formula of the product was:

[0075]

[0076] Example 8

[0077] In a 25 mL reaction tube, add B 2 Pin 2 (0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq). Then purge the reaction tube with argon, and continue to add 4-ethynyl-α,α,α-trifluorotoluene (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) to the reaction tube. Under an argon atmosphere, react at 60 °C for 10 hours. After the reaction is completed, evaporate and concentrate, and separate by column chromatography to obtain 76.2 mg of the product, with a yield of 85%.

[0078] Characterize the product, and the results are as follows: 1 H NMR (400 Mz, CDCl 3 ) δ: 7.66–7.54 (m, 4H, Ar-H), 7.43 (d, J = 18.8 Hz, 1H, CH=), 6.29 (d, J = 18.4 Hz, 1H, CH=), 1.35 (s, 12H, Bpin-CH 3 ).

[0079] The structural formula of the product is:

[0080]

[0081] Example 9 Catalyze the hydroboration reaction of methyl 3-ethynylbenzoate with CuLuYbTmErHo - 300 °C

[0082] In a 25 mL reaction tube, add B 2 Pin 2 (0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq). Then purge the reaction tube with argon, and continue to add methyl 3-ethynylbenzoate (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) to the reaction tube. Under an argon atmosphere, react at 60 °C for 10 hours. After the reaction is completed, evaporate and concentrate, and separate by column chromatography to obtain 65.7 mg of the product, with a yield of 76%.

[0083] Characterize the product, and the results are as follows: 1 H NMR (400 Mz, CDCl 3) δ: 8.20 (t, J = 1.6 Hz, 1H, ArH), 7.99 (dt, J = 7.6, 1.6 Hz 1H, Ar-H), 7.70 (dt, J = 7.8, 1.5 Hz, 1H, ArH), 7.48–7.42 (m, 2H, VinylH + ArH), 6.28 (d, J = 18.5 Hz, 1H, CH=), 3.95 (s, 3H, CH 3 ), 1.35 (s, 12H, Bpin-CH 3 )。

[0084] The structural formula of the product is:

[0085]

[0086] Example 10

[0087] In a 25 mL reaction tube, B 2 Pin 2 (0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), and potassium carbonate (0.9 mmol, 3.0 eq) were added in sequence. Then the reaction tube was purged with argon, and diphenylacetylene (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were further added to the reaction tube. The reaction was carried out at 60 °C for 10 hours under an argon atmosphere. After the reaction was completed, it was concentrated by evaporation and the product was obtained by column chromatography separation, 70.8 mg, with a yield of 77%.

[0088] The product was characterized, and the results were as follows: 1 H NMR (400 Mz, CDCl 3 ) δ: 7.44 (s, 1H, CH=), 7.36–7.26 (m, 3H, ArH), 7.26–7.21 (m, 2H, ArH), 7.20 - 7.15 (m, 3H, ArH), 7.15 - 7.09 (m, 2H, ArH), 1.37 (s, 12H, Bpin-CH 3 )。

[0089] The structural formula of the product is:

[0090]

[0091] Example 11

[0092] In a 25 mL reaction tube, B 2 Pin 2(0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq). Then the reaction tube was purged with argon, and 2-ethynylnaphthalene (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were added to the reaction tube. The reaction was carried out at 60 °C for 10 hours under an argon atmosphere. After the reaction was completed, the mixture was evaporated to dryness and concentrated, and the product (59.1 mg) was obtained by column chromatography with a yield of 70%.

[0093] The product was characterized, and the results were as follows: 1 H NMR (400 Mz, CDCl 3 ) δ: 7.91–7.82 (m, 4H, ArH), 7.75 (dd, J = 8.6, 1.8 Hz, 1H, ArH), 7.62 (d, J = 18.4 Hz, 1H), 7.54 - 7.47 (m, 2H, ArH), 6.34 (d, J = 18.5 Hz, 1H, CH=), 1.39 (s, 12H, Bpin-CH 3 ).

[0094] The structural formula of the product is:

[0095]

[0096] Example 12

[0097] In a 25 mL reaction tube, B 2 Pin 2 (0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq) were added successively. Then the reaction tube was purged with argon, and 6-ethynyl-4,4-dimethyldihydrobenzothiopyran (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) were added to the reaction tube. The reaction was carried out at 60 °C for 10 hours under an argon atmosphere. After the reaction was completed, the mixture was evaporated to dryness and concentrated, and the product (45.2 mg) was obtained by column chromatography with a yield of 45%.

[0098] The product was characterized, and the results were as follows: 1 H NMR (400 MHz, CDCl 3)δ: 7.59 (d, J = 2.1 Hz, 1H), 7.45 (d, J = 18.3 Hz, 1H), 7.16 (d, J = 8.2 Hz, 1H), 7.32 (dd, J = 8.2, 2.0 Hz, 1H), 6.20 (d, J = 18.4 Hz, 1H, CH=), 3.18 - 3.11 (m, 2H), 2.10 - 2.03 (m, 2H), 1.43 (d, J = 2.4 Hz, 18H).

[0099] The structural formula of the product is:

[0100]

[0101] Example 13

[0102] Add B successively into a 25 mL reaction tube 2 Pin 2 (0.6 mmol, 2.0 eq), catalyst (CuLuYbTmErHo - 300 °C, 9 mg), 4,4'-di-tert-butyl-2,2'-dipyridine (0.042 mmol, 14 mol%), potassium carbonate (0.9 mmol, 3.0 eq). Then purge the reaction tube with argon, and continue to add 3-ethynylthiophene (0.3 mmol, 1.0 eq) and acetonitrile (6 mL) into the reaction tube. React at 60 °C for 10 hours under an argon atmosphere. After the reaction is completed, evaporate and concentrate, and separate the product by column chromatography to obtain 18.5 mg of the product, with a yield of 26%.

[0103] Characterize the product, and the results are as follows: 1 H NMR (400 Mz, CDCl 3 ) δ: 7.44 (d, J = 18.4 Hz, 1H, CH=), 7.38–7.34 (m, 2H, Ar-H), 7.32 (m, 1H, Ar-H), 6.00 (d, J = 18.3 Hz, 1H, CH=), 1.36 (s, 12H, Bpin-CH 3 ).

[0104] The structural formula of the product is:

[0105]

[0106] It should be understood that only the preferred embodiments of the present invention are disclosed above. The uses of these embodiments are only for explaining the present invention and are not intended to limit the protection scope of the present invention. In addition, it should also be understood that after reading the technical content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and all such equivalent forms of changes or modifications also fall within the protection scope defined by the claims of this application.

Claims

1. A copper-based high entropy alloy material, characterized in that: Including Cu, Lu, Yb, Tm, Er, Ho.

2. The method for preparing a copper-based high entropy alloy material according to claim 1, characterized in that: The following steps are involved: S1. A copper-based high entropy alloy layered double hydroxide, i.e., CuLuYbTmErHo-LDHs, is prepared by a coprecipitation method using a nitrate aqueous solution of Cu, Lu, Yb, Tm, Er, and Ho and a sodium hydroxide solution; S2. Dry and grind the CuLuYbTmErHo-LDHs prepared in step S1, and thermally reduce it in an atmosphere of hydrogen and nitrogen to obtain the copper-based high entropy alloy material.

3. The method for preparing a copper-based high entropy alloy material according to claim 2, characterized in that: In step S1, during the mixing process of the aqueous nitrate solution of Cu, Lu, Yb, Tm, Er, and Ho and the sodium hydroxide solution, the pH of the mixed solution is maintained at 8-9. After titration, the resulting liquid is stirred for another 10-14 hours, and the resulting product CuLuYbTmErHo-LDHs is washed by alternating centrifugation with ethanol and water.

4. The method for preparing a copper-based high entropy alloy material according to claim 2, characterized in that: In step S2, drying in an oven at 55-65° C. for 4-8 hours and grinding into powder; The thermal reduction conditions are: thermal reduction at 290-310° C. for 2-4 hours in a tube furnace in an atmosphere of hydrogen and nitrogen.

5. The use of a copper-based high entropy alloy material as claimed in claim 1, characterized in that: It is used to catalyze the hydroboration of alkynes.

6. The use according to claim 5, characterized in that: The application steps include: in the presence of a base, a ligand, a solvent and argon, using a copper-based high entropy alloy material to catalyze alkynes and biboric acid pinacol ester to obtain alkenyl borate.

7. The use according to claim 6, characterized in that: The base is K2CO3, the ligand is 4,4'-di-tert-butyl-2,2'-bipyridine, and the solvent is acetonitrile.

8. The use according to claim 6, characterized in that: The alkynes include: phenylacetylene, 2-ethynyltoluene, 4-ethynylanisole, 1-ethynyl-3-fluorobenzene, 4-chlorophenylacetylene, 4-tert-butylphenylacetylene, 4-ethynyl-α,α,α-trifluorotoluene, 3-ethynylbenzoic acid methyl ester, diphenylacetylene, 2-ethynylnaphthalene, 6-ethynyl-4,4-dimethyldihydrobenzothiopyran, and 3-ethynylthiophene.

9. The use according to claim 6, characterized in that: The conditions for the catalytic reaction are: under an argon atmosphere, at 55-65° C. for 8-12 hours.

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