Supported Cu-based nanocluster catalyst and application thereof

Abstract

The invention discloses a supported Cu-based nanocluster catalyst and an application thereof in an alkyne hydroboration reaction, the molecular formula of a Cu-based nanocluster is Cu4 (dpph) 2 (PhC is equivalent to C) 4, and the molecular formula of the supported Cu-based nanocluster is Cu4 (dpph) 2 (PhC is equivalent to C) 4 / CNT (abbreviated as Cu4 / CNT). The Cu4 / CNT nanocluster catalyst disclosed by the invention can catalyze alkyne hydroboration reaction under a mild condition, and meanwhile, the catalyst can be recycled for five times, the activity is not obviously reduced, the substrate range is wide, and the stability and the universality are good.

Description

Technical Field

[0001] The invention relates to a supported Cu-based nanocluster catalyst and application thereof in alkyne hydroboration reaction. Background Art

[0002] Due to the unique reactivity of the CB bond, organoborane compounds have been widely used in various transformations, including the formation of carbon-carbon bonds and carbon-heteroatom bonds. Vinylborane, in particular, has a wide range of applications in organic synthesis and medicinal chemistry. Transition metal-catalyzed hydroboration of alkynes has become a direct and powerful strategy for the generation of vinylboranes. However, in the process of synthesizing vinylboranes by transition metal-catalyzed hydroboration of alkynes, the reaction yield is usually improved by increasing the reaction temperature. For example, in 2021, the Zhang group used PCN-222 (Cu) 1200nm as a catalyst to catalyze the hydroboration of alkynes at 80°C (Journal of Catalysis 401 (2021) 63–69). In 2023, Guo's group used Pt-Fe as a catalyst to catalyze the hydroboration of alkynes. At 25°C, the conversion rate was only 58%. The conversion rate increased with increasing reaction temperature. At 100°C, the conversion rate was as high as 99% (Adv. Mater. 2023, 35, 2211790). In 2024, Zheng's group used metal nanoclusters Cu 32 Se7 was used as a catalyst, 2 mL of DMSO was used as a solvent, and the alkyne hydroboration reaction was catalyzed at 50 ° C, with a yield of 99% in 9 hours (Aggregate. 2024; e679.). In 2024, Jiang group synthesized single-atom catalysts Cu1 / UiO-66-NO2, Cu1 / UiO-66 and Cu1 / UiO-66-NH2, using 10 mg of catalyst, 3 mL of ethanol, 2 μL of triethylamine, and 85 ° C to catalyze the alkyne hydroboration. Due to the electronic effect of the substituents on the catalyst, the activity of the catalyst has the following relationship Cu1 / UiO-66-NO2> Cu1 / UiO-66> Cu1 / UiO-66-NH2 (Angew. Chem. Int. Ed. 2024, e202415155 (3 of7)).

[0003] So far, the catalyst system for the hydroboration of alkynes to prepare vinyl borane still faces many challenges, such as increasing the reaction temperature or extending the reaction time in order to improve the conversion rate. Therefore, the preparation of catalysts with high activity and good performance has become a hot topic in current research. Summary of the invention

[0004] The present invention aims at the problems existing in the above-mentioned prior art and provides a supported Cu-based nanocluster catalyst and its application in the hydroboration reaction of alkynes. The supported Cu-based nanocluster catalyst of the present invention can efficiently catalyze the hydroboration reaction of alkynes under relatively mild reaction conditions, and also has good catalytic activity and stability, can be recycled for many times, has no obvious decrease in activity, and has good universality to substrates.

[0005] The supported Cu-based nanocluster catalyst of the present invention uses CNT as a carrier to support Cu-based nanoclusters, the molecular formula of the Cu-based nanoclusters is Cu4(dpph)2(PhC≡C)4, abbreviated as Cu4. The supported Cu-based nanocluster catalyst is abbreviated as Cu4 / CNT.

[0006] The actual content of Cu in the supported Cu-based nanocluster catalyst is 0.64 wt %.

[0007] The method for preparing the supported Cu-based nanocluster catalyst of the present invention comprises the following steps:

[0008] Step 1: First, synthesize Cu4 nanoclusters (Chin. J. Chem. 2021, 39, 937-941). The molecular formula of the nanoclusters is Cu4(dpph)2(PhC≡C)4, abbreviated as Cu4 nanoclusters.

[0009] Step 2: Ultrasonication is used to uniformly disperse CNT in the dichloromethane solution to obtain suspension A.

[0010] Step 3: Add the dichloromethane solution of Cu4 nanoclusters dropwise to the suspension A obtained in step 2, stir for 6 hours, centrifuge, wash and dry to obtain a supported Cu-based nanocluster catalyst Cu4 / CNT.

[0011] The invention discloses an application of a supported Cu-based nanocluster catalyst in catalyzing alkyne hydroboration reaction.

[0012] Under argon protection, alkynes and bis-pinacol diboron are used as reaction substrates, and the reaction is carried out in the presence of a base and a catalyst, with a reaction temperature of 30°C to 40°C and a reaction time of 2 h to 12 h. The above reaction conditions have super high activity for the reaction.

[0013] The alkyne includes one or more of phenylacetylene, 4-methylphenylacetylene, 4-tert-butylphenylacetylene, 4-fluorophenylacetylene, 4-chlorophenylacetylene, 4-bromophenylacetylene, 4-methoxyphenylacetylene, 3-chlorophenylacetylene, etc. The catalyst of the present invention also has good catalytic activity for alkynes containing different substituents.

[0014] The base is CH3ONa.

[0015] In the reaction system, the amount of alkyne added was 0.2 mmol, the amount of bispinacol diboron added was 0.3 mmol, the amount of base added was 0.04 mmol, and the amount of catalyst added was 40 mg~45 mg.

[0016] The catalytic reaction is carried out in a solvent system, wherein the solvent is one or more of tetradioxane, ethanol, DMSO, DMF, and toluene. Preferably, the composite solvent system of tetradioxane and ethanol is used, and the volume ratio of the two is 2:1.

[0017] The reaction time is preferably 4-8 h.

[0018] The beneficial effects of the present invention are embodied in:

[0019] 1. The catalyst is easy to prepare and has good catalytic performance.

[0020] 2. The catalyst of the present invention catalyzes the hydroboration reaction of alkynes and can achieve high-activity catalytic reaction under mild reaction conditions. The catalytic activity is basically unchanged after five cycles of use, and the substrate universality is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 ESI-MS and XRD patterns of Cu4 nanoclusters.

[0022] Figure 2 This is the crystal structure of Cu4 nanoclusters.

[0023] Figure 3 TEM image of Cu4 / CNT. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0025] Example 1: Preparation of Cu4 Nanoclusters

[0026] Pour 12 mg of Cu(NO3)2∙3H2O into a 50 mL round-bottom flask, then add 2 mL of ethanol to dissolve it. Then weigh 11.36 mg of 1,6-bis(diphenylphosphine)hexane and add it to a centrifuge tube containing 2 mL of dichloromethane to dissolve it. Then add 10 μL of phenylacetylene to form a mixed solution. Pour the solution into the ethanol solution containing Cu(NO3)2∙3H2O. The solution changes from blue to dark green and then to light green. Continue stirring for 20 minutes, slowly add the newly prepared sodium borohydride solution (0.125 mmol NaBH4 dissolved in 0.5 mL of ethanol) to the above solution, and the solution changes from green to dark red. The reaction continues at room temperature for 5 days, and the solution changes from dark red to orange and then to yellow. Centrifuge and spin dry first, then add 10 mL of n-hexane, centrifuge to retain the precipitate, and add 2 mL of dichloromethane to dissolve it. Use n-hexane / dichloromethane to grow single crystals, put them in the refrigerator, and precipitate green block crystals at 4°C for about a week. Referred to as Cu4 nanoclusters. Figure 1 ESI-MS and XRD patterns of Cu4 nanoclusters.

[0027] Example 2: Preparation of Cu4 / CNT catalyst

[0028] CNT (100 mg) was ultrasonically dispersed in 15 mL of dichloromethane solution, and then 1 mg of Cu4 nanoclusters was dissolved in 3 mL of dichloromethane and dropped into the above CNT solution drop by drop. After stirring for 6 h, the stirring was stopped. The solid was collected by centrifugation (10000 rpm). Subsequently, the solid was dried in a vacuum oven at 50 °C overnight to obtain a Cu4 / CNT catalyst. Figure 3 This is the TEM image of Cu4 / CNT. Through this characterization, it can be found that there are no metal nanoparticles on the surface of Cu4 / CNT.

[0029] Example 3: Cu4 / CNT catalyzed hydroboration of alkynes (different amounts of catalyst used).

[0030]

[0031] (1) 45 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 98.2%.

[0032] (2) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 97.6%.

[0033] (E)-4,4,5,5-tetramethyl-2-styryl-1,3,2-dioxaborolane

[0034] 1H NMR (400 MHz, CDCl3) δ 7.49 (d, J = 7.4 Hz, 2H), 7.40 (d, J = 18.6Hz, 1H), 7.36 – 7.28 (m, 3H), 6.17 (d, J = 18.4 Hz, 1H), 1.32 (s, 12H); 13CNMR (101 MHz, CHLOROFORM-D) δ 149.66, 137.64, 129.04, 128.72, 127.21, 83.50, 24.96.

[0035] Example 4: Cu4 / CNT catalyzed hydroboration of alkynes (different reaction solvents).

[0036] (1) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, and 1.5 mL tetradioxane were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 21.3%.

[0037] (2) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, and 1.5 mL ethanol were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 89.2%.

[0038] (3) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, and 1.5 mL DMSO were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 59.2%.

[0039] (4) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, and 1.5 mL DMF were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 69.2%.

[0040] (5) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, and 1.5 mL toluene were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 58.3%.

[0041] (6) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 97.6%.

[0042] Example 5: Cu4 / CNT catalyzed hydroboration of alkynes (different reaction temperatures).

[0043] (1) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 97.6%.

[0044] (2) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 78.0%.

[0045] Example 6: Cu4 / CNT catalyzed hydroboration of alkynes (different reaction bases).

[0046] (1) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 30 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 78.0%.

[0047] (2) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 30 °C under Ar protection for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 95.9%.

[0048] Example 7: Cu4 / CNT catalyzed hydroboration of alkynes (different reaction times).

[0049] (1) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 30 °C under Ar protection for 8 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 95.3%.

[0050] (2) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 °C under Ar protection for 6 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 93.9%.

[0051] (3) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 94.5%.

[0052] (4) 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol B2Pin2, 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 °C under Ar protection for 2 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 78.6%.

[0053] Example 8: CNT-catalyzed hydroboration of alkynes

[0054] 40 mg CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 ° C for 4 h under Ar protection. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was N.

[0055] Example 9: Cu4-catalyzed hydroboration of alkynes

[0056] 1 mg Cu4 catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacol)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30°C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 96.4%.

[0057] Based on the above implementation case, we selected the reaction conditions [40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacol)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetradioxane, 0.5 mL ethanol, reaction temperature of 30 °C, reaction time of 4 h, Ar protection] to test the stability of Cu4 / CNT catalyst for alkyne hydroboration. The reaction results are shown in the following implementation case.

[0058] Example 10: One cycle of Cu4 / CNT-catalyzed hydroboration of alkynes

[0059] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 ° C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 97.6%.

[0060] The recovered Cu4 / CNT catalyst was washed twice with methanol and dried in a vacuum oven at 35 °C for 12 h for the next recycling.

[0061] Example 11: Secondary Cycle of Cu4 / CNT Catalyzed Hydroboration of Alkynes

[0062] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 ° C for 4 h under Ar protection. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 97.4%.

[0063] Example 12: Three cycles of Cu4 / CNT-catalyzed hydroboration of alkynes

[0064] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 ° C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 90.6%.

[0065] Example 13: Four cycles of Cu4 / CNT-catalyzed hydroboration of alkynes

[0066] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 ° C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 92.9%.

[0067] Example 14: Five cycles of Cu4 / CNT-catalyzed hydroboration of alkynes

[0068] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacol)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 87.9%.

[0069] The following implementation case is the substrate expansion of Cu4 / CNT-catalyzed alkyne hydroboration reaction.

[0070]

[0071] Example 15: Cu4 / CNT catalyzed hydroboration of 4-methylphenylacetylene

[0072] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol 4-methylphenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 ° C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 95.4%.

[0073] Example 16: Cu4 / CNT catalyzed hydroboration of 4-tert-butylphenylacetylene

[0074] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol 4-tert-butylphenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30°C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 90.2%.

[0075] Example 17: Cu4 / CNT catalyzed hydroboration of 4-fluorophenylacetylene

[0076] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol 4-fluorophenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 ° C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 90.6%.

[0077] Example 18: Cu4 / CNT catalyzed hydroboration of 4-chlorophenylacetylene

[0078] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol 4-chlorophenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 ° C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 87.5%.

[0079] Example 19: Cu4 / CNT catalyzed hydroboration of 4-bromophenylacetylene

[0080] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacol)diboron (B2Pin2), 0.2 mmol 4-bromophenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30°C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 82.4%.

[0081] Example 20: Cu4 / CNT catalyzed hydroboration of 4-methoxyphenylacetylene

[0082] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol 4-methoxyphenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30 ° C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 96.5%.

[0083] Example 21: Cu4 / CNT catalyzed hydroboration of 3-chlorophenylacetylene

[0084] 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bispinacol diboron (B2Pin2), 0.2 mmol 3-chlorophenylacetylene, 1 mL tetradioxane, and 0.5 mL ethanol were added to a 10 mL Schlenk reaction bottle in sequence. The reaction was stirred at 30°C under Ar protection for 4 h. After the reaction was completed, the reaction solution was cooled to room temperature and the solid and liquid were separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 80.6%.

Claims

1. A supported Cu-based nanocluster catalyst, characterized in that: The supported Cu-based nanocluster catalyst uses CNT as a carrier to support Cu-based nanoclusters; the molecular formula of the Cu-based nanocluster is Cu4(dpph)2(PhC≡C)4, abbreviated as Cu4; the supported Cu-based nanocluster catalyst is abbreviated as Cu4 / CNT.

2. The supported Cu-based nanocluster catalyst according to claim 1, characterized in that: The content of Cu in the supported Cu-based nanocluster catalyst is 0.64 wt %.

3. The method for preparing the supported Cu-based nanocluster catalyst according to claim 1 or 2, characterized in that The steps include: Ultrasound was used to evenly disperse CNT in a dichloromethane solution to obtain a suspension A. A dichloromethane solution of Cu4(dpph)2(PhC≡C)4 nanoclusters was added dropwise to the suspension A, stirred for 6 hours, centrifuged, washed and dried to obtain a supported Cu-based nanocluster catalyst Cu4 / CNT.

4. Use of the supported Cu-based nanocluster catalyst according to claim 1 or 2 in catalyzing the hydroboration reaction of alkynes.

5. The use according to claim 4, characterized in that: Under argon protection, alkyne and bispinacol diboron are used as reaction substrates, and the reaction is carried out in the presence of a base and a catalyst. The reaction temperature is 30℃~40℃ and the reaction time is 2 h~12 h.

6. The use according to claim 5, characterized in that: The alkyne includes one or more of phenylacetylene, 4-methylphenylacetylene, 4-tert-butylphenylacetylene, 4-fluorophenylacetylene, 4-chlorophenylacetylene, 4-bromophenylacetylene, 4-methoxyphenylacetylene, 3-chlorophenylacetylene and the like.

7. The use according to claim 5, characterized in that: The base is CH3ONa.

8. The use according to claim 5, characterized in that: In the reaction system, the amount of alkyne added was 0.2 mmol, the amount of bispinacol diboron added was 0.3 mmol, the amount of base added was 0.04 mmol, and the amount of catalyst added was 40 mg~45 mg.

9. The use according to claim 5, characterized in that: The catalytic reaction is carried out in a solvent system, wherein the solvent is one or more of tetradioxane, ethanol, DMSO, DMF and toluene.

10. The use according to claim 9, characterized in that: The solvent is a composite solvent system of tetradioxane and ethanol, and the volume ratio of the two is 2:1.

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