Supported cu-based nanocluster catalyst and use thereof

Abstract

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

Description

TECHNICAL FIELD

[0001] The present application relates to a supported Cu-based nanocluster catalyst and its application in the hydroboration of alkynes. BACKGROUND

[0002] Due to the unique reactivity of C-B bond, organoborane compounds have been widely used in various transformation processes, including the formation of carbon-carbon and carbon-heteroatom bonds. In particular, vinyl borane, which 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 vinyl borane. However, in the process of synthesizing vinyl borane by transition metal-catalyzed hydroboration of alkynes, the reaction yield is usually improved by increasing the reaction temperature. For example, in 2021, Zhang group used PCN-222(Cu)1200nm as catalyst, 80℃ catalyzed hydroboration of alkynes (Journal of Catalysis 401 (2021) 63-69). In 2023, Guo group used Pt-Fe as catalyst to catalyze hydroboration of alkynes, at 25℃, the conversion rate was only 58%, and the conversion rate increased by increasing the reaction temperature, at 100℃, the conversion rate was as high as 99% (Adv. Mater. 2023, 35, 2211790). In 2024, Zheng group used metal nanocluster Cu 32 Se7 as catalyst, 2mL DMSO as solvent, 50℃ catalyzed hydroboration of alkynes, 9h yield up to 99% (Aggregate. 2024;e679.). In 2024, Jiang group synthesized single-atom catalyst Cu1 / UiO-66-NO2, Cu1 / UiO-66 and Cu1 / UiO-66-NH2, with 10 mg of catalyst, 3 mL of ethanol, 2 μL of triethylamine, 85℃ catalyzed hydroboration of alkynes. Due to the electronic effect of the substituents on the catalyst, the activity of the catalyst follows the 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 preparation of vinyl borane by hydroboration of alkynes still faces many challenges, such as increasing the reaction temperature or prolonging 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 spot of current research. SUMMARY

[0004] The present application provides a supported Cu-based nanocluster catalyst and its application in the hydroboration of alkynes.

[0005] The supported Cu-based nanocluster catalyst is prepared by loading Cu-based nanoclusters on CNT, and the molecular formula of the Cu-based nanoclusters is Cu4(dpph)2(PhC≡C)4, which is abbreviated as Cu4.

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

[0007] The preparation method of the supported Cu-based nanocluster catalyst comprises the following steps:

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

[0009] Step 2: ultrasonically disperse CNT in dichloromethane solution to obtain a suspension A.

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

[0011] The application of the supported Cu-based nanocluster catalyst in the catalysis of the hydroboration of alkynes.

[0012] Under the protection of argon, the reaction is carried out in the presence of alkynes and bis-pinacolato-diboron as reaction substrates, and a base and a catalyst, the reaction temperature is 30-40℃, and the reaction time is 2-12 h. The above reaction conditions have ultra-high activity for the reaction.

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

[0014] The base is CH3ONa.

[0015] The addition amount of the alkyne in the reaction system is 0.2 mmol, the addition amount of the bis-pinacolato-diboron is 0.3 mmol, the addition amount of the base is 0.04 mmol, and the addition amount of the catalyst is 40 mg to 45 mg.

[0016] The catalytic reaction is carried out in a solvent system, and the solvent is one or more of tetrahydrofuran, ethanol, DMSO, DMF and toluene. Preferably, the solvent system is a complex solvent system of tetrahydrofuran and ethanol, 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 application are embodied in:

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

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

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

[0022] Figure 2 Crystal structure of Cu4 nanoclusters.

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

[0024] The technical solutions of the present application will be further described below in combination with specific examples.

[0025] Example 1: Preparation of Cu4 nanoclusters

[0026] Into a 50 mL round bottom flask, 12 mg of Cu(N03)2*3H20 was added, then 2 mL of ethanol was added to dissolve it, then 11.36 mg of 1,6-bis(diphenylphosphino)hexane was weighed and added into a centrifuge tube containing 2 mL of dichloromethane to dissolve it, then 10 μΐ of phenylacetylene was added to form a mixed solution, which was poured into the Cu(N03)2*3H20 ethanol solution, and the solution changed from blue to dark green and then to light green. Stirring was continued for 20 minutes, and a freshly prepared sodium borohydride solution (0.125 mmol NaBH4 dissolved in 0.5 mL of ethanol) was slowly added dropwise into the above solution, and the solution changed from green to dark red. The reaction was continued at room temperature for 5 days, and the solution changed from dark red to orange yellow and then to yellow. The solution was first centrifuged and then dried, then 10 mL of n-hexane was added, and the precipitate was collected by centrifugation and dissolved in 2 mL of dichloromethane. The n-hexane / dichloromethane single crystal was placed in the refrigerator at 4°C for about a week to obtain green block crystals. The Cu4 nanocluster is abbreviated as Cu4. Figure 1 ESI-MS and XRD patterns of Cu4 nanoclusters.

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

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

[0029] Example 3: Catalytic hydroboration of alkyne by Cu4 / CNT (different catalyst amounts)

[0030]

[0031] (1) Into a 10 mL Schlenk reaction bottle, 45 mg (0.64 wt%) of Cu4 / CNT catalyst, 0.04 mmol of K2CO3, 0.3 mmol of bis(pinacolato)diboron (B2Pin2), 0.2 mmol of phenylacetylene, 1 mL of tetrahydrofuran, and 0.5 mL of ethanol were sequentially added. 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) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. 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-liquid was separated by centrifugation (10000 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 alkyne (different reaction solvents).

[0036] (1) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1.5 mL tetrahydrofuran were added successively. 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-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 21.3 %.

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

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

[0039] (4) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1.5 mL DMF were added successively. The reaction was stirred at 40 °C for 12 h under Ar protection. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 69.2 %.

[0040] (5) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1.5 mL toluene were added successively. The reaction was stirred at 40 °C for 12 h under Ar protection. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 58.3 %.

[0041] (6) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 97.6%.

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

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

[0044] (2) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 12 h. After the reaction, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was 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 alkyne (different reaction base).

[0046] (1) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol K2CO3, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 40 °C under Ar protection for 12 h. After the reaction, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 97.6%.

[0047] (2) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 12 h. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 95.9%.

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

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

[0050] (2) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 6 h. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 93.9%.

[0051] (3) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 94.5%.

[0052] (4) Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 2 h. After the reaction was completed, the reaction liquid was cooled to room temperature, and the solid-liquid was separated by centrifugation (10000 rpm). The reaction liquid was analyzed by GC, and the yield was 78.6%.

[0053] Example 8: CNT catalyzed hydroboration of alkyne

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

[0055] Example 9: Cu4 catalyzed hydroboration of alkyne

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

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

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

[0059] Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was 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 cycle.

[0061] Example 11: Second cycle of Cu4 / CNT catalyzed hydroboration of alkyne

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

[0063] Example 12: Third cycle of Cu4 / CNT catalyzed hydroboration of alkyne

[0064] Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 97.4%.

[0065] Example 13: Fourth cycle of Cu4 / CNT catalyzed hydroboration of alkyne

[0066] Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol phenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was 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 alkyne

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

[0069] The following examples are the substrate expansion of Cu4 / CNT catalyzed hydroboration of alkyne.

[0070]

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

[0072] Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol 4-methylphenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction, the temperature of the reaction solution was cooled to room temperature, and the solid-liquid was 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] Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol 4- chlorophenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature. The solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 87.5%.

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

[0076] Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol 4- chlorophenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature. The solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 87.5%.

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

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

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

[0080] Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol 4- methoxyphenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature. The solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 96.5%.

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

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

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

[0084] Into a 10 mL Schlenk flask, 40 mg (0.64 wt%) Cu4 / CNT catalyst, 0.04 mmol sodium methoxide, 0.3 mmol bis(pinacolato)diboron (B2Pin2), 0.2 mmol 4- methoxyphenylacetylene, 1 mL tetrahydrofuran, 0.5 mL ethanol were added successively. The reaction was stirred at 30 °C under Ar protection for 4 h. After the reaction was completed, the temperature of the reaction solution was cooled to room temperature. The solid-liquid was separated by centrifugation (10000 rpm). The reaction solution was analyzed by GC, and the yield was 96.5%.

Claims

1. A supported Cu-based nanocluster catalyst, characterized in that: the supported Cu-based nanocluster catalyst is a CNT-supported Cu-based nanocluster; the molecular formula of the Cu-based nanocluster is Cu4(dpph)2(PhC≡C)4, which is abbreviated as Cu4; and the supported Cu-based nanocluster catalyst is abbreviated as Cu4 / CNT. The content of Cu in the supported Cu-based nanocluster catalyst is 0.64 wt%.

2. The method for preparing the supported Cu-based nanocluster catalyst according to claim 1, characterized in that The method comprises the following steps: ultrasonic dispersion of CNT in dichloromethane solution to obtain a suspension A; dropwise addition of a dichloromethane solution of Cu4(dpph)2(PhC≡C)4 nanoclusters to the suspension A, stirring for 6 hours, centrifugation, washing and drying to obtain the supported Cu-based nanocluster catalyst Cu4 / CNT. 3.Use of the supported Cu-based nanocluster catalyst of claim 1 in catalyzing a hydroboration reaction of an alkyne. 4.The use of claim 3, characterized in that: the reaction is carried out under argon protection, with an alkyne and pinacol borane as reaction substrates, in the presence of a base and a catalyst, at a reaction temperature of 30-40℃, and for a reaction time of 2-12 hours. 5.The use of claim 4, characterized in that: the alkyne comprises one or more of phenylacetylene, 4-methylphenylacetylene, 4-tert-butylphenylacetylene, 4-fluorophenylacetylene, 4-chlorophenylacetylene, 4-bromophenylacetylene, 4-methoxyphenylacetylene and 3-chlorophenylacetylene. 6.The use of claim 4, characterized in that: the base is CH3ONa. 7.The use of claim 4, characterized in that: in the reaction system, the addition amount of the alkyne is 0.2 mmol, the addition amount of the pinacol borane is 0.3 mmol, the addition amount of the base is 0.04 mmol, and the addition amount of the catalyst is 40-45 mg. 8.The use of claim 4, characterized in that: the catalytic reaction is carried out in a solvent system, and the solvent is one or more of tetrahydrofuran, ethanol, DMSO, DMF and toluene. 9.The use of claim 8, characterized in that: the solvent is a complex solvent system of tetrahydrofuran and ethanol, and the volume ratio of the two is 2:1.

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