Supported Ag-Cu nanocluster catalysts and their application in catalytic oxidative coupling of benzylamine

Abstract

The present invention discloses a supported Ag-Cu nanocluster catalyst and its application in catalyzing the oxidative coupling reaction of benzylamine, wherein the molecular formula of the supported Ag-Cu nanocluster catalyst is Ag 22 Cu7 / CNT; the molecular formula of the nanoclusters is [Ag 22 Cu7(C≡CR) 16 (PPh3)5Cl6](PPh4), abbreviated as Ag 22 Cu7 nanoclusters. Ag of the present invention 22 The Cu7 / CNT catalyst can catalyze the oxidative coupling reaction of benzylamine under mild conditions. At the same time, the catalyst can be recycled at least five times without a significant decrease in activity and has a wide substrate applicability, making it very practical.

Description

Technical Field

[0001] The invention belongs to the field of organic catalytic synthesis, and particularly relates to a supported Ag-Cu nanocluster catalyst and an application thereof in catalyzing the oxidative coupling reaction of benzylamine. Background Art

[0002] Imine compounds play an important role in the chemical and biological fields as intermediates for the synthesis of nitrogen heterocycles, fine chemicals and drugs. Due to their huge demand, many synthetic and catalytic schemes have been developed to achieve higher conversion rates and selectivities. In the traditional process of synthesizing imines by oxidation of benzylamine, a higher reaction temperature is generally selected to increase the yield. For example, in 2020, Zhan Hongbing's group used a metal-free organic catalyst, oxygen as an oxidant, acetonitrile as a solvent, and a temperature of 100°C to carry out the oxidative coupling reaction of benzylamine (Journal of Catalysis 385 (2020) 338-344). Later, in 2022, the Manish Misra group published a report on the synthesis of imines via the oxidative coupling reaction of benzylamine. The authors conducted the oxidative coupling reaction at 160°C and found that the Al-doped material Al-20-MCM-41 was more active than the undoped material MCM-41, due to the presence of acidic centers in Al-20-MCM-41 (Asian J. Chem., 2022, 11, 2929-2934). Subsequently, it was discovered that longer reaction times could also improve catalytic activity. In 2022, the Wu Qiaolin group designed and synthesized a highly hydrophilic 2D-COF material for the oxidative coupling reaction of benzylamine. Under blue light irradiation and in water, the reaction proceeded for 20 hours, yielding a good yield (Catal. Sci. Technol., 2022, 12, 2837-2845). Furthermore, in recent years, some research groups have discovered that introducing clusters into MOF materials can enhance reaction activity. In 2022, Li Dan's research group published a report on the synthesis of imines via the oxidative coupling reaction of benzylamine. The authors prepared Co-MOF (JNU-207) and Zn-MOF (JNU-204) with photoactive organic ligands. Under blue light irradiation, the reaction was carried out for 24 hours. It was found that the introduction of Co clusters significantly enhanced the activity of the benzylamine coupling reaction (J.Mater.Chem.C, 2022, 10, 11967-11974).

[0003] To date, catalyst systems for the oxidative coupling reaction of benzylamine to imines still face many challenges, such as high reaction temperatures and long reaction times. Therefore, the preparation of highly active and high-performance catalysts has become a major research focus. Summary of the Invention

[0004] The present invention addresses the problems of the prior art and provides a supported Ag-Cu nanocluster catalyst and its use in catalyzing the oxidative coupling reaction of benzylamine. The supported Ag-Cu nanocluster catalyst employed in the present invention can efficiently catalyze the oxidative coupling reaction of benzylamine under relatively mild reaction conditions. Furthermore, the supported Ag-Cu nanocluster catalyst exhibits good catalytic activity and stability, can be recycled multiple times without significant loss of activity, and is generally compatible with a wide range of substrates.

[0005] The supported Ag-Cu nanocluster catalyst of the present invention has the molecular formula Ag 22 The molecular formula of Cu7 / CNT nanoclusters is [Ag 22 Cu7(C≡CR) 16 (PPh3)5Cl6](PPh4), abbreviated as Ag 22 Cu7 nanoclusters.

[0006] The preparation method of the supported Ag-Cu nanocluster catalyst of the present invention comprises the following steps:

[0007] Step 1: First synthesize Ag 22 Cu7 nanoclusters, the molecular formula of the nanoclusters is [Ag 22 Cu7(C≡CR) 16 (PPh3)5Cl6](PPh4), abbreviated as Ag 22 Cu7 nanoclusters (Angew. Chem. Int. Ed., 2023, e202217483(1of7)).

[0008] Step 2: The CNTs are uniformly dispersed in a dichloromethane solution by ultrasonic treatment to obtain a suspension A;

[0009] Step 3: Add Ag to the suspension A obtained in step 2. 22 Cu7 nanoclusters were prepared by dichloromethane solution, stirred for 4 h, separated, washed and dried to obtain Ag 22 Cu7 / CNT nanocomposites;

[0010] Ag prepared by the present invention 22 The actual content of Ag in Cu7 / CNT nanocomposites is (0.37-0.46) wt%.

[0011] The invention discloses an application of a supported Ag-Cu nanocluster catalyst in catalyzing the oxidative coupling reaction of benzylamine. Specifically, the oxidative coupling reaction of benzylamine is carried out in a solvent in the presence of an oxidant and a catalyst using a benzylamine compound as a reaction substrate.

[0012] The catalyst is a supported Ag-Cu nanocluster catalyst.

[0013] The oxidant is TBHP.

[0014] The solvent is selected from acetonitrile, toluene, dimethyl sulfoxide and water.

[0015] The reaction temperature is 30°C to 50°C, and the reaction time is 4h to 12h.

[0016] Furthermore, the addition amount of the benzylamine compound is 0.5 mmol, the addition amount of the oxidant is 0.12 mmol to 0.50 mmol, and the addition amount of the catalyst is 30 mg to 50 mg, all of which are reactive for the benzylamine oxidative coupling reaction.

[0017] The benzylamine compound is selected from benzylamine, 4-fluorobenzylamine, 4-chlorobenzylamine, 4-methylbenzylamine, 4-methoxybenzylamine, 3-methylbenzylamine, 3-methoxybenzylamine, and thiophene-2-methylamine.

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

[0019] 1. The material synthesis and preparation are simple, and the catalytic material performance is good.

[0020] 2. The material of the present invention can be used as a catalyst to catalyze the oxidative coupling reaction of benzylamine, and can achieve the catalytic reaction within a certain range of reaction conditions. The catalytic activity does not change significantly after at least five cycles of use, and the substrate is generally applicable to a wide range of substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Ag 22 XPS and liquid UV images of Cu7 nanoclusters.

[0022] Figure 2 Ag 22 Crystal structure of Cu7 nanoclusters.

[0023] Figure 3 Ag 22 TEM image of Cu7 / CNT. DETAILED DESCRIPTION

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

[0025] Example 1: Ag 22 Preparation of Cu7 nanoclusters

[0026] Dissolve 340 mg of silver nitrate in 40 mL of acetonitrile and add 337 μL of 3,5-bis(trifluoromethyl)phenylacetylene. Then, add 200 μL of triethylamine to the solution while stirring vigorously. The reaction mixture is stirred in the dark at room temperature for 3 hours. The resulting turbid mixture is centrifuged at 10,000 rpm for 1 minute. The precipitate is washed with excess methanol and dried under vacuum at room temperature to yield a pale yellow AgC≡CR complex.

[0027] Tetraphenylphosphine chloride (2 mg) was placed in a round-bottom flask. 4 mL of dichloromethane and 1 mL of methanol solvent were then added to the flask. AgC≡CR (14 mg) was then added to the flask. After stirring for 5 minutes, 2 mL of dichloromethane solution containing bistriphenylphosphine cuprous borohydride (6 mg) was added to the above solution. The suspension gradually dissolved, and the solution turned yellow after 10 minutes, and then turned red. Stir in the dark for 1.5 hours. After the reaction stopped, the resulting cluster solution was washed with water, and the organic phase was centrifuged at 15,000 rpm for 5 minutes. The organic phase was diffused in n-hexane at -12°C, and black crystals [Ag] were obtained after 10 days. 22 Cu7(C≡CR) 16 (PPh3)5Cl6](PPh4) nanoclusters, referred to as Ag 22 Cu7 nanoclusters. Figure 1 Ag 22 XPS and liquid UV images of Cu7 nanoclusters.

[0028] Example 2: Ag 22 Preparation of Cu7 / CNT catalyst

[0029] CNT (100 mg) was ultrasonically dispersed in 15 mL of dichloromethane solution, and then Ag was dissolved in dichloromethane (1 mL). 22 Cu7 nanoclusters (1 mg) were added dropwise to the above CNT solution. After stirring for 4 h, stirring was stopped. The product was collected by centrifugation (10000 rpm) and washed twice with dichloromethane. Then, the solid was dried in a vacuum oven at 50 ° C overnight and the solid was collected to obtain Ag. 22 Cu7 / CNT catalyst. Figure 3 Ag 22 TEM image of Cu7 / CNT. It can be seen from the image that Ag 22 There are no metal particles on the surface of Cu7 / CNT.

[0030] Example 3: CNT-catalyzed oxidative coupling reaction of benzylamine

[0031] To a 10 mL Schlenk reaction flask, 0.5 mmol of benzylamine, 30 mg of CNT catalyst, 0.25 mmol of tert-butyl hydroperoxide (TBHP), and 1 mL of H2O were added in sequence and stirred at 50°C for 8 h. After the reaction, 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 25.6%.

[0032] Example 4: Ag 22 Cu7 / CNT catalyzes the oxidative coupling reaction of benzylamine (different catalyst dosages).

[0033]

[0034] (1) Add 0.5 mmol benzylamine, 50 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL of tert-butyl hydroperoxide (TBHP) and 1 mL of water were stirred at 50°C for 8 hours. 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 96.9%.

[0035] (2) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL water were stirred at 50°C 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 (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 95.6%.

[0036] 1 H NMR (400MHz, CDCl3) δ8.41(d,J=1.5Hz,1H),7.80(dd,J=6.2,2.6Hz,2H),7.43(t q,J=4.0,2.0,1.1Hz,3H),7.39-7.31(m,4H),7.31-7.27(m,1H),4.84(s,2H)ppm; 13 C NMR (101MHz, CDCl3) δ162.14,139.42,136.28,130.90,128.74,128.63,128.41,128.12,127.12,65.20ppm.

[0037] Example 5: Ag 22 Cu7 / CNT catalyzes the oxidative coupling reaction of benzylamine (reaction temperature is different).

[0038] (1) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL water were stirred at 30°C 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 (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 42.2%.

[0039] (2) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL water were stirred at 40°C 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 (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 62.9%.

[0040] (3) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL water were stirred at 50°C 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 (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 95.6%.

[0041] Example 6: Ag 22 Cu7 / CNT catalyzes the oxidative coupling reaction of benzylamine (reaction solvents are different).

[0042] (1) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL of tert-butyl hydroperoxide (TBHP) and 1 mL of acetonitrile were stirred at 50°C for 8 hours. 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 79.1%.

[0043] (2) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL of tert-butyl hydroperoxide (TBHP) and 1 mL of toluene were stirred and reacted at 50°C for 8 hours. 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%.

[0044] (3) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL dimethyl sulfoxide were stirred at 50°C for 8 hours. 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 75.7%.

[0045] (4) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL water were stirred at 50°C 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 (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 95.6%.

[0046] Example 7: Ag 22 Cu7 / CNT catalyzes the oxidative coupling reaction of benzylamine (reaction time is different).

[0047] (1) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL water were stirred at 50°C for 12 hours. 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 98.4%.

[0048] (2) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL water were stirred at 50°C 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 (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 95.6%.

[0049] (3) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL water were stirred at 50°C for 4 hours. 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 45.9%.

[0050] Example 8: Ag 22Cu7 / CNT catalyzes the oxidative coupling reaction of benzylamine (with different amounts of oxidant).

[0051] (1) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 48 μL of tert-butyl hydroperoxide (TBHP) and 1 mL of water were stirred at 50°C for 8 hours. 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 97.2%.

[0052] (2) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 24 μL tert-butyl hydroperoxide (TBHP) and 1 mL water were stirred at 50°C 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 (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 95.6%.

[0053] (3) Add 0.5 mmol benzylamine, 30 mg Ag, and 1% dapoxetine to a 10 mL Schlenk reaction flask. 22 Cu7 / CNT catalyst, 12 μL of tert-butyl hydroperoxide (TBHP) and 1 mL of water were stirred at 50°C 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 (10,000 rpm). The reaction solution was analyzed by GC, and the yield was 70.6%.

[0054] Based on the above implementation case, we selected the reaction conditions (0.5mmol benzylamine, 30mgAg 22 Cu7 / CNT catalyst, 0.25mmol (24μL) tert-butyl hydroperoxide (TBHP), 1mL H2O, reaction temperature of 50℃, reaction time of 8h) were used to test Ag 22 The stability of the Cu7 / CNT catalyst for the oxidative coupling reaction of benzylamine is shown in the following examples.

[0055] Example 9: Ag 22 One cycle of oxidative coupling reaction of benzylamine catalyzed by Cu7 / CNT

[0056] To a 10 mL Schlenk reaction flask, 0.5 mmol of benzylamine, 30 mg of Ag, 22A Cu7 / CNT catalyst, 0.25 mmol of tert-butyl hydroperoxide (TBHP), and 1 mL of H2O were stirred at 50°C for 8 hours. After the reaction, the reaction solution was cooled to room temperature and centrifuged (10,000 rpm) to remove the solid catalyst to obtain the product. GC analysis of the reaction solution revealed a yield of 95.6%.

[0057] Recycled Ag 22 The Cu7 / CNT catalyst was washed twice with methanol and dried in a vacuum oven at 50°C for 2 h to prepare for the next recycling.

[0058] Example 10: Ag 22 Secondary Cycle of Benzylamine Oxidative Coupling Reaction Catalyzed by Cu7 / CNT

[0059] To a 10 mL Schlenk reaction flask, 0.5 mmol of benzylamine, 30 mg of Ag, 22 Cu7 / CNT catalyst, 0.25mmol tert-butyl hydroperoxide (TBHP), 1mL H2O, stirred at 50°C for 8h. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10000rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 92.5%.

[0060] Example 11: Ag 22 Three cycles of oxidative coupling reaction of benzylamine catalyzed by Cu7 / CNT

[0061] To a 10 mL Schlenk reaction flask, 0.5 mmol of benzylamine, 30 mg of Ag, 22 Cu7 / CNT catalyst, 0.25 mmol tert-butyl hydroperoxide (TBHP), 1 mL H2O, stirred at 50°C for 8 hours. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10000 rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 93.9%.

[0062] Example 12: Ag 22 Four cycles of oxidative coupling reaction of benzylamine catalyzed by Cu7 / CNT

[0063] To a 10 mL Schlenk reaction flask, 0.5 mmol of benzylamine, 30 mg of Ag, 22 Cu7 / CNT catalyst, 0.25 mmol tert-butyl hydroperoxide (TBHP), 1 mL H2O, stirred at 50°C for 8 hours. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10000 rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 93.1%.

[0064] Example 13: Ag 22 Five cycles of oxidative coupling reaction of benzylamine catalyzed by Cu7 / CNT

[0065] To a 10 mL Schlenk reaction flask, 0.5 mmol of benzylamine, 30 mg of Ag, 22 Cu7 / CNT catalyst, 0.25mmol tert-butyl hydroperoxide (TBHP), 1mL H2O, stirred at 50°C for 8h. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10000rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 91.2%.

[0066] The following implementation case is Ag 22 Substrate expansion for Cu7 / CNT-catalyzed oxidative coupling of amines to imines.

[0067]

[0068] Example 14: Ag 22 Oxidative coupling reaction of 4-fluorobenzylamine catalyzed by Cu7 / CNT

[0069] To a 10 mL Schlenk reaction flask, 0.5 mmol 4-fluorobenzylamine, 30 mg Ag 22 Cu7 / CNT catalyst, 0.25 mmol tert-butyl hydroperoxide (TBHP), and 1 mL H2O were stirred at 50°C for 12 hours. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10,000 rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 87.1%.

[0070] Example 15: Ag 22 Oxidative coupling reaction of 4-chlorobenzylamine catalyzed by Cu7 / CNT

[0071] To a 10 mL Schlenk reaction flask, 0.5 mmol 4-chlorobenzylamine, 30 mg Ag 22 Cu7 / CNT catalyst, 0.25 mmol tert-butyl hydroperoxide (TBHP), and 1 mL H2O were stirred at 50°C for 12 hours. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10,000 rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 96.7%.

[0072] Example 16: Ag 22 Oxidative Coupling Reaction of 4-Methoxybenzylamine Catalyzed by Cu7 / CNT

[0073] To a 10 mL Schlenk reaction flask, 0.5 mmol 4-methoxybenzylamine, 30 mg Ag 22 Cu7 / CNT catalyst, 0.25mmol tert-butyl hydroperoxide (TBHP), 1mL H2O, stirred at 50°C for 12h. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10000rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 97.9%.

[0074] Example 17: Ag 22 Oxidative Coupling Reaction of 4-Methylbenzylamine Catalyzed by Cu7 / CNT

[0075] To a 10 mL Schlenk reaction flask, 0.5 mmol 4-methylbenzylamine, 30 mg Ag 22 Cu7 / CNT catalyst, 0.25 mmol tert-butyl hydroperoxide (TBHP), and 1 mL H2O were stirred at 50°C for 12 hours. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10,000 rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 90.8%.

[0076] Example 18: Ag 22 Oxidative Coupling Reaction of 3-Methylbenzylamine Catalyzed by Cu7 / CNT

[0077] To a 10 mL Schlenk reaction flask, 0.5 mmol 3-methylbenzylamine, 30 mg Ag 22 Cu7 / CNT catalyst, 0.25 mmol tert-butyl hydroperoxide (TBHP), and 1 mL H2O were stirred at 50°C for 12 hours. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10,000 rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 98.7%.

[0078] Example 19: Ag 22 Oxidative Coupling Reaction of 3-Methoxybenzylamine Catalyzed by Cu7 / CNT

[0079] To a 10 mL Schlenk reaction flask, 0.5 mmol 3-methoxybenzylamine, 30 mg Ag 22 Cu7 / CNT catalyst, 0.25mmol tert-butyl hydroperoxide (TBHP), 1mL H2O, stirred at 50°C for 12h. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10000rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 88.2%.

[0080] Example 20: Ag 22 Oxidative coupling reaction of thiophene-2-methylamine catalyzed by Cu7 / CNT

[0081] To a 10 mL Schlenk reaction flask, 0.5 mmol of thiophene-2-methylamine, 30 mg of Ag 22 Cu7 / CNT catalyst, 0.25 mmol tert-butyl hydroperoxide (TBHP), 1 mL H2O, stirred at 50°C for 12 hours. After the reaction, the reaction solution was cooled to room temperature and the solid catalyst was removed by centrifugation (10,000 rpm) to obtain the product. The reaction solution was analyzed by GC, and the yield was 91.2%.

Claims

1. Use of a supported Ag-Cu nanocluster catalyst in catalyzing the oxidative coupling reaction of benzylamine compounds or thiophene-2-methylamine, characterized in that: The molecular formula of the supported Ag-Cu nanocluster catalyst is Ag 22 Cu7 / CNT; the molecular formula of the nanoclusters is [Ag 22 Cu7(C≡CR) 16 (PPh3)5Cl6](PPh4), abbreviated as Ag 22 Cu7 nanoclusters; The supported Ag-Cu nanocluster catalyst is prepared by a method comprising the following steps: Step 1: First synthesize Ag 22 Cu7 nanoclusters; Step 2: The CNTs are uniformly dispersed in a dichloromethane solution by ultrasonic treatment to obtain a suspension A; Step 3: Add Ag to the suspension A obtained in step 2. 22 Cu7 nanoclusters were prepared by dichloromethane solution, stirred for 4 h, separated, washed and dried to obtain Ag 22 Cu7 / CNT nanocomposite materials.

2. The use according to claim 1, characterized in that: The content of Ag in the supported Ag-Cu nanocluster catalyst is (0.37-0.46) wt%.

3. The use according to claim 1, characterized in that: The invention uses benzylamine compounds or thiophene-2-methylamine as reaction substrates, and carries out an oxidative coupling reaction of the benzylamine compounds or thiophene-2-methylamine in a solvent in the presence of an oxidant and a catalyst; the catalyst is a supported Ag-Cu nanocluster catalyst; and the oxidant is TBHP.

4. The use according to claim 3, characterized in that: The solvent is selected from acetonitrile, toluene, dimethyl sulfoxide and water.

5. The use according to claim 3, characterized in that: The reaction temperature is between 30°C and 50°C, and the reaction time is between 4h and 12h.

6. The use according to claim 3, characterized in that: The amount of benzylamine compound or thiophene-2-methylamine added is 0.5 mmol, the amount of oxidant added is 0.12 mmol to 0.50 mmol, and the amount of catalyst added is 30 mg to 50 mg.

7. The use according to claim 3, characterized in that: The benzylamine compound is selected from benzylamine, 4-fluorobenzylamine, 4-chlorobenzylamine, 4-methylbenzylamine, 4-methoxybenzylamine, 3-methylbenzylamine, and 3-methoxybenzylamine.

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