Tungsten-oxygen complexes, their preparation methods, and their applications in olefin oxidative cleavage and C-H bond oxidation

Abstract

The present invention discloses a tungsten-oxygen complex, a preparation method, and its application in olefin oxidative cracking and C-H bond oxidation, belonging to the technical field of metal coordination compound functional materials. The present invention utilizes bipyridine ligands and metallic tungsten to synthesize a novel tungsten-oxygen complex under H2O2 conditions. The complex has air-stable properties and can be used as a high-efficiency catalyst for olefin oxidative cracking and C-H bond oxidation to prepare carbonyl compounds. Compared with the prior art, the present invention has the following characteristics: (1) The catalyst provided by the present invention is a novel tungsten catalyst with a novel structure and is prepared for the first time; (2) The catalytic reaction is carried out under a homogeneous catalytic system and can be used not only for olefin oxidative cracking, but also for C-H bond oxidation to synthesize aldehydes and ketones; (3) The catalytic reaction uses oxygen or air as a green oxidant; (4) Abundant chemical raw materials (styrene derivatives, phenylethane derivatives) are used for the green synthesis of carbonyl compounds.

Description

Technical Field

[0001] The present invention relates to the technical field of metal coordination compound functional materials, in particular to a tungsten-oxygen complex, a preparation method thereof and application in olefin oxidative cleavage and CH bond oxidation. Background Art

[0002] At present, many literatures have reported various methods for synthesizing aldehydes and ketones by oxidative cleavage of olefins and oxidation of C-H bonds. For example, the literature (ACS Catalysis 2020, 10, 4617) reported the preparation of Fe@NPC-T iron nanocomposite catalysts by hydrothermal synthesis, using TBHP as an oxidant to directly oxidize and crack olefins into ketones. The literature (Green Chemistry 2012, 14, 3386) used CuPcS@ASMNP magnetic nanoparticle catalysts and air as an oxidant to oxidize hydrocarbon compounds into ketones. However, these catalytic systems are all heterogeneous systems with low catalytic efficiency, and most of them use strong oxidants. For homogeneous catalytic systems, several olefin and alkane catalytic oxidation systems have been developed. For example, the literature (Journal of the American Chemical Society 2021, 143, 10005) proposed the use of non-heme Mn (II) complexes to catalyze the oxidative cracking of olefins. Alternatively, under solvent-free and low catalyst loading conditions, water-soluble ruthenium complexes are used as catalysts to efficiently convert the corresponding alkanes into ketones. All of the above reports used a single catalyst to catalyze the oxidation of a single type of substance (olefins or alkanes). A previous study (ACS Catalysis 2023, 13, 13414) used graphitic carbon nitride as a catalyst to simultaneously oxidize olefins and alkanes to carbonyl compounds in the presence of oxygen, but this system was heterogeneous.

[0003] Therefore, designing and developing a green and efficient homogeneous catalytic system, using milder reaction conditions, and simultaneously oxidizing alkenes and alkanes to produce carbonyl compounds is a very worthy research topic and is very challenging. Summary of the Invention

[0004] Objectives of the invention: The first objective of the present invention is to provide a novel tungsten-oxygen complex having excellent catalytic performance and air temperature resistance. The second objective of the present invention is to provide a method for preparing the above-mentioned tungsten-oxygen complex. The third objective of the present invention is to provide the use of the above-mentioned tungsten-oxygen complex as a catalyst in catalyzing the oxidative breakage of olefins and the oxidation of C-H bonds.

[0005] Technical solution: The present invention provides a tungsten-oxygen complex, wherein the molecular structure of the tungsten-oxygen complex W-1 is as follows:

[0006]

[0007] Furthermore, the tungsten-oxygen complex W-1 is in the form of colorless solid crystals, and the unit cell parameters are: α=90°; β=90°; γ=90°;

[0008] The preparation method of the above-mentioned tungsten-oxygen complex includes the following steps: at room temperature and in a protective atmosphere, a solvent, tungsten hexachloride, 4,4-di-tert-butyl-2,2-bipyridine ligand and a reducing agent are mixed to obtain a reaction system, and the reaction is stirred. After the reaction is completed, the yellow supernatant obtained by the reaction is aspirated, n-hexane is added to the reaction system for washing until the supernatant is colorless, and then the supernatant is dried, methanol and ether are added, and after sufficient evaporation in the air and turning into blue-black, the supernatant is dried by rotation, and then acetonitrile is used as a solvent, and the reaction is carried out with hydrogen peroxide until it becomes colorless, and then the supernatant is dried to obtain tungsten-oxygen complex W-1.

[0009] Furthermore, the solvent is toluene, the protective atmosphere is nitrogen, and the reducing agent is norbornene.

[0010] Furthermore, the preparation method of the tungsten-oxygen complex is as follows: 15mL of dry toluene is added to a 100ml reaction bottle, (1eq) WCl6 is added under nitrogen protection and stirred at room temperature, then (1eq) 4,4-di-tert-butyl-2,2-bipyridine ligand is added, and finally (2eq) norbornene is added. Nitrogen is introduced through a double-row tube, and the mixture is reacted for 1 hour under magnetic stirring and then treated. After the yellow supernatant is aspirated, n-hexane is added to the system for washing until the supernatant is colorless, and then dried. Methanol and ether are added, and after evaporating in the air overnight to a blue-black color, the mixture is spin-dried, and then acetonitrile is used as a solvent, and the mixture is reacted with hydrogen peroxide until it is colorless, and then dried to obtain the complex W-1. Wherein: 4,4-di-tert-butyl-2,2-bipyridine is used as a ligand, and tungsten hexachloride is used as a metal source. NMR data: 1H NMR (400 MHz, DMSO-d6) δ 8.71 (d, J = 5.6 Hz, 2H), 8.58 (d, J = 2.0 Hz, 2H), 7.78-7.69 (m, 2H), 1.37 (s, 18H). 13C NMR (101 MHz, DMSO-d6) δ 148.93, 147.00, 124.07, 121.19, 36.40, 30.51.

[0011] The preparation reaction formula of tungsten-oxygen complex is as follows:

[0012]

[0013] The above-mentioned tungsten-oxygen complex is used as a catalyst in the oxidative cleavage of olefins and the oxidation of C-H bonds.

[0014] Furthermore, the application steps are: adding a substrate and a catalyst tungsten-oxygen complex to a solvent, placing the mixture in a reactor, irradiating the mixture with ultraviolet light under an oxidizing agent, and obtaining a target product by column chromatography; the substrate includes an olefin oxidation cleavage raw material or a C-H bond oxidation raw material, the olefin oxidation cleavage raw material is styrene and its derivatives, and the C-H bond oxidation raw material is styrene and its derivatives, wherein the structural formula of styrene and its derivatives is shown in the following formula (I), the oxidation products of styrene and its derivatives are shown in the following formula (II), the structural formula of styrene and its derivatives is shown in the following formula (III), and the oxidation products of styrene and its derivatives are shown in the following formula (IV).

[0015]

[0016] R1 = halogen, aryl or alkyl group, R2 = hydrogen atom, alkyl or aryl group, the reaction formula is as follows:

[0017]

[0018] More preferably, R1 can be -H, -F, -Cl, -Br, -Alkyl, -Aryl, etc., and R2 can be -H, -F, -Cl, -Br, -Alkyl, -Aryl, etc.

[0019] Furthermore, the molar ratio of the substrate to the catalyst tungsten-oxygen complex is 1:(0.05-0.15), and the preferred molar ratio is 1:0.05.

[0020] Furthermore, when the substrate is an olefin oxidation and cracking raw material, the oxidant is oxygen.

[0021] Furthermore, when the substrate is a CH bond oxidation raw material, the oxidant is air.

[0022] Furthermore, the solvent is acetonitrile.

[0023] Preferably, the specific structure of the olefin oxidation and cracking raw material and its product is one of the following structural formulas:

[0024] Olefin oxidation cracking raw materials and products

[0025]

[0026] Preferably, the specific structure of the CH bond oxidation raw material and its product is one of the following structural formulas:

[0027] CH bond oxidation raw materials and products

[0028]

[0029] Principle of the invention: The present invention is based on a catalytic system using the air-stable tungsten-oxygen complex W-1 as a catalyst. Under mild conditions, using the green oxidant oxygen or air, the tungsten-oxygen catalyst can catalyze the oxidative cleavage of olefins and the oxidation of C-H bonds. Under light conditions, it catalyzes the oxidative cleavage of olefins and the oxidation of C-H bonds, providing two different pathways for the preparation of carbonyl compounds, achieving a green and efficient synthesis of high-value-added carbonyl compounds. The reaction is mild and efficient, and does not require any additives.

[0030] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The preparation process of the novel tungsten-oxygen complex in the present invention is simple, low-cost, and has high catalytic activity, and the reaction is efficient and mild, and the operation is simple, which can greatly reduce the process cost; (2) Oxygen or air is used as an oxidant in the reaction of catalyzing olefin oxidative cleavage and C-H bond oxidation, which is simple, easy to obtain, green, economical, and environmentally friendly; (3) The substrate used in the present invention exists in large quantities in nature and petrochemical industry, which greatly expands the application scope of the carbonyl compound synthesis method. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the H NMR spectrum of the tungsten-oxygen complex catalyst W-1;

[0032] Figure 2 This is the carbon NMR spectrum of the tungsten-oxygen complex catalyst W-1;

[0033] Figure 3 This is the crystal structure diagram of tungsten-oxygen complex catalyst W-1;

[0034] Figure 4 is the H NMR spectrum of compound 2a;

[0035] Figure 5 is the C NMR spectrum of compound 2a;

[0036] Figure 6 is the H NMR spectrum of compound 2b;

[0037] Figure 7 is the C NMR spectrum of compound 2b;

[0038] Figure 8 is the H NMR spectrum of compound 2c;

[0039] Figure 9 is the C NMR spectrum of compound 2c;

[0040] Figure 10 is the H NMR spectrum of compound 2d;

[0041] Figure 11 is the C NMR spectrum of compound 2d;

[0042] Figure 12 is the H NMR spectrum of compound 2e;

[0043] Figure 13 is the C NMR spectrum of compound 2e;

[0044] Figure 14 is the H NMR spectrum of compound 2f;

[0045] Figure 15 This is the carbon NMR spectrum of compound 2f;

[0046] Figure 16 is the H NMR spectrum of compound 2g;

[0047] Figure 17 This is the carbon NMR spectrum of compound 2g;

[0048] Figure 18 is the H NMR spectrum of compound 2h;

[0049] Figure 19 is the C NMR spectrum of compound 2h;

[0050] Figure 20 is the H NMR spectrum of compound 4a;

[0051] Figure 21 is the C NMR spectrum of compound 4a;

[0052] Figure 22 is the H NMR spectrum of compound 4b;

[0053] Figure 23 is the C NMR spectrum of compound 4b;

[0054] Figure 24 is the H NMR spectrum of compound 4c;

[0055] Figure 25 is the C NMR spectrum of compound 4c;

[0056] Figure 26 is the H NMR spectrum of compound 4d;

[0057] Figure 27 is the C NMR spectrum of compound 4d;

[0058] Figure 28 is the H NMR spectrum of compound 4e;

[0059] Figure 29 is the C NMR spectrum of compound 4e;

[0060] Figure 30 is the H NMR spectrum of compound 4f;

[0061] Figure 31 is the C NMR spectrum of compound 4f;

[0062] Figure 32 is the H NMR spectrum of compound 4g;

[0063] Figure 33 This is the carbon NMR spectrum of compound 4g;

[0064] Figure 34 is the H NMR spectrum of compound 4h;

[0065] Figure 35 is the C NMR spectrum of compound 4h;

[0066] Figure 36 1. The diagram is a reaction process diagram and a comparison diagram of the yields obtained when the compounds prepared in Example 1 and Comparative Examples 1-2 are used as catalysts for catalyzing the oxidative cleavage reaction of olefins;

[0067] Figure 37 It is a reaction process diagram and a comparison diagram of the yields obtained when the compounds prepared in Example 1 and Comparative Examples 1-2 are used as catalysts to catalyze the C-H bond oxidation reaction. DETAILED DESCRIPTION

[0068] The present invention is further described below with reference to specific embodiments and accompanying drawings.

[0069] Example 1: Preparation of the novel tungsten-oxygen complex W-1: Add 15 mL of dry toluene to a 100 ml reaction flask, add (1 eq) WCl6 under nitrogen protection and stir at room temperature, then add (1 eq) 4,4-di-tert-butyl-2,2-bipyridine ligand, and finally add (2 eq) norbornene. Use a double-row tube to introduce nitrogen, react for 1 hour under magnetic stirring, and then treat. After the yellow supernatant is sucked out, add n-hexane to the system to wash until the supernatant is colorless, and then drain. Add methanol and ether, evaporate in the air overnight to a blue-black color, spin dry, and then use acetonitrile as a solvent to react with hydrogen peroxide until it becomes colorless, and drain to obtain the complex W-1. The nuclear magnetic resonance spectrum of catalyst W-1 is shown below. Figure 1-Figure 2 As shown. NMR data: 1 H NMR (400MHz, DMSO-d6) δ8.71(d,J=5.6Hz,2H),8.58(d,J=2.0Hz,2H),7.78-7.69(m,2H),1.37(s,18H). 13C NMR (101MHz, DMSO-d6) δ148.93,147.00,124.07,121.19,36.40,30.51.

[0070] Test method: The prepared tungsten-oxygen complex W-1 was subjected to single crystal diffraction test on a BRUKER diffractometer. The test results are as follows: Figure 3 It can be seen that the present invention synthesizes a new compound with a novel structure.

[0071] Application Example 1: Preparation of olefin oxidation cleavage product (2a): 0.2 mmol (1-cyclopropylvinyl) benzene, 5 mol% W-1, and 2 mL acetonitrile were added to a 10 ml reaction flask, and then vacuumed with a double-row tube, inserted into an oxygen ball, and irradiated with 390 nm light under magnetic stirring. The reaction was allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction, and the mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes and filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography was performed using petroleum ether and ethyl acetate (200:1, v:v) as eluents to obtain the pure product with a yield of 95%. The mass spectrometry analysis data of the product are as follows: theoretical value, 147.0810; experimental value, 147.0836. The nuclear magnetic resonance spectrum of compound 2a is shown in FIG. Figure 4-Figure 5 shown. 1 H NMR(400MHz,Chloroform-d)δ8.00(d,J=7.2Hz,2H),7.54(t,J=7.4Hz,1H),7.45(t,J =7.5Hz,2H),2.66(m,J=12.4,7.8,4.6Hz,1H),1.26-1.19(m,2H),1.05-0.98(m,2H). 13 C NMR(101MHz,Chloroform-d)δ200.8,138.1,132.9,128.6,128.1,17.2,11.8.

[0072] Application Example 2: Preparation of olefin oxidation cleavage product (2b): 0.2 mmol 1-(1-cyclopropylvinyl)-4-fluorobenzene, 5 mol% W-1, and 2 mL acetonitrile were added to a 10 mL reaction flask, and then vacuumed with a double-row tube, inserted into an oxygen balloon, and irradiated with 390 nm light under magnetic stirring. The reaction was allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction, and the mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes and filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography was performed using petroleum ether and ethyl acetate (200:1, v:v) as eluents to obtain the pure product with a yield of 87%. The mass spectrometry analysis data of the product are as follows: theoretical value, 165.0716; experimental value, 165.0752. The nuclear magnetic resonance spectrum of compound 2b is shown in FIG. Figure 6-Figure 7 shown. 1 HNMR(400MHz,Chloroform-d)δ8.03(dd,J=8.8,5.4Hz,2H),7.13(t,J=8.6Hz,2H),2.66-2.57(m,1H),1.25-1.20(m,2H),1.04(dd,J=7.7,3.6Hz,2H). 13 C NMR (101MHz, Chloroform-d) δ199.2,167.0,164.4,134.5,134.4,130.7,130.6,115.8,115.6,17.1,11.8.

[0073] Application Example 3: Preparation of olefin oxidation cleavage product (2c): 0.2 mmol 4,4'-(ethylene-1,1-diyl)bis(fluorobenzene), 5 mol% W-1, and 2 mL acetonitrile were added to a 10 mL reaction flask. The mixture was then evacuated using a double-row tube, pierced with an oxygen balloon, and irradiated with 390 nm light under magnetic stirring. The reaction was allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes, then filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (200:1, v:v) as eluents to obtain the pure product in a yield of 68%. The mass spectrometry analysis data of the product are as follows: theoretical value, 219.0621; experimental value, 219.0644. The nuclear magnetic resonance spectrum of compound 2c is shown in FIG. Figure 8-Figure 9 shown. 1 H NMR (400MHz, Chloroform-d) δ7.80 (dd, J=8.9, 5.4Hz, 4H), 7.15 (dd, J=8.9, 8.4Hz, 4H). 13C NMR (101MHz, Chloroform-d) δ193.9,166.8,164.2,133.8,133.7,132.6,132.5,115.8,115.5.

[0074] Application Example 4: Preparation of Oxidative Fragmentation Product (2d): 0.2 mmol 1-methyl-4-vinylbenzene, 5 mol% W-1, and 2 mL acetonitrile were added to a 10 mL reaction flask. The mixture was then evacuated using a double-row tube, pierced with an oxygen balloon, and irradiated with 390 nm light under magnetic stirring. The reaction was allowed to proceed at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes, then filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (300:1, v:v) as eluents to obtain the pure product in a yield of 78%. The mass spectrometry data for the product are as follows: theoretical value, 121.0653; experimental value, 121.0662. The nuclear magnetic resonance spectrum of compound 2d is shown in Figure 2. Figure 10-11 shown. 1 H NMR (400MHz, Chloroform-d) δ9.96 (s, 1H), 7.77 (d, J = 8.2Hz, 2H), 7.33 (d, J = 7.9Hz, 2H), 2.44 (s, 3H). 13 C NMR(101MHz,Chloroform-d)δ192.2,145.7,134.3,130.0,129.8,22.0.

[0075] Application Example 5: Preparation of Oxidative Fragmentation Product (2e): 0.2 mmol 1-chloro-4-vinylbenzene, 5 mol% W-1, and 2 mL acetonitrile were added to a 10 mL reaction flask. The mixture was then evacuated using a double-row tube, pierced with an oxygen balloon, and irradiated with 390 nm light under magnetic stirring. The reaction was allowed to proceed at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined, dried over anhydrous MgSO₄ for 30 minutes, and filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (300:1, v:v) as eluents to obtain the pure product in an 81% yield. The mass spectrometry data for this product are as follows: theoretical value, 141.0107; experimental value, 141.0115. The nuclear magnetic resonance spectrum of compound 2e is shown in Figure 2. Figure 12-13 shown. 1 H NMR (400MHz, Chloroform-d) δ9.98 (s, 1H), 7.82 (d, J = 8.5Hz, 2H), 7.51 (d, J = 8.4Hz, 2H). 13CNMR(101MHz,Chloroform-d)δ191.0,141.1,134.8,131.0,129.6.

[0076] Application Example 6: Preparation of olefin oxidation cleavage product (2f): 0.2 mmol 1-((3-methylbut-2-en-1-yl)oxy)-4-(prop-1-en-2-yl)benzene, 5 mol% W-1, and 2 mL acetonitrile were added to a 10 mL reaction flask. The mixture was then evacuated using a double-row tube, pierced with an oxygen balloon, and irradiated with 390 nm light under magnetic stirring. The reaction was allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes and filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (150:1, v:v) as eluents to obtain the pure product in a yield of 52%. The mass spectrometry analysis data of the product are as follows: theoretical value, 205.1229; experimental value, 205.1257. The nuclear magnetic resonance spectrum of compound 2f is shown in FIG. Figure 14-15 shown. 1 H NMR(400MHz,Chloroform-d)δ7.92(d,J=8.9Hz,2H),6.93(d,J=8.9Hz,2H),5. 51-5.44(m,1H),4.57(d,J=6.8Hz,2H),2.55(s,3H),1.80(s,3H),1.75(s,3H). 13 C NMR (101MHz, Chloroform-d) δ197.0,162.9,139.1,130.7,119.0,114.4,65.1,26.5,26.0,18.4.

[0077] Application Example 7: Preparation of Oxidative Fragmentation Product (2g): To a 10ml reaction flask, add 0.2mmol of 1-fluoro-4-(prop-1-en-2-yl)benzene, 5mol% of W-1, and 2mL of acetonitrile. Then, evacuate the mixture using a double-row tube, insert an oxygen balloon, and irradiate with 390nm light under magnetic stirring. The reaction is allowed to proceed at room temperature for 12 hours. 1mL of water is added to the reaction solution to terminate the reaction. The mixture is extracted three times with 2mL of ethyl acetate. The organic phases are combined, dried over anhydrous MgSO4 for 30 minutes, and filtered. The filtrate is concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (200:1, v:v) as eluents to obtain the pure product in a 90% yield. The mass spectrometry data for this product are as follows: theoretical value, 139.0559; experimental value, 139.0578. The nuclear magnetic resonance spectrum of compound 2g is shown in Figure 2. Figure 16-17 shown. 1HNMR (400MHz, Chloroform-d) δ7.97 (dd, J=8.9, 5.4Hz, 2H), 7.15-7.10 (m, 2H), 2.58 (s, 3H). 13 C NMR (101MHz, Chloroform-d) δ196.7,167.1,115.9,115.7,29.8.

[0078] Application Example 8: Preparation of Oxidative Fragmentation Product (2h): 0.2 mmol 2-vinylnaphthalene, 5 mol% W-1, and 2 mL acetonitrile were added to a 10 mL reaction flask. The mixture was then evacuated using a double-row tube, pierced with an oxygen balloon, and irradiated with 390 nm light under magnetic stirring. The reaction was allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO₄ for 30 minutes, then filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (250:1, v:v) as eluents to obtain the pure product in a 70% yield. The mass spectrometry data for the product are as follows: theoretical value, 157.0653; experimental value, 157.0659. The nuclear magnetic resonance spectrum of compound 2h is shown in Figure 2. Figure 18-19 shown. 1 H NMR (400MHz, Chloroform-d) δ10.16 (s, 1H), 8.34 (s, 1H), 8.01 (d, J = 7.8Hz, 1H), 7.95-7.88 (m, 3H), 7.66-7.57 (m, 2H). 13 C NMR (101MHz, Chloroform-d) δ192.5,136.6,134.7,134.2,132.7,129.6,129.2,128.2,127.7,127.2,122.9.

[0079] Application Example 9: Preparation of C-H bond oxidation product (4a): Add 0.4 mmol ethylbenzene, 5 mol% W-1, and 0.5 mL acetonitrile to a 10 ml reaction flask, insert an air ball, irradiate with 390 nm light under magnetic stirring, and react at room temperature for 12 hours. Add 1 mL of water to the reaction solution to terminate the reaction, extract three times with 2 mL of ethyl acetate, combine the organic phases, dry with anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate with a rotary evaporator, and then use petroleum ether and ethyl acetate (200:1, v:v) as eluents to obtain the pure product after column chromatography with a yield of 55%. The mass spectrometry analysis data of the product are as follows: theoretical value, 121.0653; experimental value, 121.0664. The nuclear magnetic resonance spectrum of compound 4a is shown in FIG. Figure 20-21 shown. 1H NMR (400MHz, Chloroform-d) δ8.00-7.92(m,2H),7.60-7.53(m,1H),7.51-7.43(m,2H),2.61(s,3H). 13 C NMR (101MHz, Chloroform-d) δ198.36,137.19,133.23,128.68,128.42,26.76.

[0080] Application Example 10: Preparation of C-H bond oxidation product (4b): 0.4 mmol 1-bromo-4-ethylbenzene, 5 mol% W-1, and 0.5 mL acetonitrile were added to a 10 mL reaction flask, pierced with an air balloon, and irradiated with 390 nm light under magnetic stirring. The reaction was allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes and filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (200:1, v:v) as eluents to obtain the pure product in an 81% yield. The mass spectrometry data of the product are as follows: theoretical value, 198.9759; experimental value, 198.9764. The nuclear magnetic resonance spectrum of compound 4b is shown in FIG. Figure 22-23 shown. 1 H NMR (400MHz, Chloroform-d) δ7.80 (d, J = 8.6 Hz, 2H), 7.58 (d, J = 8.6 Hz, 2H), 2.57 (s, 3H). 13 C NMR (101MHz, Chloroform-d) δ197.17,135.87,131.98,129.94,128.41,26.66.

[0081] Application Example 11: Preparation of C-H bond oxidation product (4c): 0.4 mmol 4-ethyl-1,1'-biphenyl, 5 mol% W-1, and 0.5 mL acetonitrile were added to a 10 mL reaction flask. An air balloon was inserted and the mixture was irradiated with 390 nm light under magnetic stirring. The reaction was allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes and filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (150:1, v:v) as eluents to obtain the pure product in an 82% yield. The mass spectrometry data for the product are as follows: theoretical value, 197.0966; experimental value, 197.0974. The nuclear magnetic resonance spectrum of compound 4c is shown in Figure 4. Figure 24-25 shown. 1H NMR (400MHz, Chloroform-d) δ8.04(d,J=8.4Hz,2H),7.69(d,J=8.4Hz,2H),7.63(d,J=6.9Hz,2H),7.48(t,J=7.3Hz,2H),7.41(t,J=7.3Hz,1H),2.64(s,3H). 13 C NMR (101MHz, Chloroform-d) δ197.90,145.87,139.95,135.93,129.09,129.04,128.37,127.38,127.33,26.78.

[0082] Application Example 12: Preparation of C-H bond oxidation product (4d): 0.4 mmol 1-chloro-4-ethylbenzene, 5 mol% W-1, and 0.5 mL acetonitrile were added to a 10 mL reaction flask, pierced with an air balloon, and irradiated with 390 nm light under magnetic stirring. The reaction was allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes and filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (200:1, v:v) as eluents to obtain the pure product in a yield of 67%. The mass spectrometry data of the product are as follows: theoretical value, 155.0264; experimental value, 155.0286. The nuclear magnetic resonance spectrum of compound 4d is shown in Figure 4. Figure 26-Figure 27 shown. 1 H NMR (400MHz, Chloroform-d) δ7.88 (d, J = 8.6 Hz, 2H), 7.42 (d, J = 8.6 Hz, 2H), 2.58 (s, 3H). 13 C NMR (101MHz, Chloroform-d) δ196.97,139.66,135.50,129.82,129.03,26.67.

[0083] Application Example 13: Preparation of C-H bond oxidation product (4e): 0.4 mmol 4-ethylbenzonitrile, 5 mol% W-1, and 0.5 mL acetonitrile were added to a 10 mL reaction flask, and an air balloon was inserted. The mixture was magnetically stirred and irradiated with 390 nm light. The reaction was allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes, then filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (200:1, v:v) as eluents to obtain the pure product in a 66% yield. The mass spectrometry data for the product are as follows: theoretical value, 146.0606; experimental value, 146.0615. The nuclear magnetic resonance spectrum of compound 4e is shown in Figure 4. Figure 28-Figure 29 shown. 1 H NMR (400MHz, Chloroform-d) δ8.03 (d, J = 7.8 Hz, 2H), 7.76 (d, J = 7.5 Hz, 2H), 2.63 (s, 3H). 13 C NMR (101MHz, Chloroform-d) δ196.70,139.99,132.62,128.81,118.05,116.46,26.89.

[0084] Application Example 14: Preparation of C-H bond oxidation product (4f): 0.4 mmol 1-(allyloxy)-4-ethylbenzene, 5 mol% W-1, and 0.5 mL acetonitrile were added to a 10 mL reaction flask, and an air balloon was inserted. The mixture was irradiated with 390 nm light under magnetic stirring and allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes and filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (150:1, v:v) as eluents to obtain the pure product in a yield of 50%. The mass spectrometry data of the product are as follows: theoretical value, 177.0916; experimental value, 177.0943. The nuclear magnetic resonance spectrum of compound 4f is shown in FIG. Figure 30-Figure 31 shown. 1 H NMR(400MHz,Chloroform-d)δ7.94(d,J=8.9Hz,2H),6.95(d,J=8.9Hz,2H),6.12-5.99(m,1H), 5.43(dd,J=17.3,1.5Hz,1H),5.33(dd,J=10.5,1.4Hz,1H),4.61(d,J=5.3Hz,2H),2.56(s,3H). 13 C NMR (101MHz, Chloroform-d) δ196.96,162.58,132.57,130.69,130.49,118.32,114.48,68.97,26.46.

[0085] Application Example 15: Preparation of C-H bond oxidation product (4g): Add 0.4mmol diphenylmethane, 5mol% W-1, and 0.5mL acetonitrile to a 10ml reaction flask, insert an air balloon, irradiate with 390nm light under magnetic stirring, and react at room temperature for 12 hours. Add 1mL of water to the reaction solution to terminate the reaction, extract three times with 2mL of ethyl acetate, combine the organic phases, dry over anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate using a rotary evaporator, and then use petroleum ether and ethyl acetate (100:1, v:v) as eluents to obtain the pure product after column chromatography with a yield of 62%. The mass spectrometry analysis data of the product are as follows: theoretical value, 183.0810; experimental value, 183.0832. The nuclear magnetic resonance spectrum of compound 4g is shown in Figure 4. Figure 32-Figure 33 shown. 1 H NMR (400MHz, Chloroform-d) δ7.83-7.79 (m, 4H), 7.59 (t, J = 7.4Hz, 2H), 7.48 (t, J = 7.5Hz, 4H). 13 C NMR(101MHz,Chloroform-d)δ196.92,137.68,132.56,130.19,128.40.

[0086] Application Example 16: Preparation of C-H bond oxidation product (4h): 0.4 mmol 9,10-dihydroanthracene, 5 mol% W-1, and 0.5 mL acetonitrile were added to a 10 mL reaction flask, and an air balloon was inserted. The mixture was irradiated with 390 nm light under magnetic stirring and allowed to react at room temperature for 12 hours. 1 mL of water was added to the reaction solution to terminate the reaction. The mixture was extracted three times with 2 mL of ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4 for 30 minutes, then filtered. The filtrate was concentrated using a rotary evaporator and then column chromatography using petroleum ether and ethyl acetate (100:1, v:v) as eluents to obtain the pure product in a 60% yield. The mass spectrometry analysis data for the product are as follows: theoretical value, 209.0603; experimental value, 209.0618. The nuclear magnetic resonance spectrum of compound 4h is shown in Figure 2. Figure 34-35 shown. 1 H NMR (400MHz, Chloroform-d) δ8.35-8.28(m,4H),7.83-7.78(m,4H). 13 CNMR(101MHz,Chloroform-d)δ183.28,134.23,133.61,127.33.

[0087] Comparative Example 1: An oxygen-bridged binuclear tungsten complex was used, and no hydrogen peroxide was added during the preparation process. The structural formula is as follows:

[0088]

[0089] Comparative Example 2: The difference from Example 1 is that a methoxybipyridine ligand is used, and the obtained compound has the following structural formula:

[0090]

[0091] The tungsten-oxygen complex W-1 prepared in Example 1, the oxygen-bridged binuclear tungsten complex prepared in Comparative Example 1, and the compound prepared in Comparative Example 2 were tested for their catalytic performance in olefin oxidative cleavage and C-H bond oxidation. The results are as follows: Figure 36 and Figure 37 shown.

[0092] Figure 36 In the catalytic oxidative cleavage of olefins, the catalytic yield of the tungsten-oxygen complex in Example 1 was the highest at 95%, while the catalytic yields of the compounds prepared in Comparative Examples 1 and 2 were only 68% or 74%. It can be seen that the tungsten-oxygen complex prepared in Example 1 has the best catalytic effect on the catalytic oxidative cleavage reaction of olefins.

[0093] Figure 37 In the catalytic C-H bond oxidation reaction, the catalytic yield of Example 1 was the highest at 81%, while the catalytic yields of the compounds prepared in Comparative Examples 1 and 2 were only 55% or 68%. It can be seen that the tungsten-oxygen complex prepared in Example 1 has a better catalytic effect on the C-H bond oxidation reaction. This is because the tungsten-oxygen complex prepared in Example 1 has a strong electron donating ability, which is beneficial to improving the W Ⅵ The stability of the complex and its good solubility are conducive to the progress of the catalytic reaction.

Claims

1. A tungsten-oxygen complex, characterized in that: The molecular structure of the tungsten-oxygen complex W-1 is as follows: 。 2. The tungsten-oxygen complex according to claim 1, characterized in that The tungsten-oxygen complex W-1 is in the form of colorless solid crystals, and the unit cell parameters are: a =12.07Å; b = 8.59Å; c =18.54Å; α=90°; β=90°; γ=90°; Volume =1925.91Å 3 .

3. A method for preparing the tungsten-oxygen complex according to claim 1, characterized in that: The method comprises the following steps: mixing a solvent, tungsten hexachloride, 4,4-di-tert-butyl-2,2-bipyridine ligand and a reducing agent at room temperature and in a protective atmosphere to obtain a reaction system, performing a stirring reaction, aspirating a yellow supernatant obtained by the reaction after completion, adding n-hexane to the reaction system for washing until the supernatant becomes colorless, draining the supernatant, adding methanol and ether, fully volatilizing in the air to turn blue-black, rotating to dryness, and then reacting with hydrogen peroxide using acetonitrile as a solvent until the supernatant becomes colorless, and draining the supernatant to obtain a tungsten-oxygen complex W-1.

4. The method according to claim 3, characterized in that: The solvent is toluene, the protective atmosphere is nitrogen, and the reducing agent is norbornene.

5. Use of the tungsten-oxygen complex according to claim 1 as a catalyst in olefin oxidative cleavage and C-H bond oxidation, characterized in that: The raw materials for olefin oxidation and cleavage are styrene and its derivatives, and the raw materials for CH bond oxidation are ethylbenzene and its derivatives. The oxidation products of styrene and its derivatives are shown in the following formula (II), and the oxidation products of ethylbenzene and its derivatives are shown in the following formula (IV). Formula (II); Formula (IV); R1 = halogen, aryl or alkyl group, R2 = hydrogen atom, alkyl or aryl group.

6. The use according to claim 5, characterized in that The application steps are: adding a substrate and a catalyst tungsten-oxygen complex into a solvent, placing the mixture in a reactor, irradiating the mixture with ultraviolet light under an oxidizing agent, and obtaining a target product through column chromatography; the substrate is a raw material for olefin oxidation cleavage or a raw material for CH bond oxidation.

7. The use according to claim 6, characterized in that The molar ratio of the substrate to the catalyst tungsten-oxygen complex is 1:(0.05-0.15).

8. The use according to claim 6, characterized in that When the substrate is an olefin oxidation and cracking raw material, the oxidant is oxygen.

9. The use according to claim 6, characterized in that When the substrate is a CH bond oxidation raw material, the oxidant is air.

10. The use according to claim 6, characterized in that The solvent is acetonitrile.

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