Tungsten-oxygen complex as well as preparation method and application thereof in olefin oxidative cleavage and C-H bond oxidation

Abstract

The invention discloses a tungsten-oxygen complex as well as a preparation method and application thereof in olefin oxidative cleavage and C-H bond oxidation, and belongs to the technical field of metal coordination compound functional materials. The novel tungsten-oxygen complex is synthesized under the condition of H2O2 by utilizing a bipyridine ligand and metal tungsten, and the complex has the characteristic of air stability and can be used as a high-efficiency catalyst for preparing carbonyl compounds by olefin oxidative cleavage and C-H bond oxidation. Compared with the prior art, the catalyst provided by the invention has the following characteristics: (1) the catalyst provided by the invention is a novel tungsten catalyst, is novel in structure and is prepared for the first time; (2) the catalytic reaction is carried out under a homogeneous catalytic system, so that the catalytic reaction can be used for oxidative cracking of olefin and can also be used for oxidative synthesis of aldehyde ketone from C-H bonds; (3) oxygen or air is used as a green oxidant in the catalytic reaction; and (4) carrying out green synthesis of carbonyl compounds by using abundant chemical raw materials (styrene derivatives and phenylethane derivatives).

Description

Technical Field

[0001] The invention relates to the technical field of metal coordination compound functional materials, and in particular to a tungsten-oxygen complex and a preparation method thereof, and application thereof in olefin oxidation 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 CH bonds. For example, the literature (ACS Catalysis 2020, 10, 4617) reported the preparation of Fe@NPC-T iron nanocomposite catalyst by hydrothermal synthesis, using TBHP as an oxidant to directly oxidize and crack olefins into ketones. The literature (Green Chemistry 2012, 14, 3386) uses 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 olefin oxidative cracking. Or, in the absence of solvents and low catalyst loading conditions, water-soluble ruthenium complexes are used as catalysts to efficiently convert the corresponding alkanes into ketones. The above reports all use one catalyst to achieve the catalytic oxidation of one type of substance (olefins or alkanes). The literature (ACS Catalysis 2023, 13, 13414) uses graphite carbon nitride as a catalyst to simultaneously oxidize olefins and alkanes to synthesize carbonyl compounds under oxygen conditions, but this system is a heterogeneous system.

[0003] Therefore, designing and developing a green and efficient homogeneous catalytic system, using milder reaction conditions, and oxidizing olefins and alkanes to produce carbonyl compounds are very worthy research topics and are very challenging. Summary of the invention

[0004] Purpose of the invention: The first purpose of the present invention is to provide a new type of tungsten-oxygen complex with excellent catalytic performance and air temperature resistance. The second purpose of the present invention is to provide a method for preparing the above-mentioned tungsten-oxygen complex. The third purpose of the present invention is to provide the use of the above-mentioned tungsten-oxygen complex as a catalyst in catalyzing olefin oxidative breakage and CH bond oxidation.

[0005] Technical solution: The tungsten-oxygen complex provided by the present invention has a molecular structure of the tungsten-oxygen complex W-1 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 a stirring reaction is performed. After the reaction is completed, the yellow supernatant obtained by the reaction is sucked out, n-hexane is added to the reaction system to wash until the supernatant is colorless, and then it is drained, methanol and ether are added, and after fully volatilizing in the air and turning into blue-black, it is spin-dried, and then acetonitrile is used as a solvent, and it is reacted with hydrogen peroxide until it is colorless, and then it is drained to obtain a 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 specifically as follows: add 15mL of dry toluene to a 100ml reaction bottle, add (1eq) WCl6 under nitrogen protection and stir at room temperature, then add (1eq) 4,4-di-tert-butyl-2,2-bipyridine ligand, and finally add (2eq) norbornene. Nitrogen is introduced through a double-row tube, reacted for 1 hour under magnetic stirring, and then treated. After the yellow supernatant is sucked out, 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 blue-black, it is spin-dried, and then acetonitrile is used as a solvent, reacted with hydrogen peroxide until colorless, and then dried to obtain the complex W-1. Among them: 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 (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.

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

[0012]

[0013] The above tungsten-oxygen complex is used as a catalyst in the oxidative cleavage of olefins and the oxidation of CH 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 oxidant, and obtaining a target product by column chromatography; the substrate comprises an olefin oxidation cleavage raw material or a CH bond oxidation raw material, the olefin oxidation cleavage raw material is styrene and its derivatives, and the CH bond oxidation raw material is ethylbenzene 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 ethylbenzene and its derivatives is shown in the following formula (III), and the oxidation products of ethylbenzene 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] Further 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 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 cleavage 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 with an air-stable tungsten-oxygen complex W-1 as a catalyst. Under mild conditions, the green oxidant oxygen or air is used to enable the tungsten-oxygen catalyst to catalyze the oxidative breakage of olefins and the oxidation of CH bonds. Under light conditions, it catalyzes the oxidative breakage of olefins and the oxidation of CH bonds, providing two different pathways for the preparation of carbonyl compounds, thereby achieving a green and efficient synthesis of carbonyl compounds with high added value. The reaction is mild and efficient, and no additives are required.

[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 oxidation and CH 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 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 carbon NMR spectrum of compound 2a;

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

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

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

[0039] Fig. 9 is the carbon NMR spectrum of compound 2c;

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

[0041] Fig.11 is the carbon NMR spectrum of compound 2d;

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

[0043] Fig.13 is the carbon NMR spectrum of compound 2e;

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

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

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

[0047] Fig.17 is the carbon NMR spectrum of compound 2g;

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

[0049] Fig.19 is the carbon NMR spectrum of compound 2h;

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

[0051] Fig.21 is the carbon NMR spectrum of compound 4a;

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

[0053] Fig.23 is the carbon NMR spectrum of compound 4b;

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

[0055] Fig.25 is the carbon NMR spectrum of compound 4c;

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

[0057] Fig. 27 is the carbon NMR spectrum of compound 4d;

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

[0059] Fig.29 is the carbon NMR spectrum of compound 4e;

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

[0061] Fig.31 is the carbon NMR spectrum of compound 4f;

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

[0063] Fig.33 is the carbon NMR spectrum of compound 4g;

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

[0065] Fig.35 is the carbon NMR spectrum of compound 4h;

[0066] Fig.36 It is a reaction process diagram of the olefin oxidation cleavage reaction catalyzed by the compounds prepared in Example 1 and Comparative Examples 1-2 as catalysts and a comparison diagram of the obtained yields;

[0067] Fig.37 It is a reaction process diagram of the CH bond oxidation reaction catalyzed by the compounds prepared in Example 1 and Comparative Examples 1-2 as catalysts and a comparison diagram of the obtained yields. DETAILED DESCRIPTION

[0068] The present invention is further described below in conjunction with specific embodiments and drawings.

[0069] Example 1: Preparation of the novel tungsten-oxygen complex W-1: Add 15 mL of dry toluene to a 100 ml reaction bottle, 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 pass nitrogen, react for 1 hour under magnetic stirring, treat, suck out the yellow supernatant, 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 the 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): Add 0.2mmol (1-cyclopropylvinyl) benzene, 5mol% W-1, and 2mL acetonitrile to a 10ml reaction bottle, then evacuate with a double-row tube, insert an oxygen ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate with a rotary evaporator, and after concentration, use petroleum ether and ethyl acetate (200:1, v:v) as eluents, and obtain a pure product after column chromatography 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 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): Add 0.2mmol 1-(1-cyclopropylvinyl)-4-fluorobenzene, 5mol% W-1, and 2mL acetonitrile to a 10ml reaction bottle, then evacuate with a double-row tube, insert an oxygen ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate with a rotary evaporator, and after concentration, use petroleum ether and ethyl acetate (200:1, v:v) as eluents, and obtain a pure product after column chromatography 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 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): Add 0.2mmol4,4'-(ethylene-1,1-diyl)bis(fluorobenzene), 5mol%W-1, and 2mL acetonitrile to a 10ml reaction bottle, then evacuate with a double-row tube, insert an oxygen ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate with a rotary evaporator, and after concentration, use petroleum ether and ethyl acetate (200:1, v:v) as eluents, and obtain a pure product after column chromatography with 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 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 olefin oxidation cleavage product (2d): Add 0.2mmol 1-methyl-4-vinylbenzene, 5mol% W-1, and 2mL acetonitrile to a 10ml reaction bottle, then evacuate with a double-row tube, insert an oxygen ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; the filtrate is concentrated with a rotary evaporator, and after concentration, petroleum ether and ethyl acetate (300:1, v:v) are used as eluents, and the pure product is obtained after column chromatography with a yield of 78%. The mass spectrometry analysis data of 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 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 olefin oxidation cleavage product (2e): Add 0.2mmol 1-chloro-4-vinylbenzene, 5mol% W-1, and 2mL acetonitrile to a 10ml reaction bottle, then evacuate with a double-row tube, insert an oxygen ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; the filtrate is concentrated with a rotary evaporator, and after concentration, petroleum ether and ethyl acetate (300:1, v:v) are used as eluents, and the pure product is obtained after column chromatography with a yield of 81%. The mass spectrometry analysis data of the product are as follows: theoretical value, 141.0107; experimental value, 141.0115. The nuclear magnetic resonance spectrum of compound 2e is shown in 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): Add 0.2mmol 1-((3-methylbut-2-en-1-yl)oxy)-4-(prop-1-en-2-yl)benzene, 5mol% W-1, and 2mL acetonitrile to a 10ml reaction bottle, then evacuate with a double-row tube, insert an oxygen ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; the filtrate is concentrated with a rotary evaporator, and after concentration, petroleum ether and ethyl acetate (150:1, v:v) are used as eluents, and the pure product is obtained after column chromatography with 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 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 olefin oxidation cleavage product (2g): Add 0.2mmol 1-fluoro-4-(prop-1-en-2-yl)benzene, 5mol% W-1, and 2mL acetonitrile to a 10ml reaction bottle, then evacuate with a double-row tube, insert an oxygen ball, 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 and dry with anhydrous MgSO4 for 30 minutes, filter; concentrate the filtrate with a rotary evaporator, and after concentration, use petroleum ether and ethyl acetate (200:1, v:v) as eluents, and obtain a pure product after column chromatography with a yield of 90%. The mass spectrometry analysis data of the product are as follows: theoretical value, 139.0559; experimental value, 139.0578. The nuclear magnetic resonance spectrum of compound 2g is shown in Figure 16-Figure 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 olefin oxidation cleavage product (2h): Add 0.2mmol 2-vinylnaphthalene, 5mol% W-1, and 2mL acetonitrile to a 10ml reaction bottle, then evacuate with a double-row tube, insert an oxygen ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; the filtrate is concentrated with a rotary evaporator, and after concentration, petroleum ether and ethyl acetate (250:1, v:v) are used as eluents, and the pure product is obtained after column chromatography with a yield of 70%. The mass spectrometry analysis data of 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 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 CH bond oxidation product (4a): Add 0.4mmol ethylbenzene, 5mol% W-1, and 0.5mL acetonitrile to a 10ml reaction bottle, insert an air ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate with a rotary evaporator, and after concentration, use petroleum ether and ethyl acetate (200:1, v:v) as eluents, and 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 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 CH bond oxidation product (4b): Add 0.4mmol 1-bromo-4-ethylbenzene, 5mol% W-1, and 0.5mL acetonitrile to a 10ml reaction bottle, insert an air ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate with a rotary evaporator, and after concentration, use petroleum ether and ethyl acetate (200:1, v:v) as eluents, and obtain a pure product after column chromatography with a yield of 81%. The mass spectrometry analysis 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 Figure 22-Figure 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 CH bond oxidation product (4c): Add 0.4mmol 4-ethyl-1,1'-biphenyl, 5mol% W-1, and 0.5mL acetonitrile to a 10ml reaction bottle, insert an air ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; the filtrate is concentrated with a rotary evaporator, and after concentration, petroleum ether and ethyl acetate (150:1, v:v) are used as eluents, and the pure product is obtained after column chromatography with a yield of 82%. The mass spectrometry analysis data of 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 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 CH bond oxidation product (4d): Add 0.4mmol 1-chloro-4-ethylbenzene, 5mol% W-1, and 0.5mL acetonitrile to a 10ml reaction bottle, insert an air ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; the filtrate is concentrated with a rotary evaporator, and after concentration, petroleum ether and ethyl acetate (200:1, v:v) are used as eluents, and the pure product is obtained after column chromatography with a yield of 67%. The mass spectrometry analysis 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 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 CH bond oxidation product (4e): Add 0.4mmol 4-ethylbenzonitrile, 5mol% W-1, and 0.5mL acetonitrile to a 10ml reaction bottle, insert an air ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate with a rotary evaporator, and after concentration, use petroleum ether and ethyl acetate (200:1, v:v) as eluents, and obtain the pure product after column chromatography with a yield of 66%. The mass spectrometry analysis data of 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 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 CH bond oxidation product (4f): Add 0.4mmol 1-(allyloxy)-4-ethylbenzene, 5mol% W-1, and 0.5mL acetonitrile to a 10ml reaction bottle, insert an air ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate with a rotary evaporator, and after concentration, use petroleum ether and ethyl acetate (150:1, v:v) as eluents, and obtain the pure product after column chromatography with a yield of 50%. The mass spectrometry analysis 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 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 CH bond oxidation product (4g): Add 0.4mmol diphenylmethane, 5mol% W-1, and 0.5mL acetonitrile to a 10ml reaction bottle, insert an air ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; concentrate the filtrate with a rotary evaporator, and after concentration, use petroleum ether and ethyl acetate (100:1, v:v) as eluents, and 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 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 CH bond oxidation product (4h): Add 0.4mmol 9,10-dihydroanthracene, 5mol% W-1, and 0.5mL acetonitrile to a 10ml reaction bottle, insert an air ball, 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 and dry with anhydrous MgSO4 for 30 minutes, and filter; the filtrate is concentrated with a rotary evaporator, and after concentration, petroleum ether and ethyl acetate (100:1, v:v) are used as eluents, and the pure product is obtained after column chromatography with a yield of 60%. The mass spectrometry analysis data of 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 34-Figure 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 oxidation cleavage and CH bond oxidation. The results are as follows: Fig.36 and Fig.37 shown.

[0092] Fig.36 In the catalytic oxidative cleavage of olefins, the catalytic yield of the tungsten-oxygen complex in Example 1 is 95%, which is the highest, while the catalytic yields of the compounds prepared in Comparative Examples 1 and 2 are 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] Fig.37 In the catalytic CH bond oxidation, the catalytic yield of Example 1 is 81%, which is the highest, while the catalytic yields of the compounds prepared in Comparative Examples 1 and 2 are only 55% or 68%. It can be seen that the tungsten-oxygen complex prepared in Example 1 has a better catalytic effect on the CH bond oxidation reaction. This is because the tungsten-oxygen complex prepared in Example 1 has a strong electron donation ability, which is beneficial to improve the W Ⅵ The stability of the complex and its good solubility are conducive to 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: α=90°; β=90°; γ=90°; 3. A method for preparing the tungsten-oxygen complex according to claim 1, characterized in that: The method comprises 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 a stirring reaction is performed. After the reaction is completed, a yellow supernatant obtained by the reaction is sucked out, n-hexane is added to the reaction system for washing until the supernatant becomes colorless, and then the supernatant is drained, methanol and ether are added, and the supernatant is fully volatilized in the air to turn into blue-black, and then the supernatant is dried by rotation, and acetonitrile is used as a solvent, and the reaction is carried out with hydrogen peroxide until the supernatant becomes colorless, and then the supernatant is drained 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 CH bond oxidation.

6. The use according to claim 5, characterized in that: 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 oxidant, and obtaining a target product by column chromatography; the substrate comprises an olefin oxidation cleavage raw material or a CH bond oxidation raw material, the olefin oxidation cleavage raw material is styrene and its derivatives, and the CH bond oxidation raw material is ethylbenzene and its derivatives, wherein the structural formula of styrene and its derivatives is shown in the following formula (I), the oxidation product of styrene and its derivatives is shown in the following formula (II), the structural formula of ethylbenzene and its derivatives is shown in the following formula (III), and the oxidation product of ethylbenzene and its derivatives is shown in the following formula (IV). R1 = halogen, aryl or alkyl group, R2 = hydrogen atom, alkyl or aryl group.

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 cleavage 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.

Images