A method for photocatalytic three-component cascade efficient construction of isoxazolines

Abstract

This invention belongs to the field of organic synthesis technology, specifically relating to a photocatalytic method for the efficient tandem construction of isoxazoline from three components. The method involves dissolving substituted or unsubstituted trichlorotoluene and a compound containing a double bond in 1,2-dichloroethane, then adding tert-butyl nitrite, a base, and a photocatalyst. The reaction is carried out under inert gas conditions with visible light irradiation and stirring at room temperature. After the reaction is complete, the solvent is removed under reduced pressure, and the crude product is purified by silica gel column chromatography to obtain the isoxazoline skeleton. This invention utilizes a photocatalyst that triggers the tandem reaction initiation step under mild conditions. By controlling the photocatalyst structure and reaction conditions, precise regulation of the activity and selectivity of the reaction intermediates can be achieved, thereby efficiently constructing the isoxazoline skeleton. This method has broad research potential and application prospects.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for the efficient construction of isoxazoline by photocatalysis of three components in series. Background Technology

[0002] Isoxazoline, an important class of five-membered nitrogen-containing heterocyclic compounds, has a core skeleton widely found in natural products, drug molecules, pesticides, and functional materials. It is also a key ligand precursor in transition metal-catalyzed reactions. In the pharmaceutical field, molecules containing isoxazoline structures exhibit various biological activities such as antibacterial, anti-inflammatory, and antitumor activity, serving as important cores for innovative drug development. In agriculture, isoxazoline-based herbicides have become market hotspots due to their high selectivity and ecological safety. However, traditional synthetic methods have many limitations, such as reliance on expensive and toxic transition metal catalysts, cumbersome intermediate preparation, and harsh reaction conditions. These not only increase costs but also generate significant amounts of waste, making it difficult to meet the demands of green chemistry and industrial production. Therefore, developing efficient and environmentally friendly isoxazoline synthesis methods is of significant practical importance.

[0003] Photocatalysis, as a representative of green synthesis technology, has made groundbreaking progress in the field of organic chemistry in recent years. Compared with traditional thermocatalysis, photocatalysis utilizes visible light as an energy source, generating excited-state species through the absorption of photons by the photocatalyst. It can achieve the activation and transformation of thermodynamically stable substrates under mild conditions, exhibiting significant advantages such as high energy efficiency and environmental friendliness. Furthermore, photocatalytic systems can precisely control the generation and transformation of reactive intermediates, providing novel approaches for constructing complex molecular frameworks. Although photocatalysis shows great potential in organic synthesis, its application in the synthesis of isoxazolines is still in the exploratory stage. Existing reports mostly focus on simple binary reactions and suffer from problems such as narrow substrate scope and difficulty in controlling stereoselectivity. There is an urgent need to develop more efficient and universal photocatalytic synthesis strategies.

[0004] Tandem reactions, as a "one-pot" synthetic mode, allow substrates to be directly converted into target products through a series of multiple reactions in a single reaction system. This minimizes reaction steps, avoids raw material losses and environmental pollution caused by intermediate separation and purification, and significantly improves synthetic efficiency and atom economy. Combining photocatalysis with tandem reactions holds promise for overcoming the limitations of traditional isoxazoline synthesis: photocatalysis can trigger the initiation step of tandem reactions under mild conditions, and by controlling the structure of the photocatalyst and reaction conditions, the activity and selectivity of reaction intermediates can be precisely controlled, thereby efficiently constructing the isoxazoline skeleton. Currently, the application of photocatalytic three-component tandem reactions in organic synthesis is still in its early stages, and there are no mature reports on its use in the construction of isoxazolines. This field has broad research potential and application prospects. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides a method for the efficient construction of isoxazoline using a photocatalytic three-component tandem reaction. The photocatalyst of this invention triggers the initiation step of the tandem reaction under mild conditions. By controlling the structure of the photocatalyst and the reaction conditions, precise control over the activity and selectivity of the reaction intermediates is achieved, thereby efficiently constructing the isoxazoline skeleton. This method has broad research potential and application prospects.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for the efficient construction of isoxazoline using a photocatalytic three-component tandem method, comprising the following steps: Substituted or unsubstituted trichlorotoluene and a compound containing a double bond were dissolved in 1,2-dichloroethane. Then, tert-butyl nitrite, a base, and a photocatalyst were added. The reaction was carried out under an inert gas atmosphere with visible light irradiation and stirring at room temperature. After the reaction was completed, the solvent was removed under reduced pressure. The crude product was then purified by silica gel column chromatography to obtain the product isoxazoline.

[0007] The reaction mechanism of this invention is as follows: Under the action of light and a photocatalyst, substituted or unsubstituted trichlorotoluene first transforms into an aldehyde group (trichloromethyl group), which then reacts with tert-butyl nitrite to form a dipole. This dipole undergoes a 3+2 cycloaddition with a compound containing a double bond, followed by intramolecular elimination to generate an isoxazoline compound. Taking the reaction of trichlorotoluene and styrene as an example, under the action of light and a photocatalyst, trichlorotoluene first produces benzaldehyde, which then reacts with TBN to form a dipole. This dipole undergoes a 3+2 cycloaddition with styrene, followed by intramolecular elimination to generate an isoxazoline compound. The reaction process is as follows: It should be noted that in the applicant's previous patent application CN121974865A, a method for synthesizing isoxazole compounds under visible light catalysis was described. In this method, the olefin compound was dissolved in 1,2-dichloroethane, followed by the addition of tert-butyl nitrite, tribromomethane, a base, and a photocatalyst. The reaction was carried out under an inert gas atmosphere with visible light irradiation and stirring at room temperature. After the reaction was complete, the solvent was removed under reduced pressure, and the crude product was purified by silica gel column chromatography to obtain the isoxazole compound. The reaction mechanism is as follows: under the action of light and a photocatalyst, the double bonds in the olefin compound undergo free radical addition, followed by intramolecular nucleophilic substitution and elimination processes to obtain the isoxazole compound. Taking styrene as an example, under the action of light and a photocatalyst, the olefin undergoes free radical addition, followed by intramolecular nucleophilic substitution and elimination processes to obtain the isoxazole compound. The reaction process is as follows: Furthermore, the substituted or unsubstituted trichlorotoluene is any one of the following structural formulas: .

[0008] Furthermore, the compound containing double bonds is any one of the following structural formulas: .

[0009] Furthermore, the molar ratio of the substituted or unsubstituted trichlorotoluene, the compound containing double bonds, tert-butyl nitrite, and the base is 1-2:1-2:1-4:1-6.

[0010] Furthermore, the molar ratio of the substituted or unsubstituted trichlorotoluene, the compound containing double bonds, tert-butyl nitrite, and the base is 1:2:3:2.

[0011] Furthermore, the amount of the photocatalyst is 1%-5% of the molar amount of the substituted or unsubstituted trichlorotoluene.

[0012] Further, the base is N,N-diisopropylethylamine.

[0013] Furthermore, the photocatalyst is Na2-Eosin Y.

[0014] Furthermore, the visible light irradiation refers to irradiation using a blue LED light source with a power of 35 W.

[0015] Furthermore, the stirring reaction time is 12-18 hours, and the inert gas is N2.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a photocatalytic method for the efficient tandem construction of isoxazoline from three components. Substituted or unsubstituted trichlorotoluene and a compound containing a double bond are dissolved in 1,2-dichloroethane. Then, tert-butyl nitrite, a base, and a photocatalyst are added. The reaction is carried out under inert gas atmosphere with visible light irradiation and stirring at room temperature. After the reaction is complete, the solvent is removed under reduced pressure. The crude product is then purified by silica gel column chromatography to obtain the isoxazoline skeleton. This invention's photocatalyst triggers the tandem reaction initiation step under mild conditions. By controlling the photocatalyst structure and reaction conditions, the activity and selectivity of the reaction intermediates can be precisely controlled, thereby efficiently constructing the isoxazoline skeleton with a yield of up to 85%. Furthermore, it minimizes reaction steps, avoids raw material loss and environmental pollution caused by intermediate separation and purification, and significantly improves synthesis efficiency and atom economy, demonstrating broad research potential and application prospects. Detailed Implementation

[0017] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0019] Example 1: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis 0.5 mmol of trichlorotoluene and 0.75 mmol of styrene were dissolved in 1.0 mL of 1,2-dichloroethane. Then, 1.5 mmol of tert-butyl nitrite, 1.0 mmol of DIPEA, and 2% of the molar amount of trichlorotoluene photocatalyst Na2-Eosin Y were added. The mixture was stirred under a N2 atmosphere and reacted at room temperature under a 35W blue LED lamp for 12 hours. After the reaction was completed, the solvent was removed under reduced pressure, and the crude product was purified by silica gel column chromatography to obtain a yellow oily product 4a with a yield of 74%.

[0020] The reaction equation is: The NMR data for compound 4a are as follows: 1H NMR (400 MHz, CDCl3) δ 7.74 (dt, J = 7.4, 3.5 Hz, 2H), 7.52 – 7.38(m, 7H), 7.39 – 7.31 (m, 1H), 5.77 (dd, J = 11.0, 8.3 Hz, 1H), 3.81 (dd, J =16.7, 11.0 Hz, 1H), 3.37 (dd, J = 16.7, 8.3 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.2, 141.0, 130.2, 129.5, 128.80, 128.79, 128.3, 126.8, 125.9, 82.6, 43.2.

[0021] Example 2: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 2 and Example 1 is that in Example 2, the amounts of trichlorotoluene (1 mmol), styrene (0.5 mmol), tert-butyl nitrite (1 mmol), and DIPEA (3 mmol) are the same as in Example 1. The final yield of isoxazoline 4a was 42%.

[0022] Example 3: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 3 and Example 1 is that in Example 3, the amount of tert-butyl nitrite was 1 mmol and the amount of DIPEA was 3 mmol, while the rest remained the same as in Example 1. The final yield of isoxazoline 4a was 53%.

[0023] Example 4: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 4 and Example 1 is that in Example 4, tert-butyl nitrite was 0.5 mmol and DIPEA was 3 mmol, while the rest remained the same as in Example 1. The final yield of isoxazoline 4a was 35%.

[0024] Example 5: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 5 and Example 1 is that in Example 5, DIPEA was 3 mmol, while the rest remained the same as in Example 1. The final yield of isoxazoline 4a was 65%.

[0025] Example 6: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 6 and Example 1 is that in Example 6, the amount of tert-butyl nitrite was 2 mmol and the amount of DIPEA was 3 mmol; otherwise, the amounts were the same as in Example 1. The final yield of isoxazoline 4a was 62%.

[0026] Example 7: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 7 and Example 1 is that in Example 7, DIPEA was 0.5 mmol, while the rest remained the same as in Example 1. The final yield of isoxazoline 4a was 56%.

[0027] Example 8: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 8 and Example 1 is that in Example 8, DIPEA was 2 mmol, while the rest remained the same as in Example 1. The final yield of isoxazoline 4a was 63%.

[0028] Example 9: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 9 and Example 1 is that in Example 9, DIPEA was 2.5 mmol, while the rest remained the same as in Example 1. The final yield of isoxazoline 4a was 61%.

[0029] Example 10: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 10 and Example 1 is that the amount of styrene in Example 10 is 0.5 mmol, while the rest remains the same as in Example 1. The final yield of isoxazoline 4a was 70%.

[0030] Example 11: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Example 11 and Example 1 is that the amount of styrene in Example 11 is 1 mmol, while the rest remains the same as in Example 1. The final yield of isoxazoline 4a was 73%.

[0031] Comparative Example 1: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, the amount of trichlorotoluene was 1 mmol, styrene was 0.5 mmol, tert-butyl nitrite was 1 mmol, and the base was Et3N at a concentration of 3 mmol. All other components remained the same as in Example 1. The final yield of isoxazoline 4a was 26%.

[0032] Comparative Example 2: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, the amount of trichlorotoluene was 1 mmol, styrene was 0.5 mmol, tert-butyl nitrite was 1 mmol, and the base was DMAP at a concentration of 3 mmol. All other components remained the same as in Example 1. A trace amount of isoxazoline 4a was ultimately obtained.

[0033] Comparative Example 3: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, the amount of trichlorotoluene was 1 mmol, styrene was 0.5 mmol, tert-butyl nitrite was 1 mmol, and the base was DABCO at a concentration of 3 mmol. All other components remained the same as in Example 1. The final yield of isoxazoline 4a was 15%.

[0034] Comparative Example 4: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Comparative Example 4 and Example 1 is that in Comparative Example 4, the amount of trichlorotoluene was 1 mmol, styrene was 0.5 mmol, tert-butyl nitrite was 1 mmol, and the base DIPEA was not added; otherwise, the contents remained the same as in Example 1. The final yield of isoxazoline 4a was 8%.

[0035] Comparative Example 5: A method for the efficient construction of isoxazoline 4a by photocatalytic tandem three-component synthesis The difference between Comparative Example 5 and Example 1 is that the reaction in Comparative Example 5 was carried out in the dark, while the rest was the same as in Example 1, and isoxazoline 4a was not obtained in the end.

[0036] Example 12: A method for the efficient construction of isoxazoline 4b by photocatalytic tandem three-component synthesis The difference between Example 12 and Example 1 is that in Example 12, compound 2b is used instead of styrene. The structural formula of compound 2b is: The structural formula of the synthesized compound 4b is: Compound 4b is a yellow oil with a yield of 83%.

[0037] The NMR data for compound 4b are as follows: 1H NMR (400 MHz, CDCl3) δ 7.76 – 7.69 (m, 2H), 7.44 (p, J = 3.2 Hz,3H), 7.38 – 7.32 (m, 2H), 6.97 – 6.90 (m, 2H), 5.71 (dd, J = 10.8, 8.7 Hz,1H), 3.83 (s, 3H), 3.75 (dd, J = 16.7, 10.9 Hz, 1H), 3.35 (dd, J = 16.7, 8.6Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 159.6, 156.3, 132.8, 130.1, 129.6, 128.8,127.4, 126.7, 114.2, 82.5, 55.4, 42.9.

[0038] Example 13: A method for the efficient construction of isoxazoline 4c by photocatalytic tandem three-component synthesis The difference between Example 13 and Example 1 is that in Example 13, compound 2c is used instead of styrene. The structural formula of compound 2c is: The structural formula of the synthesized compound 4c is: Compound 4c is a yellow oil with a yield of 81%.

[0039] The NMR detection data of compound 4c are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.78 – 7.69 (m, 2H), 7.44 (p, J = 3.2 Hz,3H), 7.33 (d, J = 8.1 Hz, 2H), 7.22 (d, J = 7.9 Hz, 2H), 5.74 (dd, J = 10.9,8.5 Hz, 1H), 3.78 (dd, J = 16.7, 10.9 Hz, 1H), 3.36 (dd, J = 16.7, 8.4 Hz,1H), 2.39 (s, 3H). 13 C NMR (101 MHz, CDCl3) δ 156.2, 138.1, 137.9, 130.1, 129.6, 129.5, 128.8, 126.8, 126.0, 82.6, 43.1, 21.2.

[0040] Example 14: A method for the efficient construction of isoxazoline 4d by photocatalytic tandem three-component synthesis The difference between Example 14 and Example 1 is that in Example 14, compound 2d is used instead of styrene. The structural formula of compound 2d is: The structural formula of the synthesized compound 4d is: Compound 4d is a yellow oil with a yield of 85%.

[0041] The NMR data for compound 4d are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.77 – 7.72 (m, 2H), 7.46 (dd, J = 5.7, 2.7Hz, 5H), 7.39 (d, J = 8.4 Hz, 2H), 5.76 (dd, J = 10.9, 8.5 Hz, 1H), 3.79 (dd,J = 16.6, 10.9 Hz, 1H), 3.40 (dd,J = 16.6, 8.4 Hz, 1H), 1.38 (s, 9H). 13 C NMR (101 MHz, CDCl3) δ 156.2, 151.3, 137.9, 130.1, 129.6, 128.8, 126.8, 125.8,125.7, 82.6, 43.0, 34.6, 31.4.

[0042] Example 15: A method for the efficient construction of isoxazoline 4e by photocatalytic tandem three-component synthesis The difference between Example 15 and Example 1 is that in Example 15, compound 2e is used instead of styrene. The structural formula of compound 2e is: The structural formula of the synthesized compound 4e is: Compound 4e is a yellow oil with a yield of 79%.

[0043] The NMR detection data for compound 4e are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.72 (dd, J = 6.6, 3.1 Hz, 2H), 7.47 – 7.39 (m, 7H), 5.77 (dd, J = 11.0, 8.1 Hz, 1H), 4.61 (s, 2H), 3.81 (dd, J = 16.7,11.0 Hz, 1H), 3.35 (dd, J = 16.7, 8.1 Hz, 1H). 13C NMR (101 MHz, CDCl3) δ156.1, 141.3, 137.5, 130.3, 129.3, 129.1, 128.8, 126.8, 126.3, 82.1, 45.9,43.2.

[0044] Example 16: A method for the efficient construction of isoxazoline 4f using a photocatalytic three-component tandem process. The difference between Example 16 and Example 1 is that in Example 16, compound 2f is used instead of styrene. The structural formula of compound 2f is: The structural formula of the synthesized compound 4f is: Compound 4f is a yellow oil with a yield of 72%.

[0045] The NMR data for compound 4f are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.72 (dt, J = 7.6, 3.9 Hz, 2H), 7.48 – 7.37(m, 5H), 7.08 (t, J = 8.7 Hz, 2H), 5.74 (dd, J = 10.9, 8.3 Hz, 1H), 3.80 (dd,J = 16.7, 11.0 Hz, 1H), 3.33 (dd,J = 16.7, 8.2 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 162.6 (d, J = 246.7 Hz), 156.2, 136.7 (d, J = 3.2 Hz), 130.3, 129.3,128.8, 127.7 (d, J = 8.3 Hz), 126.8, 115.7 (d, J = 21.6 Hz), 82.0, 43.2. 19 FNMR (376 MHz, CDCl3) δ -113.8.

[0046] Example 17: A method for efficiently constructing 4g of isoxazoline using a photocatalytic three-component tandem process. The difference between Example 17 and Example 1 is that in Example 17, compound 2g is used instead of styrene, and the structural formula of compound 2g is: The structural formula of the synthesized compound 4g is: The compound was obtained in a yellow oil (4g), with a yield of 74%.

[0047] The NMR detection data of compound 4g are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.75 – 7.68 (m, 2H), 7.44 (d, J = 4.8 Hz,3H), 7.36 (s, 4H), 5.74 (dd, J = 10.5, 8.5 Hz, 1H), 3.81 (dd, J = 16.7, 11.0Hz, 1H), 3.32 (dd, J = 16.7, 8.0 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.1,139.5, 134.0, 130.3, 129.2, 129.0, 128.8, 127.3, 126.8, 81.8, 43.2.

[0048] Example 18: A method for the efficient construction of isoxazoline in 4h via photocatalytic three-component tandem assembly The difference between Example 18 and Example 1 is that in Example 18, compound 2h is used instead of styrene. The structural formula of compound 2h is: The structural formula of the synthesized compound 4h is: The compound was a yellow oil after 4 hours, with a yield of 69%.

[0049] The NMR data of compound 4h are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.77 – 7.68 (m, 2H), 7.53 (d, J = 8.1 Hz,2H), 7.50 – 7.40 (m, 3H), 7.30 (d, J = 8.6 Hz, 2H), 5.73 (dd, J = 10.8, 8.1Hz, 1H), 3.82 (dd, J = 16.6, 11.0 Hz, 1H), 3.32 (dd, J = 16.6, 8.0 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.1, 140.0, 131.9, 130.3, 129.2, 128.8, 127.6, 126.8, 122.2, 81.8, 43.2.

[0050] Example 19: A method for the efficient construction of isoxazoline 4i by photocatalytic tandem three-component synthesis The difference between Example 19 and Example 1 is that in Example 19, compound 2i is used instead of styrene. The structural formula of compound 2i is: The structural formula of the synthesized compound 4i is: Compound 4i is a yellow oil with a yield of 58%.

[0051] The NMR data for compound 4i are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.74 – 7.69 (m, 2H), 7.66 (d, J = 8.3 Hz, 2H), 7.55 (d, J = 8.2 Hz, 2H), 7.44 (qd, J = 4.3, 1.5 Hz, 3H), 5.83 (dd, J =11.1, 7.8 Hz, 1H), 3.87 (dd, J = 16.6, 11.1 Hz, 1H), 3.34 (dd, J = 16.6, 7.8Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.0, 145.07, 145.06, 130.4, 129.1,128.8, 126.8, 126.1, 125.8 (q, J = 3.8 Hz), 81.6, 43.4. 19 F NMR (376 MHz, CDCl3) δ -62.6.

[0052] Example 20: A method for the efficient construction of isoxazoline 4j by photocatalytic tandem three-component synthesis The difference between Example 20 and Example 1 is that in Example 20, compound 2j is used instead of styrene, and the structural formula of compound 2j is: The structural formula of the synthesized compound 4j is: Compound 4j is a yellow oil with a yield of 52%.

[0053] The NMR data for compound 4j are as follows: 1H NMR (400 MHz, CDCl3) δ 7.69 (ddd, J= 6.7, 3.3, 1.9 Hz, 4H), 7.53 (d, J = 8.3 Hz, 2H), 7.43 (qd, J = 5.4, 3.0 Hz,3H), 5.81 (dd, J = 11.1, 7.6 Hz, 1H), 3.88 (dd, J = 16.7, 11.2 Hz, 1H), 3.32 (dd, J = 16.7, 7.6 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.0, 146.4, 132.7, 130.5, 128.9, 126.8, 126.5, 118.6, 112.0, 81.4, 43.3.

[0054] Example 21: A method for the efficient construction of isoxazoline 4k by photocatalytic tandem three-component synthesis The difference between Example 21 and Example 1 is that in Example 21, compound 2k is used instead of styrene. The structural formula of compound 2k is: The structural formula of the synthesized compound 4k is: Compound 4K is a yellow oil with a yield of 43%.

[0055] The NMR detection data for compound 4k are as follows: 1 H NMR (400 MHz, CDCl3) δ 8.26 (d, J = 8.7 Hz, 2H), 7.71 (dd, J = 7.4,2.1 Hz, 2H), 7.60 (d, J = 8.6 Hz, 2H), 7.50 – 7.39 (m, 3H), 5.87 (dd, J =11.2, 7.6 Hz, 1H), 3.92 (dd, J = 16.6, 11.2 Hz, 1H), 3.34 (dd, J = 16.7, 7.5Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.0, 148.3, 130.6, 128.9, 128.8, 126.8,126.6, 124.1, 81.1, 43.4.

[0056] Example 22: A method for the efficient construction of isoxazoline 4l by photocatalytic tandem three-component synthesis The difference between Example 22 and Example 1 is that in Example 22, compound 21 is used instead of styrene. The structural formula of compound 21 is: The structural formula of the synthesized compound 4l is: Compound 4l is a yellow oil with a yield of 64%.

[0057] The NMR detection data of compound 4l are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.73 (dd, J = 6.7, 3.0 Hz, 2H), 7.45 (q, J =3.7 Hz, 3H), 7.33 (d, J = 5.0 Hz, 1H), 7.14 (d, J = 3.5 Hz, 1H), 7.02 (dd, J= 4.9, 3.7 Hz, 1H), 5.99 (dd, J = 10.6, 8.1 Hz, 1H), 3.79 (dd, J = 16.7, 10.6Hz, 1H), 3.51 (dd, J = 16.6, 8.1 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.4, 143.4, 130.3, 129.3, 128.8, 127.0, 125.8, 125.5, 78.5, 43.0.

[0058] Example 23: A method for the efficient construction of isoxazoline 4m by photocatalytic tandem three-component synthesis The difference between Example 23 and Example 1 is that in Example 23, compound 2m is used instead of styrene. The structural formula of compound 2m is: The structural formula of the synthesized compound 4m is: Compound 4M is a yellow oil with a yield of 70%.

[0059] The NMR data for compound 4m are as follows: 1H NMR (400 MHz, CDCl3) δ 8.63 – 8.53 (m, 1H), 7.75 – 7.66 (m, 3H), 7.57 (d, J = 7.8 Hz, 1H), 7.42 – 7.35 (m, 3H), 7.25 – 7.15 (m, 1H), 5.84 (dd,J = 10.2, 7.5 Hz, 1H), 3.82 (ddd, J = 16.8, 11.1, 1.5 Hz, 1H), 3.70 (ddd, J =16.8, 6.9, 1.5 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 159.9, 156.5, 149.4, 137.0, 130.2, 129.3, 128.7, 126.8, 123.0, 120.6, 82.4, 41.5.

[0060] Example 24: A method for the efficient construction of isoxazoline 4n by photocatalytic tandem three-component synthesis The difference between Example 24 and Example 1 is that in Example 24, compound 2n is used instead of styrene. The structural formula of compound 2n is: The structural formula of the synthesized compound 4n is: Compound 4n is a yellow oil with a yield of 53%.

[0061] The NMR detection data of compound 4n are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.75 – 7.70 (m, 2H), 7.59 (dd, J = 5.2, 3.6Hz, 1H), 7.47 – 7.42 (m, 3H), 7.34 (dd, J = 5.6, 3.2 Hz, 2H), 7.25 – 7.21 (m,1H), 6.25 (d, J = 9.5 Hz, 1H), 4.57 (td, J = 9.3, 2.7 Hz, 1H), 3.55 – 3.48(m, 1H), 3.27 (dd, J = 16.8, 2.6 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 158.6,140.8, 140.7, 129.9, 129.6, 129.1, 128.8, 127.7, 127.2, 125.9, 124.8, 89.5,50.4, 36.6.

[0062] Example 25: A method for the efficient construction of isoxazoline 4o by photocatalytic tandem three-component synthesis The difference between Example 25 and Example 1 is that in Example 25, compound 2o is used instead of styrene, and the structural formula of compound 2o is: The structural formula of the synthesized compound 4o is: Compound 4o is a yellow oil with a yield of 61%.

[0063] The NMR detection data of compound 4o are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.75 – 7.69 (m, 2H), 7.48 – 7.40 (m, 5H), 7.39 – 7.33 (m, 2H), 7.32 – 7.28 (m, 1H), 6.75 (dd, J = 15.8, 4.6 Hz, 1H), 6.37 – 6.28 (m, 1H), 5.41 – 5.32 (m, 1H), 3.64 – 3.55 (m, 1H), 3.29 – 3.21(m, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.6, 136.0, 133.3, 130.1, 129.6, 128.8,128.7, 128.2, 127.0, 126.73, 126.71, 82.1, 40.9.

[0064] Example 26: A method for the efficient construction of isoxazoline 4p by photocatalytic tandem three-component synthesis The difference between Example 26 and Example 1 is that in Example 26, compound 2p is used instead of styrene. The structural formula of compound 2p is: The structural formula of the synthesized compound 4p is: Compound 4p is a yellow oil with a yield of 70%.

[0065] The NMR detection data for compound 4p are as follows: 1H NMR (400 MHz, CDCl3) δ 7.73 (dt, J = 7.5, 3.6 Hz, 2H), 7.50 – 7.42(m, 5H), 7.34 (q, J = 5.5 Hz, 3H), 5.59 (dd, J = 10.7, 7.6 Hz, 1H), 3.70 (dd,J = 16.3, 10.8 Hz, 1H), 3.56 (dd,J = 16.3, 7.6 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.4, 131.9, 130.4, 129.1, 128.9, 128.8, 128.3, 126.9, 122.0, 86.5, 86.4, 70.5, 42.4.

[0066] Example 27: A method for the efficient construction of isoxazoline 4q by photocatalytic tandem three-component synthesis The difference between Example 27 and Example 1 is that in Example 27, compound 2q is used instead of styrene, and the structural formula of compound 2q is: The structural formula of the synthesized compound 4q is: Compound 4q is a yellow oil with a yield of 52%.

[0067] The NMR detection data of compound 4q are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.75 – 7.64 (m, 2H), 7.49 – 7.37 (m, 3H), 5.72 (dd, J = 6.7, 1.6 Hz, 1H), 3.95 (dq, J = 9.5, 7.1 Hz, 1H), 3.74 – 3.58(m, 1H), 3.43 (dd, J = 17.4, 6.7 Hz, 1H), 3.25 (dd, J = 17.3, 1.6 Hz, 1H), 1.32 – 1.13 (m, 3H). 13 C NMR (101 MHz, CDCl3) δ 157.0, 130.3, 128.7, 126.9, 103.0, 63.8, 41.6, 29.7, 15.0.

[0068] Example 28: A method for the efficient construction of isoxazoline 4r by photocatalytic tandem three-component synthesis The difference between Example 28 and Example 1 is that in Example 28, compound 2r is used instead of styrene. The structural formula of compound 2r is: The structural formula of the synthesized compound 4r is: Compound 4r is a yellow oil with a yield of 47%.

[0069] The NMR detection data of compound 4r are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.68 (dt, J = 7.5, 3.8 Hz, 2H), 7.42 (dd, J= 5.0, 1.8 Hz, 3H), 7.38 – 7.33 (m, 2H), 7.29 (dd, J = 8.0, 2.5 Hz, 3H), 5.07– 4.98 (m, 1H), 3.35 (dd, J = 16.6, 10.2 Hz, 1H), 3.21 (dd, J = 13.8, 6.1 Hz, 1H), 3.09 (dd, J = 16.6, 7.8 Hz, 1H), 2.92 (dd, J = 13.8, 7.3 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.5, 136.9, 130.0, 129.7, 129.4, 128.7, 128.7, 126.8, 126.6, 81.9, 41.1, 39.4.

[0070] Example 29: A method for the efficient construction of isoxazoline 4S by photocatalytic tandem three-component synthesis The difference between Example 29 and Example 1 is that in Example 29, compound 2s is used instead of styrene. The structural formula of compound 2s is: The structural formula of the synthesized compound 4S is: Compound 4S is a yellow oil with a yield of 55%.

[0071] The NMR data for compound 4s are as follows: 1H NMR (400 MHz, CDCl3) δ 7.72 – 7.66 (m, 2H), 7.41 (d, J = 6.5 Hz, 3H), 4.80 – 4.71 (m, 1H), 3.41 (dd, J = 16.4, 10.3 Hz, 1H), 2.99 (dd, J =16.4, 8.2 Hz, 1H), 1.82 (dddd, J = 10.0, 6.8, 4.6, 1.6 Hz, 1H), 1.65 (dddd, J= 13.4, 6.7, 3.9 Hz, 1H), 1.52 – 1.37 (m, 4H), 0.95 (t, J = 7.0 Hz, 3H). 13 CNMR (101 MHz, CDCl3) δ 156.4, 129.9, 129.9, 128.7, 126.6, 81.5, 39.9, 35.0, 27.7, 22.6, 14.0.

[0072] Example 30: A method for the efficient construction of isoxazoline 4t using a photocatalytic three-component tandem process. The difference between Example 30 and Example 1 is that in Example 30, compound 2t is used instead of styrene. The structural formula of compound 2t is: The structural formula of the synthesized compound 4t is: Compound 4t is a yellow oil with a yield of 79%.

[0073] The NMR data for compound 4t are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.69 – 7.65 (m, 2H), 7.43 – 7.38 (m, 3H), 5.18 (dd, J = 10.3, 7.9 Hz, 1H), 3.80 (s, 3H), 3.66 – 3.65 (m, 1H), 3.64 (d,J = 3.2 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 170.7, 156.1, 130.5, 128.8, 128.5, 126.9, 52.8, 38.9.

[0074] Example 31: A method for the efficient construction of isoxazoline 4u using a photocatalytic three-component tandem process. The difference between Example 31 and Example 1 is that in Example 31, compound 2u is used instead of styrene. The structural formula of compound 2u is: The structural formula of the synthesized compound 4u is: Compound 4u is a yellow oil with a yield of 81%.

[0075] The NMR data for compound 4t are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.70 – 7.63 (m, 2H), 7.40 (d, J = 6.4 Hz,3H), 5.21 – 5.11 (m, 1H), 4.25 (q, J = 7.1 Hz, 2H), 3.63 (d, J = 9.7 Hz, 2H),1.30 (t, J = 7.2 Hz, 3H). 13 C NMR (101 MHz, CDCl3) δ 170.2, 156.0, 130.5, 128.8, 128.6, 126.9, 78.1, 62.0, 38.8, 14.1.

[0076] Example 32: A method for the efficient construction of isoxazoline 4v by photocatalytic tandem three-component synthesis The difference between Example 32 and Example 1 is that in Example 32, compound 2v is used instead of styrene. The structural formula of compound 2v is: The structural formula of the synthesized compound 4v is: Compound 4V is a yellow oil with a yield of 76%.

[0077] The NMR detection data of compound 4V are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.71 – 7.62 (m, 2H), 7.41 (dd, J = 5.2, 1.8Hz, 3H), 4.26 (qd, J = 7.1, 2.0 Hz, 2H), 3.89 (d, J = 16.9 Hz, 1H), 3.22 (d,J = 16.9 Hz, 1H), 1.72 (s, 3H), 1.32 (t, J = 7.1 Hz, 3H). 13C NMR (101 MHz, CDCl3) δ 172.1, 156.3, 130.3, 129.1, 128.7, 126.7, 86.2, 62.1, 44.7, 23.7,14.1.

[0078] Example 33: A method for the efficient construction of isoxazoline 4w using a photocatalytic three-component tandem process. The difference between Example 33 and Example 1 is that in Example 33, compound 2w is used instead of styrene. The structural formula of compound 2w is: The structural formula of the synthesized compound 4w is: Compound 4w is a yellow oil with a yield of 72%.

[0079] The NMR data for compound 4w are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.71 – 7.65 (m, 2H), 7.45 – 7.39 (m, 3H), 5.23 (t, J = 9.1 Hz, 1H), 4.85 – 4.75 (m, 2H), 3.68 (d, J = 9.2 Hz, 2H), 2.54(t, J = 1.8 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 169.4, 156.0, 130.6, 128.8, 128.4, 127.0, 77.7, 75.9, 53.2, 38.9.

[0080] Example 34: A method for the efficient construction of isoxazoline 4x by photocatalytic tandem three-component synthesis The difference between Example 34 and Example 1 is that in Example 34, compound 2x is used instead of styrene. The structural formula of compound 2x is: The structural formula of the synthesized compound 4x is: Compound 4x is a yellow oil with a yield of 80%.

[0081] The NMR detection data for compound 4x are as follows: 1H NMR (400 MHz, CDCl3) δ 7.68 (dt, J = 5.4, 1.9 Hz, 2H), 7.48 – 7.36(m, 3H), 5.07 (dd, J = 11.9, 6.3 Hz, 1H), 3.65 (dd, J = 17.0, 6.3 Hz, 1H), 3.50 (dd, J = 17.0, 11.9 Hz, 1H), 2.76 (qt, J = 7.7, 4.0 Hz, 2H), 1.09 (t, J= 7.2 Hz, 3H). 13 C NMR (101 MHz, CDCl3) δ 210.1, 156.7, 130.5, 128.8, 128.6, 126.9, 84.1, 37.4, 32.2, 7.1.

[0082] Example 35: A method for the efficient construction of isoxazoline 4y using a photocatalytic three-component tandem process The difference between Example 35 and Example 1 is that in Example 35, compound 2y is used instead of styrene. The structural formula of compound 2y is: The structural formula of the synthesized compound 4y is: Compound 4y is a yellow oil with a yield of 75%.

[0083] The NMR data for compound 4y are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.68 (dt, J = 8.3, 2.1 Hz, 2H), 7.53 – 7.44(m, 3H), 5.39 (dd, J = 10.6, 6.3 Hz, 1H), 3.83 – 3.70 (m, 2H). 13 C NMR (101MHz, CDCl3) δ 156.4, 131.3, 129.1, 127.4, 127.1, 117.2, 66.6, 41.2.

[0084] Example 36: A method for the efficient construction of isoxazoline 4z by photocatalytic tandem three-component synthesis The difference between Example 36 and Example 1 is that in Example 36, compound 2z is used instead of styrene. The structural formula of compound 2z is: The structural formula of the synthesized compound 4z is: Compound 4z is a yellow oil with a yield of 83%.

[0085] The NMR data for compound 4z are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.73 – 7.67 (m, 2H), 7.40 (dd, J = 5.2, 1.9Hz, 3H), 5.38 (dd, J = 11.2, 7.6 Hz, 1H), 4.18 (dd, J = 16.8, 7.6 Hz, 1H), 3.38 (dd, J = 16.8, 11.2 Hz, 1H), 3.21 (s, 3H), 3.01 (s, 3H). 13 C NMR (101MHz, CDCl3) δ 167.4, 157.3, 130.3, 128.9, 128.7, 126.9, 78.2, 37.3, 37.0,36.2.

[0086] Example 37: A method for the efficient construction of isoxazoline 4aa via photocatalytic tandem three-component synthesis The difference between Example 37 and Example 1 is that in Example 37, compound 2aa is used instead of styrene. The structural formula of compound 2aa is: The structural formula of the synthesized compound 4aa is: Compound 4aa is a yellow oil with a yield of 61%.

[0087] The NMR data for compound 4aa are as follows: 1 H NMR (400 MHz, CDCl3) δ 8.07 – 8.01 (m, 2H), 7.71 (td, J = 6.0, 2.8Hz, 1H), 7.65 – 7.58 (m, 4H), 7.50 – 7.42 (m, 3H), 5.59 (dd, J = 10.9, 4.6Hz, 1H), 4.11 (dd, J = 18.3, 4.5 Hz, 1H), 3.83 (dd, J = 18.3, 10.9 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.9, 135.2, 134.6, 131.2, 129.8, 129.3, 128.9, 127.3, 127.1, 93.3, 36.9.

[0088] Example 38: A method for the efficient construction of isoxazoline 4ab by photocatalytic tandem three-component synthesis The difference between Example 38 and Example 1 is that in Example 38, compound 1ab is used instead of trichlorotoluene. The structural formula of compound 1ab is: The structural formula of the synthesized compound 4ab is: Compound 4ab is a yellow oil with a yield of 76%.

[0089] The NMR detection data of compound 4ab are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.67 – 7.63 (m, 2H), 7.43 – 7.35 (m, 7H), 5.77 (dd, J = 11.0, 8.3 Hz, 1H), 3.77 (dd, J = 16.7, 11.0 Hz, 1H), 3.34 (dd,J = 16.6, 8.3 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 155.2, 140.7, 136.1, 129.0, 128.8, 128.4, 128.0, 125.9, 82.9, 43.0.

[0090] Example 39: A method for the efficient construction of isoxazoline 4ac by photocatalytic tandem three-component synthesis The difference between Example 39 and Example 1 is that in Example 39, compound 1ac is used instead of trichlorotoluene. The structural formula of compound 1ac is: The structural formula of the synthesized compound 4ab is: Compound 4ac is a yellow oil with a yield of 72%.

[0091] The NMR detection data of compound 4ac are as follows: 1 H NMR (400 MHz, CDCl3) δ 8.12 – 8.06 (m, 2H), 7.80 – 7.75 (m, 2H), 7.42 – 7.32 (m, 5H), 5.80 (dd, J = 11.1, 8.4 Hz, 1H), 3.95 (s, 3H), 3.81 (dd,J = 16.7, 11.1 Hz, 1H), 3.38 (dd,J = 16.7, 8.4 Hz, 1H). 13C NMR (101 MHz, CDCl3) δ 166.5, 155.5, 140.6, 133.6, 131.3, 130.0, 128.8, 128.4, 126.6, 125.9, 83.1, 52.3, 42.8.

[0092] Example 40: A method for the efficient construction of isoxazoline 4ad using a photocatalytic three-component tandem process. The difference between Example 40 and Example 1 is that in Example 40, compound 1ad is used instead of trichlorotoluene. The structural formula of compound 1ad is: The structural formula of the synthesized compound 4ab is: Compound 4ad is a yellow oil with a yield of 77%.

[0093] The NMR data for compound 4ad are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.93 (d, J = 12.1 Hz, 2H), 7.70 (d, J = 7.4Hz, 1H), 7.57 (td, J = 7.7, 2.9 Hz, 1H), 7.40 (dt, J = 17.5, 3.8 Hz, 5H), 5.83 (ddd, J = 11.2, 8.3, 3.6 Hz, 1H), 3.83 (ddd, J = 16.5, 11.1, 3.7 Hz, 1H), 3.39 (ddd, J = 16.7, 8.3, 3.8 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 155.1,140.5, 130.4, 129.8, 129.3, 128.9, 128.4, 126.64 (dd, J = 7.4, 3.8 Hz), 125.8, 123.51 (dd, J = 7.8, 3.9 Hz), 83.1, 42.8. 19 F NMR (376 MHz, CDCl3) δ -62.9.

[0094] Example 41: A method for the efficient construction of isoxazoline 4ae using photocatalytic tandem three-component synthesis The difference between Example 41 and Example 1 is that in Example 41, compound 1ae is used instead of trichlorotoluene. The structural formula of compound 1ae is: The structural formula of the synthesized compound 4ae is: Compound 4ae is a yellow oil with a yield of 65%.

[0095] The NMR data for compound 4ae are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.72 (dd, J = 7.5, 2.0 Hz, 1H), 7.48 – 7.31(m, 8H), 5.79 (dd, J = 10.9, 8.5 Hz, 1H), 3.95 (dd, J = 17.1, 10.8 Hz, 1H),3.54 (dd, J = 17.1, 8.5 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 156.2, 140.6, 132.9, 130.9, 130.6, 83.3, 45.5.

[0096] Example 42: A method for the efficient construction of isoxazoline 4af using photocatalytic tandem three-component synthesis The difference between Example 42 and Example 1 is that in Example 42, compound 1af is used instead of trichlorotoluene. The structural formula of compound 1af is: The structural formula of the synthesized compound 4af is: Compound 4af is a yellow oil with a yield of 71%.

[0097] The NMR data for compound 4af are as follows: 1 H NMR (400 MHz, CDCl3) δ 7.78 (d, J = 1.5 Hz, 1H), 7.57 – 7.54 (m,1H), 7.49 (d, J = 8.4 Hz, 1H), 7.43 – 7.35 (m, 5H), 5.79 (dd, J = 11.0, 8.4Hz, 1H), 3.75 (dd, J = 16.7, 11.1 Hz, 1H), 3.32 (dd, J = 16.7, 8.4 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 154.4, 140.4, 134.2, 133.1, 130.8, 129.5, 128.9,128.5, 125.8, 83.2, 42.7.

[0098] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for photocatalytic three-component tandem high-efficiency construction of isoxazoline, characterized in that, Includes the following steps: Substituted or unsubstituted trichlorotoluene and a compound containing a double bond were dissolved in 1,2-dichloroethane. Then, tert-butyl nitrite, a base, and a photocatalyst were added. The reaction was carried out under an inert gas atmosphere with visible light irradiation and stirring at room temperature. After the reaction was completed, the solvent was removed under reduced pressure. The crude product was then purified by silica gel column chromatography to obtain the product isoxazoline.

2. The method for efficiently constructing isoxazoline from three components via photocatalysis according to claim 1, characterized in that, The substituted or unsubstituted trichlorotoluene is any one of the following structural formulas: 。 3. The method for efficiently constructing isoxazoline by photocatalysis of three components in tandem, as described in claim 1, is characterized in that... The compound containing a double bond is any one of the following structural formulas: 。 4. The method for efficiently constructing isoxazoline from three components via photocatalysis according to claim 1, characterized in that, The molar ratio of the substituted or unsubstituted trichlorotoluene, the compound containing double bonds, tert-butyl nitrite, and the base is 1-2:1-2:1-4:1-6.

5. The method for efficiently constructing isoxazoline by photocatalysis of three components in series according to claim 3, characterized in that, The molar ratio of the substituted or unsubstituted trichlorotoluene, the compound containing a double bond, tert-butyl nitrite, and the base is 1:2:3:

2.

6. The method for efficiently constructing isoxazoline from three components via photocatalysis according to claim 1, characterized in that, The amount of the photocatalyst is 1%-5% of the molar amount of the substituted or unsubstituted trichlorotoluene.

7. The method for efficiently constructing isoxazoline by photocatalysis of three components in series according to claim 1, characterized in that, The base is N,N-diisopropylethylamine.

8. The method for efficiently constructing isoxazoline from three components via photocatalysis according to claim 1, characterized in that, The photocatalyst is Na2-Eosin Y.

9. The method for efficiently constructing isoxazoline by photocatalysis of three components in series according to claim 1, characterized in that, The visible light irradiation refers to irradiation using a blue LED light source with a power of 35 W.

10. The method for efficiently constructing isoxazoline by photocatalysis of three components in tandem, as described in claim 1, is characterized in that, The stirring reaction takes 12-18 hours, and the inert gas is N2.

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