A photocatalytic synthesis method of 1,2-naphthalene dicarboxylic acid diethyl ester compounds
By using a photocatalytic synthesis method, a coupling cyclization reaction is carried out between styrene compounds and α-diazoiodonium salt in the presence of a catalyst. This solves the problems of complex raw materials and high cost in the synthesis of polysubstituted naphthalene compounds in the past, and realizes the synthesis of inexpensive, green and easy-to-purify polysubstituted naphthalene compounds, which is suitable for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTH CHINA UNIV OF TECH
- Filing Date
- 2026-01-14
- Publication Date
- 2026-05-29
Smart Images
Figure CN122102904A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic synthesis technology, specifically to a photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds. Background Technology
[0002] Naphthalene and its derivatives typically exhibit a variety of biological activities (e.g., anti-inflammatory, anticancer, antibacterial, antiviral, antituberculosis, antihypertensive, antidiabetic, etc.), making them a class of heterocyclic compounds with high medicinal value. The naphthalene group is an important backbone for many drug molecules, thus the development of multi-substituted naphthalene compounds has become a research hotspot in the field of organic synthesis. Furthermore, multi-substituted naphthalene compounds are also important compounds in materials science, which can be used to prepare dyes, sensors, etc., and are expected to become candidate materials in the field of organic electronics. However, existing synthetic methods for multi-substituted naphthalene compounds generally suffer from problems such as complex raw material preparation processes, harsh reaction conditions, large amounts of catalysts, expensive catalysts, high product purification difficulty, high production costs, and environmental pollution, making it difficult to fully meet practical application needs.
[0003] Therefore, it is of great significance to develop a method for synthesizing polysubstituted naphthalene compounds that uses inexpensive and readily available raw materials, is simple and efficient, has mild reaction conditions, high atom economy, easy-to-purify products, low production costs, and is green and safe. Summary of the Invention
[0004] The purpose of this invention is to provide a photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds.
[0005] The technical solution adopted in this invention is: A photocatalytic synthesis method for 1,2-naphthalenedicarboxylic acid diethyl ester compounds includes the following steps: dispersing a styrene-based compound, an α-diazoiodonium salt, and a catalyst in an organic solvent, followed by a coupling cyclization reaction under light irradiation. The styrene-based compound is... or (2-Vinylnaphthalene), where R is selected from -H, methyl, trifluoromethyl, phenyl, acetoxy (CH3COO-), -Cl or -Br, and α-diazoiodomonium salt is... This yields diethyl 1,2-naphthalenedicarboxylate compounds.
[0006] Note: The structural formulas of diethyl 1,2-naphthalenedicarboxylate compounds are as follows: or .
[0007] Preferably, the molar ratio of the styrene compound and the α-diazoiodonium salt is 1:2 to 4.
[0008] Preferably, the α-diazo iodoium salt is prepared by a method comprising the following steps: dissolving iodophenyl diacetic acid in a solvent and placing it in an ice bath, then adding trimethylsilyl trifluoromethanesulfonate, then adding ethyl diazonate in batches, then reacting at room temperature, and then separating and purifying the product.
[0009] Preferably, the molar ratio of iodophenyl diacetic acid, trimethylsilyl trifluoromethanesulfonate, and ethyl diazonate is 1:0.8-1.2:2-3.
[0010] Preferably, the solvent is dichloromethane.
[0011] Preferably, the reaction time is 40 min to 80 min.
[0012] Preferably, the molar ratio of the styrene compound to the catalyst is 1:0.01 to 0.02.
[0013] Preferably, the catalyst is at least one of tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate), tris(4,7-biphenyl-1,10-o-phenanthroline)ruthenium dichloride, and tris[4,4'-bis(tert-butyl)-2,2'-bipyridine]ruthenium hexafluorophosphate(II).
[0014] More preferably, the catalyst is tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate).
[0015] Preferably, the ratio of the styrene compound to the organic solvent is 1 mmol: 10 mL to 50 mL.
[0016] Preferably, the organic solvent is at least one of N,N-dimethylformamide, N-methylpyrrolidone, and N,N-dimethylacetamide.
[0017] Preferably, the coupling cyclization reaction is carried out under blue light irradiation and at a temperature of -30°C to 0°C.
[0018] More preferably, the coupling cyclization reaction is carried out under conditions of blue light irradiation at a wavelength of 456 nm and a temperature of -30°C to 0°C.
[0019] Preferably, the coupling cyclization reaction is carried out in an argon atmosphere.
[0020] Preferably, the coupling cyclization reaction takes place over a period of 0.5 h to 1 h.
[0021] Preferably, the reaction products are subjected to column chromatography after the coupling cyclization reaction is completed.
[0022] Preferably, the eluent used in the column chromatography consists of petroleum ether and ethyl acetate.
[0023] The beneficial effects of this invention are: the photocatalytic synthesis method of 1,2-naphthalenedicarboxylic acid diethyl ester compounds of this invention has the advantages of inexpensive and readily available raw materials, simplicity and efficiency, mild reaction conditions, high atom economy, easy product purification, low production cost, and green safety, and is suitable for large-scale industrial production. Attached Figure Description
[0024] Figure 1 The image shows the 1H NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 1.
[0025] Figure 2 This is the carbon NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 1.
[0026] Figure 3 The image shows the 1H NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 2.
[0027] Figure 4 This is the carbon NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 2.
[0028] Figure 5 The image shows the 1H NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 3.
[0029] Figure 6 This is the carbon NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 3.
[0030] Figure 7 The image shows the 1H NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 4.
[0031] Figure 8 This is the carbon NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 4.
[0032] Figure 9 The image shows the 1H NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 5.
[0033] Figure 10 This is the carbon NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 5.
[0034] Figure 11 The image shows the 1H NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 6.
[0035] Figure 12 This is the carbon NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 6.
[0036] Figure 13 The image shows the 1H NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 7.
[0037] Figure 14 This is the carbon NMR spectrum of the diethyl 1,2-naphthalenedicarboxylate compound synthesized in Example 7. Detailed Implementation
[0038] The present invention will be further explained and described below with reference to specific embodiments.
[0039] The preparation methods of α-diazoiodoium salts in Examples 1-7 are as follows (Reference: Chem. Eur. J. 2025,31, e202403509): 5 mmol of iodophenyl diacetic acid was dissolved in 10 mL of dichloromethane (analytical grade) and placed in an ice bath. Then, 5 mmol of trimethylsilyl trifluoromethanesulfonate was added, followed by the addition of 12 mmol of ethyl diazonate in portions over 10 min. The ice bath was then removed until nitrogen gas was observed to escape. The mixture was stirred at room temperature for 1 h, and the solvent was removed by vacuum. The crude product was then dissolved in a diethyl ether-dichloromethane mixed solvent (diethyl ether to dichloromethane volume ratio of 5:1) and recrystallized at -30 °C for 12 h. After filtration, the solid was washed with 200 mL of diethyl ether to obtain α-diazoiodoium salts.
[0040] The synthesis reaction of α-diazo iodine salt is as follows: .
[0041] Example 1: A photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds, comprising the following steps: 23.6 mg (0.2 mmol) of 1-methyl-4-vinylbenzene, 280 mg (0.6 mmol) of α-diazoiodonium salt and 3.4 mg (0.002 mmol) of tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate) salt were added to 2 mL of N,N-dimethylformamide (analytical grade). The mixture was then stirred for 1 h under an argon atmosphere, irradiated with blue light at a wavelength of 456 nm, and at a temperature of -30 °C. The solvent was then removed by rotary evaporation, followed by column chromatography. The eluent for column chromatography consisted of petroleum ether and ethyl acetate in a volume ratio of 30:1, yielding 42.0 mg of diethyl 1,2-naphthalenedicarboxylate (yield: 70%).
[0042] The proton NMR spectrum of the 1,2-naphthalenedicarboxylic acid diethyl ester compound synthesized in this embodiment is shown below. Figure 1 As shown, the carbon NMR spectrum is as follows: Figure 2 As shown.
[0043] Spectral analysis: 1 H NMR (500 MHz, CDCl3): δ 7.96 (d, J = 8.6 Hz, 1H), 7.87 (d, J = 8.6 Hz, 1H), 7.78 (d, J = 8.4 Hz, 1H), 7.64 (s, 1H), 7.47 - 7.39 (m, 1H), 4.58 (d, J =7.1 Hz, 2H), 4.41 (d, J = 7.1 Hz, 2H), 2.52 (s, 3H), 1.44 (dt, J = 20.4, 7.1 Hz, 6H).
[0044] 13 C NMR (126 MHz, CDCl3): δ 169.35, 165.95, 137.68, 134.32, 133.46, 130.75, 129.53, 129.10, 127.91, 124.99, 124.87, 124.20, 61.89, 61.62, 22.03,14.27, 14.19.
[0045] HR-MS: Theoretical value [M+Na] + :C 17 H 18 O4Na: 309.1097, measured value: 309.1104.
[0046] In summary, the structural formula of the 1,2-naphthalenedicarboxylic acid diethyl ester compound (CAS No.: 134030-32-3) synthesized in this embodiment is as follows: .
[0047] Example 2: A photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds, comprising the following steps: 36.0 mg (0.2 mmol) of 4-vinyl-1,1'-biphenyl, 280 mg (0.6 mmol) of α-diazoiodonium salt and 3.4 mg (0.002 mmol) of tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate) salt were added to 2 mL of N,N-dimethylformamide (analytical grade). The mixture was then stirred for 1 h under an argon atmosphere, irradiated with blue light at a wavelength of 456 nm, and at a temperature of -30 °C. The solvent was then removed by rotary evaporation, followed by column chromatography. The eluent for column chromatography consisted of petroleum ether and ethyl acetate in a volume ratio of 30:1, yielding 19.0 mg of diethyl 1,2-naphthalenedicarboxylate (yield: 26%).
[0048] The proton NMR spectrum of the 1,2-naphthalenedicarboxylic acid diethyl ester compound synthesized in this embodiment is shown below. Figure 3 As shown, the carbon NMR spectrum is as follows: Figure 4 As shown.
[0049] Spectral analysis: 1 H NMR (500 MHz, CDCl3): δ 8.12 - 8.00 (m, 2H), 7.96 (q, J = 8.1, 6.8 Hz, 2H), 7.87 (dd, J = 8.5, 1.7 Hz, 1H), 7.75 - 7.65 (m, 2H), 7.50 (t, J = 7.7 Hz,2H), 7.45 - 7.38 (m, 1H), 4.58 (q, J = 7.2 Hz, 2H), 4.43 (q, J = 7.1 Hz, 2H), 1.45 (dt, J = 14.5, 7.1 Hz, 6H).
[0050] 13 C NMR (126 MHz, CDCl3): δ 169.13, 165.85, 140.46, 135.15, 134.23, 129.67, 129.18, 129.02, 128.64, 128.28, 127.90, 127.56, 125.52, 125.11,123.90, 61.99, 61.74, 14.27, 14.25.
[0051] HR-MS: Theoretical value [M+Na] + :C 22 H 20O4Na: 371.1259, measured value: 371.1253.
[0052] In summary, the structural formula of the 1,2-naphthalenedicarboxylic acid diethyl ester compound (CAS No.: 134030-33-4) synthesized in this embodiment is as follows: .
[0053] Example 3: A photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds, comprising the following steps: 27.7 mg (0.2 mmol) of 1-chloro-4-vinyl, 280 mg (0.6 mmol) of α-diazoiodonium salt and 3.4 mg (0.002 mmol) of tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate) salt were added to 2 mL of N,N-dimethylformamide (analytical grade). The mixture was then stirred for 1 h under an argon atmosphere, irradiated with blue light at a wavelength of 456 nm, and at a temperature of -30 °C. The solvent was then removed by rotary evaporation, followed by column chromatography. The eluent for column chromatography consisted of petroleum ether and ethyl acetate in a volume ratio of 30:1, yielding 11.3 mg of diethyl 1,2-naphthalenedicarboxylate (yield: 19%).
[0054] The proton NMR spectrum of the 1,2-naphthalenedicarboxylic acid diethyl ester compound synthesized in this embodiment is shown below. Figure 5 As shown, the carbon NMR spectrum is as follows: Figure 6 As shown.
[0055] Spectral analysis: 1 H NMR (500 MHz, CDCl3): δ 8.01 (d, J = 8.6 Hz, 1H), 7.95 - 7.88 (m,2H), 7.83 (d, J = 8.8 Hz, 1H), 7.54 (dd, J = 8.7, 1.9 Hz, 1H), 4.57 (q, J =7.2 Hz, 2H), 4.42 (q, J = 7.1 Hz, 2H), 1.44 (dt, J = 19.0, 7.2 Hz, 6H).
[0056] 13C NMR (126 MHz, CDCl3): δ 168.47, 165.59, 138.22, 133.96, 133.81,133.23, 130.05, 129.62, 129.35, 129.33, 126.41, 125.41, 125.00, 62.17, 61.86,14.22, 14.13.
[0057] HR-MS: Theoretical value [M+Na] + :C 16 H 15 ClO4Na: 329.0557, Measured value: 329.0558.
[0058] In summary, the structural formula of the 1,2-naphthalenedicarboxylic acid diethyl ester compounds synthesized in this embodiment is as follows: .
[0059] Example 4: A photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds, comprising the following steps: 34.4 mg (0.2 mmol) of 1-trifluoromethyl-4-vinylbenzene, 280 mg (0.6 mmol) of α-diazoiodonium salt and 3.4 mg (0.002 mmol) of tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate) salt were added to 2 mL of N,N-dimethylformamide (analytical grade). The mixture was then stirred for 1 h under an argon atmosphere, irradiated with blue light at a wavelength of 456 nm, and at a temperature of -30 °C. The solvent was then removed by rotary evaporation, followed by column chromatography. The eluent used in the column chromatography consisted of petroleum ether and ethyl acetate in a volume ratio of 30:1, yielding 15.6 mg of diethyl 1,2-naphthalenedicarboxylate compounds (yield: 23%).
[0060] The proton NMR spectrum of the 1,2-naphthalenedicarboxylic acid diethyl ester compound synthesized in this embodiment is shown below. Figure 7 As shown, the carbon NMR spectrum is as follows: Figure 8 As shown.
[0061] Spectral analysis: 1 H NMR (400 MHz, CDCl3): δ 8.24 (s, 1H), 8.17 (d, J = 8.7 Hz, 1H), 8.03(t, J = 8.5 Hz, 2H), 7.80 (dd, J = 8.7, 1.7 Hz, 1H), 4.62 (q, J= 7.2 Hz, 2H), 4.47(q, J = 7.1 Hz, 2H), 1.47 (dt, J = 15.1, 7.1 Hz, 6H).
[0062] 13 C NMR (126 MHz, CDCl3): δ 168.25, 165.39, 136.05, 135.71, 129.41,129.35, 128.38, 127.34, 126.62, 124.01, 123.92, 123.88, 62.32, 62.02, 14.22,14.14.
[0063] HR-MS: Theoretical value [M+Na] + :C 17 H 15 F3O4Na: 363.0820, measured value: 363.0818.
[0064] In summary, the structural formula of the 1,2-naphthalenedicarboxylic acid diethyl ester compounds synthesized in this embodiment is as follows: .
[0065] Example 5: A photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds, comprising the following steps: 30.8 mg (0.2 mmol) of 2-vinylnaphthalene, 280 mg (0.6 mmol) of α-diazoiodomonium salt and 3.4 mg (0.002 mmol) of tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate) salt were added to 2 mL of N,N-dimethylformamide (analytical grade). The mixture was then stirred for 1 h under an argon atmosphere, irradiated with blue light at a wavelength of 456 nm, and at a temperature of -30 °C. The solvent was then removed by rotary evaporation, followed by column chromatography. The eluent for column chromatography consisted of petroleum ether and ethyl acetate in a volume ratio of 30:1, yielding 32.9 mg of diethyl 1,2-naphthalenedicarboxylate (yield: 51%).
[0066] The proton NMR spectrum of the 1,2-naphthalenedicarboxylic acid diethyl ester compound synthesized in this embodiment is shown below. Figure 9 As shown, the carbon NMR spectrum is as follows: Figure 10 As shown.
[0067] Spectral analysis: 1H NMR (500 MHz, CDCl3): δ 8.62 - 8.52 (m, 1H), 8.15 (s, 1H), 7.96 -7.87 (m, 2H), 7.81 (s, 1H), 7.71 (d, J = 8.7 Hz, 1H), 7.61 (pd, J = 7.0, 1.6 Hz, 2H), 4.63 (q, J = 7.2 Hz, 2H), 4.44 (q, J = 7.2 Hz, 2H), 1.46 - 1.40 (m, 6H).
[0068] 13 C NMR (126 MHz, CDCl3): δ 171.57, 166.50, 135.68, 133.39, 133.36, 130.28, 129.93, 129.45, 129.19, 127.32, 127.24, 126.87, 126.80, 126.72,126.66, 125.45, 62.27, 61.73, 14.29, 13.84.
[0069] HR-MS: Theoretical value [M+H] + :C 17 H 17 N2O2: 323.1278, measured value: 323.1285.
[0070] In summary, the structural formula of the 1,2-naphthalenedicarboxylic acid diethyl ester compounds synthesized in this embodiment is as follows: .
[0071] Example 6: A photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds, comprising the following steps: 32.4 mg (0.2 mmol) of 2-ethyl-7-acetoxynaphthalene-1,2-dicarboxylic acid ester, 280 mg (0.6 mmol) of α-diazoiodonium salt, and 3.4 mg (0.002 mmol) of tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate) salt were added to 2 mL of N,N-dimethylformamide (analytical grade). The mixture was then stirred for 1 h under an argon atmosphere, irradiated with blue light at a wavelength of 456 nm, and at a temperature of -30 °C. The solvent was then removed by rotary evaporation, followed by column chromatography. The eluent for column chromatography consisted of petroleum ether and ethyl acetate in a volume ratio of 30:1, yielding 13.9 mg of diethyl 1,2-naphthalenedicarboxylic acid compounds (yield: 21%).
[0072] The proton NMR spectrum of the 1,2-naphthalenedicarboxylic acid diethyl ester compound synthesized in this embodiment is shown below. Figure 11 As shown, the carbon NMR spectrum is as follows: Figure 12 As shown.
[0073] Spectral analysis: 1 H NMR (500 MHz, CDCl3): δ 8.00 (d, J = 8.6 Hz, 1H), 7.92 (dd, J = 14.0, 8.8 Hz, 2H), 7.63 (d, J = 2.3 Hz, 1H), 7.39 (dd, J = 8.9, 2.2 Hz, 1H), 4.54 (q, J =7.2 Hz, 2H), 4.42 (q, J = 7.2 Hz, 2H), 2.36 (s, 3H), 1.43 (dt, J = 10.1, 7.2 Hz, 6H).
[0074] 13 C NMR (126 MHz, CDCl3): δ 169.29, 168.69, 165.78, 149.72, 134.40,133.00, 129.94, 129.53, 129.33, 126.18, 124.99, 123.99, 116.99, 62.06, 61.80,21.19, 14.23, 14.12.
[0075] HR-MS: Theoretical value [M+H] + :C 18 H 19O6: 331.1176, Measured value: 331.1183.
[0076] In summary, the structural formula of the 1,2-naphthalenedicarboxylic acid diethyl ester compounds synthesized in this embodiment is as follows: .
[0077] Example 7: A photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds, comprising the following steps: 36.6 mg (0.2 mmol) of 1-bromo-4-ethylbenzene, 280 mg (0.6 mmol) of α-diazoiodonium salt and 3.4 mg (0.002 mmol) of tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate) salt were added to 2 mL of N,N-dimethylformamide (analytical grade). The mixture was then stirred for 1 h under an argon atmosphere, irradiated with blue light at a wavelength of 456 nm, and at a temperature of -30 °C. The solvent was then removed by rotary evaporation, followed by column chromatography. The eluent for column chromatography consisted of petroleum ether and ethyl acetate in a volume ratio of 30:1, yielding 14.0 mg of diethyl 1,2-naphthalenedicarboxylate (yield: 18%).
[0078] The proton NMR spectrum of the 1,2-naphthalenedicarboxylic acid diethyl ester compound synthesized in this embodiment is shown below. Figure 13 As shown, the carbon NMR spectrum is as follows: Figure 14 As shown.
[0079] Spectral analysis: 1 H NMR (400 MHz, CDCl3): δ 8.09 (d, J = 1.9 Hz, 1H), 8.04 (d, J = 8.6 Hz, 1H), 7.91 (d, J = 8.7 Hz, 1H), 7.78 (d, J = 8.8 Hz, 1H), 7.69 (dd, J = 8.7, 1.9 Hz, 1H), 4.59 (q, J = 7.1 Hz, 2H), 4.45 (q, J = 7.1 Hz, 2H), 1.46 (dt, J = 15.4, 7.1Hz, 6H).
[0080] 13C NMR (126 MHz, CDCl3): δ 168.50, 165.56, 133.91, 133.41, 131.86, 130.44, 129.65, 129.42, 128.27, 126.30, 125.55, 122.09, 62.22, 61.90, 14.24,14.15.
[0081] HR-MS: Theoretical value [M+Na] + :C 16 H 15 BrO4Na: 373.0051, Measured value: 373.0050.
[0082] In summary, the structural formula of the 1,2-naphthalenedicarboxylic acid diethyl ester compounds synthesized in this embodiment is as follows: .
[0083] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A photocatalytic synthesis method for diethyl 1,2-naphthalenedicarboxylate compounds, characterized in that, Includes the following steps: Styrene compounds, α-diazoiodonium salts, and catalysts were dispersed in an organic solvent, followed by a coupling cyclization reaction under light irradiation. The styrene compounds were... or In the formula, R is selected from -H, methyl, trifluoromethyl, phenyl, acetoxy, -Cl or -Br, and α-diazoiodonium salt is... This yields diethyl 1,2-naphthalenedicarboxylate compounds.
2. The photocatalytic synthesis method according to claim 1, characterized in that: The molar ratio of the styrene compounds and α-diazoiodonium salts is 1:2 to 4.
3. The photocatalytic synthesis method according to claim 1 or 2, characterized in that: The α-diazo iodoium salt is prepared by a method comprising the following steps: dissolving iodophenyl diacetic acid in a solvent and placing it in an ice bath, then adding trimethylsilyl trifluoromethanesulfonate, then adding ethyl diazonium in batches, then reacting at room temperature, and then separating and purifying the product.
4. The photocatalytic synthesis method according to claim 1, characterized in that: The molar ratio of the styrene compound to the catalyst is 1:0.01 to 0.
02.
5. The photocatalytic synthesis method according to claim 1 or 4, characterized in that: The catalyst is at least one of tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate), tris(4,7-biphenyl-1,10-o-phenanthroline)ruthenium dichloride, and tris[4,4'-bis(tert-butyl)-2,2'-bipyridine]ruthenium hexafluorophosphate(II).
6. The photocatalytic synthesis method according to claim 1, characterized in that: The organic solvent is at least one of N,N-dimethylformamide, N-methylpyrrolidone, and N,N-dimethylacetamide.
7. The photocatalytic synthesis method according to claim 1, characterized in that: The coupling cyclization reaction was carried out under blue light irradiation and at a temperature of -30℃ to 0℃.
8. The photocatalytic synthesis method according to claim 1 or 7, characterized in that: The coupling cyclization reaction takes 0.5 h to 1 h.
9. The photocatalytic synthesis method according to claim 1, characterized in that: After the coupling cyclization reaction was completed, the reaction products were subjected to column chromatography.
10. The photocatalytic synthesis method according to claim 9, characterized in that: The column chromatography uses an eluent composed of petroleum ether and ethyl acetate.