A method of visible light-induced decarboxylative halogenation of aromatic carboxylic acids catalyzed by 2,7-dinitro-9,10-phenanthrenequinone aggregates

Abstract

The application belongs to the field of organic synthesis, and discloses a method for visible light induced 2,7-dinitro-9,10-phenanthrenequinone aggregate catalytic decarboxylation halogenation of aromatic carboxylic acid. The method is carried out under light irradiation, 2,7-dinitro-9,10-phenanthrenequinone aggregate is used as a photocatalyst, aromatic carboxylic acid is used as a raw material, halogenation reagent is used as a halogen source, and aromatic halide is generated by decarboxylation coupling in the presence of alkali. The method uses a metal-free small organic molecule photocatalyst, is clean and pollution-free, has mild reaction conditions, is simple to operate, has good selectivity, and has high conversion rate; cheap and easily available aromatic carboxylic acid with diverse structures is used as a substrate; the method has wide application range of substrates, and good compatibility for various substituted benzoic acid and heterocyclic aromatic carboxylic acid.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis and provides a method for the decarboxylation and halogenation of aromatic carboxylic acids catalyzed by visible light-induced 2,7-dinitro-9,10-phenanthroquinone aggregates. Background Technology

[0002] Aromatic halides are an important class of organic synthesis intermediates with wide applications in pharmaceuticals, pesticides, and functional materials. Therefore, developing mild, efficient, and highly selective synthetic methods for aromatic halides is of great significance. Aromatic carboxylic acids are ideal precursors for the preparation of aromatic halides due to their wide availability, structural diversity, and good stability. However, traditional decarboxylation halogenation methods often require the use of stoichiometric toxic metal reagents (such as silver and mercury) or harsh high-temperature conditions [Organic Letter, 2024, 26(40): 8572-8576.], which limits their application scope.

[0003] In recent years, visible light photocatalysis has developed rapidly in the field of organic synthesis due to its green and mild characteristics, providing new ideas for the decarboxylation conversion of aromatic carboxylic acids. For example, the Macmillan group reported a room-temperature decarboxylation halogenation method of aromatic carboxylic acids via ligand-metal charge transfer (LMCT) [Journal of the American Chemical Society, 2022, 144(18): 8296-8305]. The Jin group achieved the decarboxylation bromination reaction of aromatic carboxylic acids using iron photocatalysis [Organic Letter, 2025, 27(25): 6862-686]. However, most of these methods rely on metal catalysts, which are costly and may lead to metal residue problems. Although there have been reports on decarboxylation using small organic molecule photocatalysts to form charge transfer complexes [Chem, 2023, 9(10): 2997-3012], developing a metal-free, mild, substrate-wide, and highly efficient direct decarboxylation halogenation method of aromatic carboxylic acids remains an important research direction in the field of organic synthesis. Summary of the Invention

[0004] This invention provides a visible-light photocatalytic method for the decarboxylation and halogenation of aromatic carboxylic acids. This method uses 2,7-dinitro-9,10-phenanthroquinone aggregates as a photocatalyst, achieving highly efficient decarboxylation and halogenation (bromination and chlorination) of various aromatic carboxylic acids under mild room temperature conditions. This method has advantages such as simple operation, no need for metal catalysts, broad substrate applicability, and good functional group compatibility.

[0005] The technical solution of the present invention: A visible light-induced decarboxylation and halogenation method for aromatic carboxylic acids catalyzed by 2,7-dinitro-9,10-phenanthroquinone aggregates is disclosed. Under light irradiation, aromatic carboxylic acids (including aryl and heteroaryl carboxylic acids) are used as raw materials, 2,7-dinitro-9,10-phenanthroquinone aggregates are used as photocatalysts, and a halogenating agent is used as the halogen source. A base and solvent are added, and aromatic halogenated products are generated through decarboxylation coupling. The synthetic route is as follows: In the formula, Ar is one of the substituted aryl group, substituted or unsubstituted heteroaryl group; X is Br or Cl.

[0006] The concentration of the aromatic carboxylic acid used in the reaction system was 0.05 mol / L.

[0007] The photocatalyst used is 2,7-dinitro-9,10-phenanthroquinone aggregate.

[0008] The halogen source used is one of carbon tetrabromide, 1,3-dichloro-5,5-dimethylhydantoin, N-bromosuccinimide, or 1,3-dibromo-5,5-dimethylhydantoin.

[0009] The alkali used is cesium carbonate.

[0010] The solvents used are selected from acetonitrile, tetrahydrofuran, dimethyl sulfoxide, and toluene.

[0011] The wavelength range of the illumination is part or all of the 395 nm to 410 nm band.

[0012] The molar ratio of the photocatalyst to the aromatic carboxylic acid used is 1:5 to 1:20.

[0013] The molar ratio of the halogen source to the aromatic carboxylic acid used is 2:1 to 2.5:1.

[0014] The molar ratio of the alkali to the aromatic carboxylic acid used is 1.2:1.

[0015] The reaction time is 12 to 16 hours.

[0016] The beneficial effects of this invention are as follows: The preparation method of this invention uses organic small molecule 2,7-dinitro-9,10-phenanthroquinone aggregate as a photocatalyst, avoiding the problem of metal residue; the reaction conditions are mild and can be carried out at room temperature, making the operation simple; the substrate has a wide range of applicability, showing good reactivity and functional group compatibility for a variety of substituted benzoic acids and heterocyclic aromatic carboxylic acids; the reaction has good selectivity and high conversion rate, and has certain industrial application prospects. Attached Figure Description

[0017] Figure 1It is 2,7-dinitro-9,10-phenanthrenequinone from Example 1. 1 H NMR spectrum.

[0018] Figure 2 It is 2,7-dinitro-9,10-phenanthrenequinone from Example 1. 13 C NMR spectrum.

[0019] Figure 3 This is the UV-Vis absorption spectrum of 2,7-dinitro-9,10-phenanthroquinone in Example 2.

[0020] Figure 4 This is the fluorescence emission spectrum of 2,7-dinitro-9,10-phenanthroquinone in Example 2.

[0021] Figure 5 This is the dynamic light scattering particle size distribution of 2,7-dinitro-9,10-phenanthroquinone in Example 2.

[0022] Figure 6 The cyclic voltammetry curves are for 2,7-dinitro-9,10-phenanthroquinone in Example 2.

[0023] Figure 7 This is the photocurrent response spectrum of 2,7-dinitro-9,10-phenanthroquinone in Example 2.

[0024] Figure 8 This is the nanosecond transient absorption spectrum of 2,7-dinitro-9,10-phenanthroquinone in Example 2.

[0025] Figure 9 It is the 1-bromo-4-nitrobenzene in Example 3 1 H NMR spectrum.

[0026] Figure 10 It is the 1-bromo-4-nitrobenzene in Example 3 13 C NMR spectrum.

[0027] Figure 11 It is the 1-chloro-4-nitrobenzene in Example 4 1 H NMR spectrum.

[0028] Figure 12 It is the 1-chloro-4-nitrobenzene in Example 4 13 C NMR spectrum.

[0029] Figure 13 It is the 2-chloro-6-phenylpyridine in Example 5 1 H NMR spectrum.

[0030] Figure 14 It is the 2-chloro-6-phenylpyridine in Example 5 13 C NMR spectrum. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0032] Example 1: Synthesis of 2,7-dinitro-9,10-phenanthroquinone; 9,10-phenanthrenequinone (15 mmol, 3.12 g) and 40 mL of fuming nitric acid were added sequentially to a dry 100 mL three-necked flask. The reaction apparatus was placed in an oil bath, and the temperature was raised to 95 °C. Then, 5 mL of concentrated sulfuric acid was slowly added, followed by reflux under air for 45 min. The exhaust gas emitted during the reaction was purified by absorption with a saturated sodium carbonate aqueous solution. After the reaction was completed, the reaction mixture was poured into a 30 mL ice-water mixture. After the system returned to the normal temperature, it was filtered and washed successively with water and anhydrous ethanol until the filtrate was clear. The obtained solid was collected and recrystallized with glacial acetic acid. After standing overnight, a yellow solid precipitated. After filtration, the solid was dried in a vacuum drying oven at 55 °C to obtain the final product 2,7-dinitro-9,10-phenanthrenequinone.

[0033] 2,7-Dinitro-9,10-phenanthrenequinone Yellow solid; 1 H NMR (400 MHz, DMSO- d 6 ) δ 8.82–8.65 (m, 4H), 8.58 (dd, J = 8.8, 2.6 Hz, 2H); 13 C NMR (100 MHz, DMSO- d 6 ) δ 176.2, 148.8, 138.9, 134.0, 128.9, 128.1, 123.1. Example 2: Photophysical property testing of 2,7-dinitro-9,10-phenanthroquinone; Prepare acetonitrile solutions of 2,7-dinitro-9,10-phenanthrenequinone at concentrations of 0.02 mM, 0.5 mM, 1 mM, 2 mM, 4 mM, 5 mM, 6 mM, 8 mM, 10 mM, and 20 mM for later use. A 1 mM solution was placed in a 1×1 cm high-precision quartz cuvette and subjected to UV-Vis absorption spectroscopy using a Lambda 1050+ UV-Vis spectrophotometer. Solutions of 5 mM, 6 mM, 8 mM, 10 mM, and 20 mM were placed in 1×1 cm high-precision quartz cuvettes and their fluorescence emission spectra were measured using an FP-6500 fluorescence spectrometer. Solutions of 4 mM, 6 mM, 10 mM, and 20 mM were placed in 1×1 cm high-precision quartz cuvettes and their dynamic light scattering nanoparticle size was measured using a Nano-ZS90 nanoparticle size analyzer. Cyclic voltammetry tests were performed using 0.5 mM, 1 mM, 2 mM, and 5 mM solutions on a BAS 100B electrochemical analyzer. The experiment employed a three-electrode system: a glassy carbon electrode as the working electrode, a platinum wire as the counter electrode, and a saturated calomel electrode as the reference electrode. The electrolyte was 0.1... For M, tetrabutylammonium hexafluorophosphate (NBu4PF6), nitrogen gas was bubbled through the atmosphere for 3 min to remove oxygen before measurement, with a scan rate of 50 mV / s. 1 mg, 3 mg, and 5 mg of 2,7-dinitro-9,10-phenanthrenequinone were weighed and dissolved in 1 mL of ethanol, then 50 mL of ethanol was added. Nafion 117 solution was sonicated for 30 minutes to form a homogeneous suspension. Then, 150 ml of the suspension was taken using a pipette. The suspension was evenly drop-coated onto the FTO glass surface and then immersed in 60... The electrode was dried in an oven to form a stable working electrode. Photocurrent was measured using a BAS 100B electrochemical analyzer, using a platinum wire counter electrode, an Ag / AgCl electrode as a reference electrode, a 0.5 mM sodium sulfate solution as the electrolyte, and a xenon lamp as the light source. The illumination interval was 20 seconds (20 seconds on, 20 seconds off), and the photocurrent response was recorded. A 0.02 mM solution was placed in a 1×1 cm high-precision quartz cuvette, and nanosecond transient absorption experiments were performed using an LP980 laser flash photolysis instrument. Nitrogen gas was bubbled for 10 min before the test to remove dissolved oxygen. The transient absorption decay signal was recorded, and the lifetime value was obtained by fitting the data using LP980 software.

[0034] Example 3: Synthesis of 1-bromo-4-nitrobenzene; Under air atmosphere, p-nitrobenzoic acid (50.1 mg, 0.30 mmol), 2,7-dinitro-9,10-phenanthrenequinone (20.1 mg, 0.06 mmol, 20 mol%), carbon tetrabromide (199.0 mg, 0.60 mmol, 2.0 equiv.), cesium carbonate (117.3 mg, 0.36 mmol, 1.2 equiv.), and acetonitrile (3 mL) were added sequentially to a 20 mL quartz tube reactor. The reaction tube was placed in a photoreactor and reacted at room temperature for 12 h under 10 W 390 nm LED illumination. After the reaction was completed, the solvent was removed under reduced pressure, and 1-bromo-4-nitrobenzene was finally separated by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 10:1), with a yield of 98%.

[0035] 1-Bromo-4-nitrobenzene White solid; 1 H NMR (400 MHz, Chloroform-d) δ 8.10 (d, J = 9.0 Hz, 2H),7.69 (d, J = 9.0 Hz, 2H); 13 C NMR (101 MHz, Chloroform-d) δ 147.0, 132.6, 129.9, 125.0.

[0036] Example 4: Synthesis of 1-chloro-4-nitrobenzene; Under air atmosphere, p-nitrobenzene (50.1 mg, 0.30 mmol), DNPO (20.1 mg, 0.06 mmol, 20 mol%), 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) (147.8 mg, 0.75 mmol, 2.5 equiv.), cesium carbonate (117.3 mg, 0.36 mmol, 1.2 equiv.), and acetonitrile (3 mL) were added sequentially to a 20 mL quartz tube reactor. The reaction tube was placed in a photoreactor and reacted at room temperature for 12 h under 10 W 390 nm LED illumination. After the reaction was completed, the solvent was removed under reduced pressure, and 1-chloro-4-nitrobenzene was finally separated by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 10:1), with a yield of 66%.

[0037] 1-Chloro-4-nitrobenzene White solid; 1H NMR (400 MHz, Chloroform-d) δ 8.18 (d, J = 9.0 Hz, 2H), 7.52 (d, J = 9.0 Hz, 2H); 13 C NMR (101 MHz, Chloroform-d) δ 146.4, 141.3,129.5, 124.8. Example 5: Synthesis of 2-chloro-6-phenylpyridine; Under air atmosphere, 6-phenylpyridine-2-carboxylic acid (59.8 mg, 0.30 mmol), DNPO (20.1 mg, 0.06 mmol, 20 mol%), 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) (147.8 mg, 0.75 mmol, 2.5 equiv.), cesium carbonate (117.3 mg, 0.36 mmol, 1.2 equiv.), and acetonitrile (3 mL) were added sequentially to a 20 mL quartz tube reactor. The reaction tube was placed in a photoreactor and reacted at room temperature for 12 h under 10 W 390 nm LED illumination. After the reaction was completed, the solvent was removed under reduced pressure, and 2-chloro-6-phenylpyridine was finally separated by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 15:1), with a yield of 77%.

[0038] 2-Chloro-6-phenylpyridine White solid; 1 H NMR (500 MHz, Chloroform-d) δ 8.00 (d, J = 6.8 Hz, 2H), 7.70 (t, J = 7.7 Hz, 1H), 7.65 (d, J = 7.6 Hz, 1H), 7.46 (dt, J = 13.3, 6.9Hz, 3H), 7.26 (d, J = 7.7 Hz, 1H); 13 C NMR (126 MHz, Chloroform-d) δ 158.1,151.3, 139.3, 137.7, 129.6, 128.8, 127.0, 122.5, 118.6. Example 6: Synthesis of 1-bromo-4-tert-butylbenzene; Under air atmosphere, p-tert-butylbenzoic acid (53.5 mg, 0.30 mmol), DNPO (20.1 mg, 0.06 mmol, 20 mol%), carbon tetrabromide (199.0 mg, 0.60 mmol, 2.0 equiv.), cesium carbonate (117.3 mg, 0.36 mmol, 1.2 equiv.), and acetonitrile (3 mL) were added sequentially to a 20 mL quartz tube reactor. The reaction tube was placed in a photoreactor and reacted at room temperature for 12 h under 10 W 390 nm LED illumination. After the reaction was completed, the solvent was removed under reduced pressure, and 1-bromo-4-tert-butylbenzene was finally separated by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 10:1), with a yield of 56%.

[0039] 1-Bromo-4-tert-butylbenzene Colorless liquid; 1 H NMR (400 MHz, Chloroform-d) δ 7.41 (d, J = 8.6 Hz, 2H), 7.26 (d, J = 8.6 Hz, 2H), 1.30 (s, 9H); 13 C NMR (101 MHz, Chloroform-d) δ150.1, 131.0, 127.2, 119.2, 31.2, 30.7. Example 7: Synthesis of 2-bromo-6-methoxypyridine; Under air atmosphere, 6-methoxypyridine-2-carboxylic acid (45.9 mg, 0.30 mmol), 2,7-dinitro-9,10-phenanthrenequinone (20.1 mg, 0.06 mmol, 20 mol%), carbon tetrabromide (199.0 mg, 0.60 mmol, 2.0 equiv.), cesium carbonate (117.3 mg, 0.36 mmol, 1.2 equiv.), and acetonitrile (3 mL) were added sequentially to a 20 mL quartz tube reactor. The reaction tube was placed in a photoreactor and reacted at room temperature for 12 h under 10 W 390 nm LED illumination. After the reaction was completed, the solvent was removed under reduced pressure, and 2-bromo-6-methoxypyridine was finally separated by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 15:1), with a yield of 61%.

[0040] 2-Bromo-6-methoxypyridine Colorless liquid; 1H NMR (400 MHz, Chloroform-d) δ 7.41 – 7.33 (m, 1H), 7.01(d, J = 7.5 Hz, 1H), 6.64 (d, J = 7.5 Hz, 1H), 3.89 (s, 3H); 13 C NMR (101 MHz, Chloroform-d) δ 163.6, 140.2, 138.5, 120.1, 109.3, 53.9. Example 8: Synthesis of 2,3,6-trichloropyridine; Under air atmosphere, 3,6-dichloropyridine-2-carboxylic acid (57.6 mg, 0.30 mmol), 2,7-dinitro-9,10-phenanthrenequinone (20.1 mg, 0.06 mmol, 20 mol%), 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) (147.8 mg, 0.75 mmol, 2.5 equiv.), cesium carbonate (117.3 mg, 0.36 mmol, 1.2 equiv.), and acetonitrile (3 mL) were added sequentially to a 20 mL quartz tube reactor. The reaction tube was placed in a photoreactor and reacted at room temperature for 16 h under 10 W 390 nm LED illumination. After the reaction was completed, the solvent was removed under reduced pressure, and 2,3,6-trichloropyridine was finally separated by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 10:1), with a yield of 94%.

[0041] 2,3,6-Trichloropyridine White solid; 1 H NMR (500 MHz, Chloroform-d) δ 7.72 (d, J = 8.2 Hz, 1H),7.24 (d, J = 8.2 Hz, 1H); 13 C NMR (126 MHz, Chloroform-d) δ 148.3, 148.1,140.7, 129.5, 123.9. HRMS (ESI) m / z: [M + H] + calcd for C5H3Cl3N + 181.9326; found 181.9330. Example 8: Synthesis of 2-chloropyrazine Under air atmosphere, pyrazine-2-carboxylic acid (37.2 mg, 0.30 mmol), 2,7-dinitro-9,10-phenanthroquinone (20.1 mg, 0.06 mmol, 20 mol%), 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) (147.8 mg, 0.75 mmol, 2.5 equiv.), cesium carbonate (117.3 mg, 0.36 mmol, 1.2 equiv.), and acetonitrile (3 mL) were added sequentially to a 20 mL quartz tube reactor. The reaction tube was placed in a photoreactor and reacted at room temperature for 12 h under 10 W 390 nm LED illumination. After the reaction was completed, the solvent was removed under reduced pressure, and 2-chloropyrazine was finally separated by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 10:1), with a yield of 62%.

[0042] 2-Chlorpyrazine Colorless liquid; 1 H NMR (400 MHz, Chloroform-d) δ 8.55 (d, J = 1.5 Hz, 1H), 8.45 (d, J = 2.6 Hz, 1H), 8.33 (dd, J = 2.6, 1.5 Hz, 1H); 13 C NMR (101 MHz, Chloroform-d) δ 149.1, 144.5, 143.5, 142.1. The photophysical properties of 2,7-dinitro-9,10-phenanthroquinone in Example 2 were analyzed: Depend on Figure 3 It is known that 2,7-dinitro-9,10-phenanthrenequinone has obvious absorption characteristics in the visible light region, with a maximum absorption wavelength of 490 nm. In addition, there is also a relatively broad absorption band in the 350-410 nm region, indicating that 2,7-dinitro-9,10-phenanthrenequinone can effectively absorb light energy and enter the excited state under the excitation of the corresponding light source, thereby initiating a photocatalytic cycle.

[0043] Depend on Figure 4It was observed that when the concentration of 2,7-dinitro-9,10-phenanthrenequinone was 5 mM, the fluorescence emission intensity was extremely weak. As the concentration gradually increased from 5 mM to 20 mM, the fluorescence emission peak of 2,7-dinitro-9,10-phenanthrenequinone underwent a significant red shift, moving from 532 nm to 542 nm. This is a typical characteristic of aggregate formation, indicating that 2,7-dinitro-9,10-phenanthrenequinone molecules form ordered aggregates through π–π stacking at high concentrations. The formation of these aggregates may affect the excited-state energy levels and electron transport properties of the molecule, providing a structural basis for the efficient single-electron transfer process in subsequent catalytic reactions.

[0044] Depend on Figure 5 It is known that 2,7-dinitro-9,10-phenanthrenequinone can form nano- to submicron-sized aggregates in acetonitrile. With increasing concentration of 2,7-dinitro-9,10-phenanthrenequinone in acetonitrile, the average size of the aggregates decreases from 1000 nm to 25 nm. This may be because the initial aggregates are a loose network structure containing a large amount of solvent, resulting in a large "hydrodynamic diameter." Upon further aggregation, these loose aggregates undergo internal restructuring, expelling the internal solvent and forming a denser aggregate. Dense spheres diffuse much faster in liquids than loose networks. Therefore, although the actual physical size of the aggregates may not change significantly, their equivalent hydrodynamic diameter decreases substantially. This result confirms that 2,7-dinitro-9,10-phenanthrenequinone can form nanoscale aggregates in situ under the reaction conditions.

[0045] Depend on Figure 6 It was found that when the concentration of 2,7-dinitro-9,10-phenanthrenequinone in acetonitrile increased from 0.5 mM to 5 mM, its corresponding maximum reduction potential increased from -1.27 V to -1.37 V. This indicates that the redox potential of 2,7-dinitro-9,10-phenanthrenequinone can be controlled by increasing or decreasing the concentration. The excited-state reduction potential of 2,7-dinitro-9,10-phenanthrenequinone was calculated. The above results indicate that the redox potential of 2,7-dinitro-9,10-phenanthrenequinone aggregates can be effectively controlled by adjusting the concentration of 2,7-dinitro-9,10-phenanthrenequinone in organic solvents.

[0046] Depend on Figure 7It was observed that when the light source was turned on, the FTO electrode modified with 2,7-dinitro-9,10-phenanthroquinone rapidly generated a photocurrent signal; when the light source was turned off, the photocurrent signal rapidly decayed to the baseline level. The photocurrent intensity increased with the 2,7-dinitro-9,10-phenanthroquinone loading from 1 mg to 5 mg. The generation of photocurrent indicates that 2,7-dinitro-9,10-phenanthroquinone can effectively generate electron-hole pairs under photoexcitation, and the photogenerated electrons can migrate through the external circuit to form a current, demonstrating that 2,7-dinitro-9,10-phenanthroquinone has good photogenerated carrier separation and transport capabilities, thereby promoting the single-electron transfer process between the electrode and the substrate.

[0047] Depend on Figure 8 As shown by the LP980 software fitting, the excited-state lifetime of 2,7-dinitro-9,10-phenanthrenequinone is 5.8 μs, which is much longer than that of common organic photocatalysts (typically in the nanosecond to submicrosecond range). This indicates that the molecule has good excited-state stability, thus ensuring efficient photocatalytic reactions.

Claims

1. A method for the visible light-induced decarboxylation and halogenation of aromatic carboxylic acids catalyzed by 2,7-dinitro-9,10-phenanthroquinone aggregates, characterized in that, Under light irradiation, aromatic halides were generated via decarboxylation coupling using aromatic carboxylic acids as raw materials, 2,7-dinitro-9,10-phenanthroquinone aggregates as photocatalysts, and halogenating reagents as halogen sources, with the addition of alkali and solvent. The synthetic route is as follows: In the formula, Ar is one of the substituted aryl group, substituted or unsubstituted heteroaryl group; X is Br or Cl.

2. The method for catalyzing the decarboxylation and halogenation of aromatic carboxylic acids by visible light-induced 2,7-dinitro-9,10-phenanthroquinone aggregates according to claim 1, characterized in that, The aromatic carboxylic acids include aryl carboxylic acids and heteroaryl carboxylic acids; The photocatalyst used is 2,7-dinitro-9,10-phenanthroquinone aggregate; The halogen source used is one of carbon tetrabromide, 1,3-dichloro-5,5-dimethylhydantoin, N-bromosuccinimide, and 1,3-dibromo-5,5-dimethylhydantoin; The alkali used is cesium carbonate; The solvents used are selected from acetonitrile, tetrahydrofuran, dimethyl sulfoxide, and toluene.

3. The method for catalyzing the decarboxylation and halogenation of aromatic carboxylic acids by visible light-induced 2,7-dinitro-9,10-phenanthroquinone aggregates according to claim 1, characterized in that, The concentration of the aromatic carboxylic acid used in the reaction system was 0.05 mol / L; The molar ratio of the photocatalyst to the aromatic carboxylic acid used is 1:5 to 1:20; The molar ratio of the halogen source to the aromatic carboxylic acid used is 2:1 to 2.5:1; The molar ratio of the alkali to the aromatic carboxylic acid used is 1.2:

1.

4. The method for catalyzing the decarboxylation and halogenation of aromatic carboxylic acids by visible light-induced 2,7-dinitro-9,10-phenanthroquinone aggregates according to claim 1, characterized in that, The wavelength range of the illumination is part or all of the 395 nm to 410 nm band.

5. The method for catalyzing the decarboxylation and halogenation of aromatic carboxylic acids by visible light-induced 2,7-dinitro-9,10-phenanthroquinone aggregates according to claim 1, characterized in that, The reaction time is 12 to 16 hours.

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