Dual-band acridine formic acid anthracene methyl ester photocatalyst as well as preparation method and application thereof

Abstract

The invention discloses a dual-band acridine formic acid anthracene methyl ester photocatalyst as well as a preparation method and application thereof, and belongs to the field of heterocyclic compounds. The invention designs and synthesizes a novel acridine formic acid anthracene methyl ester photocatalyst, which has good compatibility in two wavebands of 365 nm and 405 nm, can realize photocatalysis of disulfide compounds and aryl formyl peroxide compounds, and provides a new thought for preparation of sulfoxide compounds with asymmetric structures; the reaction conditions are mild, the reaction time is short, the photocatalyst can be recycled, the circulation loss is low, the circulation efficiency is high, the production efficiency is greatly improved, and the production period and cost are reduced; the product is free of transition metal residues and high in yield.

Description

Technical Field

[0001] This invention belongs to the field of heterocyclic compounds, specifically relating to a dual-band acridine carboxylic acid anthraquinone methyl ester photocatalyst, its preparation method, and its application. Background Technology

[0002] Asymmetric sulfoxides are an important class of organosulfur compounds, characterized by a unique sulfinyl group (>S=O) and a chiral center. Due to their significant pharmaceutical, biological, and chemical activities, these compounds are crucial structural units in organic chemical engineering, widely found in natural products, ligands, pharmaceuticals, and functional materials, and have broad applications in pharmaceuticals, chemicals, and biology.

[0003] Traditional methods typically use sulfur-containing compounds as raw materials, employing oxidation reactions to prepare structurally asymmetric sulfoxide compounds. For example, the most widely used synthetic route starts with thioethers and proceeds with hydrogen peroxide, m-chloroperbenzoic acid (m-CPBA), nitric acid, sodium hypochlorite, and sodium periodate to prepare structurally asymmetric sulfoxide compounds. This type of synthetic route mainly relies on selecting suitable oxidants, controlling appropriate reaction temperatures, and even adding transition metal catalysts. Therefore, it suffers from problems such as high energy consumption, metal residues in the products, and environmental unfriendliness, all of which limit the large-scale use of this process.

[0004] Photocatalytic synthesis, with its higher efficiency and milder reaction conditions, has become an important technique in the field of synthetic reactions in recent years. However, there are few reports on the synthesis of sulfoxide compounds under photocatalytic conditions, mainly due to the lack of sulfinyl inducers. This means that the highly reactive raw materials commonly used in existing processes cannot be extended to photocatalytic reactions. For example, the paper (Green Chemistry, 2014, 16, 3986-3992) reported the synthesis of β-ketosulfoxides from olefins using thiophenol as a sulfur source and oxygen from the air as an oxidant, catalyzed by an organic photocatalyst. Similarly, the paper (Green Chemistry, 2017, 19, 3520-3524) reported a process for the selective synthesis of sulfoxides from thiols and olefins at room temperature via visible light catalysis using an organic photocatalyst.

[0005] However, the inventors noted that the above synthetic routes all use highly reactive olefins, and the products are mainly alkylaryl sulfoxides. The synthesis process of structurally asymmetric diaryl sulfoxides is still one of the problems that urgently need to be solved.

[0006] Furthermore, most existing reports on photocatalysts utilize a single wavelength light source or directly employ a white light source. Photocatalysts compatible with both wavelengths, especially those adapted to commonly used lithography sources in industry at present, such as those compatible with both 365 nm and 405 nm, are rare. Therefore, developing a photocatalytic system that is compatible with both wavelengths and does not involve transition metal catalysts is a hot research topic. Summary of the Invention

[0007] In view of the problems mentioned in the background art, the purpose of this invention is to provide a dual-band acridine carboxylic acid anthracene methyl ester photocatalyst, its preparation method and application. A novel acridine carboxylic acid anthracene methyl ester photocatalyst was designed and synthesized, which can simultaneously achieve high-efficiency catalysis in two bands and the recycling and reuse of the catalyst, effectively reducing production costs.

[0008] This invention provides a dual-band acrylonitrile formate anthraquinone photocatalyst, with the following structure: .

[0009] This invention also provides a method for preparing the above-mentioned dual-band acrylonitrile anthracene methyl ester photocatalyst, comprising the following steps: S1. Under a nitrogen atmosphere, 9-chloromethylanthracene, 9-carboxylic acid acridine, homogeneous catalyst, base and organic solvent are added to the reactor; S2. Heat and stir, and monitor the reaction by TLC thin-layer chromatography; S3. After the reaction is complete, the solvent is removed, and the target acridine carboxylic acid anthraquinone ester photocatalyst is obtained by column chromatography.

[0010] In a preferred embodiment, the equivalent ratio of 9-chloromethylanthracene, 9-carboxylic acid acridine, homogeneous catalyst, and base in S1 is (1-2):1:(0.2-2):(2-4).

[0011] In a preferred embodiment, the homogeneous catalyst in S1 is tetrabutylammonium bromide, the base is cesium carbonate, and the organic solvent is N,N-dimethylformamide.

[0012] In a preferred embodiment, the reaction temperature during heating and stirring in S2 is 55-90°C.

[0013] This invention also provides the application of the above-mentioned dual-band acrylonitrile carboxylic acid anthraquinone ester photocatalyst in the photocatalytic preparation of structurally asymmetric sulfoxide compounds from disulfide compounds and peroxide arylformyl compounds.

[0014] As a preferred embodiment, the method for catalytically preparing structurally asymmetric sulfoxide compounds includes the following steps: adding disulfide compounds, arylformyl peroxide compounds, acridine carboxylic acid anthraquinone ester photocatalyst, base and organic solvent into a reaction vessel, placing it under light sources with wavelengths of 365 nm and 405 nm respectively, stirring the reaction under an oxygen atmosphere at room temperature, monitoring the reaction by TLC thin-layer chromatography, removing the solvent after the reaction is complete, and obtaining the product by column chromatography.

[0015] In a preferred embodiment, the disulfide compound is , where R 1 Selected from 4-CH3C6H4, 4-BrC6H4, 2-Napthyl, n-C5H 11 Any one of them.

[0016] In a preferred embodiment, the arylformyl peroxide compound is , where R 2 Choose from either C6H5 or 2-Thienyl.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The photocatalytic system of this invention does not require the participation of transition metal catalysts. It uses a novel acridine carboxylic acid anthraquinone ester photocatalyst designed and synthesized, providing a new approach for the preparation of structurally asymmetric sulfoxide compounds.

[0018] 2. The acridine carboxylic acid anthraquinone ester photocatalyst prepared in this invention has good compatibility in both 365 nm and 405 nm wavelength bands.

[0019] 3. The acridine carboxylic acid anthraquinone methyl ester photocatalyst prepared by this invention can be recycled with low recycling loss. Attached Figure Description

[0020] Figure 1 The TM1 photocatalyst prepared in Example 1 of this invention 1 H-NMR spectrum.

[0021] Figure 2 The TM1 photocatalyst prepared in Example 1 of this invention 13 C-NMR spectrum.

[0022] Figure 3 The UV-Vis spectrum of the TM1 photocatalyst prepared in Example 1 of this invention.

[0023] Figure 4 The image shows the electron paramagnetic resonance (EPR) spectrum under 365 nm light illumination.

[0024] Figure 5The image shows the electron paramagnetic resonance (EPR) spectrum under 405 nm light illumination.

[0025] Figure 6 The product of Experimental Example 1 of the present invention 1 H-NMR spectrum.

[0026] Figure 7 The product of Experimental Example 1 of the present invention 13 C-NMR spectrum.

[0027] Figure 8 The product of Experimental Example 2 of the present invention 1 H-NMR spectrum.

[0028] Figure 9 The product of Experimental Example 2 of the present invention 13 C-NMR spectrum.

[0029] Figure 10 The product of Experimental Example 3 of the present invention 1 H-NMR spectrum.

[0030] Figure 11 The product of Experimental Example 3 of the present invention 13 C-NMR spectrum.

[0031] Figure 12 The product of Test Example 4 of this invention 1 H-NMR spectrum.

[0032] Figure 13 The product of Test Example 4 of this invention 13 C-NMR spectrum.

[0033] Figure 14 The product of Experimental Example 5 of this invention 1 H-NMR spectrum.

[0034] Figure 15 The product of Experimental Example 5 of this invention 13 C-NMR spectrum. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with embodiments. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] Example 1 A method for preparing a dual-band acridine carboxylic acid anthraquinone photocatalyst includes the following steps: 1. Add 9-chloromethylanthracene (1.5 eq), 9-carboxylic acid acridine (1 mmol, 1 eq), cesium carbonate (3 eq), and tetrabutylammonium bromide (1 eq) to a 50 mL single-necked flask equipped with a magnetic stirrer; purge with nitrogen three times, and then add 5 mL of N,N-dimethylformamide.

[0038] 2. Turn on the stirrer and heat to 80°C to carry out the reaction. Take samples during the reaction for TLC monitoring.

[0039] 3. After the initial reaction of 9-carboxylic acid acridine was essentially complete (approximately 4 hours), the reaction solution was brought to room temperature, 10 mL of water was added, and the reaction solution was transferred to a separatory funnel and extracted twice with DCM. The organic phase was back-extracted twice with water and dried over anhydrous sodium sulfate. The solvent was removed by vacuum distillation. The crude product was separated by column chromatography to obtain a white solid TM1 (351 mg, yield: 85%).

[0040] The reaction formula is:

[0041] Figure 1 It is a TM1 photocatalyst 1 H-NMR spectrum; 1 H NMR (400 MHz, CDCl3): δ 8.59 - 8.50 (m, 3H), 8.19 (d, J = 8.74 Hz, 2H), 8.05 (d, J = 9.89 Hz, 2H), 7.94 (d, J = 8.75 Hz, 2H), 7.71 (t, J = 7.65 Hz, 2H), 7.63 (t, J = 7.33 Hz, 2H), 7.51 (d, J = 7.83 Hz, 2H), 7.40 (t, J = 7.99 Hz, 2H), 6.73 (s, 2H). Figure 2 It is a TM1 photocatalyst 13 C-NMR spectrum; 13 C NMR (100 MHz, CDCl3): δ 167.8, 148.7, 136.7, 131.5, 131.3, 130.3, 130.0, 129.9, 129.4, 127.2, 127.1, 125.4, 125.3, 125.2, 123.9, 122.5, 60.8. Example 2 UV-Vis spectrum The UV-Vis absorption spectra were measured on a Shimadzu UV-1900 UV-Vis spectrophotometer, using toluene as the solvent (photosensitizer concentration: 4 × 10⁻⁶). -5 mol / L).

[0042] According to Beer-Lambert law, the molar extinction coefficient ε = A is calculated. bn / c, where A bn ρ represents the absorbance of the UV-Vis absorption spectrum, and c represents the concentration (mol / L). The results are shown in Table 1. The UV-Vis spectrum of the prepared TM1 is shown below. Figure 3 As shown.

[0043] Table 1. Molar extinction coefficient of TM1

[0044] This indicates that TM1 has very high absorption intensity in the light regions near 365 nm and 405 nm, which means that this type of compound has good photo-radical conversion ability under these two light sources, and has the prerequisite for catalyzing / initiating photo-induced radical reactions.

[0045] Example 3 Electron spin resonance (EPR) characterization ESR-ST experiments were performed on a Bruker-BioSpin ESR5000 electron spin resonance spectrometer with a field strength of 0-650 mT, a power of 9.5 GHz, and a frequency modulation of 100 kHz. Under stirring conditions, TM1 photocatalyst (0.01 mmol) and radical scavenger methylpyridine N-oxide (DMPO, 0.02 mmol) were sequentially added to a solution of THF (1.0 mL). In the dark, the sample was irradiated for 1-3 min using handheld 365 nm and 405 nm LEDs, respectively. 25 μL of the sample was placed in an EPR test tube, nitrogen gas was introduced to purge oxygen, and then the tube was placed in the test chamber.

[0046] Figure 4 , Figure 5 The EPR spectrum shows that under illumination from 365 nm and 405 nm light sources, different peak shapes are produced, indicating that different free radicals are generated under different light sources. However, the signal intensities are similar, indicating that the concentration of free radicals generated is similar under different light source conditions. The EPR test results show that TM1 has great potential to initiate synthetic reactions with the same mechanism.

[0047] Example 4 Catalytic performance characterization

[0048] 1. Experimental steps: A method for synthesizing photo-promoted structurally asymmetric sulfoxides includes the following steps: S1. Add disulfide compound (0.3 mmol, 1.0 eq), arylformyl peroxide compound (1.5 eq), TM1 (0.2 eq), sodium carbonate (2 eq) and 1,2-dichloroethane (DCE, 3.5 mL) in sequence, and mix thoroughly. S2. The reaction was stirred at room temperature under LED light source with wavelengths of 365 nm or 405 nm until the disulfide compounds were completely consumed by TLC monitoring, which took about 12 hours. S3. Remove the solvent under reduced pressure, and separate the residue by column chromatography (petroleum ether / ethyl acetate as eluent, volume ratio 5:1; silica gel column) to obtain the corresponding structurally asymmetric sulfoxide compound.

[0049] 2. Yield: Yield = [(Actual product yield) ÷ (Theoretical product yield)] × 100%.

[0050] 3. Purity: NMR spectroscopy was performed. 1 H NMR and 13 All C NMR measurements were performed using a Bruker AM-400 instrument. The test temperature was room temperature, and the solvent was deuterated chloroform. (Reference selection follows.) 1 ¹H NMR: CHCl₃ was 7.26 ppm; 13 C NMR: CHCl3 was 77.2 ppm.

[0051] Table 2 shows the experimental examples of disulfide compounds and arylformyl peroxides with different functional groups, along with their yields and purities. The NMR spectra of Examples 1-5 are shown in [Table 2]. Figures 6-15 .

[0052] Table 2 Yield and Purity Test Results

[0053] NMR data of the product from Experiment Example 1: 1 H NMR (400 MHz, CDCl3) δ = 7.63 (d, J = 7.6 Hz, 2H), 7.53 (d, J = 7.7 Hz, 2H), 7.48 - 7.41 (m, 3H), 7.25 (d, J = 7.8 Hz (2H), 2.36 (s, 3H). 13 C NMR (100 MHz, CDCl3) δ = 145.81, 142.48, 141.66, 130.88, 130.04,129.26, 125.01, 124.71, 21.39 (-CH3) (ppm).

[0054] NMR data of the product from Experiment Example 2: 1 H NMR (400 MHz, CDCl3) δ = 7.63 (d, J = 5.4 Hz, 2H), 7.60 (d, J = 7.8 Hz, 2H), 7.52 (d, J = 7.6 Hz, 2H), 7.47 (m, J = 2.2 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ = 144.17, 143.80, 131.52, 130.37, 128.48,125.23, 124.55, 123.72 (ppm).

[0055] NMR data of the product from Experiment Example 3: 1 H NMR (400 MHz, CDCl3) δ = 8.31 (s, 1H), 7.94 (d, J = 4.6 Hz, 1H), 7.85 (t, J = 8.5 Hz, 2H), 7.69 (d, J = 6.9 Hz, 2H), 7.58 - 7.55(m, 2H), 7.50 (d, J = 8.5 Hz, 1H), 7.44 (d, J= 6.0 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ = 145.41, 142.55, 134.40, 132.81, 131.14,129.73, 129.37, 128.66, 128.04, 127.92, 127.31, 125.35, 125.02, 120.70 (ppm).

[0056] NMR data of the product from Experiment Example 4: 1 H NMR (400 MHz, CDCl3) δ = 7.62 (d, J = 7.6 Hz,2H), 7.56 - 7.48 (m, 3H), 2.78 (t, J = 7.6 Hz, 2H), 1.80 - 1.72 (m, 1H), 1.41- 1.31 (m, 5H), 0.88 (t, J = 6.9 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ = 144.13, 130.89, 129.18, 124.04, 57.38, 30.80, 22.25, 21.88, 13.78 (ppm).

[0057] NMR data of product from Experiment Example 5: 1 H NMR (400 MHz, CDCl3) δ = 7.58 (t, J = 5.8 Hz, 3H), 7.54 (d, J = 3.5 Hz, 1H), 7.32 (d, J = 7.8 Hz, 2H), 7.06 (t, J = 3.9 Hz, 1H), 2.41 (s, 3H). 13 C NMR (100 MHz, CDCl3) δ = 147.45, 141.00, 131.06, 130.04, 128.92,126.22, 123.42, 20.43 (-CH3) (ppm).

[0058] Example 5 Catalyst Cyclic Testing The catalyst recycling activity was tested using Experimental Example 1 in Example 4. After the initial reaction was completed, the catalyst was recycled and steps 1-3 were repeated to test the product yield of the secondary reaction. Then the catalyst was recycled again and the product yield of 0-7 recycling cycles was tested. The test results are shown in Table 3.

[0059]

[0060] Table 3 Results of Cyclic Tests

[0061] It can be seen that the acridine carboxylic acid anthraquinone ester photocatalyst of the present invention can be separated, purified and recycled, with up to seven cycles, and still achieves an acceptable yield.

[0062] The embodiments described above are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they are not intended to limit the present invention. It should be noted that various changes and modifications can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dual-band acridine carboxylic acid anthraquinone methyl ester photocatalyst, characterized in that, The structure is as follows: 。 2. The preparation method of the dual-band acridine carboxylic acid anthraquinone methyl ester photocatalyst according to claim 1, characterized in that, Includes the following steps: S1. Under a nitrogen atmosphere, 9-chloromethylanthracene, 9-carboxylic acid acridine, homogeneous catalyst, base and organic solvent are added to the reactor; S2. Heat and stir, and monitor the reaction by TLC thin-layer chromatography; S3. After the reaction is complete, the solvent is removed, and the target acridine carboxylic acid anthraquinone ester photocatalyst is obtained by column chromatography.

3. The preparation method of the dual-band acrylonitrile carboxylic acid anthraquinone photocatalyst according to claim 2, characterized in that, The equivalent ratio of 9-chloromethylanthracene, 9-carboxylic acid acridine, homogeneous catalyst, and base in S1 is (1-2):1:(0.2-2):(2-4).

4. The preparation method of the dual-band acrylonitrile carboxylic acid anthraquinone photocatalyst according to claim 2, characterized in that, The homogeneous catalyst in S1 is tetrabutylammonium bromide, the base is cesium carbonate, and the organic solvent is N,N-dimethylformamide.

5. The preparation method of the dual-band acridine carboxylic acid anthraquinone methyl ester photocatalyst according to claim 2, characterized in that, The reaction temperature in S2, with heating and stirring, is 55-90℃.

6. The application of the dual-band acridine carboxylic acid anthraquinone ester photocatalyst of claim 1 in the photocatalytic preparation of structurally asymmetric sulfoxide compounds from disulfide compounds and aryl peroxide compounds.

7. The application according to claim 6, characterized in that, The method for catalytically preparing structurally asymmetric sulfoxide compounds includes the following steps: adding disulfide compounds, arylformyl peroxide compounds, acridine carboxylic acid anthraquinone ester photocatalyst, base and organic solvent into a reaction vessel, placing it under light sources with wavelengths of 365 nm and 405 nm respectively, stirring the reaction under an oxygen atmosphere at room temperature, monitoring the reaction by TLC thin-layer chromatography, removing the solvent after the reaction is complete, and obtaining the product by column chromatography.

8. The application according to claim 7, characterized in that, The disulfide compound is , where R 1 Selected from 4-CH3C6H4, 4-BrC6H4, 2-Napthyl, n-C5H 11 Any one of them.

9. The application according to claim 7, characterized in that, The peroxide aryl formyl compound is , where R 2 Choose from either C6H5 or 2-Thienyl.

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