A method for photo-driven solid-state nitroarene spontaneous hydrogen transfer amination

Abstract

The application discloses a kind of light-driven solid nitroaromatics spontaneous hydrogen transfer amination method, it is related to organic synthesis technical field, comprising the following steps: step one: weighing solid p-nitroanisole, according to certain amount of proportion, 4,4'-dipyridyl and B2 (OH) 4 are sequentially added to corresponding amount of p-nitroanisole.The application is combined by using the method of photocatalysis and solid phase catalysis method, photocatalysis and solid phase catalysis method are combined, the best reaction duration, the best illumination condition that can convert nitro group into amino group are screened out to p-nitroanisole as substrate, and the best reaction ratio of p-nitroanisole and B2 (OH) 4 and 4,4'-dipyridyl, i.e.the scheme does not need combustible hydrogen, high pressure equipment or metal catalyst, and also does not need the participation of solid state catalytic reaction of organic solvent, using light source catalysis, nitroaromatics containing sensitive groups such as N heterocycle, halogen, aldehyde group, alkynyl, conjugated group can obtain product with higher yield.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and in particular to a light-driven spontaneous hydrogen transfer amination method for solid nitroaromatic hydrocarbons. Background Technology

[0002] In solid-state synthesis, reactant molecules are in a confined state with relatively stable molecular conformations, which greatly limits their ability to participate in reactions in the solid state. Based on topological chemistry theory, solid-state synthesis reactions can generally be divided into four stages: First, crystal defects, deformation, and molecular loosening occur within one or several nucleus points. Second, old chemical bonds break and new bonds are formed under given conditions. Third, a small number of products rapidly form a solid / solution within the original crystal. Fourth, product crystallization and separation occur. The rate-limiting step in solid-state reactions is the diffusion of atoms or ions through the crystalline phases of reactants, intermediates, and products. This process is slow, requiring days or even weeks, and often necessitates high-temperature treatment and consumes a large amount of energy. Solar-driven photoactivation synergistic solid-state self-assembly catalysis provides a promising technical path for achieving spontaneous, efficient, and highly selective solid-state synthesis under mild reaction conditions. This method can serve as a potential alternative to traditional thermocatalysis, helping to construct low-energy chemical production processes. Research on photothermal effects has covered multiple fields, including energy utilization, biomedical applications, catalytic conversion, and the development of intelligent devices. Against the backdrop of the current global energy crisis, energy consumption has become a core bottleneck restricting the development of modern chemical industry. Solar-driven organic synthesis strategies can efficiently convert solar radiation energy into chemical energy and store it, providing an innovative solution for alleviating energy challenges and promoting sustainable chemical manufacturing. While traditional photocatalytic strategies exhibit excellent efficiency in liquid-phase organic reactions, their application in solid-state systems faces certain limitations: the penetration ability of light in solid matrices decreases, and molecular migration is restricted, significantly limiting photocatalytic efficiency. This problem is particularly pronounced under spontaneous conditions without external stimulation. Photoactivation technology remains primarily limited to liquid-phase reaction systems and typically requires additional stirring to achieve optimal catalytic performance. Despite these challenges, solid-state photocatalysis holds immense potential in advancing sustainable energy and environmental technologies and is a promising core tool in green chemistry applications. Therefore, developing visible-light-responsive photocatalytic materials has become a core research objective in this field, ultimately aiming to achieve spontaneous solar-driven solid-state synthesis. Solar-driven photoactivation synergistic with solid-state self-assembly catalysis holds promise for opening up new pathways for spontaneous, efficient, and highly selective solid-state synthesis under mild conditions. Furthermore, driving organic synthesis with the solar photoeffect holds the potential to replace traditional thermocatalytic technologies, enabling low-energy chemical production. Therefore, it is necessary to design a photo-driven spontaneous hydrogen transfer amination method for solid-state nitroaromatics to address the aforementioned issues. Summary of the Invention

[0003] The purpose of this invention is to provide a light-driven spontaneous hydrogen transfer amination method for solid nitroaromatic hydrocarbons, thereby solving the problem of designing a novel solar energy-driven method mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a light-driven spontaneous hydrogen transfer amination method for solid-state nitroaromatic hydrocarbons, comprising the following steps: Step 1: Weigh out solid p-nitroanisole and add corresponding amounts of 4,4'-bipyridine and B2(OH)4 in a specific molar ratio. Stir to ensure the mixture is fully homogeneous. The reaction equation is shown below: ; Step 2: Place the reaction system after mixing in Step 1 under the predetermined light conditions and carry out the visible light reaction at room temperature for the predetermined reaction time. During the reaction, keep the environment stable and avoid external interference. Step 3: After the reaction in Step 2 is completed, transfer a small amount of the reaction mixture into a centrifuge tube, add an appropriate amount of solvent to completely dissolve the sample, and monitor the reaction progress using thin-layer chromatography to observe the product formation. Step 4: Monitor the reaction progress by HPLC. After 8 hours, the reaction yield is >99%. Use column chromatography to separate and purify the reaction product. Dissolve the separated yellow solid product and test it to verify the correctness of the structure of the obtained product.

[0005] Furthermore, the dosage of p-nitroanisole solid in step one is 0.1 mmol.

[0006] Furthermore, the light intensities under the illumination conditions in step two are 15 W, 40 W, 60 W, and 100 W, respectively.

[0007] Furthermore, the light-protected temperature under room temperature conditions in step two is 40°C. o C. Protect from light, 60 o C. Protect from light, 80 o C. Avoid light.

[0008] Furthermore, the solvent in step three is ethyl acetate.

[0009] Furthermore, the organic solvent used to dissolve the yellow solid product in step four is deuterated chloroform.

[0010] Furthermore, the device used to detect the dissolved product in step four is an NMR spectrometer.

[0011] Compared with the prior art, the beneficial effects of this invention are as follows: This light-driven solid-state spontaneous hydrogen transfer amination method for nitroaromatics: By combining photocatalysis and solid-phase catalysis, the promoting effect of B2(OH)4 and 4,4'-bipyridine on nitro reduction is studied. By combining photocatalysis and solid-phase catalysis, this method uses p-nitroanisole as a substrate to screen out the optimal reaction time, optimal light conditions, and optimal reaction ratio of p-nitroanisole, B2(OH)4, and 4,4'-bipyridine to convert nitro to amino groups. That is, this scheme does not require combustible hydrogen, high-pressure equipment, or metal catalysts, nor does it require the participation of organic solvents in solid-state catalysis. Using light source catalysis, nitroaromatics containing sensitive groups such as N-heterocyclic compounds, halogens, aldehydes, alkynes, and conjugated groups can be obtained in high yields. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating the effect of different reaction times on the reaction yield of the present invention; Figure 2 This is a schematic diagram illustrating the effect of different mixing ratios of bipyridine and diboronic acid on the reaction according to the present invention. Figure 3 This is a schematic diagram illustrating the yield study under different light intensities according to the present invention; Figure 4 This is a schematic diagram illustrating the influence of thermodynamic driving on the reaction under dark reaction conditions according to the present invention. Figure 5 This is a schematic diagram illustrating the screening study of bipyridine reaction yields at different ratios according to the present invention. Figure 6 This is a schematic diagram of the NMR results for Embodiment Six of the present invention; Figure 7 This is a schematic diagram of the NMR results for Embodiment Seven of the present invention. Figure 1 ; Figure 8 This is a schematic diagram of the NMR results for Embodiment Seven of the present invention. Figure 2 ; Figure 9 This is a schematic diagram of the NMR results for Embodiment 8 of the present invention. Figure 1 ; Figure 10 This is a schematic diagram of the NMR results for Embodiment 8 of the present invention. Figure 2 ; Figure 11 This is a schematic diagram of the NMR results for Embodiment Nine of the present invention. Figure 1 ; Figure 12 This is a schematic diagram of the NMR results for Embodiment Nine of the present invention. Figure 2 ; Figure 13 This is a schematic diagram of the NMR results for Embodiment 10 of the present invention. Figure 1 ; Figure 14 This is a schematic diagram of the NMR results for Embodiment 10 of the present invention. Figure 2 ; Figure 15 This is a schematic diagram of the NMR results for Example 11 of the present invention. Figure 1 ; Figure 16 This is a schematic diagram of the NMR results for Example 11 of the present invention. Figure 2 ; Figure 17 This is a schematic diagram of the NMR results for Embodiment Twelve of the present invention. Figure 1 ; Figure 18 This is a schematic diagram of the NMR results for Embodiment Twelve of the present invention. Figure 2 . Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] This invention provides the following technical solution: a light-driven spontaneous hydrogen transfer amination method for solid-state nitroaromatic hydrocarbons, comprising the following steps: Step 1: Weigh out solid p-nitroanisole and add corresponding amounts of 4,4'-bipyridine and B2(OH)4 in a specific molar ratio. Stir to ensure the mixture is fully homogeneous. The reaction equation is shown below: ; Step 2: Place the reaction system after mixing in Step 1 under the predetermined light conditions and carry out the light reaction at room temperature for the predetermined reaction time. During the reaction, keep the environment stable and avoid external interference. Step 3: After the reaction in Step 2 is completed, transfer a small amount of the reaction mixture into a centrifuge tube, add an appropriate amount of solvent to completely dissolve the sample, and monitor the reaction progress using thin-layer chromatography to observe the product formation. Step 4: During the HPLC monitoring of the reaction process in Step 3, the reaction yield was >99% after 8 hours. The reaction product was separated and purified by column chromatography. The separated yellow solid product was dissolved and tested to verify the correctness of the structure of the obtained product. Specifically, the ratios of some reaction conditions are shown in the table below. The temperature was kept constant. The optimal reaction conditions were: 0.1 mmol of p-nitroanisole, 0.1 mmol of 4,4'-bipyridine, and 1.8 mmol of B2(OH)4, with a reaction time of 8 h and complete consumption of the starting materials.

[0015] Specifically, the reaction time was screened under optimal ratio conditions, and the raw materials were completely consumed after 8 hours. Figure 1 As shown: Specifically, by varying the amount of B2(OH)4 added to change the ratio of 4,4'-bipyridine to B2(OH)4, the optimal ratio was found to be 0.056, at which point the yield reached 99%. Therefore, it is speculated that this ratio affects the reaction yield. Figure 2 As shown: The dosage of p-nitrobenzene ether solid in step one is 0.1 mmol; The light intensities under the illumination conditions in step two are 15W, 40W, 60W, and 100W, respectively; Specifically, different light intensities were screened, with selections made under illumination conditions of 15W, 40W, 60W, and 100W. The yields were found to be 84%, 87%, 94%, and 99% under these conditions, respectively. Therefore, 100W illumination was chosen as the final light source. Figure 3 As shown: In step two, the light-protected temperatures under room temperature conditions are 40°C. o C. Protect from light, 60 o C. Protect from light, 80 o C. Protect from light; Specifically, the reaction yields at different temperatures were screened, under conditions of room temperature and in the dark, at 40°C. o C. Protect from light, 60 o C. Protect from light, 80 o C, when kept away from light, yields were 5%, 87%, 92%, 55%, and 56%, respectively. Figure 4 As shown: The solvent in step three is ethyl acetate; Specifically, ethyl acetate is a moderately polar solvent that can effectively dissolve nitroaromatics, bipyridine and possible products without interfering with subsequent thin-layer chromatography analysis. At the same time, ethyl acetate is inexpensive and volatile, which facilitates the separation and purification of subsequent products. Furthermore, the polarity of ethyl acetate is suitable for separating nitroaromatic derivatives, avoiding side reactions between the solvent and the products or raw materials. The organic solvent used to dissolve the yellow solid product in step four is deuterated chloroform; Specifically, deuterated chloroform is a standard solvent for nuclear magnetic resonance (NMR) testing. Its deuterium atoms can provide a field-locking signal, ensuring the stability of the spectrum. Chloroform has a wide solubility, especially suitable for non-polar or moderately polar organic compounds. It can clearly display the characteristic peaks of the product and verify the structure of hydrogen transfer amination products. At the same time, the deuterated solvent has high chemical inertness, avoiding reaction with the product or causing signal overlap. The equipment used to detect the dissolved products in step four is an NMR spectrometer; Specifically, it can clarify the molecular structure and purity by analyzing the chemical shifts, coupling constants and integral ratios of hydrogen, carbon and other nuclei. At the same time, NMR can distinguish isomers or byproducts, ensuring the chemical selectivity of the amination reaction.

[0016] Example 1: A light-driven spontaneous hydrogen transfer amination method for solid-state nitroaromatic hydrocarbons, comprising the following steps: Step 1: Weigh 0.1 mmol of p-nitrobenzene ether solid, add 0.1 mmol of 4,4'-bipyridine and 1.8 mmol of B2(OH)4 in sequence, and stir to make the mixture fully homogeneous; Step 2: Place the reaction system after mixing in Step 1 under 100W light at room temperature and carry out the reaction for the predetermined time. During the reaction, keep the environment stable and avoid external interference. Step 3: After the reaction in Step 2 is completed, transfer a small amount of the reaction mixture into a centrifuge tube, add an appropriate amount of ethyl acetate solvent to completely dissolve the sample, and monitor the reaction progress using thin-layer chromatography to observe the product formation. Step 4: During the HPLC monitoring of the reaction process in Step 3, the reaction yield was >99% after 8 hours. The reaction product was separated and purified by column chromatography. The separated yellow solid product was dissolved in deuterated chloroform and detected by NMR spectroscopy to verify the correctness of the structure of the obtained product. The structural formula of compound 2a is as follows: (2a) The obtained product was analyzed, and the analytical data are as follows: Yellow solid, >99% yield. 1 HNMR (500MHz, CDCl3) δ6.75 (d, 2H), δ6.65 (d, 2H), 3.75 (s, 3H), 3.43 (s, 2H). 13 CNMR (126MHz, CDCl3) δ153.04, 139.94, 116.64, 114.98, 55.90.

[0017] Example 2: A light-driven spontaneous hydrogen transfer amination method for solid-state nitroaromatic hydrocarbons, comprising the following steps: Step 1: Weigh 0.1 mmol of 8-nitroquinoline, add 0.1 mmol of 4,4'-bipyridine and 1.8 mmol of B2(OH)4 in sequence, and stir to make the mixture fully homogeneous; Step 2: Place the reaction system after mixing in Step 1 under 100W light at room temperature and carry out the reaction for the predetermined time. During the reaction, keep the environment stable and avoid external interference. Step 3: After the reaction in Step 2 is completed, transfer a small amount of the reaction mixture into a centrifuge tube, add an appropriate amount of ethyl acetate solvent to completely dissolve the sample, and monitor the reaction progress using thin-layer chromatography to observe the product formation. Step 4: During the HPLC monitoring of the reaction process in Step 3, the reaction yield was >99% after 4 hours. The target compound was then obtained by recrystallization or column chromatography purification to yield the black solid product 2b. The structural formula of compound 2b is as follows: (2b) The obtained product was analyzed, and the analysis data are as follows: Yellow solid, >99% yield. 1 HNMR (500MHz, CDCl3) δ 8.77 (dd, 1H), 8.06 (dd, 1H), 7.40–7.28 (m, 2H), 7.22–7.07 (d, 1H), 6.93 (d, 1H), 5.02 (s, 2H). 13 CNMR (126MHz, CDCl3) δ147.59, 144.10, 138.56, 136.20, 129.03, 127.56, 121.51, 116.22, 110.25.

[0018] Example 3: A light-driven spontaneous hydrogen transfer amination method for solid-state nitroaromatic hydrocarbons, comprising the following steps: Step 1: Weigh 0.1 mmol of 4-nitrobenzenethiophenol, add 0.1 mmol of 4,4'-bipyridine and 1.8 mmol of B2(OH)4 in sequence, and stir to make the mixture fully homogeneous; Step 2: Place the reaction system after mixing in Step 1 under 100W light at room temperature and carry out the reaction for the predetermined time. During the reaction, keep the environment stable and avoid external interference. Step 3: After the reaction in Step 2 is completed, transfer a small amount of the reaction mixture into a centrifuge tube, add an appropriate amount of ethyl acetate solvent to completely dissolve the sample, and monitor the reaction progress using thin-layer chromatography to observe the product formation. Step 4: During the HPLC monitoring of the reaction process in Step 3, the reaction yield was >99% after 4 hours. The target compound was then obtained by recrystallization or column chromatography purification, yielding the green solid product 2c. The structural formula of compound 2c is as follows: (2c) The obtained product was analyzed, and the analytical data are as follows: Yellow solid, >99% yield. 1 HNMR (500MHz, DMSO) δ7.05 (d, 2H), 6.49 (d, 2H), 5.48 (s, 2H), δ7.05 (s, 1H). 13 CNMR (126MHz, DMSO) δ150.01, 134.35, 120.75, 114.17 Example 4: A light-driven spontaneous hydrogen transfer amination method for solid-state nitroaromatic hydrocarbons, comprising the following steps: Step 1: Weigh 0.1 mmol of 4-trifluoromethylnitrobenzene, add 0.1 mmol of 4,4'-bipyridine and 1.8 mmol of B2(OH)4 in sequence, and stir to make the mixture fully homogeneous; Step 2: Place the reaction system after mixing in Step 1 under 100W light at room temperature and carry out the reaction for the predetermined time. During the reaction, keep the environment stable and avoid external interference. Step 3: After the reaction in Step 2 is completed, transfer a small amount of the reaction mixture into a centrifuge tube, add an appropriate amount of ethyl acetate solvent to completely dissolve the sample, and monitor the reaction progress using thin-layer chromatography to observe the product formation. Step 4: During the HPLC monitoring of the reaction process in Step 3, the reaction yield was >99% after 4 hours. The target compound was then obtained by recrystallization or column chromatography purification, resulting in a beige liquid. The structural formula of compound 2d is as follows: (2d) The obtained product was analyzed, and the analysis data are as follows: Yellow liquid, >99% yield. 1 HNMR (500MHz, CDCl3) δ7.39 (d, J=8.3Hz, 2H), 6.69 (d, J=8.3Hz, 2H), 3.94 (s, 2H). 13 CNMR(126MHz, CDCl3) δ149.51, 126.88(q), 126.04, 123.9, 120.3(d), 114.32; Example 5: A light-driven spontaneous hydrogen transfer amination method for solid-state nitroaromatic hydrocarbons, comprising the following steps: Step 1: Weigh 0.1 mmol of 2-nitrophenylacetylene, add 0.1 mmol of 4,4'-bipyridine and 1.8 mmol of B2(OH)4 in sequence, and stir to make the mixture fully homogeneous; Step 2: Place the reaction system after mixing in Step 1 under 100W light at room temperature and carry out the reaction for the predetermined time. During the reaction, keep the environment stable and avoid external interference. Step 3: After the reaction in Step 2 is completed, transfer a small amount of the reaction mixture into a centrifuge tube, add an appropriate amount of ethyl acetate solvent to completely dissolve the sample, and monitor the reaction progress using thin-layer chromatography to observe the product formation. Step 4: During the HPLC monitoring of the reaction process in Step 3, the reaction yield was >88% after 4 hours. The target compound was then obtained by recrystallization or column chromatography purification, yielding a beige liquid 2e. The structural formula of compound 2e is as follows: (2e) The obtained product was analyzed, and the analysis data are as follows: Yellow liquid, >99% yield. 1 HNMR (400MHz, CDCl3) δ7.36 (dd, J=8.0, 1.7Hz, 1H), 7.24–7.06 (m, 1H), 6.70 (t, J=7.1Hz, 2H), 4.28 (s, 2H), 3.42 (s, 1H). 13 CNMR (101MHz, CDCl3) δ148.58, 132.61, 130.17, 117.78, 114.36, 106.54, 82.61, 80.68; In summary, a novel solar-driven method was designed for the spontaneous hydrogen transfer amination reaction of solid nitro aromatic hydrocarbons. This transformation can achieve the efficient and highly selective synthesis of aromatic amines under ambient temperature conditions, requiring only continuous light irradiation, and has a wide range of applicable substrates. Example 6: This example, based on Example 1, attempts to reduce the ratio of 4,4'-bipyridine to B2(OH)4 by adding water. Using 0.1 mmol of nitrobenzyl ether as the substrate, a certain amount of 4,4'-bipyridine, B2(OH)4, and H2O are added for condition screening. The reaction is still carried out under 100W illumination, and the conditions are further screened. Some of the screened conditions are as follows: Figure 5As shown, and it was finally determined that the reaction yield reached 99% with the addition of 10% 4,4'-bipyridine, 5 eq B2(OH)4, and 10 eq H2O, and the starting materials were completely consumed. The reaction formula is shown below:

[0019] In this reaction, water did not participate but acted as a dispersant to make the reaction more uniform. Based on this, excess deuterated water was added to verify the hydrogen source. The NMR results are as follows. Figure 6 As shown, it is speculated that the hydrogen source comes from B2(OH)4. After adding 10 eq of water, the ratio of 4,4'-bipyridine to B2(OH)4 decreased to 0.02. Therefore, it is speculated that bipyridine acts as a catalyst. The participation of water makes the distribution of 4,4'-bipyridine more uniform. The reaction was investigated under optimal conditions by light and dark protection, that is, the raw materials were completely consumed under 100W light. Example 7: This example is based on Example 6, but with a substitution of the nitro compound. The structure and data analysis of this compound are shown below, and the NMR results are as follows. Figure 7 and Figure 8 As shown:

[0020] The obtained product was analyzed, and the analytical data were: brown solid, >99% yield. 1 HNMR (500MHz, CDCl3) δ 8.77 (dd, 1H), 8.06 (dd, 1H), 7.40–7.28 (m, 2H), 7.22–7.07 (d, 1H), 6.93 (d, 1H), 5.02 (s, 2H). 13 CNMR (126MHz, CDCl3) δ147.59, 144.10, 138.56, 136.20, 129.03, 127.56, 121.51, 116.22, 110.25; Example 8: This example is based on Example 6, but with a substitution of the nitro compound. The structure and data analysis of this compound are shown below, and the NMR results are as follows. Figure 9 and Figure 10 As shown:

[0021] The obtained product was analyzed, and the analytical data were: brown solid, >99% yield. 1 HNMR (500MHz, DMSO) δ7.05 (d, 2H), 6.49 (d, 2H), 5.48 (s, 2H), δ7.05 (s, 1H). 13CNMR (126MHz, DMSO) δ150.01, 134.35, 120.75, 114.17; Example 9: This example is based on Example 6, but with a substitution of the nitro compound. The structure and data analysis of this compound are shown below, and the NMR results are as follows. Figure 11 and Figure 12 As shown:

[0022] The obtained product was analyzed, and the analytical data were: yellow liquid, >99% yield. 1 HNMR (500MHz, CDCl3) δ7.39 (d, J=8.3Hz, 2H), 6.69 (d, J=8.3Hz, 2H), 3.94 (s, 2H) .13CNMR (126MHz, CDCl3) δ149.51, 126.88 (q), 126.04, 123.9, 120.3 (d), 114.32; Example 10: This example is based on Example 6, but with a substitution of the nitro compound. The structure and data analysis of this compound are shown below, and the NMR results are as follows. Figure 13 and Figure 14 As shown:

[0023] The obtained product was analyzed, and the analytical data are as follows: yellow liquid, >99% yield. 1H NMR (400MHz, CDCl3) δ 7.36 (dd, J=8.0, 1.7Hz, 1H), 7.24–7.06 (m, 1H), 6.70 (t, J=7.1Hz, 2H), 4.28 (s, 2H), 3.42 (s, 1H). 13 CNMR (101MHz, CDCl3) δ148.58, 132.61, 130.17, 117.78, 114.36, 106.54, 82.61, 80.68; Example 11: This example is based on Example 6, but with a substitution of the nitro compound. The structure and data analysis of this compound are shown below, and the NMR results are as follows. Figure 15 and Figure 16 As shown:

[0024] The obtained product was analyzed, and the analytical data were as follows: white solid, 44% yield. 1HNMR (400MHz, CDCl3) δ7.32–7.26 (m, 2H), 7.02 (m, 1H), 6.96–6.92 (m, 2H), 6.90–6.86 (m, 2H), 6.71–6.67 (m, 2 H), 3.57 (s, 2H).13CNMR (101MHz, CDCl3) δ159.34, 149.02, 143.11, 129.98, 122.50, 121.61, 117.64, 116.71; Example 12: This example is based on Example 6, but with a substitution of the nitro compound. The structure and data analysis of this compound are shown below, and the NMR results are as follows. Figure 17 and Figure 18 As shown:

[0025] The obtained product was analyzed, and the analytical data were: white solid, 60% yield. 1 HNMR (500MHz, CDCl3) δ7.79 - 7.73 (m, 2H), 7.58–7.45 (m, 2H), 7.40 - 7.30 (m, 2H), 6.80 (d, 1H), 4.15 (s, 2H). 13 CNMR (126MHz, CDCl3) δ142.17, 134.49, 128.64, 126.44, 125.94, 124.95, 123.76, 120.90, 119.06, 109.79.

[0026] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0027] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A light-driven spontaneous hydrogen transfer amination method for solid-state nitroaromatic hydrocarbons, characterized in that, Includes the following steps: Step 1: Weigh out solid p-nitroanisole and add corresponding amounts of 4,4'-bipyridine and B2(OH)4 in a specific molar ratio. Stir to ensure the mixture is fully homogeneous. The reaction equation is shown below: ； Step 2: Place the reaction system after mixing in Step 1 under the predetermined light conditions and carry out the visible light reaction at room temperature for the predetermined reaction time. During the reaction, keep the environment stable and avoid external interference. Step 3: After the reaction in Step 2 is completed, transfer a small amount of the reaction mixture into a centrifuge tube, add an appropriate amount of solvent to completely dissolve the sample, and monitor the reaction progress using thin-layer chromatography to observe the product formation. Step 4: During the HPLC monitoring of the reaction process in Step 3, the reaction yield was >99% after 8 hours. The reaction product was separated and purified by column chromatography. The separated yellow solid product was dissolved and tested to verify the correctness of the structure of the obtained product.

2. The method for spontaneous hydrogen transfer amination of solid-state nitroaromatic hydrocarbons driven by light according to claim 1, characterized in that: The dosage of p-nitroanisole solid in step one is 0.1 mmol.

3. The method for spontaneous hydrogen transfer amination of solid-state nitroaromatic hydrocarbons driven by light according to claim 1, characterized in that: The light intensities under the illumination conditions in step two are 15 W, 40 W, 60 W, and 100 W, respectively.

4. The method for spontaneous hydrogen transfer amination of solid-state nitroaromatic hydrocarbons driven by light according to claim 1, characterized in that: In step two, the light-protected temperatures under room temperature conditions are 40°C, 60°C, and 80°C.

5. The method for spontaneous hydrogen transfer amination of solid-state nitroaromatic hydrocarbons driven by light according to claim 1, characterized in that: The solvent in step three is ethyl acetate.

6. The method for spontaneous hydrogen transfer amination of solid-state nitroaromatic hydrocarbons driven by light according to claim 1, characterized in that: The organic solvent used to dissolve the yellow solid product in step four is deuterated chloroform.

7. The method for spontaneous hydrogen transfer amination of solid-state nitroaromatic hydrocarbons driven by light according to claim 1, characterized in that: The device used to detect the dissolved product in step four is an NMR spectrometer.

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