阅读说明：本技术 一种绿色的可见光催化的乙酸酯化合物的制备方法 (Preparation method of green visible light catalyzed acetate compound ) 是由 万小兵 廉鹏程 李如一 万潇 项紫欣 刘航 曹志宇 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种绿色的可见光催化的乙酸酯化合物的制备方法,该方法中以LED灯作为光源提供能量,经济易得的一、二、三级醇作为反应底物,三氟甲磺酸铈为催化剂,市场可购买的2,3-丁二酮为原料。与现有技术相比较,本发明方法具有以下优点：1)采用绿色、温和、高效、节能、环境友好的可见光催化的反应模式；2)反应体系简单且底物范围广,一、二、三级醇均适用于该方法；3)无需添加脱水剂；4)反应产率较高；5)操作比较简单；6)原料廉价易得；7)反应可以实现克级规模及药物分子的后期修饰。(The invention discloses a preparation method of a green visible light catalyzed acetate compound, wherein an LED lamp is used as a light source to provide energy, economic and easily obtained primary, secondary and tertiary alcohols are used as reaction substrates, cerium trifluoromethanesulfonate is used as a catalyst, and commercially available 2, 3-butanedione is used as a raw material. Compared with the prior art, the method has the following advantages: 1) a green, mild, efficient, energy-saving and environment-friendly visible light catalytic reaction mode is adopted; 2) the reaction system is simple and the substrate range is wide, and the primary alcohol, the secondary alcohol and the tertiary alcohol are all suitable for the method; 3) no dehydrating agent is added; 4) the reaction yield is high; 5) the operation is simple; 6) the raw materials are cheap and easy to obtain; 7) the reaction can realize gram-scale and later modification of drug molecules.)

1. A preparation method of a green visible light catalyzed acetate compound is characterized in that under the catalysis of metal salt and under the irradiation of visible light, alcohol and ketone are used as raw materials to react to prepare the acetate compound.

2. The method of claim 1, wherein the ketone is 2, 3-butanedione, 1-phenylpropane-1, 2-dione, 2, 3-pentanedione, 2, 3-hexanedione, acetone; the chemical structural formula of the alcohol is as follows:

in the formula, R₁Selected from acyl alcohol group, phenylsulfonyl alkyl group, substituted or unsubstituted aralkyl group, wherein the substituent is methyl, tert-butyl, methoxy, nitro, cyano, ester group, phenyl, alkynyl, fluorine, chlorine, bromine, iodine, trifluoromethyl, trifluoromethoxy, acetoxy, acyl group, etc.; r₂Selected from hydrogen or alkyl; r₃Selected from hydrogen or alkyl.

3. The method of claim 1, wherein the reaction is performed in a solvent selected from the group consisting of petroleum ether, 1, 2-dichloroethane, 1,1, 1-trichloroethane, 1,1, 2-trichloroethane, nitromethane, acetonitrile, ethyl acetate, acetone, and ethanol.

4. The method of claim 1, wherein the visible light is LED light.

5. The method for producing a green visible light-catalyzed acetate compound according to claim 1, wherein the reaction time is 12 to 40 hours.

6. The method of claim 1, wherein the metal salt is selected from the group consisting of cerium trichloride, manganese chloride, copper triflate, cerium triflate, copper chloride, and iron sulfate.

7. The method of claim 1, wherein the molar ratio of the alcohol to the ketone to the metal salt is 1: 3 to 5: 0.01 to 0.1.

8. The process according to claim 1, wherein the reaction is carried out in air or oxygen.

9. The acetate compound produced by the process according to claim 1 for producing a green visible light-catalyzed acetate compound.

10. Under the catalysis of metal salt and under the irradiation of visible light, alcohol and ketone are used as raw materials in preparing acetate compound.

Technical Field

The invention relates to a preparation method of an acetate compound catalyzed by green visible light, belonging to the technical field of organic synthesis.

Background

Lipid compounds are important structural skeletons and generally exist in the fields of medicines, agricultural chemicals, polymers, functional organic materials, natural products and the like. According to statistics, the application of ester compounds in drug synthesis accounts for 25%. Many drug molecules contain an acetate backbone, such as Diltiazem (Diltiazem): a calcium ion antagonist is used for treating hypertension and coronary heart disease angina pectoris; nitazoxanide (Nitazoxanide): has antiprotozoal, intestinal parasite resisting, antibacterial, and antiviral effects. Therefore, the synthesis of acetate compounds is particularly important. Through literature investigation, the existing methods for synthesizing acetate compounds have some defects, such as harsh reaction conditions, low yield, narrow substrate range (most substrates are limited to primary and secondary alcohols), high reaction temperature, use of expensive metal catalysts, excessive acid-base additives, single reaction mode (most thermal reactions), and the like. For example:

(1) in 1999, Oriyama subject group was at-78 deg.C toN,N,N',N'Preparing ester compound from benzoyl chloride and alcohol by using Tetramethylethylenediamine (TMEDA) as base and dichloromethane as solvent. The process substrates are limited to primary and secondary alcohols, tertiary alcohols are completely unreactive, and the process is very moisture sensitive and requires the addition of excess molecular sieve to remove water. (see: Sano, T.; Ohashi, K.; Oriyama, T. Remarkably Fast Acylation of alcohol with Benzoyl Chloride purified by TMEDA).Synthesis1999, 1999, 07, 1141-1144.）；

(2) In 2005, the Sakakura group reported that ammonium diarylsulfonate catalyzed the direct condensation of carboxylic acids and alcohols to produce ester compounds. This reaction utilizes the hydrophobic effect of the ammonium diarylsulfonate to activate the esterification reaction, so that the reaction proceeds smoothly in the direction of ester formation. However, this method requires a pre-prepared lewis acid and the reaction substrate is relatively limited. (see: Ishihara, K.; Nakagawa, S.; Sakakura, A. bulk diammonum arylenesulfonates as Selective Esterification Catalysts).ChemInform. 2005, 36, 34.）；

(3) In 2015, the Nguyen group adopted 1, 1-dichlorocycloheptatriene (Tropcl)₂) And triethylamine to reactThe acid is prepared into acyl chloride, and then the esterification reaction of alcohol is realized. The reaction needs to be carried out stepwise and an excess of organic base is used, and the tertiary alcohol reaction does not occur. (see: Nguyen, T.V. Lyons, D.J.M. A novel aromatic carbon-based coupled reagent for identification and amino reactions.Chem. Commun.2015, 51, 15, 3131-3134.）；

(4) In 1999, the Pittman group, using acetic acid as the acyl source, selectively di-esterifies diols via cyclic ketene acetal intermediates. The method has good substrate universality, but excessive organic alkali is used, and the substrate needs to be obtained from glycol pre-preparation, so the conditions are complicated. (see: Wu, Z.; Stanley, R.; Pittman, C. U., Jr., Selective characterization of Diols through Cyclic Ketene acids Intermediates.J. Org. Chem.1999, 64, 8386-8395.）；

(5) In 2007, the Adapa group successfully prepared acetate compounds with ruthenium tris (acetylacetonate) as a catalyst and acetic anhydride as an acyl source. Although the method has high yield, a relatively expensive metal catalyst is used, and the acetic anhydride is easy to hydrolyze, so that the method is not beneficial to industrial large-scale synthesis application. (see: Varala, R.; Nasreen, A.; Adapa, S. R.; Ruthenium (III); Acetylacetate [ Ru (acac))₃] — An efficient recyclable catalyst for the acetylation of phenols, alcohols, and amines under neat conditions. Can. J. Chem.2007, 85, 148-152.）；

(6) The alpha-hydroxyketone subunit exists in various natural products with biological significance, and the compound can be used for preparing cherry pit, cinnamon, rum, tobacco, coumarin and tropical fruit type essence. Among the common organic functional groups, the acetate group can serve as a useful protecting group for the hydroxyl group in the alpha-hydroxyketone. In 2007, the Huang nationality team realizes the alpha-acetyl oxidation of ketone by using acetophenone as a raw material, acetic anhydride as an acyl source and hydrogen peroxide and iodobenzene as oxidants. The process yields well, but requires the addition of excess oxidant as well as lewis acid. (see: Huang, G.; Sheng, J.; Li, X.; Tang, M.; Gao, B., An effective Met)hod for the α-Acetoxylation of Ketones. Synthesis2007, 2007, 1165-1168.）

In summary, the synthesis methods of these acetates reported at present are complicated in reaction process, use excessive alkali, harsh in reaction conditions, single in reaction mode (mostly thermal reaction), and basically limited in substrates to primary and secondary alcohols. Therefore, it is particularly important to develop a visible light catalysis method for preparing acetate, which has the advantages of abundant raw material sources, wide substrate application range, greenness, mildness, high efficiency, energy conservation and environmental friendliness.

Disclosure of Invention

The invention aims to provide a green, environment-friendly, energy-saving and efficient visible light catalysis method for synthesizing an acetate compound, wherein 'light' in photochemical reaction is a special reagent capable of participating in the reaction, and compared with the classical thermochemical reaction, the photochemical reaction has the following characteristics: (1) thermochemical reaction needs larger activation energy and can be carried out only by heating to a certain temperature; the activation energy required by photochemical reaction is very small, so that the photochemical reaction can be rapidly carried out at room temperature; (2) complex molecules often contain multiple reactive groups. In the thermochemical reaction, other groups need to be protected to react with one group; the photochemical reaction can excite a specific group to initiate the reaction; (3) in most cases, the thermochemical reaction is different from the photochemical reaction, and thus a product which cannot be synthesized by the thermochemical reaction can be synthesized by the photochemical reaction. Based on the properties of photochemical reaction, the invention has the advantages of obvious superiority, cheap and easily-obtained light source LED lamps in the reaction system, abundant raw material sources, wide universality of reaction substrates (the first, second, third and third grade alcohols are compatible with the system), mild reaction conditions, no need of any acid-base additive, economic cerium trifluoromethanesulfonate as a catalyst, cheap 2, 3-butanedione and alcohol as raw materials, and simple and convenient reaction operation.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:

a process for preparing the green acetate compound by visible light catalysis includes such steps as catalytic reaction between alcohol and ketone under the irradiation of visible light and the catalysis of metallic salt to prepare the acetate compound.

In the technical scheme, the reaction is carried out in a solvent, and the solvent is petroleum ether, 1, 2-dichloroethane, 1,1, 1-trichloroethane, 1,1, 2-trichloroethane, nitromethane, acetonitrile, ethyl acetate, acetone or ethanol.

In the above technical scheme, the chemical structural formula of the alcohol is as follows:

the ketone is 2, 3-butanedione, 1-phenylpropane-1, 2-dione, 2, 3-pentanedione, 2, 3-hexanedione, or acetone.

The chemical structural formula of the acetate compound is as follows:

in the above chemical formula, R₁Selected from acyl alcohol group, phenylsulfonyl alkyl group, substituted or unsubstituted aralkyl group, wherein the substituent is methyl, tert-butyl, methoxy, nitro, cyano, ester group, phenyl, alkynyl, fluorine, chlorine, bromine, iodine, trifluoromethyl, trifluoromethoxy, acetoxy, acyl group, etc.; r₂Selected from hydrogen or alkyl; r₃Selected from hydrogen or alkyl.

In the technical scheme, the visible light is LED light, and the LED lamp is a white lamp, a green lamp or a blue lamp; the wattage is 18-50W; in a preferred technical scheme, the LED lamp is a blue lamp; the wattage of the blue lamp was 40W.

In the present invention, the reaction time is 12 to 40 hours, and preferably 24 hours.

In the invention, the catalyst is cerium trichloride, manganese chloride, copper trifluoromethanesulfonate, cerium trifluoromethanesulfonate, copper chloride and ferric sulfate. In a preferred technical scheme, the catalyst is cerium trifluoromethanesulfonate.

In the invention, the molar ratio of the alcohol to the ketone to the metal salt is 1: 3-5: 0.01-0.1, preferably 1: 4: 0.05.

In the invention, the reaction substrates are cheap primary, secondary and tertiary alcohols and ketones, the light source is an economical and easily available LED lamp, the solvent is nitromethane, and the catalyst is cerium trifluoromethanesulfonate, so that the catalyst can be directly purchased and obtained. The reaction of the present invention is carried out in air or oxygen. After the reaction is finished, drying the mixture by using anhydrous sodium sulfate, removing the solvent by using a rotary evaporator, adsorbing the solvent by using silica gel, and carrying out simple column chromatography to obtain the acetate compound.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. the method adopts a green, mild and environment-friendly visible light catalysis mode to prepare the acetate compound. The photochemical reaction is a synthesis method with the purposes of cleanness, energy conservation and conservation, and generally does not need activation energy or only needs very small activation energy; meanwhile, the photochemical reaction can select a corresponding light source according to different absorption wavelengths of all groups in the molecule, and selectively excite a certain group to initiate the reaction; the method has the characteristics that the reaction substrate range is wide (first, second, third and third alcohols are all suitable for the method), dehydrating agents are not needed, the reaction conditions are simple, the reaction yield is high, gram-scale can be achieved, the reaction conditions are green and mild, and the late modification can be carried out on drug molecules;

2. the technology of the invention does not need to adopt expensive and pre-prepared acyl source, and the 2, 3-butanedione can directly participate in the reaction, thereby avoiding the problem of complicated operation; compared with the prior art, the method has the advantages that cerium trifluoromethanesulfonate is used as a catalyst, so that excessive acid-base additives or dehydrating agents are avoided;

3. the technology of the invention uses commercially available alcohol or artificially synthesized alkamine and bi-alcohol derivatives as reaction raw materials, and compared with the prior art, the substrate synthesis is simpler.

Detailed Description

The invention is further described below with reference to examples:

the specific preparation operation and the test method of the invention are conventional methods in the field, and the product acetate compound can be efficiently obtained in oxygen under the irradiation of visible light by only using alcohol, ketone, a metal salt catalyst and an organic solvent as reaction systems. The method adopts a green, environment-friendly, mild, efficient and energy-saving visible light catalysis strategy to synthesize the acetate compound, the light source is an economical and easily-obtained LED lamp, the reaction substrates of alcohol, 2, 3-butanedione, organic solvent and catalyst cerium trifluoromethanesulfonate are commercial products, and the acetate compound can be directly purchased and obtained. Unless otherwise specified, the following experiments were all carried out in oxygen at room temperature.

Example one

To a 25 mL Schlenk tube were added alcohol 1a (0.2 mmol, 43.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order; after stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3a was obtained by simple column chromatography with a yield of 90%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹ (400 MHz, CDCl₃) δ 7.87 – 7.82 (m, 2H), 7.75 – 7.70 (m, 2H), 4.10 (t, J = 6.3 Hz, 2H), 3.73 (t, J = 6.3 Hz, 2H), 2.04 (s, 3H), 1.77 – 1.67 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171.0, 168.3, 133.9, 132.0, 123.2, 63.7, 37.5, 26.0, 25.2, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₅NO₄+H⁺: 276.1230, Found: 276.1227. IR (neat, cm^-1): υ 2850, 1751, 1600, 1535, 1460, 1380, 1202, 1008, 719, 620.

The following results were obtained by changing the catalyst or solvent with 1a (0.2 mmol) and 2 (0.8 mmol) as substrates:

^areaction conditions are as follows: oxygen atmosphere, 1a (0.2 mmol), 2a (4.0 equiv.), Ce (OTf)₃ (5% equiv.), solvent (0.5 mL), 40W blue LEDs for 24 h.^cAir;^dnitrogen gas;^eno illumination is needed.

Example two

To a 25 mL Schlenk tube were added alcohol 1b (0.2 mmol, 38.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give the product 3b in 85% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹ (400 MHz, CDCl₃) δ 8.05 – 8.03 (m, 2H), 7.58 – 7.54 (m, 1H), 7.44 – 7.42 (m, 2H), 4.36 (t, J = 6.2 Hz, 2H), 4.14 (t, J = 6.2 Hz, 2H), 2.05 (s, 3H), 1.88 – 1.79 (m, 4H). ¹³C NMR (101 MHz, CDCl₃) δ 171.1, 166.5, 132.9, 130.2, 129.5, 128.3, 64.4, 63.9, 25.4, 25.3, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₆O₄+H⁺: 237.1121, Found: 237.1117. IR (neat, cm^-1): υ 2899, 1736, 1602, 1584, 1451, 1366, 1234, 1176, 1026, 915, 709.

EXAMPLE III

To a 25 mL Schlenk tube were added alcohol 1c (0.2 mmol, 41.6 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give the product 3c in 85% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹ (400 MHz, CDCl₃) δ 7.94 – 7.92 (m, 2H), 7.25 – 7.23 (m, 2H), 4.34 (t, J = 6.2 Hz, 2H), 4.14 (t, J = 6.2 Hz, 2H), 2.41 (s, 3H), 2.05 (s, 3H), 1.87 – 1.76 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171.1, 166.6, 143.5, 129.5, 129.0, 127.5, 64.2, 64.0, 25.4, 25.3, 21.6, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₆O₄+H⁺: 237.1121, Found: 237.1117. IR (neat, cm^-1): υ 2924, 1736, 1612, 1577, 1449, 1386, 1271, 1020, 920, 753, 690.

Example four

To a 25 mL Schlenk tube were added alcohol 1d (0.2 mmol, 64.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give 3d as a product in 76% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹ (400 MHz, CDCl₃) δ 8.00 – 7.98 (m, 1H), 7.80 – 7.78 (m, 1H), 7.43 – 7.39 (m, 1H), 7.18 – 7.13 (m, 1H), 4.37 (t, J = 6.2 Hz, 2H), 4.14 (t, J = 6.2 Hz, 2H), 2.06 (s, 3H), 1.87 – 1.78 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171.0, 166.5, 141.2, 135.2, 132.5, 130.8, 127.8, 93.9, 65.1, 63.8, 25.3, 25.2, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₅IO₄+H⁺: 363.0088, Found: 363.0082. IR (neat, cm^-1): υ 2853, 1724, 1583, 1463, 1388, 1234, 1014, 740, 606.

EXAMPLE five

To a 25 mL Schlenk tube were added alcohol 1e (0.2 mmol, 43.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give the product 3e in 85% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹ (400 MHz, CDCl₃) δ 8.15 (d, J = 8.6 Hz, 2H), 7.76 (d, J = 8.6 Hz, 2H), 4.40 (t, J = 6.3 Hz, 2H), 4.15 (t, J = 6.3 Hz, 2H), 2.06 (s, 3H), 1.90 – 1.79 (m, 2H). ¹³C NMR (100 MHz, CDCl₃) δ 171.0, 164.8, 133.9, 132.2, 130.0, 117.9, 116.3, 65.2, 63.7, 25.5, 25.2, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₅NO₄+Na⁺: 284.0893, Found: 284.0889. IR (neat, cm^-1): υ 2853, 2232, 1721, 1610, 1569, 1491, 1388, 1237, 1105, 729, 691.

EXAMPLE six

To a 25 mL Schlenk tube were added alcohol 1f (0.2 mmol, 64.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3f was obtained by simple column chromatography with a yield of 78%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹ (400 MHz, CDCl₃) δ 7.81 – 7.79 (m, 2H), 7.75 – 7.73 (m, 2H), 4.35 (t, J = 6.2 Hz, 2H), 4.14 (t, J = 6.2 Hz, 2H), 2.06 (s, 3H), 1.84 – 1.77 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171.0, 165.9, 137.6, 130.9, 129.6, 100.7, 64.6, 63.8, 25.3, 25.3, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₅IO₄+H⁺: 363.0088, Found: 363.0081. IR (neat, cm^-1): υ 2853, 1716, 1585, 1470, 1364, 1232, 1006, 920, 752, 682.

EXAMPLE seven

To a 25 mL Schlenk tube were added in this order 1g (0.2 mmol, 44.8 mg) of an alcohol, 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL). After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give 3g of product in 63% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹ (400 MHz, CDCl₃) δ 7.80 – 7.78 (m, 1H), 7.49 – 7.45 (m, 0H), 7.00 – 6.96 (m, 2H), 4.33 (t, J = 6.1 Hz, 2H), 4.14 (t, J = 6.1 Hz, 2H), 3.90 (s, 3H), 2.05 (s, 3H), 1.85 – 1.79 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171.2, 166.2, 159.1, 133.5, 131.5, 120.1, 112, 64.3, 64.1, 55.9, 25.4, 25.4, 21.0. HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₈O₅+H⁺: 267.1227, Found: 267.1222. IR (neat, cm^-1): υ 2840, 1723, 1601, 1583, 1465, 1240, 1131, 727, 647.

Example eight

To a 25 mL Schlenk tube were added alcohol 1h (0.2 mmol, 44.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. Removing solvent with rotary evaporator, adsorbing with silica gel, and performing simple column chromatography to obtain product with yield of 82% for 3 hr. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹ (400 MHz, CDCl₃) δ 7.46 – 7.38 (m, 1H), 6.98 – 6.94 (m, 2H), 4.40 (t, J = 6.1 Hz, 2H), 4.13 (t, J = 6.1 Hz, 2H), 2.06 (s, 3H), 1.85 – 1.73 (m, 7H). ¹³C NMR (100 MHz, CDCl₃) δ 171.1, 161.7 (d, J = 39.2 Hz), 159.3 (d, J = 6.2 Hz,), 132.7 (t, J = 10.5 Hz), 112.0 (dd, J = 24.3, 1.3 Hz), 65.4, 63.8, 25.2, 25.1, 20.9. ¹⁹F NMR (377 MHz, CDCl₃) δ -110.5 (s, 2F). HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₄F₂O₄+H⁺: 273.0933, Found: 273.0930. IR (neat, cm^-1): υ 2857, 1730, 1624, 1594, 1469, 1288, 1110, 768, 634.

Example nine

To a 25 mL Schlenk tube were added alcohol 1i (0.2 mmol, 56.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3i was obtained by simple column chromatography with a yield of 75%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹ (400 MHz, CDCl₃) δ 4.43 (t, J = 6.2 Hz, 2H), 4.13 (t, J = 6.2 Hz, 2H), 2.06 (s, 3H), 1.82 – 1.77 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171.0, 159.0, 66.2, 63.7, 25.1, 25.1, 20.8. ¹⁹F NMR (377 MHz, CDCl₃) δ -138.4 – -138.5 (m, 2F), -148.7– -148.8 (m, 1F), -160.4 – -160.5 (m, 2F). HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₁F₅O₄+Na⁺: 349.0470, Found: 349.0466. IR (neat, cm^-1): υ 2859, 1736, 1652, 1524, 1496, 1387, 1222, 1038, 754, 699.

Example ten

To a 25 mL Schlenk tube were added alcohol 1j (0.2 mmol, 27.2 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3j was obtained by simple column chromatography with a yield of 50%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.93 – 7.91 (m, 1H), 7.63 – 7.59 (m, 1H), 7.51 – 7.47 (m, 2H), 5.35 (s, 2H), 2.24 (s, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 192.1, 170.4, 134.1, 133.9, 128.8, 127.7, 66.0, 20.6. HRMS (ESI-TOF): Anal Calcd. For. C₁₀H₁₀O₃+H⁺: 179.0703, Found: 179.0701. IR (neat, cm^-1) The compound of upsilon 2849, 1748, 1702, 1597, 1450, 1372, 1216, 912, 731, 647.2-hydroxyacetophenone can be used for preparing cherry pit, cinnamon, rum, tobacco, coumarin and tropical fruit essence. Compound 3j is derived from the drug molecule.

EXAMPLE eleven

To a 25 mL Schlenk tube were added alcohol 1k (0.2 mmol, 38.2 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give 3k as a 97% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.89 – 7.85 (m, 2H), 7.77 – 7.72 (m, 2H), 4.32 (t, J = 5.3 Hz, 2H), 3.97 (t, J = 5.3 Hz, 2H), 2.03 (s, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.8, 168.0, 134.0, 131.9, 123.3, 61.5, 37.0, 20.7. HRMS (ESI-TOF): Anal Calcd. For. C₁₂H₁₁NO₄+H⁺: 234.0761, Found: 234.0758. IR (neat, cm^-1): υ 5825, 1772, 1705, 1615, 1559, 1369, 1273, 1153, 983, 717.

Gram-order reaction:

to a 25 mL Schlenk tube were added alcohol 1aq (100 mmol, 19.1 g), 2, 3-butanedione (400 mmol, 34.45 g), cerium triflate (5 mmol, 2.95 g), and nitromethane (100 mL) in that order. Then irradiated with 3X 40W blue LED in oxygen, and after stirring conventionally for 40 hours, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give 3aq with 95% yield.

Example twelve

To a 25 mL Schlenk tube were added 1l of an alcohol (0.2 mmol, 38.2 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in this order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give 3l of product with 61% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.92 – 7.87 (m, 2H), 7.82 – 7.78 (m, 2H), 2.41 (s, 1H). ¹³C NMR (101 MHz, CDCl₃) δ 166.5, 161.9, 134.7, 128.8, 123.9, 17.6. HRMS (ESI-TOF): Anal Calcd. For. C₁₀H₇NO₄+H⁺: 206.0448, Found: 206.0450. IR (neat, cm^-1): υ 2850, 1808, 1785, 1609, 1466, 1236, 967, 720, 694.

EXAMPLE thirteen

To a 25 mL Schlenk tube were added alcohol 1m (0.2 mmol, 40.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3m was obtained by simple column chromatography with a yield of 63%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.81 (dd, J = 3.7, 1.2 Hz, 1H), 7.56 (dd, J= 5.0, 1.2 Hz, 1H), 7.11 (dd, J = 5.0, 3.7 Hz, 1H), 4.33 (t, J = 6.2 Hz, 2H), 4.14 (t, J = 6.2 Hz, 2H), 2.06 (s, 3H), 1.83 – 1.74 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171.1, 162.2, 133.7, 133.4, 132.3, 127.7, 64.5, 63.9, 25.4, 25.3, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₁H₁₄O₄S+H⁺: 243.0686, Found: 243.0684. IR (neat, cm^-1): υ 2855, 1735, 1525, 1450, 1386, 1257, 1076, 948, 750, 635.

Example fourteen

To a 25 mL Schlenk tube were added alcohol 1n (0.2 mmol, 40.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give the product 3n in 74% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.10 – 8.08 (m, 2H), 7.29 – 7.27 (m, 2H), 4.37 (t, J = 6.2 Hz, 2H), 4.14 (t, J = 6.2 Hz, 2H), 2.06 (s, 3H), 1.86 – 1.78 (m, 2H). ¹³C NMR (100 MHz, CDCl₃) δ 171.1, 165.3, 152.6, 131.5, 128.6, 120.2, 64.7, 63.9, 25.4, 25.3, 20.9.¹⁹F NMR (377 MHz, CDCl₃) δ -57.7 (s, 1F). HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₅F₃O₅+H⁺: 321.0944, Found: 321.0940. IR (neat, cm^-1): υ 2858, 1721, 1607, 1506, 1470, 1388, 1242, 1161, 951, 708, 634.

Example fifteen

To a 25 mL Schlenk tube were added alcohol 1o (0.2 mmol, 50.4 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product was obtained by simple column chromatography with a yield of 80%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.10 (s, 4H), 4.39 (t, J = 6.3 Hz, 2H), 4.15 (t, J = 6.3 Hz, 2H), 3.95 (s, 3H), 2.06 (s, 3H), 1.85 – 1.79 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171.0, 166.2, 165.7, 134.0, 133.89, 129.5, 129.4, 64.8, 63.8, 52.4, 25.3, 25.3, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₅H₁₈O₆+H⁺: 295.1176, Found: 295.1173. IR (neat, cm^-1): υ 2853, 1716, 1615, 1577, 1408, 1268, 1235, 1102, 962, 728.

Example sixteen

To a 25 mL Schlenk tube were added alcohol 1p (0.2 mmol, 49.2 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in this order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. Removing the solvent by a rotary evaporator, adsorbing by silica gel, and performing simple column chromatography to obtain the product 3p with the yield of 92%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.37 – 7.31 (m, 1H), 7.23 – 7.2 (m, 1H), 7.08 – 7.03 (m, 1H), 4.42 (t, J = 6.2 Hz, 2H), 4.12 (t, J = 6.2 Hz, 2H), 2.05 (s, 1H), 1.83 – 1.75 (m, 1H). ¹³C NMR (100 MHz, CDCl₃) δ 171.0, 163.1, 159.7 (d, J = 253.3 Hz), 132.3 (d, J = 5.0 Hz), 131.5 (d, J = 9.1 Hz), 125.5 (d, J= 3.5 Hz), 122.5 (d, J = 20.4 Hz), 114.4 (d, J = 21.5 Hz,), 65.6, 63.8, 25.2, 25.1, 20.9. ¹⁹F NMR (377 MHz, CDCl₃) δ -112.2 (s, 1F). HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₄ ³⁵ClFO₄+H⁺: 289.0637, Found: 289.0634; Anal Calcd. For. C₁₃H₁₄ ³⁷ClFO₄+H⁺: 291.0608, Found: 291.0605. IR (neat, cm^-1): υ 2856, 1732, 1602, 1576, 1450, 1387, 1268, 1055, 901, 787, 634.

Example seventeen

To a 25 mL Schlenk tube were added alcohol 1q (0.2 mmol, 46.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give 3q with a yield of 70%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.59 (d, J = 4.0 Hz, 1H), 6.93 (d, J = 4.0 Hz, 1H), 4.31 (t, J = 6.2 Hz, 2H), 4.12 (t, J = 6.2 Hz, 2H), 2.06 (s, 3H), 1.82 – 1.73 (m, 4H).¹³C NMR (100 MHz, CDCl₃) δ 171.0, 161.1, 137.3, 132.9, 131.8, 127.2, 64.8, 63.8, 25.3, 25.2, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₁H₁₃ ³⁵ClO₄S+H⁺: 277.0296, Found: 277.0294; Anal Calcd. For. C₁₁H₁₃ ³⁷ClO₄S+H⁺: 279.0266, Found: 279.0264. IR (neat, cm^-1): υ 3103, 2854, 1736, 1536, 1423, 1233, 1058, 916, 811, 743, 606.

EXAMPLE eighteen

To a 25 mL Schlenk tube were added alcohol 1r (0.2 mmol, 41.6 mg), 2, 3-butanedione (1.6 mmol, 137.8 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give the product 3r in 80% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.03 – 8.01 (m, 2H), 7.56 – 7.52 (m, 1H), 7.44 – 7.41 (m, 2H), 5.28 – 5.22 (m, 1H), 5.05 – 5.00 (m, 1H), 1.98 (s, 3H), 1.95 – 1.90 (m, 2H), 1.36 (d, J = 6.3 Hz, 2H), 1.27 (d, J = 6.3 Hz, 2H). ¹³C NMR (100 MHz, CDCl₃) δ 170.5, 166.0, 132.8, 130.5, 129.4, 128.2, 68.0, 67.4, 42.2, 21.1, 20.5, 20.4. HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₈O₄+H⁺: 251.1278, Found: 251.1274. IR (neat, cm^-1): υ 2853, 1773, 1608, 1507, 1427, 1367, 1234, 986, 728.

Example nineteen

To a 25 mL Schlenk tube were added alcohol 1s (0.2 mmol, 41.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in this order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. Removing solvent with rotary evaporator, adsorbing with silica gel, and performing simple column chromatography to obtain product 3s with yield of 88%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.87 – 7.83 (m, 2H), 7.75 – 7.70 (m, 2H), 4.11 (t, J = 6.1 Hz, 2H), 3.81 (t, J = 6.1 Hz, 2H), 2.07 – 2.01 (m, 2H), 2.00 (s, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.9, 168.2, 133.9, 132.0, 123.2, 61.8, 35.0, 27.4, 20.8. HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₃NO₄+H⁺: 248.0917, Found: 248.0913. IR (neat, cm^-1): υ 2900, 1771, 1614, 1527, 1467, 1365, 1188, 1001, 717, 605.

Example twenty

To a 25 mL Schlenk tube were added alcohol 1t (0.2 mmol, 54.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in this order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. Removing solvent with rotary evaporator, adsorbing with silica gel, and performing simple column chromatography to obtain product 3t with yield of 80%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.11 – 8.09 (m, 2H), 7.67 – 7.61 (m, 4H), 7.48 – 7.44 (m, 2H), 7.41 – 7.37 (m, 1H), 4.38 (t, J = 6.2 Hz, 2H), 4.15 (t, J = 6.2 Hz, 2H), 2.06 (s, 3H), 1.89 – 1.80 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171., 166.4, 145.6, 139.9, 130.0, 129.0, 128.9, 128.1, 127.2, 127.0, 64.4, 63.9, 25.4, 25.4, 20.9. HRMS (ESI-TOF): Anal Calcd. For. C₁₉H₂₀O₄+H⁺: 313.1434, Found: 313.1429. IR (neat, cm^-1): υ 2854, 1772, 1713, 1609, 1564, 1487, 1188, 907, 727, 647.

Example twenty one

To a 25 mL Schlenk tube were added alcohol 1u (0.2 mmol, 51.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. Removing solvent with rotary evaporator, adsorbing with silica gel, and performing simple column chromatography to obtain product 3u with yield of 88%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.32 (d, J = 2.1 Hz, 1H), 8.17 (dd, J = 8.6, 2.1 Hz, 1H), 7.97 (d, J = 8.6 Hz, 1H), 4.43 (t, J = 6.2 Hz, 2H), 4.14 (t, J = 6.2 Hz, 2H), 2.06 (s, 3H), 1.85 – 1.78 (m, 4H). ¹³C NMR (100 MHz, CDCl₃) δ 171.0, 164.2, 149.4, 135.9, 134.6, 131.9, 125.9, 121.4, 65.9, 63.7, 25.2, 25.2, 20.8. HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₄ ³⁵ClNO₆+Na⁺: 338.0402, Found: 338.0400; Anal Calcd. For. C₁₃H₁₄ ³⁷ClNO₆+Na⁺: 340.0372, Found: 340.037. IR (neat, cm^-1): υ 2853, 1731, 1600, 1589, 1349, 1236, 1044, 806, 731.

Example twenty two

To a 25 mL Schlenk tube were added alcohol 1v (0.2 mmol, 50.6 mg), 2, 3-butanedione (1.6 mmol, 137.8 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by rotary evaporator, adsorbed on silica gel and the product 3v was obtained by simple column chromatography with a yield of 65%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.86 – 8.85 (m, 1H), 8.44 – 8.41 (m, 1H), 8.38 – 8.35 (m, 1H), 7.69 – 7.65 (m, 1H), 4.50 (t, J = 7.0 Hz, 2H), 2.31 (t, J = 7.0 Hz, 2H), 1.98 (s, 3H), 1.55 (s, 6H). ¹³C NMR (100 MHz, CDCl₃) δ 170.4, 164.4, 148.3, 135.2, 132.0, 129.6, 127.4, 124.5, 80.5, 62.2, 39.1, 26.4, 22.3. HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₇NO₆+Na⁺: 318.0948, Found: 318.0947. IR (neat, cm^-1): υ 2932, 1722, 1617, 1532, 1440, 1387, 1294, 1096, 915, 822, 716, 652.

Example twenty three

To a 25 mL Schlenk tube were added alcohol 1w (0.2 mmol, 57.6 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product was obtained by simple column chromatography in 85% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis. Flurbiprofen is mainly used for rheumatoid arthritis, osteoarthritis, ankylosing spondylitis and the like in clinic. It can also be used for symptomatic treatment of soft tissue diseases (such as sprain and strain) and mild and moderate pain (such as dysmenorrhea, postoperative pain, toothache, etc.). The later modification of the drug molecules of the compounds can obtain the acetate compounds 3w, which can be used for further research work.

¹H NMR (400 MHz, CDCl₃) δ 7.54 – 7.52 (m, 2H), 7.45 – 7.34 (m, 4H), 7.16 – 7.12 (m, 2H), 4.32 – 4.20 (m, 4H), 3.78 (q, J = 7.2 Hz, 1H), 2.01 (s, 3H), 1.54 (d, J = 7.2 Hz, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 173.7, 170.7, 159.60 (d, J = 248.2 Hz), 141.5 (d, J = 7.7 Hz), 135.4 (d, J = 1.4 Hz), 130.7 (d, J= 4.0 Hz), 128.9 (d, J = 2.9 Hz), 128.4, 127.8 (d, J = 13.7 Hz), 127.6, 123.5 (d, J = 3.3 Hz), 115.2 (d, J = 23.7 Hz), 62.5, 61.9, 44.9, 20.6, 18.2. ¹⁹F NMR (377 MHz, CDCl₃) δ -117.6 (s, 1F). HRMS (ESI-TOF): Anal Calcd. For. C₁₉H₁₉FO₄+Na⁺: 353.1160, Found: 353.1157. IR (neat, cm^-1): υ 2855, 1735, 1600 1515, 1402, 1237, 915, 822, 723.

Example twenty-four

To a 25 mL Schlenk tube were added alcohol 1X (0.2 mmol, 44.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product was obtained by simple column chromatography in 76% yield 3 x. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis. Acetylsalicylic acid is a drug molecule commonly used as an intermediate for pesticides; (ii) a rodenticide intermediate; antipyretic analgesic raw material medicine; (ii) an antibiotic; alkaloids, and the like. The acetate 3x derived from the medicine may change the physicochemical property and the drug effect of the medicine.

¹H NMR (400 MHz, CDCl₃) δ 8.04 (d, J = 7.8 Hz, 1H), 7.58 (t, J = 7.7 Hz, 1H), 7.33 (t, J = 7.6 Hz, 1H), 7.11 (d, J = 8.1 Hz, 1H), 4.47 (dd, J = 5.4, 3.5 Hz, 2H), 4.38 (dd, J = 5.4, 3.5 Hz, 2H), 2.35 (s, 3H), 2.09 (s, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.8, 169.6, 164.1, 150.7, 134.1, 131.8, 126.0, 123.8, 122.8, 62.7, 62.0, 20.9, 20.7. HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₄O₆+Na⁺: 289.0683, Found: 289.0682. IR (neat, cm^-1): υ 1729, 1608, 1485, 1371, 1230, 1161, 905, 726, 648.

Example twenty-five

To a 25 mL Schlenk tube were added alcohol 1y (0.2 mmol, 41.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by rotary evaporator, adsorbed on silica gel and the product 3y was obtained by simple column chromatography with a yield of 91%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.88 – 7.85 (m, 2H), 7.75 – 7.72 (m, 2H), 5.22 (dd, J = 10.1, 5.2 Hz, 1H), 3.86 – 3.84 (m, 2H), 1.99 (s, 3H), 1.32 – 1.29 (m, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.6, 168.2, 134.0, 131.8, 123.3, 68.4, 41.9, 21.1, 17.6. HRMS (ESI-TOF): Anal Calcd. For. C₁₇H₂₀Cl₂O₅ +H⁺: 248.0917, Found: 248.0913. IR (neat, cm^-1): υ 1775, 1713, 1615, 1468, 1397, 1241, 1036, 906, 723, 648.

Example twenty-six

To a 25 mL Schlenk tube were added alcohol 1z (0.2 mmol, 55.2 mg), 2, 3-butanedione (1.6 mmol, 137.8 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3z was obtained by simple column chromatography with a yield of 60%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.80 (d, J = 8.4 Hz, 1H), 7.48 (d, J = 2.0 Hz, 1H), 7.30 (dd, J = 8.4, 2.0 Hz, 1H), 4.43 (t, J = 7.0 Hz, 2H), 2.26 (t, J= 7.0 Hz, 2H), 1.96 (s, 3H), 1.53 (s, 6H). ¹³C NMR (101 MHz, CDCl₃) δ 170.4, 164.7, 138.3, 134.9, 132.4, 131.0, 128.2, 127.0, 80.6, 62.0, 39.0, 26.4, 22.4. HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₆Cl₂O₄+Na⁺: 341.0318, Found: 341.0313; Anal Calcd. For. C₁₄H₁₆ ³⁵Cl³⁷ClO₄+Na⁺: 343.0288, Found: 343.0284; Anal Calcd. For. C₁₄H₁₆ ³⁷Cl₂O₄+Na⁺: 345.0259, Found: 345.0254. IR (neat, cm^-1): υ 2900, 1736, 1624, 1582, 1418, 1228, 956, 727, 648.

Example twenty-seven

To a 25 mL Schlenk tube were added alcohol 1aa (0.2 mmol, 55.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product was obtained by simple column chromatography with a yield of 62% 3 aa. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.87 – 7.82 (m, 2H), 7.76 – 7.71 (m, 2H), 7.32 – 7.31 (m, 2H), 7.22 – 7.20 (m, 2H), 5.96 (d, J = 7.8 Hz, 1H), 5.68 (q, J = 7.3 Hz, 1H), 3.47 (d, J = 7.1 Hz, 2H), 1.86 (s, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.2, 167.7, 140.9, 136.5, 134.0, 131.6, 129.0, 127.2, 124.8, 124.6, 123.3, 72.8, 54.7, 38.0, 20.6. HRMS (ESI-TOF): Anal Calcd. For. C₁₉H₁₅NO₄+H⁺: 322.1074, Found: 322.1070. IR (neat, cm^-1): υ 2850, 1705, 1600, 1450, 1205, 905, 710.

Example twenty-eight

To a 25 mL Schlenk tube were added alcohol 1ab (0.2 mmol, 43.8 mg), 2, 3-butanedione (1.6 mmol, 137.8 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. Removing solvent with rotary evaporator, adsorbing with silica gel, and performing simple column chromatography to obtain product 3ab with yield of 70%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.90 – 7.85 (m, 2H), 7.77 – 7.72 (m, 2H), 4.07 (s, 2H), 2.01 (s, 3H), 1.50 (s, 6H). ¹³C NMR (100 MHz, CDCl₃) δ 170.7, 168.4, 134.0, 131.9, 123.3, 81.0, 44.8, 24.8, 22.4. HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₅NO₄+Na⁺: 284.0893, Found: 284.0892. IR (neat, cm^-1): υ 2850, 1769, 1614, 1515, 1464, 1339, 1224, 1076, 727, 606.

Example twenty-nine

To a 25 mL Schlenk tube were added alcohol 1ac (0.2 mmol, 37.2 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3ac was obtained by simple column chromatography with a yield of 99%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.94 – 7.92 (m, 2H), 7.70 – 7.67 (m, 1H), 7.61 –7.57 (m, 2H), 4.40 (t, J = 6.1 Hz, 2H), 3.48 (t, J = 6.1 Hz, 2H), 1.82 (s, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.1, 139.3, 133.9, 129.2, 128.0, 57.5, 54.9, 20.3. HRMS (ESI-TOF): Anal Calcd. For. C₁₀H₁₂O₄S+H⁺: 229.0529, Found: 229.0525. IR (neat, cm^-1): υ 2900, 1605, 1580, 1350, 1251, 750.

Example thirty

To a 25 mL Schlenk tube were added alcohol 1ad (0.2 mmol, 38.8 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. Removing the solvent by a rotary evaporator, adsorbing by silica gel, and performing simple column chromatography to obtain the product 3ad with a yield of 82%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.05 –8.02 (m, 2H), 7.58 – 7.54 (m, 1H), 7.44 –7.42 (m, 1H), 5.14 – 5.08 (m, 1H), 4.44 – 4.32 (m, 2H), 2.09 – 1.97 (m, 5H), 1.31 (d, J = 6.3 Hz, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.6, 166.5, 132.9, 130.1, 129.5, 128.3, 68.0, 61.3, 34.8, 21.2, 20.1. HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₆O₄+H⁺: 237.1121, Found: 237.1118. IR (neat, cm^-1): υ 2869, 1709, 1613, 1586, 1396, 1240, 818, 676.

Example thirty one

To a 25 mL Schlenk tube were added alcohol 1ae (0.2 mmol, 41.6 mg), 2, 3-butanedione (1.6 mmol, 137.8 mg), cerium triflate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3ae was obtained by simple column chromatography with a yield of 70%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.03 (dd, J = 8.2, 1.2 Hz, 2H), 7.58 – 7.54 (m, 1H), 7.46 – 7.42 (m, 2H), 4.43 (t, J = 6.8 Hz, 2H), 2.28 (t, J = 6.8 Hz, 2H), 1.96 (s, 3H), 1.54 (s, 6H). ¹³C NMR (100 MHz, CDCl₃) δ 170.5, 166.6, 133.0, 130.2, 129.5, 128.4, 80.8, 61.2, 39.1, 26.5, 22.4. HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₈O₄+Na⁺: 273.1097, Found: 273.1093. IR (neat, cm^-1): υ 2929, 1717, 1652, 1585, 1471, 1222, 1176, 903, 723 649.

Example thirty-two

To a 25 mL Schlenk tube were added alcohol 1af (0.2 mmol, 52.8 mg), 2, 3-butanedione (1.6 mmol, 137.8 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product was obtained by simple column chromatography with a yield of 75% 3 af. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.97 – 7.94 (m, 2H), 7.47 – 7.44 (m, 2H), 4.41 (t, J = 6.8 Hz, 2H), 2.26 (t, J = 6.8 Hz, 2H), 1.96 (s, 3H), 1.54 (s, 6H), 1.34 (s, 9H). ¹³C NMR (100 MHz, CDCl₃) δ 170.5, 166.6, 156.6, 129.4, 127.4, 125.3, 80.8, 61.0, 39.2, 35.1, 31.1, 26.5, 22.4. HRMS (ESI-TOF): Anal Calcd. For. C₁₈H₂₆O₄+Na⁺: 329.1723, Found: 329.1713. IR (neat, cm^-1): υ 2870, 1716, 1610, 1570, 1472, 1388, 1277, 905, 725.

Example thirty-three

To a 25 mL Schlenk tube were added alcohol 1ag (0.2 mmol, 46.6 mg), 2, 3-butanedione (1.6 mmol, 137.8 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and subjected to simple column chromatography to give the product 3ag with a yield of 66%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.15 – 8.12 (m, 2H), 7.77 – 7.74 (m, 2H), 4.47 (t, J = 6.9 Hz, 2H), 2.30 (t, J = 6.9 Hz, 2H), 1.96 (s, 3H), 1.54 (s, 6H). ¹³C NMR (100 MHz, CDCl₃) δ 170.4, 164.8, 133.9, 132.2, 130.0, 117.9, 116.4, 80.5, 62.0, 38.9, 26.4, 22.3. HRMS (ESI-TOF): Anal Calcd. For. C₁₅H₁₇NO₄+Na⁺: 298.1050, Found: 298.1049. IR (neat, cm^-1): υ 2931, 2205, 1770, 1611, 1514, 1465, 1368, 1249, 1045, 767, 691.

Example thirty-four

To a 25 mL Schlenk tube were added alcohol 1ah (0.2 mmol, 59.4 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give the product 3ah at 80% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.78 – 7.74 (m, 2H), 7.70 – 7.66 (m, 2H), 2.86 (s, 2H), 2.46 (d, J = 2.8 Hz, 4H), 2.37 (s, 2H), 2.21 – 2.12 (m, 4H), 1.98 (s, 3H), 1.71 – 1.62 (m, 2H). ¹³C NMR (100 MHz, CDCl₃) δ 170.1, 169.4, 133.7, 131.7, 122.6, 80.1, 61.5, 43.8, 39.8, 39.0, 34.7, 30.7, 22.5. HRMS (ESI-TOF): Anal Calcd. For. C₂₀H₂₁NO₄+Na⁺: 362.1363, Found: 362.1361. IR (neat, cm^-1): υ 2917, 1729, 1697, 1558, 1250, 958, 863, 711, 676.

Example thirty-five

To a 25 mL Schlenk tube were added alcohol 1ai (0.2 mmol, 51.2 mg), 2, 3-butanedione (1.6 mmol, 137.8 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3ai was obtained by simple column chromatography with a yield of 65%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.02 (d, J = 8.3 Hz, 2H), 7.46 (d, J = 8.3 Hz, 2H), 4.61 (s, 2H), 4.43 (t, J = 6.8 Hz, 2H), 2.27 (t, J = 6.8 Hz, 2H), 1.96 (s, 3H), 1.54 (s, 6H). ¹³C NMR (100 MHz, CDCl₃) δ 170.5, 166.0, 142.3, 130.2, 130.0, 128.5, 80.7, 61.4, 45.3, 39.1, 26.5, 22.4. HRMS (ESI-TOF): Anal Calcd. For. C₁₅H₁₉ ³⁵ClO₄+Na⁺: 321.0864, Found: 321.0863; Anal Calcd. For. C₁₅H₁₉ ³⁷ClO₄+Na⁺: 323.0835, Found: 323.0834. IR (neat, cm^-1): υ 2936, 1713, 1613, 1454, 1369, 1222, 948, 726.

Example thirty-six

To a 25 mL Schlenk tube were added alcohol 1aj (0.2 mmol, 44.2 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give the product 3aj in 60% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.89 – 7.84 (m, 2H), 7.77 – 7.72 (m, 2H), 5.36 – 5.31 (m, 1H), 4.31 (dd, J = 12.1, 4.1 Hz, 1H), 4.16 (dd, J = 12.1, 5.8 Hz, 1H), 3.96 (d, J = 5.2 Hz, 2H), 2.09 (s, 3H), 2.04 (s, 3H).¹³C NMR (100 MHz, CDCl₃) δ 170.5, 170.4, 168.0, 134.2, 131.8, 123.4, 69.3, 63.0, 38.1, 20.8, 20.7. HRMS (ESI-TOF): Anal Calcd. For. C₁₅H₁₅NO₆+H⁺: 306.0972, Found: 306.0969. IR (neat, cm^-1): υ 2852, 1775, 1713, 1615, 1468, 1390, 1220, 1034, 794, 627.

Example thirty-seven

To a 25 mL Schlenk tube were added alcohol 1ak (0.2 mmol, 49.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and subjected to simple column chromatography to give 3ak in 77% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.85 – 7.80 (m, 2H), 7.73 – 7.69 (m, 2H), 5.27 – 5.25 (m, 1H), 4.53 – 4.46 (m, 1H), 2.58 – 2.51 (m, 1H), 2.24 – 2.15 (m, 1H), 2.12 (s, 3H), 1.95 – 1.89 (m, 2H), 1.81 – 1.72 (m, 3H), 1.60 – 1.51 (m, 1H). ¹³C NMR (100 MHz, CDCl₃) δ 170.5, 168.3, 133.8, 131.8, 123.0, 70.0, 45.8, 33.0, 29.1, 28.6, 21.4, 20.1. HRMS (ESI-TOF): Anal Calcd. For. C₁₆H₁₇NO₄+Na⁺: 310.1050, Found: 310.1048. IR (neat, cm^-1): υ 2868, 1760, 1702, 1613, 1455, 1397, 1211, 1075, 896, 714.

Example thirty-eight

To a 25 mL Schlenk tube were added alcohol 1al (0.2 mmol, 117.2 mg), 2, 3-butanedione (1.6 mmol, 137.8 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. Removing solvent with rotary evaporator, adsorbing with silica gel, and performing simple column chromatography to obtain product 3al with yield of 60%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.95 (d, J = 8.0 Hz, 2H), 7.84 – 7.80 (m, 4H), 4.09 (s, 4H), 2.00 (s, 6H), 1.51 (s, 12H). ¹³C NMR (100 MHz, CDCl₃) δ 170.7, 167.3, 167.1, 138.8, 135.6, 132.8, 132.5, 124.9, 123.7, 80.9, 45.3, 24.8, 22.5. ¹⁹F NMR (377 MHz, CDCl₃) δ -63.3 (s, 6F). HRMS (ESI-TOF): Anal Calcd. For. C₃₁H₂₈F₆N₂O₈+Na⁺: 693.1642, Found: 693.1632. IR (neat, cm^-1): υ 2942, 1778, 1465, 1426, 1202, 1168, 1016, 727, 606.

Example thirty-nine

To a 25 mL Schlenk tube were added alcohol 1am (0.2 mmol, 47.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3am was obtained by simple column chromatography with a yield of 80%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.76 (d, J = 8.3 Hz, 1H), 7.33 (d, J = 2.2 Hz, 1H), 7.17 (dd, J = 8.3, 2.2 Hz, 1H), 5.24 – 5.17 (m, 1H), 3.93 (s, 3H), 3.82 – 3.80 (m, 2H), 1.99 (s, 3H), 1.29 (d, J = 6.5 Hz, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.6, 168.0, 167.9, 164.7, 134.5, 125.0, 123.7, 119.8, 108.0, 68.5, 56.0, 41.9, 21.1, 17.6. HRMS (ESI-TOF): Anal Calcd. For. C₁₄H₁₅NO₅+H⁺: 278.1023, Found: 278.1020. IR (neat, cm^-1): υ 2844, 1770, 1616, 1489, 1286, 1093, 955, 769, 605.

Example forty

To a 25 mL Schlenk tube were added alcohol 1an (0.2 mmol, 48.2 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg) and nitromethane (0.5 mL) in this order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and purified by simple column chromatography to give the product 3an in 82% yield. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 7.68 (t, J = 7.3 Hz, 2H), 5.24 – 5.17 (m, 1H), 3.87 – 3.78 (m, 2H), 1.98 (s, 3H), 1.29 (d, J = 6.5 Hz, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.7, 166.2, 155.7 (d, J = 15.3 Hz), 153.1 (d, J = 15.3 Hz), 128.7 (t, J = 6.0 Hz), 113.3 (dd, J = 14.6, 7.5 Hz), 68.3, 42.5, 21.0, 17.7. ¹⁹F NMR (377 MHz, CDCl₃) δ -125.6 (s, 2F). HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₁₁F₂NO₄+H⁺: 284.0729, Found: 284.0725. IR (neat, cm^-1): υ 2850, 1780, 1714, 1622, 1494, 1397, 1295, 1030, 907, 727, 605.

Example forty one

To a 25 mL Schlenk tube were added alcohol 1ao (0.2 mmol, 51.0 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3ao was obtained by simple column chromatography with a yield of 85%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 8.32 (s, 1H), 8.04 (dd, J = 6.2, 3.3 Hz, 2H), 7.69 (dd, J = 6.2, 3.3 Hz, 2H), 5.32 – 5.24 (m, 1H), 3.95 – 3.86 (m, 2H), 2.00 (s, 3H), 1.33 (d, J = 6.5 Hz, 3H). ¹³C NMR (100 MHz, CDCl₃) δ 170.6, 167.8, 135.3, 130.2, 129.1, 127.4, 124.7, 68.4, 42.1, 21.1, 17.7. HRMS (ESI-TOF): Anal Calcd. For. C₁₇H₁₅NO₄+H⁺: 298.1074, Found: 298.1070. IR (neat, cm^-1): υ 2852, 1766, 1602, 1515, 1376, 1242, 1182, 1032, 764.

Example forty two

To a 25 mL Schlenk tube were added alcohol 1ap (0.2 mmol, 68.2 mg), 2, 3-butanedione (0.8 mmol, 68.9 mg), cerium trifluoromethanesulfonate (0.01 mmol, 5.9 mg), and nitromethane (0.5 mL) in that order. After stirring for 24 hours under 40W blue LED illumination, the reaction was quenched with saturated sodium sulfite solution, extracted 3 times with ethyl acetate, and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, adsorbed on silica gel and the product 3ap was obtained by simple column chromatography with a yield of 83%. The main test data of the prepared product are as follows, and the actual synthesized product is consistent with the theoretical analysis through analysis.

¹H NMR (400 MHz, CDCl₃) δ 5.24 – 5.19 (m, 1H), 3.89 – 3.80 (m, 2H), 1.99 (s, 3H), 1.31 (d, J = 6.5 Hz, 3H).¹³C NMR (100 MHz, CDCl₃) δ 170.8, 163.4, 140.2, 129.7, 127.4, 68.2, 42.8, 21.0, 17.7. HRMS (ESI-TOF): Anal Calcd. For. C₁₃H₉Cl₄NO₄+Na⁺: 405.9178, Found: 405.9181. IR (neat, cm^-1): υ 2851, 1774, 1426, 1357, 1301, 1194, 1045, 740, 628。