A method for photocatalytic synthesis of alpha-acyloxy ketones

Abstract

The application discloses a method for photocatalytic synthesis of alpha-acyloxy ketone, which comprises the following steps: adding aryl ketone compound shown in formula (I) and acid shown in formula (II) into a reaction solvent, adding a base, stirring and reacting under the condition of light and air or oxygen atmosphere at 20-60 DEG C for 24-72 hours, and obtaining ketone alpha-acyloxy derivative through post-treatment after the reaction is completed. 1 R is taken from hydrogen or C1-C6 alkyl substituents, such as methyl, propyl, isopropyl, and benzyl, etc. 2 R is taken from C1-C6 alkyl linear or branched alkyl, or heterocyclic group, aryl, etc. The application has the advantages of simple operation, cheap and easily available raw materials, mild reaction, green safety, good substrate compatibility and high yield.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for photocatalytic synthesis of α-acyloxyketones. Background Technology

[0002] α-Acyloxyketone compounds are widely found in natural products and often serve as key structural frameworks for physiologically active molecules and drug molecules. Studies have shown that substances containing these structural fragments possess numerous biological activities, such as antibacterial, anti-inflammatory, anti-tuberculosis, anticonvulsant, and antitumor effects. Their hydrolyzed α-hydroxyketone compounds exhibit broad physiological activities and can be used in the synthesis of many natural products (terpenes and alkaloids), making them a very important class of synthons.

[0003] Traditional methods for synthesizing α-acyloxyketones involve prefunctionalizing the ketone, often by first substituting a halogen atom at the α-position, followed by a nucleophilic substitution reaction. In recent years, α-haloketones have frequently been used as intermediates in some one-step α-acyloxyketone synthesis reactions (ChemistrySelect. 2019, 4, 12333–12336; CN113200850A). The rapid development of transition metals in catalysis has also driven the synthesis of α-acyloxyketones. Metals such as thallium, palladium, and copper have exhibited extremely high catalytic activity under different conditions depending on their valence states (Chem. Commun. 2001, 11, 956–957; Chem. Lett. 2013, 42, 1388-1390; Org. Chem. Front. 2017, 4, 163–169). Some iodine-containing reagents are also classic catalysts for oxidation reactions. They possess catalytic performance comparable to metals, while avoiding the post-treatment problems associated with metal waste, making them highly green and efficient catalysts. In 2005, Ochia et al. first successfully synthesized the α-acyloxylation of ketones catalyzed by iodobenzene (J. Am. Chem. Soc. 2005, 127, 12244–12245). Subsequently, high-iodine reagents such as [hydroxy(p-nitrobenzenesulfonyl)iodo]benzene (HNIB) and tert-butylammonium iodide have been widely used in the synthesis of α-acyloxyketones (Angew. Chem. Int. Ed. 2011, 50, 5331–5334). Furthermore, iodine salts and elemental iodine can also act as catalysts to promote the synthesis of α-acyloxyketones (Org. Biomol. Chem. 2016, 14, 5936–5939; RSCAdv. 2017, 7, 20394-20397). Besides ketones as raw materials, some alkenes, alkynes, epoxides, and alcohols can also serve as substrates or one of the substrates for the synthesis of α-acyloxyketones (Asian J.Org.Chem.2016,5,48–51; Org.Biomol.Chem.2016,14,10998–11001; CN107011162A). The above reactions or methods all suffer from drawbacks to varying degrees, including cumbersome operation, demanding reaction conditions, expensive or unavailable reagents, difficult waste disposal, environmental pollution, and safety hazards due to the use of large amounts of oxidants. Photocatalytic radical reactions, with their advantages of mild conditions, environmental friendliness, safety, and high efficiency, have gradually become a research hotspot. Therefore, there is an urgent need to develop a milder, greener, and more efficient method to achieve the efficient synthesis of α-acyloxyketones. Summary of the Invention

[0004] To address the above problems, the purpose of this invention is to provide a simple, mild, green, and safe photocatalytic synthesis method for α-acyloxyketones.

[0005] To achieve the above objectives, the following technical solution is proposed:

[0006] A photocatalytic synthesis method for α-acyloxyketones involves adding an aryl ketone compound of formula (I) and an acid of formula (II) to a reaction solvent, adding a base, and reacting under light irradiation at 20-60°C with stirring. After the reaction is complete, the reaction solution is post-treated to obtain the target compound, a phenylacetone α-acyloxylated derivative of formula (III). The reaction equation is as follows:

[0007]

[0008] In formula (I), the aryl group attached to the carbonyl group is naphthyl, substituted naphthyl, 2,3-dihydrobenzofuranyl, phenyl or substituted phenyl, wherein the substituent of the substituted phenyl group is C1-C6 alkyl, phenylthio or hydroxy-substituted C1-C6 alkyl.

[0009] In equations (I) and (II), R 1 Derived from hydrogen, C1-C6 alkyl or C1-C6 substituted alkanes, preferably methyl, propyl, isopropyl, and benzyl, etc.;

[0010] In equations (II) and (III), R 2 It is derived from one of the following: cyclohexyl, cyclopentyl, C1-C6 straight-chain alkane or branched alkyl, vinyl, cyclopentylmethyl, 2-tetrahydrofuranyl, phenyl-substituted C1-C4 straight-chain alkane or branched alkyl, 2-thienyl, 1-naphthyl, phenyl or substituted phenyl, wherein the substituent of the substituted phenyl is a C1-C4 alkyl, nitro or halogen.

[0011] Furthermore, the light source is visible light such as blue light or white light.

[0012] Furthermore, the photocatalyst is Bengal rose red. The molar amount of the photocatalyst is 0.01 to 0.1 times, preferably 0.02 to 0.05 times, the molar amount of the aryl ketone compound shown in formula (I).

[0013] Furthermore, the base used is an inorganic or organic base such as sodium bicarbonate, sodium carbonate, potassium carbonate, sodium hydroxide, tripotassium phosphate, sodium acetate, triethylamine, or 2,4,6-trimethylpyridine. The molar amount of the base is 0.5 to 2 times the molar amount of the aryl ketone compound shown in formula (I).

[0014] Furthermore, the reaction solvent is one or any combination of the following: dimethyl sulfoxide, acetonitrile, and water; the volume ratio of the reaction solvent to the molar amount of the aryl ketone compound shown in formula (I) is 2 to 8:1, with volume in mL and molar amount in mmol.

[0015] Furthermore, the molar ratio of the ketone shown in formula (I) to the acid shown in formula (II) is 1:1 to 1:10.

[0016] Furthermore, air or oxygen is used as the oxidant.

[0017] Further, the post-processing process is as follows: after the reaction is completed, the reaction solution is quenched with excess saturated sodium bicarbonate solution, ethyl acetate is added, then a small amount of water is added, the layers are separated, the aqueous layer is extracted with ethyl acetate three times, the organic layers are combined, dried with anhydrous Na2SO4 and concentrated under reduced pressure to obtain the crude product, the crude product is separated and purified by chromatographic column to obtain the α-acyloxylated aryl ketone compound represented by the target compound (Ⅲ).

[0018] Further, the synthesis method of the α-acyloxyketone is carried out according to the following steps: A ketone of formula (I), a base, Bengal rose red, an acid of formula (II), and a reaction solvent are added to a reactor equipped with a magnetic stirrer. Oxygen is replaced, and the mixture is stirred at 20-60°C under light irradiation. After the reaction is complete, the reaction solution is quenched with excess saturated sodium bicarbonate solution, ethyl acetate is added, followed by a small amount of water. The mixture is separated, and the aqueous layer is extracted three times with ethyl acetate. The combined organic layers are dried over anhydrous Na2SO4 and concentrated under reduced pressure to obtain the crude product. The crude product is purified by column chromatography to obtain the α-acyloxylated aryl ketone compound of formula (III). The eluent for column purification is petroleum ether / ethyl acetate with a volume ratio of 40:1 to 20:1.

[0019] The synthesis method of α-acyloxyketones provided by this invention has mild reaction conditions, simple operation, and inexpensive and readily available reagents. It avoids problems such as difficult post-processing, environmental pollution, and safety hazards caused by the use of transition metals and strong oxidants. It is also applicable to most acetone compounds, benzoic acid compounds, and most fatty acid compounds. Detailed Implementation

[0020] Example 1: 1-Oxo-1-phenyl-2-pentyl cyclohexanoate (III-3aa)

[0021]

[0022] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) cyclohexane (232 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with a 3W blue light and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10 mL), followed by the addition of ethyl acetate (20 mL) and a small amount of water (2 mL). The mixture was separated and extracted three times with ethyl acetate (15 mL x 3). The combined organic layers were dried over 7.5 g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 81% and an HPLC purity of 98.5%.

[0023] 1 H NMR (600MHz, CDCl3) δ7.97–7.94(m,2H),7.62–7.57(m,1H),7.49(t,J=7.8Hz,2H),5.88(dd,J=7.6,5.4Hz,1H),2.45(tt,J=11.2,3.7Hz,1H),2.01–1. 93(m,2H),1.88–1.83(m,2H),1.78(dt,J=12.9,3.9Hz,2H),1.66(dt,J=12. 3,4.2Hz,1H),1.58–1.45(m,4H),1.37–1.21(m,3H),0.97(t,J=7.4Hz,3H). 13 CNMR(151MHz, CDCl3)δ197.01,175.72,134.94,133.41,128.73,128.40,74.64,42.83,33.35,28.93,28.86,25.75,25.38,25.33,18.91,13.72.

[0024] Example 2: 1-O-1-phenyl-2-pentyl acetate (III-3ab)

[0025]

[0026] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) acetic acid (108 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), acetonitrile (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 30°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10 mL), followed by ethyl acetate (20 mL) and a small amount of water (2 mL). The mixture was separated and extracted three times with ethyl acetate (15 mL x 3). The combined organic layers were dried over 7.5 g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 50% and an HPLC purity of 98.0%.

[0027] 1 H NMR(600MHz, CDCl3)δ7.96(dd,J=8.4,1.3Hz,2H),7.63–7.57(m,1H),7.53–7.47(m,2H),5.89(d d,J=8.2,4.7Hz,1H),2.18(s,3H),1.90–1.79(m,2H),1.57–1.45(m,2H),0.97(t,J=7.4Hz,3H). 13 C NMR (151MHz, CDCl3) δ196.73,170.70,134.81,133.51,128.78,128.40,75.14,33.40,20.69,18.85,13.70.

[0028] Example 3: 1-O-1-Phenyl-2-pentyl acrylate (III-3ac)

[0029]

[0030] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (64 mg, 0.6 mmol, 2.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) acrylic acid (130 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with a white light of 3W and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10 mL), followed by the addition of ethyl acetate (20 mL) and a small amount of water (2 mL). The mixture was separated and extracted three times with ethyl acetate (15 mL x 3). The combined organic layers were dried over 7.5 g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 31% and an HPLC purity of 97.0%.

[0031] 1 H NMR (400MHz, CDCl3) δ8.02–7.95(m,2H),7.65–7.56(m,1H),7.50(t,J=7.7Hz,2H),6.50(dd,J=17.3,1.4Hz,1H),6.25(dd,J=17.3,10.4H z,1H),5.98(dd,J=7.0,5.8Hz,1H),5.91(dd,J=10.4,1.4Hz,1H),1.90(td,J=7.7,6.0Hz,2H),1.61–1.47(m,2H),0.98(t,J=7.4Hz,3H). 13 C NMR (101MHz, CDCl3) δ196.50,165.72,134.85,133.51,131.70,128.78,128.42,127.77,75.19,33.44,18.85,13.70.

[0032] Example 4: 1-O-1-phenyl-2-pentyl 2-methylvaleric acid (III-3ad)

[0033]

[0034] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium bicarbonate (25 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) 2-methylpentanoic acid (209 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), acetonitrile (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 54% and an HPLC purity of 98.0%.

[0035] 1 H NMR (600MHz, CDCl3) δ7.95(dd,J=8.0,1.6Hz,2H),7.58(t,J=7.4Hz,1H),7.48(t,J=7.6Hz,2H),5.87(td,J=6.6,3.2Hz,1H),2.58(dq,J=8.6,6.9Hz, 1H),1.90–1.81(m,2H),1.78–1.66(m,1H),1.59–1.30(m,5H),1.19(dd,J= 7.0,5.1Hz,3H),0.97(td,J=7.4,1.4Hz,3H),0.92(td,J=7.3,6.1Hz,3H). 13 C NMR (151MHz, CDCl3) δ196.99 (d, J = 3.0Hz), 176.52, 135.02 (d, J = 5.5Hz), 133.37 (d, J = 3.7Hz), 128.71, 128.38, 74.72 (d, J = 12.8Hz), 39 .06, 35.80 (d, J = 12.7Hz), 33.31, 20.31 (d, J = 9.9Hz), 18.90 (d, J = 2.7Hz), 16.96 (d, J = 10.8Hz), 13.95 (d, J = 5.0Hz), 13.68 (d, J = 2.7Hz).

[0036] Example 52: 1-oxo-1-phenyl-2-pentyl ester of 2-tetrahydrofuranoic acid (III-3ae)

[0037]

[0038] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (6 mg, 0.006 mmol, 0.02 equiv), compound (II) 2-tetrahydrofuranic acid (209 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 55℃ for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 20:1 to obtain the target product with a yield of 44% and an HPLC purity of 97.5%.

[0039] 1 H NMR(600MHz, CDCl3)δ7.96–7.91(m,2H),7.60(td,J=7.3,1.5Hz,1H),7.49(t d, J=7.8, 1.7Hz, 2H), 5.94 (dd, J=8.2, 4.5Hz, 1H), 4.60 (ddd, J=13.0, 8.4, 5. 0Hz,1H),4.09–4.01(m,1H),3.99–3.91(m,1H),2.34–2.22(m,2H),2.17–2.0 1(m,1H),2.01–1.80(m,3H),1.55–1.45(m,2H),0.96(td,J=7.4,2.6Hz,3H). 13 C NMR (151MHz, CDCl3) δ196.38 (d, J = 26.2Hz), 173.21 (d, J = 11.6Hz), 134.78 (d, J = 3.3Hz), 133.55 (d, J = 2.8Hz), 128.79 (d, J = 2.1Hz), 128.38 (d, J = 2.9Hz) ,76.26,75.30(d,J=3.7Hz),69.49(d,J=3.2Hz),33.31(d,J=6.7Hz),30.26 (d, J = 26.7Hz), 25.10 (d, J = 8.3Hz), 18.79 (d, J = 6.7Hz), 13.67 (d, J = 6.7Hz).

[0040] Example 6: 1-O-1-Phenyl-2-pentyl 2-methyl-2-phenylpropionic acid (III-3af)

[0041]

[0042] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) 2-methyl-2-phenylpropionic acid (246 mg, 1.5 mmol, 5.0 equiv), add acetonitrile (1.3 mL), and replace with oxygen. The reaction system was irradiated with 3W blue light and stirred at 25°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 69% and an HPLC purity of 97.0%.

[0043] 1 H NMR (600MHz, CDCl3) δ7.91(dd,J=8.0,1.5Hz,2H),7.58(t,J=7.4Hz,1H),7.46(t,J=7.7Hz,2H),7.40(d,J=7.2Hz,2H),7.35(t,J=7.7Hz,2H) ,7.26(t,J=7.3Hz,1H),5.81(dd,J=7.7,5.5Hz,1H),1.82–1.76(m,2H),1.69(s,3H),1.63(s,3H),1.40–1.29(m,2H),0.88(t,J=7.4Hz,3H). 13 C NMR (151MHz, CDCl3) δ196.79,176.43,144.28,134.93,133.34,128.69,128.3 9,128.30,126.70,125.86,75.55,46.50,33.14,26.81,26.13,18.71,13.54.

[0044] Example 72: 1-oxo-1-phenyl-2-pentyl 2-thiophenecarboxylic acid (III-3ag)

[0045]

[0046] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), tripotassium phosphate (64 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) 2-thiophenecarboxylic acid (230 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 60℃ for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 65% and an HPLC purity of 97.0%.

[0047] 1 H NMR (400MHz, CDCl3) δ8.04–7.99(m,2H),7.89(dd,J=3.8,1.3Hz,1H),7.60(tdd,J=5.3,3.6,1.3Hz,2H),7.55–7.46(m,2H ),7.13(dd,J=5.0,3.8Hz,1H),6.08(dd,J=7.5,5.4Hz,1H),2.06–1.94(m,2H),1.68–1.52(m,2H),1.02(t,J=7.4Hz,3H). 13 C NMR (101MHz, CDCl3) δ196.34,161.77,134.87,134.04,133.79,133.51,133.01,132.93,128.80,128.48,127.83,75.83,33.50,18.89,13.74.

[0048] Example 8: 1-O-1-phenyl-2-pentyl benzoate (III-3ah)

[0049]

[0050] Add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (16 mg, 0.15 mmol, 0.5 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) benzoic acid (220 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), and dimethyl sulfoxide (1.0 mL) to a test tube equipped with a magnetic stirrer, and leave the tube open. The reaction system was irradiated with 3W blue light and stirred at 55℃ for 24 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 52% and an HPLC purity of 98.0%.

[0051] 1 H NMR (600MHz, CDCl3) δ8.13(dd,J=8.3,1.4Hz,2H),8.06–8.01(m,2H),7.65–7.57(m,2H),7.50(dt,J=22. 4,7.8Hz,4H),6.14(dd,J=8.2,4.7Hz,1H),2.06–1.97(m,2H),1.67–1.58(m,2H),1.03(t,J=7.4Hz,3H). 13 C NMR (151MHz, CDCl3) δ196.56,166.23,134.89,133.54,133.28,129.89,129.61,128.82,128.48,128.43,75.57,33.54,18.99,13.80.

[0052] Example 91: 1-O-1-phenyl-2-pentyl 1-naphthoic acid (III-3ai)

[0053]

[0054] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) 1-naphthoic acid (258 mg, 1.5 mmol, 5.0 equiv), add dimethyl sulfoxide (1.3 mL), and replace with oxygen. The reaction system was irradiated with 3W blue light and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 67% and an HPLC purity of 97.5%.

[0055] 1 H NMR (400MHz, CDCl3) δ8.98(dd,J=8.6,1.2Hz,1H),8.38(dd,J=7.3,1.3Hz,1H),8.09(ddt,J=13.9,8.2,1.1Hz,3H),7.91(dt,J=8.1,1.0Hz,1H), 7.64(ddt,J=8.6,6.8,1.4Hz,2H),7.59–7.51(m,4H),6.29(dd,J=7.4,5.3Hz,1H),2.12–2.02(m,2H),1.74–1.60(m,2H),1.05(t,J=7.4Hz,3H). 13 C NMR (101MHz, CDCl3) δ196.79,167.23,135.03,133.84,133.65,133.58,131.49,130.58,128 .89,128.53,128.50,127.85,126.67,126.28,125.89,124.57,75.76,33.60,19.08,13.84.

[0056] Example 104: 1-O-1-phenyl-2-pentyl methylbenzoate (III-3aj)

[0057]

[0058] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) 4-methylbenzoic acid (245 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 20°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10 mL), followed by ethyl acetate (20 mL) and a small amount of water (2 mL). The mixture was separated and extracted three times with ethyl acetate (15 mL x 3). The combined organic layers were dried over 7.5 g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 48% and an HPLC purity of 98.0%.

[0059] 1 H NMR (400MHz, CDCl3) δ8.06–7.99(m,4H),7.64–7.58(m,1H),7.54–7.47(m,2H),7.27(d,J=7.8Hz,2H), 6.12(dd,J=7.7,5.1Hz,1H),2.43(s,3H),2.07–1.96(m,2H),1.71–1.53(m,2H),1.02(t,J=7.4Hz,3H). 13 C NMR (101MHz, CDCl3) δ196.71,166.27,144.00,134.99,133.46,129.91,129.13,128.79,128.47,126.89,75.41,33.55,21.70,18.98,13.79.

[0060] Example 112,4-Dichlorobenzoic acid 1-oxo-1-phenyl-2-pentyl ester (III-3ak)

[0061]

[0062] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium hydroxide (12 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) 2,4-dichlorobenzoic acid (287 mg, 1.5 mmol, 5.0 equiv), add dimethyl sulfoxide (1.3 mL), and replace with oxygen. The reaction system was irradiated with 3W blue light and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 35% and an HPLC purity of 97.0%.

[0063] Example 12: 1-O-1-Phenylacetyl hippurate (III-3al)

[0064]

[0065] In a test tube equipped with a magnetic stirrer, add compound (I) phenylpentanone (49 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) hippuric acid (107 mg, 0.6 mmol, 2.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 43% and an HPLC purity of 97.0%.

[0066] 1H NMR (400MHz, CDCl3) δ7.99–7.91(m,2H),7.85–7.78(m,2H),7.65–7.58(m,1H),7.54–7.47(m,3H),7.43(t,J=7.5Hz,2H),6.79(s,1H),5.99(d d,J=7.7,5.1Hz,1H),4.50(dd,J=18.5,5.8Hz,1H),4.30(dd,J=18.4,4.6Hz,1H),1.96–1.82(m,2H),1.59–1.43(m,2H),0.97(t,J=7.4Hz,3H). 13 C NMR (101MHz, CDCl3) δ196.16,169.93,167.56,134.54,133.75,133.70,13 1.76,128.89,128.57,128.37,127.08,76.33,41.71,33.37,18.74,13.63.

[0067] Example 13: 3-Methyl-1-oxo-1-phenyl-2-butyl cyclohexanecarboxylate (III-3ba)

[0068]

[0069] In a test tube equipped with a magnetic stirrer, add compound (I) phenyl isobutyl ketone (49 mg, 0.3 mmol, 1.0 equiv), sodium acetate (25 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) cyclohexane (232 mg, 3 mmol, 6.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 55°C for 36 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10 mL), followed by ethyl acetate (20 mL) and a small amount of water (2 mL). The mixture was separated and extracted three times with ethyl acetate (15 mL x 3). The combined organic layers were dried over 7.5 g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 30% and an HPLC purity of 98.0%.

[0070] 1H NMR (400MHz, CDCl3) δ8.00–7.92(m,2H),7.62–7.56(m,1H),7.52–7.45(m,2H),5.74(d,J=4.8Hz,1H),2.48(tt,J=11.1,3.7Hz,1H),2.24–2.37(m, 1H),2.05–1.93(m,2H),1.84–1.72(m,2H),1.71–1.61(m,1H),1.60–1.44 (m,2H),1.41–1.21(m,3H),1.05(d,J=6.9Hz,3H),0.96(d,J=6.8Hz,3H). 13 C NMR (101MHz, CDCl3) δ196.91,175.68,135.84,133.27,128.68,128.35,78.82,42.90,30.22,29.01,28.84,25.78,25.40,25.32,19.53,17.02.

[0071] Example 14: 1-Oxo-1,3-diphenyl-2-propane cyclohexanecarboxylic acid (III-3ca)

[0072]

[0073] In a test tube equipped with a magnetic stirrer, add compound (I) phenyl ethyl ketone (63 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) cyclohexane (116 mg, 0.9 mmol, 3.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with a 3W blue light and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10 mL), followed by ethyl acetate (20 mL) and a small amount of water (2 mL). The mixture was separated and extracted three times with ethyl acetate (15 mL x 3). The combined organic layers were dried over 7.5 g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 51% and an HPLC purity of 98.0%.

[0074] 1H NMR (400MHz, CDCl3) δ8.02–7.93(m,2H),7.66–7.56(m,1H),7.49(t,J=7.7Hz,2H) ,7.35–7.23(m,5H),6.09(dd,J=9.1,4.2Hz,1H),3.23(dd,J=14.4,4.2Hz,1H),3. 12(dd,J=14.4,9.1Hz,1H),2.40(tt,J=11.0,3.7Hz,1H),1.97–1.81(m,2H),1.80 –1.68(m,2H),1.67–1.59(m,1H),1.43(pd,J=12.3,3.3Hz,2H),1.35–1.19(m,3H). 13 C NMR (101MHz, CDCl3) δ196.38,175.33,136.43,134.99,133.50,129.35,128. 75,128.48,126.95,75.27,42.70,37.44,28.76,28.74,25.73,25.30,25.27.

[0075] Example 15: 1-O-1-(4-methylphenyl)-2-propylcyclohexanoate (III-3da)

[0076]

[0077] In a test tube equipped with a magnetic stirrer, add compound (I) 4'-methylphenylacetone (45 mg, 0.3 mmol, 1.0 equiv), triethylamine (30 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) cyclohexane (384 mg, 3.0 mmol, 10.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 47% and an HPLC purity of 98.5%.

[0078] 1H NMR (400MHz, CDCl3) δ7.90–7.81(m,2H),7.27(d,J=7.9Hz,2H),5.95(q,J=7.0Hz,1H),2.41(s,3H),2.03– 1.88(m,2H),1.81–1.71(m,2H),1.64(ddd,J=10.9,4.2,2.2Hz,1H),1.55–1.40(m,5H),1.37–1.19(m,3H). 13 C NMR (101MHz, CDCl3) δ196.61,175.43,144.36,132.00,129.39,128.59,70.83,42.80,28.92,28.82,25.73,25.35,25.33,21.67,17.07.

[0079] Example 16: 1-O-1-(4-phenylthiophenyl)-2-propyl cyclohexanecarboxylic acid (III-3ea)

[0080]

[0081] Add compound (I) 4'-phenylthiophenylacetone (61 mg, 0.25 mmol, 1.0 equiv), sodium carbonate (26 mg, 0.25 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) cyclohexane (232 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), and dimethyl sulfoxide (1.0 mL) to a test tube equipped with a magnetic stirrer, and leave the tube open. The reaction system was irradiated with 3W blue light and stirred at 40°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10 mL), followed by ethyl acetate (20 mL) and a small amount of water (2 mL). The mixture was separated and extracted three times with ethyl acetate (15 mL x 3). The combined organic layers were dried over 7.5 g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 40% and an HPLC purity of 98.0%.

[0082] 1H NMR (400MHz, CDCl3) δ7.84–7.79(m,2H),7.55–7.47(m,2H),7.42(dt,J=4.7,2.9Hz,3H),7.25–7.20(m,2H),5.90(q,J=7.0Hz,1H ),2.41(tt,J=11.2,3.7Hz,1H),2.01–1.88(m,2H),1.81–1.71(m,2H),1.70–1.59(m,1H),1.55–1.39(m,5H),1.38–1.19(m,3H). 13 CNMR(101MHz,CDCl3)δ196.05,175.41,145.64,133.98,131.90,131.75,129.71, 129.02,128.89,127.47,70.76,42.77,28.90,28.81,25.73,25.34,25.32,16.99.

[0083] Example 17: 1-O-1-(4-(3-hydroxypropyl)phenyl)-2-propyl cyclohexanoate (III-3fa)

[0084]

[0085] In a test tube equipped with a magnetic stirrer, add compound (I) 4'-(3-hydroxypropyl)phenylacetone (57 mg, 0.3 mmol, 1.0 equiv), potassium carbonate (41 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) cyclohexane (232 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 20:1 to obtain the target product with a yield of 58% and an HPLC purity of 97.0%.

[0086] 1H NMR (400MHz, CDCl3) δ7.92–7.83(m,2H),7.30(d,J=8.4Hz,2H),5.95(q,J=7.0Hz,1H),3.67(t,J=6.3Hz,2H),2.77(dd,J=8.8,6.7Hz,2H), 2.41(tt,J=11.2,3.6Hz,1H),2.07(s,1H),2.01–1.84(m,4H),1.79–1.71(m,2H),1.68–1.58(m,1H),1.55–1.39(m,5H),1.37–1.18(m,3H). 13 C NMR (101MHz, CDCl3) δ196.74,175.53,148.31,132.39,128.80,128.71,70. 90,61.85,42.79,33.72,32.12,28.89,28.81,25.72,25.33,25.31,17.05.

[0087] Example 18: 1-O-1-(2-methyl-4-tert-butylphenyl)-2-propyl cyclohexanoate (III-3ga)

[0088]

[0089] In a test tube equipped with a magnetic stirrer, add compound (I) 2'-methyl-4'-tert-butylphenylacetone (61 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) cyclohexane (38 mg, 0.3 mmol, 1.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with 25W blue-violet light and stirred at 55℃ for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10mL), followed by ethyl acetate (20mL) and a small amount of water (2mL). The mixture was separated and extracted three times with ethyl acetate (15mL x 3). The combined organic layers were dried over 7.5g anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 36% and an HPLC purity of 97.0%.

[0090] 1H NMR (400MHz, CDCl3) δ7.67–7.61(m,1H),7.31–7.25(m,2H),5.81(q,J=7.0Hz,1H),2.48(s,3H),2.45–2.3 4(m,1H),1.96–1.85(m,2H),1.80–1.69(m,2H),1.68–1.60(m,1H),1.52–1.42(m,5H),1.23–1.37(m,12H). 13 C NMR (101MHz, CDCl3) δ200.73,175.50,154.97,138.46,132.82,128.86,128.31,122 .48,72.57,42.81,34.79,31.05,28.87,28.76,25.74,25.33,25.30,20.99,16.45.

[0091] Example 19: 1-O-1-(4-methylnaphth-1-yl)-2-propyl cyclohexanoate (III-3ha)

[0092]

[0093] In a test tube equipped with a magnetic stirrer, add compound (I) 4'-methylnaphth-1-ylethyl ketone (60 mg, 0.3 mmol, 1.0 equiv), sodium carbonate (32 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (30 mg, 0.03 mmol, 0.10 equiv), compound (II) cyclohexane (308 mg, 2.4 mmol, 8.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with a 3W blue light and stirred at 55°C for 72 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10 mL), followed by the addition of ethyl acetate (20 mL) and a small amount of water (2 mL). The mixture was separated and extracted three times with ethyl acetate (15 mL x 3). The combined organic layers were dried over 7.5 g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 40:1 to obtain the target product with a yield of 52% and an HPLC purity of 97.5%.

[0094] 1H NMR (400MHz, CDCl3) δ8.49–8.43(m,1H),8.09–8.04(m,1H),7.89(d,J=7.3Hz,1H),7.64–7.56(m,2H),7.37(dd,J=7.3,1.0Hz,1H),5.98(q,J=7.0H z,1H),2.76(s,3H),2.45(tt,J=11.2,3.7Hz,1H),2.03–1.90(m,2H),1.8 3–1.74(m,2H),1.70–1.62(m,1H),1.58–1.42(m,5H),1.40–1.21(m,3H). 13 C NMR (101MHz, CDCl3) δ200.84,175.69,139.74,132.99,132.34,130.60,127.51,127.24,126. 43,125.97,125.21,124.32,73.09,42.84,28.97,28.82,25.75,25.36,25.32,19.98,16.47.

[0095] Example 20: 1-O-1-(2,3-dihydrobenzofuran-5-yl)-2-propyl cyclohexanecarboxylic acid (III-3ia)

[0096]

[0097] In a test tube equipped with a magnetic stirrer, add compound (I) 2,3-dihydrobenzofuran-5-ylethyl ketone (53 mg, 0.3 mmol, 1.0 equiv), 2,4,6-trimethylpyridine (36 mg, 0.3 mmol, 1.0 equiv), Bengal rose red (15 mg, 0.015 mmol, 0.05 equiv), compound (II) cyclohexanecarboxylic acid (232 mg, 1.8 mmol, 6.0 equiv), water (0.3 mL), dimethyl sulfoxide (1.0 mL), and oxygen replacement. The reaction system was irradiated with 3W blue light and stirred at 55°C for 48 hours. After the reaction was completed, excess saturated sodium bicarbonate solution was added to quench the reaction (10 mL), followed by ethyl acetate (20 mL) and a small amount of water (2 mL). The mixture was separated and extracted three times with ethyl acetate (15 mL x 3). The combined organic layers were dried over 7.5 g of anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified on a silica gel column using petroleum ether / ethyl acetate at a volume ratio of 30:1 to obtain the target product with a yield of 30% and an HPLC purity of 97.0%.

[0098] 1H NMR (400MHz, CDCl3) δ7.87–7.75(m,2H),6.81(d,J=8.4Hz,1H),5.92(q,J=7.0Hz,1H),4.66(t,J=8.8Hz,2H),3.24(t,J=8.7Hz,2 H),2.41(tt,J=11.3,3.7Hz,1H),2.01–1.88(m,2H),1.81–1.71(m,2H),1.70–1.58(m,1H),1.54–1.39(m,5H),1.35–1.22(m,3H). 13 C NMR (101MHz, CDCl3) δ195.37,175.48,164.75,130.42,127.93,127.68,125.87, 109.20,72.23,70.66,42.81,28.97,28.91,28.83,25.73,25.34,25.33,17.25.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for photocatalytic synthesis of α-acyloxyketones, characterized in that... The aryl ketone compound represented by formula (I) and the acid represented by formula (II) were added to the reaction solvent, along with a base and a photocatalyst. The reaction was carried out under air or oxygen atmosphere and light conditions at 20-60 °C with stirring for 24-72 hours. After the reaction was completed, the reaction solution was post-treated to obtain the target compound, the phenylacetone α-acyloxylated derivative of formula (III), with the following reaction equation: ； In formula (I), the aryl group attached to the carbonyl group is naphthyl, 2,3-dihydrobenzofuranyl, phenyl or substituted phenyl, and the substituent of the substituted phenyl group is C1-C6 alkyl, phenylthio or hydroxy-substituted C1-C6 alkyl. In equations (I) and (III), R 1 Derived from hydrogen, C1-C6 alkyl, or C1-C6 substituted alkyl; In equations (II) and (III), R 2 It is derived from one of the following: cyclohexyl, cyclopentyl, C1-C6 straight-chain alkane or branched alkyl, vinyl, cyclopentylmethyl, 2-tetrahydrofuranyl, phenyl-substituted C1-C4 straight-chain alkane or branched alkyl, 2-thienyl, 1-naphthyl, phenyl or substituted phenyl, wherein the substituent of the substituted phenyl is a C1-C4 alkyl, nitro or halogen; The illumination is performed under visible light, and the light source is blue light or white light. The photocatalyst is Bengal rose red; The reaction solvent is one or any combination of the following: dimethyl sulfoxide, acetonitrile, and water.

2. The method for photocatalytic synthesis of α-acyloxyketones according to claim 1, characterized in that... The molar amount of the photocatalyst is 0.01 to 0.1 times the molar amount of the aryl ketone compound shown in formula (I).

3. The method for photocatalytic synthesis of α-acyloxyketones according to claim 2, characterized in that... The molar amount of the photocatalyst is 0.02 to 0.05 times the molar amount of the aryl ketone compound shown in formula (I).

4. The method for photocatalytic synthesis of α-acyloxyketones according to claim 1, characterized in that... The base used is sodium bicarbonate, sodium carbonate, potassium carbonate, sodium hydroxide, tripotassium phosphate, sodium acetate, triethylamine or 2,4,6-trimethylpyridine, and the molar amount of the base is 0.5 to 2 times the molar amount of the aryl ketone compound shown in formula (I).

5. The method for photocatalytic synthesis of α-acyloxyketones according to claim 1, characterized in that, The volume ratio of the reaction solvent to the amount of aryl ketone compound shown in formula (I) is 2 to 8:1, with volume in mL and amount in mmol.

6. A method for photocatalytic synthesis of α-acyloxyketones according to claim 1, characterized in that... The molar ratio of the ketone shown in formula (I) to the acid shown in formula (II) is 1:1 to 1:

10.

7. The method for photocatalytic synthesis of α-acyloxyketones according to claim 1, characterized in that... The reaction takes place in an oxygen atmosphere.

8. The method for photocatalytic synthesis of α-acyloxyketones according to claim 1, characterized in that... The post-processing procedure is as follows: After the reaction is completed, the reaction solution is quenched with saturated sodium bicarbonate solution, ethyl acetate is added, then water is added, the mixture is separated, the aqueous layer is extracted with ethyl acetate several times, the organic layers are combined, dried with anhydrous Na2SO4 and concentrated under reduced pressure to obtain the crude product, the crude product is separated and purified by chromatographic column to obtain the α-acyloxylated aryl ketone compound represented by the target compound (Ⅲ).

9. A method for photocatalytic synthesis of α-acyloxyketones according to claim 1, characterized in that... The following steps were performed: ketone (I), base, Bengal rose red, acid (II), and reaction solvent were added to a reactor equipped with a magnetic stirrer. After oxygen replacement, the mixture was stirred at 20-60 °C under light irradiation. After the reaction was completed, the reaction solution was quenched with excess saturated sodium bicarbonate solution, ethyl acetate was added, followed by water. The mixture was separated, and the aqueous layer was extracted several times with ethyl acetate. The combined organic layers were dried with anhydrous Na2SO4 and concentrated under reduced pressure to obtain the crude product. The crude product was purified by column chromatography to obtain the α-acyloxylated aryl ketone compound represented by the target compound (III). The eluent for column purification was petroleum ether / ethyl acetate with a volume ratio of 40:1 to 20:

1.

10. The method for photocatalytic synthesis of α-acyloxyketones according to claim 1, characterized in that... In equations (I) and (III), R 1 Derived from methyl, propyl, isopropyl or benzyl.

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