Photoelectric synthesis method of ketone compound

Abstract

The invention discloses a photoelectric synthesis method of ketone compounds, and relates to the technical field of organic photoelectric synthesis. The method solves the technical problem that in-situ activation of aromatic formic acid and direct coupling of hydrocarbon are difficult to realize in the prior art to prepare ketone compounds. According to the invention, illumination is continuously carried out in a reaction system, constant current is introduced, carboxylic acid and hydrocarbon are taken as reactants, chlorine free radicals are formed through an iron catalyst, an intermediate of the chlorine free radicals carries out hydrogen exchange on the hydrocarbon to obtain an alkyl free radical, and an intermediate of an acyl nickel compound is formed at a cathode at the same time; then the intermediate captures alkyl free radicals, and a reduction elimination process is carried out to obtain ketone products. In the reaction, electrons provided by current in a system are used as a cheap and clean oxidant, so that the use of an additional oxidant is avoided, the reaction operation is simple, and the condition is mild. The ketone compound prepared by the invention is applied to the field of treatment of neurodegenerative diseases.

Description

Technical Field

[0001] The invention relates to the technical field of organic photoelectric synthesis, and in particular to a method for preparing ketone compounds. Background Art

[0002] Ketone compounds are widely found in drugs, natural products, and agricultural products. Their synthesis is a very important topic in chemical research. Especially in the treatment of neurodegenerative diseases, ketone drugs are very effective. For example, Tolcapone is a clinical drug used to treat Parkinson's disease.

[0003] Carboxylic acid compounds are important building blocks for the rapid construction of high-value-added organic molecules and are also easily available bulk chemicals. Some of the existing attractive ketone synthesis pathways are the reaction of Grignard reagents with carboxylic acids and their derivatives, and metal catalysis, photochemistry, and peroxide oxidation have all been reported. Although the corresponding ketone compounds can be effectively obtained, there are still some inherent disadvantages, such as the need to use equivalent oxidants or reductants, harsh reaction conditions, cumbersome post-treatment, and the use of organometallic reagents to a certain extent will lead to limited substrate universality and functional group diversity. In addition, pre-activated carboxylic acid derivatives are sometimes required, and the method is not simple and efficient. The development of green and simple synthetic methods to directly synthesize ketone compounds by directly activating hydrocarbons and carboxylic acids is still a topic to be studied. Therefore, it is particularly important to use simple carboxylic acids and hydrocarbons to achieve intermolecular coupling to synthesize ketones under mild conditions. Summary of the invention

[0004] The present invention solves the technical problem that it is difficult to realize the in-situ activation of aromatic formic acid and direct coupling with hydrocarbons to prepare ketone compounds with existing reaction technologies, and provides a photoelectric synthesis method for ketone compounds. The present invention uses a photoelectrochemical synthesis strategy, continuously illuminates the reaction system and passes a constant current, takes simple carboxylic acids and hydrocarbons as reactants, and forms chlorine free radicals through a ligand-to-metal charge transfer process after the iron catalyst is photoexcited at the anode. The chlorine free radical intermediate captures hydrogen from the hydrocarbon to obtain an alkyl free radical. At the same time, the nickel catalyst and the acid anhydride generated by the in-situ activation of the carboxylic acid undergo an oxidative addition process at the cathode to form an acyl nickel compound intermediate, which then captures the alkyl free radical, and then undergoes a reduction elimination process to obtain ketone products, and the catalytic cycle of the nickel catalyst is completed through a change in valence state.

[0005] A photoelectric synthesis method of ketone compounds is specifically carried out according to the following steps:

[0006] 1. Place an anode electrode and a cathode electrode in a quartz tube, add a carboxylic acid compound, a hydrocarbon compound, diethyl pyrocarbonate, an iron catalyst, a nickel catalyst, a ligand, a base and LiCl in an inert gas atmosphere, then add an ultra-dry solvent and seal the system;

[0007] The carboxylic acid compound is benzoic acid, 4-chlorobenzoic acid, 4-fluorobenzoic acid, 4-methylbenzoic acid, 2-methylbenzoic acid, 3-phenylpropionic acid, cyclohexylcarboxylic acid or ketoprofen;

[0008] The ligand is 4,4′-di-tert-butyl-2,2′-bipyridine;

[0009] 2. Continuously irradiate the closed system in step 1 under light with a wavelength of 390-395 nm, while continuously passing a constant current and stirring to obtain a crude product;

[0010] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain the ketone compound.

[0011] Furthermore, the hydrocarbon in step 1 is cyclopentane, cyclohexane, norbornane, tetraethylsilane, trimethylacetonitrile, toluene, 4-chlorotoluene, 4-cyanotoluene, 4-methyltoluene or cyclopentanone.

[0012] Furthermore, the base in step 1 is sodium carbonate.

[0013] Furthermore, the ultra-dry solvent in step 1 is ultra-dry acetonitrile.

[0014] Furthermore, the iron catalyst in step 1 is ferrous chloride tetrahydrate.

[0015] Furthermore, the nickel catalyst in step 1 is nickel perchlorate hexahydrate.

[0016] Furthermore, in step 1, the ratio of the carboxylic acid compound to the ultra-dry solvent is 0.2mmol:2mL; the ratio of the hydrocarbon to the ultra-dry solvent is 2mmol:2mL; the ratio of diethyl pyrocarbonate to the ultra-dry solvent is 0.4mmol:2mL; the ratio of the iron catalyst to the ultra-dry solvent is 0.02mmol:2mL; the ratio of the nickel catalyst to the ultra-dry solvent is 0.03mmol:2mL; the ratio of the ligand to the ultra-dry solvent is 0.02mmol:2mL; the ratio of LiCl to the ultra-dry solvent is 0.4mmol:2mL; and the ratio of the base to the ultra-dry solvent is 0.2mmol:2mL.

[0017] Furthermore, in step 1, the anode electrode is a carbon felt electrode, and the cathode electrode is a carbon felt electrode.

[0018] Furthermore, in step 2, the current of the constant current is controlled to be 4 mA, the temperature of the condensation pump connected to the photoreactor is 16° C., the continuous power-on and illumination time is 12 hours; and TLC is used to monitor the progress of the reaction.

[0019] Furthermore, the solvent used for the thin layer chromatography separation and purification in step 3 is a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 30:1.

[0020] The general reaction formula of the present invention is as follows:

[0021]

[0022] The ketone compounds prepared by the present invention are aryl ketone compounds or alkyl ketone compounds. When aromatic carboxylic acids are used as substrates, aryl ketone compounds can be generated; when alkyl carboxylic acids are used as substrates, alkyl ketone compounds can be obtained.

[0023] The reaction mechanism of the present invention is shown in FIG. Figure 3 shown.

[0024] Initially, the process starts with the Fe(III) complex (A), which is excited by light to produce its excited state (B). The excited state [FeCl4] - The catalyst undergoes a ligand-to-metal charge transfer (LMCT) process to generate chlorine radicals, which react with alkanes to form an activated carbon-centered radical intermediate (D). - Oxidized at the anode to recover [FeCl4] - The cycle is completed. At the same time, the Ni(II) catalyst precursor is reduced at the cathode to generate Ni(0) species (E), and the intermediate E is further oxidized and added with the anhydride to form an acyl Ni(II) species (F). The carbon-centered free radical is captured by the Ni(II) intermediate F to generate a Ni(III) species (G), which is then subjected to a reduction elimination process to obtain the target ketone product, forming a Ni(I) species (H), which is then reduced at the cathode to generate the active Ni(0) intermediate E to complete the cycle.

[0025] Beneficial effects of the present invention:

[0026] Compared with the prior art, the present invention synthesizes ketone compounds through a simple, green and efficient method, which mainly has the following advantages:

[0027] (1) The reaction uses the electrons provided by the current in the system as a cheap and clean oxidant, avoiding the use of external oxidants. The reaction operation is simple and the conditions are mild.

[0028] (2) The carboxylic acid compound, hydrocarbon compound, diethyl pyrocarbonate, iron catalyst, nickel catalyst, ligand, base, LiCl and ultra-dry solvent used in the reaction system are all simple, cheap and readily available commercial compounds. The carbon felt electrode used is also a relatively cheap electrode sheet, making the reaction system simple and economical.

[0029] (3) The reaction system has a wide range of substrate applications and can be used to synthesize a variety of aromatic or alkyl ketone compounds. The reaction substrates may include polysubstituted carboxylic acid compounds, cycloalkane compounds, silane compounds, nitrile compounds, and aromatic or alkyl ketone compounds with different substituents.

[0030] The ketone compounds prepared by the invention are used in the field of treating neurodegenerative diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the ketone compound (4-1) obtained in Example 1 1 H NMR spectrum;

[0032] Figure 2 is the ketone compound (4-1) obtained in Example 1 13 C NMR spectrum;

[0033] Figure 3 It is the reaction mechanism diagram of the present invention. DETAILED DESCRIPTION

[0034] Specific implementation method 1: This implementation method is a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0035] 1. Place an anode electrode and a cathode electrode in a quartz tube, add a carboxylic acid compound, a hydrocarbon compound, diethyl pyrocarbonate, an iron catalyst, a nickel catalyst, a ligand, a base and LiCl in an inert gas atmosphere, then add an ultra-dry solvent and seal the system;

[0036] The carboxylic acid compound is benzoic acid, 4-chlorobenzoic acid, 4-fluorobenzoic acid, 4-methylbenzoic acid, 2-methylbenzoic acid, 3-phenylpropionic acid, cyclohexylcarboxylic acid or ketoprofen;

[0037] The ligand is 4,4'-di-tert-butyl-2,2'-bipyridine;

[0038] 2. Continuously irradiate the closed system in step 1 under light with a wavelength of 390-395 nm, while continuously passing a constant current and stirring to obtain a crude product;

[0039] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain the ketone compound.

[0040] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the hydrocarbon compound in step 1 is cyclopentane, cyclohexane, norbornane, tetraethylsilane, trimethylacetonitrile, toluene, 4-chlorotoluene, 4-cyanotoluene, 4-methyltoluene or cyclopentanone. The rest is the same as specific embodiment 1.

[0041] Specific embodiment 3: This embodiment is different from specific embodiment 1 or 2 in that the base in step 1 is sodium carbonate. The rest is the same as specific embodiment 1 or 2.

[0042] Specific embodiment 4: This embodiment differs from any one of specific embodiments 1 to 3 in that the ultra-dry solvent in step 1 is ultra-dry acetonitrile. The rest is the same as any one of specific embodiments 1 to 3.

[0043] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the iron catalyst in step 1 is ferrous chloride tetrahydrate. The rest is the same as specific embodiments 1 to 4.

[0044] Specific embodiment 6: This embodiment is different from specific embodiments 1 to 5 in that the nickel catalyst in step 1 is nickel perchlorate hexahydrate. The rest is the same as specific embodiments 1 to 5.

[0045] Specific embodiment 7: This embodiment is different from specific embodiments 1 to 6 in that: in step 1, the ratio of the carboxylic acid compound to the ultra-dry solvent is 0.2mmol:2mL; the ratio of the hydrocarbon compound to the ultra-dry solvent is 2mmol:2mL; the ratio of diethyl pyrocarbonate to the ultra-dry solvent is 0.4mmol:2mL; the ratio of the iron catalyst to the ultra-dry solvent is 0.02mmol:2mL; the ratio of the nickel catalyst to the ultra-dry solvent is 0.03mmol:2mL; the ratio of the ligand to the ultra-dry solvent is 0.02mmol:2mL; the ratio of LiCl to the ultra-dry solvent is 0.4mmol:2mL; the ratio of the base to the ultra-dry solvent is 0.2mmol:2mL. Others are the same as specific embodiments 1 to 6.

[0046] Specific implementation eight: This implementation differs from specific implementations one to seven in that the anode electrode in step one is a carbon felt electrode, and the cathode electrode is a carbon felt electrode. The rest is the same as specific implementations one to seven.

[0047] Specific embodiment 9: This embodiment is different from specific embodiments 1 to 8 in that: the current of step 2 for controlling the constant current is 4 mA, the temperature of the condensation pump connected to the photoreactor is 16° C., the continuous power-on and light-irradiation time is 12 hours; and TLC is used to monitor the reaction progress. Others are the same as specific embodiments 1 to 8.

[0048] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the solvent used for separation and purification by thin layer chromatography in step 3 is a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 30:1. The rest is the same as specific embodiments 1 to 9.

[0049] The content of the present invention is not limited to the content of the above-mentioned embodiments. The combination of one or several specific embodiments can also achieve the purpose of the invention.

[0050] Embodiment 1:

[0051] The present embodiment provides a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0052] 1. Place two carbon felt electrodes in a 10 mL quartz tube and add 0.2 mmol benzoic acid, 2 mmol cyclohexane, 0.4 mmol diethyl pyrocarbonate, and 0.02 mmol FeCl in an inert gas atmosphere. 2. 4H2O, 0.03mmol Ni(ClO4) 2. 6H2O, 0.04mmol 4,4′-di-tert-butyl-2,2′bipyridine, 0.4mmol Na2CO3 and 0.4mmol LiCl, and then add 2mL of ultra-dry acetonitrile solvent, and seal the system;

[0053] 2. The closed system in step 1 was continuously irradiated under 390-395 nm light, and a constant current of 4 mA was continuously passed. The temperature of the condensation pump connected to the photoreactor was 16°C. The reaction was stirred for 12 h, and the reaction progress was monitored by TLC to obtain a crude product.

[0054] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain a product, which is identified as an aromatic ketone compound (4-1) by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum, and its structural formula is:

[0055]

[0056] Purity 99%, yield 66%; its NMR data analysis is: 1 H NMR (400MHz, Chloroform-d) δ7.94 (d, J = 7.8Hz, 2H), 7.57-7.49 (m, 1H), 7.45 (t, J = 7.1Hz, 2H), 3.26 (tt, J = 11. 5,3.3Hz,1H),1.91-1.82(m,4H),1.77-1.69(m,1H),1.45-1.34(m,2H),1.44-1.33(m,2H),1.32-1.28(m,1H).

[0057] 13 C NMR (101MHz, Chloroform-d) δ204.01,136.38,132.81,128.65,45.67,29.48,26.03,25.92.

[0058] Embodiment 2:

[0059] The present embodiment provides a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0060] 1. Place two carbon felt electrodes in a 10 mL quartz tube and add 0.2 mmol 4-chlorobenzoic acid, 2 mmol cyclohexane, 0.4 mmol diethyl pyrocarbonate, and 0.02 mmol FeCl in an inert gas atmosphere. 2. 4H2O, 0.03mmol Ni(ClO4) 2. 6H2O, 0.04mmol 4,4′-di-tert-butyl-2,2′bipyridine, 0.4mmol Na2CO3 and 0.4mmol LiCl, and then add 2mL of ultra-dry acetonitrile solvent, and seal the system;

[0061] 2. The closed system in step 1 was continuously irradiated under 390-395 nm light, and a constant current of 4 mA was continuously passed. The temperature of the condensation pump connected to the photoreactor was 16°C. The reaction was stirred for 12 h, and the reaction progress was monitored by TLC to obtain a crude product.

[0062] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain a product, which is identified as an aromatic ketone compound (4-2) by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum, and its structural formula is:

[0063]

[0064] Purity 99%, yield 50%; its NMR data analysis is: 1 H NMR (400MHz, CDCl3) δ7.92-7.85(m,2H),7.46-7.40(m,2H),3.20(td,J=11.1,5.6Hz,1H),1.89-1.82(m,4H),1.80-1.68(m,1H),1.55-1.33(m,5H).

[0065] 13 C NMR (101MHz, CDCl3) δ202.73,139.19,134.65,129.78,128.96,45.69,29.42,25.96,25.86.

[0066] Embodiment 3:

[0067] The present embodiment provides a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0068] 1. Place two carbon felt electrodes in a 10 mL quartz tube and add 0.2 mmol 3-phenylpropionic acid, 2 mmol cyclohexane, 0.4 mmol diethyl pyrocarbonate, and 0.02 mmol FeCl in an inert gas atmosphere. 2. 4H2O, 0.03mmol Ni(ClO4) 2. 6H2O, 0.04mmol 4,4′-di-tert-butyl-2,2′bipyridine, 0.4mmol Na2CO3 and 0.4mmol LiCl, and then add 2mL of ultra-dry acetonitrile solvent, and seal the system;

[0069] 2. The closed system in step 1 was continuously irradiated under 390-395 nm light, and a constant current of 4 mA was continuously passed. The temperature of the condensation pump connected to the photoreactor was 16°C. The reaction was stirred for 12 h, and the reaction progress was monitored by TLC to obtain a crude product.

[0070] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain a product, which is identified as an alkyl ketone compound (5-1) by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum, and its structural formula is:

[0071]

[0072] Purity 99%, yield 38%; its NMR data analysis is: 1 H NMR(400MHz, CDCl3)δ7.27(dd,J=8.7,5.1Hz,2H),7.23-7.13(m,3H),2.88(td,J=7.7,2.8 Hz,2H),2.76(td,J=7.5,2.9Hz,2H),2.31(tt,J=11.1,3.3Hz,1H),1.86-1.72(m,4H),1.70 -1.60(m,1H),1.33-1.18(m,5H).

[0073] 13 C NMR (101MHz, CDCl3) δ203.66,143.53,133.83,129.33,128.46,45.57,29.54,26.04,25.95,21.66.

[0074] Example 4

[0075] The present embodiment provides a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0076] 1. Place two carbon felt electrodes in a 10 mL quartz tube and add 0.2 mmol cyclohexanecarboxylic acid, 2 mmol cyclohexane, 0.4 mmol diethyl pyrocarbonate, and 0.02 mmol FeCl in an inert gas atmosphere. 2. 4H2O, 0.03mmol Ni(ClO4) 2. 6H2O, 0.04mmol 4,4′-di-tert-butyl-2,2′bipyridine, 0.4mmol Na2CO3 and 0.4mmol LiCl, and then add 2mL of ultra-dry acetonitrile solvent, and seal the system;

[0077] 2. The closed system in step 1 was continuously irradiated under 390-395 nm light, and a constant current of 4 mA was continuously passed. The temperature of the condensation pump connected to the photoreactor was 16°C. The reaction was stirred for 12 h, and the reaction progress was monitored by TLC to obtain a crude product.

[0078] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain a product, which is identified as an alkyl ketone compound (5-2) by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum, and its structural formula is:

[0079]

[0080] Purity 99%, yield 32%; its NMR data analysis is: 1 H NMR (400MHz, Chloroform-d) δ2.49 (t, J = 10.5Hz, 2H), 1.79-1.76 (m, 8H), 1.69-1.66 (m, 2H), 1.38-1.16 (m, 10H).

[0081] 13 C NMR (101 MHz, Chloroform-d) δ 217.17, 49.20, 28.62, 25.91, 25.77.

[0082] Embodiment 5:

[0083] The present embodiment provides a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0084] 1. Place two carbon felt electrodes in a 10 mL quartz tube and add 0.2 mmol benzoic acid, 2 mmol cyclopentane, 0.4 mmol diethyl pyrocarbonate, and 0.02 mmol FeCl in an inert gas atmosphere. 2. 4H2O, 0.03mmol Ni(ClO4)2. 6H2O, 0.04mmol 4,4′-di-tert-butyl-2,2′bipyridine, 0.4mmol Na2CO3 and 0.4mmol LiCl, and then add 2mL of ultra-dry acetonitrile solvent, and seal the system;

[0085] 2. The closed system in step 1 was continuously irradiated under 390-395 nm light, and a constant current of 4 mA was continuously passed. The temperature of the condensation pump connected to the photoreactor was 16°C. The reaction was stirred for 12 h, and the reaction progress was monitored by TLC to obtain a crude product.

[0086] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain a product, which is identified as an aromatic ketone compound (4-3) by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum, and its structural formula is:

[0087]

[0088] Purity 99%, yield 52%; its NMR data analysis is: 1 H NMR (400MHz, CDCl3) δ8.04-7.87(m,2H),7.60-7.49(m,1H),7.49-7.39(m,2H),3.72(p,J=7.9Hz,1H),2.02-1.83(m,4H),1.81-1.57(m,4H).

[0089] 13 C NMR (101MHz, CDCl3) δ202.91, 136.96, 132.79, 128.57, 128.53, 46.40, 30.03, 26.38.

[0090] Embodiment 6:

[0091] The present embodiment provides a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0092] 1. Place two carbon felt electrodes in a 10 mL quartz tube and add 0.2 mmol benzoic acid, 0.4 mmol norbornane, 0.4 mmol diethyl pyrocarbonate, and 0.02 mmol FeCl in an inert gas atmosphere. 2. 4H2O, 0.03mmol Ni(ClO4) 2. 6H2O, 0.04mmol 4,4′-di-tert-butyl-2,2′bipyridine, 0.4mmol Na2CO3 and 0.4mmol LiCl, and then add 2mL of ultra-dry acetonitrile solvent, and seal the system;

[0093] 2. The closed system in step 1 was continuously irradiated under 390-395 nm light, and a constant current of 4 mA was continuously passed. The temperature of the condensation pump connected to the photoreactor was 16°C. The reaction was stirred for 12 h, and the reaction progress was monitored by TLC to obtain a crude product.

[0094] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain a product, which is identified as an aromatic ketone compound (4-4) by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum, and its structural formula is:

[0095]

[0096] Purity 99%, yield 36%; its NMR data analysis is: 1 H NMR (400MHz, CDCl3) δ7.99-7.94(m,2H),7.57-7.51(m,1H),7.47-7.43(m,2H),3.22(dd,J=9.0,5.5Hz,1H),2.53-2.52(m ,1H),2.39-2.32(m,1H),2.06-1.99(m,1H),1.68-1.54(m,2H),1.52-1.38(m,3H),1.35-1.26(m,1H),1.19-1.11(m,1H).

[0097] 13 C NMR (101MHz, CDCl3) δ201.48,136.61,132.71,128.55,128.53,77.31,49.56,41.07,36.34,36.25,33.72,29.81,29.09.

[0098] Embodiment 7:

[0099] The present embodiment provides a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0100] 1. Place two carbon felt electrodes in a 10 mL quartz tube and add 0.2 mmol 3-phenylpropionic acid, 2 mmol p-chlorotoluene, 0.4 mmol diethyl pyrocarbonate, and 0.02 mmol FeCl in an inert gas atmosphere. 2. 4H2O, 0.03mmol Ni(ClO4) 2. 6H2O, 0.04mmol 4,4′-di-tert-butyl-2,2′bipyridine, 0.4mmol Na2CO3 and 0.4mmol LiCl, and then add 2mL of ultra-dry acetonitrile solvent, and seal the system;

[0101] 2. The closed system in step 1 was continuously irradiated under 390-395 nm light, and a constant current of 4 mA was continuously passed. The temperature of the condensation pump connected to the photoreactor was 16°C. The reaction was stirred for 12 h, and the reaction progress was monitored by TLC to obtain a crude product.

[0102] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain a product, which is identified as an alkyl ketone compound (5-3) by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum, and its structural formula is:

[0103]

[0104] Purity 99%, yield 45%; its NMR data analysis is: 1 H NMR (400MHz, CDCl3) δ7.27 (dd, J=8.1, 6.3Hz, 4H), 7.24-7.18 (m, 1H), 7.14 (d, J=7.5Hz ,2H),7.08(d,J=8.0Hz,2H),3.63(s,2H),2.89(t,J=7.4Hz,2H),2.78(t,J=7.4Hz,2H).

[0105] 13 C NMR (101MHz, CDCl3) δ206.94,140.83,133.07,132.50,130.86,128.92,128.61,128.42,126.28,49.54,43.74,29.84.

[0106] Embodiment 8:

[0107] The present embodiment provides a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0108] 1. Place two carbon felt electrodes in a 10 mL quartz tube and add 0.2 mmol 3-phenylpropanoic acid, 2 mmol neopentane chloride, 0.4 mmol diethyl pyrocarbonate, and 0.02 mmol FeCl in an inert gas atmosphere. 2. 4H2O, 0.03mmol Ni(ClO4) 2. 6H2O, 0.04mmol 4,4′-di-tert-butyl-2,2′bipyridine, 0.4mmol Na2CO3 and 0.4mmol LiCl, and then add 2mL of ultra-dry acetonitrile solvent, and seal the system;

[0109] 2. The closed system in step 1 was continuously irradiated under 390-395 nm light, and a constant current of 4 mA was continuously passed. The temperature of the condensation pump connected to the photoreactor was 16°C. The reaction was stirred for 12 h, and the reaction progress was monitored by TLC to obtain a crude product.

[0110] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain a product, which is identified as a ketone compound (5-4) by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum, and its structural formula is:

[0111]

[0112] Purity 99%, yield 35%; its NMR data analysis is: 1 H NMR (400MHz, CDCl3) δ7.29-7.25(m,2H),7.20-7.16(m,3H),3.53(s,2H),2.87(t,J=7.6Hz,2H),2.72(t,J=7.6Hz,2H),2.44(s,2H),1.06(s,6H).

[0113] 13 C NMR (101MHz, CDCl3) δ209.02,141.07,128.57,128.41,126.18,54.63,49.79,46.07,35.45,29.73,25.69.

[0114] Embodiment 9:

[0115] The present embodiment provides a photoelectric synthesis method of ketone compounds, which is specifically carried out according to the following steps:

[0116] 1. Place two carbon felt electrodes in a 10 mL quartz tube and add 0.2 mmol ketoprofen, 2 mmol cyclohexane, 0.4 mmol diethyl pyrocarbonate, and 0.02 mmol FeCl in an inert gas atmosphere. 2. 4H2O, 0.03mmol Ni(ClO4) 2. 6H2O, 0.04mmol 4,4′-di-tert-butyl-2,2′bipyridine, 0.4mmol Na2CO3 and 0.4mmol LiCl, and then add 2mL of ultra-dry acetonitrile solvent, and seal the system;

[0117] 2. The closed system in step 1 was continuously irradiated under 390-395 nm light, and a constant current of 4 mA was continuously passed. The temperature of the condensation pump connected to the photoreactor was 16°C. The reaction was stirred for 12 h, and the reaction progress was monitored by TLC to obtain a crude product.

[0118] 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain a product, which is identified as a ketone compound (5-5) by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum, and its structural formula is:

[0119]

[0120] Purity 99%, yield 30%; its NMR data analysis is: 1 H NMR (400MHz, CDCl3) δ7.82-7.77(m,2H),7.70-7.65(m,2H),7.61(t,J=7.4Hz,1H),7.53-7.40(m,4H),4.01(q,J=6.9Hz,1H),2.50-2.39(m,1 H),1.86-1.84(m,1H),1.80-1.73(m,1H),1.70-1.67(m,2H),1.55-1.4 8(m,1H),1.40(d,J=7.0Hz,3H),1.35-1.23(m,3H),1.18-1.11(m,2H).

[0121] 13 C NMR (101MHz, CDCl3) δ213.48,196.68,141.11,138.13,137.53,132.67,131.84,130.15,1 29.74,128.99,128.83,128.41,50.83,49.80,29.35,28.36,25.88,25.77,25.37,18.36.

[0122] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A photoelectric synthesis method of ketone compounds, characterized in that The method is specifically carried out in the following steps:

1. Place an anode electrode and a cathode electrode in a quartz tube, add a carboxylic acid compound, a hydrocarbon compound, diethyl pyrocarbonate, an iron catalyst, a nickel catalyst, a ligand, a base and LiCl in an inert gas atmosphere, then add an ultra-dry solvent and seal the system; The carboxylic acid compound is benzoic acid, 4-chlorobenzoic acid, 4-fluorobenzoic acid, 4-methylbenzoic acid, 2-methylbenzoic acid, 3-phenylpropionic acid, cyclohexylcarboxylic acid or ketoprofen; The ligand is 4,4'-di-tert-butyl-2,2'-bipyridine; 2. Continuously irradiate the closed system in step 1 under light with a wavelength of 390-395 nm, while continuously passing a constant current and stirring to obtain a crude product; 3. The crude product obtained in step 2 is subjected to reduced pressure distillation to remove the solvent, and then separated and purified by thin layer chromatography to obtain the ketone compound.

2. The photoelectric synthesis method of ketone compounds according to claim 1, characterized in that In step 1, the hydrocarbon compound is cyclopentane, cyclohexane, norbornane, tetraethylsilane, trimethylacetonitrile, toluene, 4-chlorotoluene, 4-cyanotoluene, 4-methyltoluene or cyclopentanone.

3. The photoelectric synthesis method of ketone compounds according to claim 1, characterized in that The base in step 1 is sodium carbonate.

4. The photoelectric synthesis method of ketone compounds according to claim 1, characterized in that The ultra-dry solvent in step 1 is ultra-dry acetonitrile.

5. The photoelectric synthesis method of ketone compounds according to claim 1, characterized in that The iron catalyst in step 1 is ferrous chloride tetrahydrate.

6. The photoelectric synthesis method of ketone compounds according to claim 1, characterized in that The nickel catalyst in step 1 is nickel perchlorate hexahydrate.

7. The photoelectric synthesis method of ketone compounds according to claim 1, characterized in that In step 1, the dosage ratio of the carboxylic acid compound to the ultra-dry solvent is 0.2mmol:2mL; the dosage ratio of the hydrocarbon to the ultra-dry solvent is 2mmol:2mL; the dosage ratio of diethyl pyrocarbonate to the ultra-dry solvent is 0.4mmol:2mL; the dosage ratio of the iron catalyst to the ultra-dry solvent is 0.02mmol:2mL; the dosage ratio of the nickel catalyst to the ultra-dry solvent is 0.03mmol:2mL; the dosage ratio of the ligand to the ultra-dry solvent is 0.02mmol:2mL; the dosage ratio of LiCl to the ultra-dry solvent is 0.4mmol:2mL; and the dosage ratio of the base to the ultra-dry solvent is 0.2mmol:2mL.

8. The photoelectric synthesis method of ketone compounds according to claim 1, characterized in that In step 1, the anode electrode is a carbon felt electrode, and the cathode electrode is a carbon felt electrode.

9. The photoelectric synthesis method of ketone compounds according to claim 1, characterized in that Step 2: The current of the constant current is controlled to be 4 mA, the temperature of the condensation pump connected to the photoreactor is 16° C., the continuous power-on and illumination time is 12 hours; and the reaction progress is monitored by TLC.

10. The photoelectric synthesis method of ketone compounds according to claim 1, characterized in that The solvent used for the thin layer chromatography separation and purification in step 3 is a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 30:1.

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