A method for preparing organic ketone compounds by light and metal synergistic catalysis

Abstract

The present invention discloses a method for preparing an organic ketone compound by synergistic catalysis of light and metal. The method realizes the reaction of keto acid and pyridinium tetrafluoroborate to generate an organic ketone compound under the synergistic catalytic conditions of a photocatalyst and a metal catalyst. The keto acid is oxidized to generate an acyl radical by a photocatalyst, and then the pyridinium tetrafluoroborate is reduced by a reduced photocatalyst to generate a carbon radical. Finally, the metal catalyst captures the generated acyl radical and carbon radical, and the metal catalyst further eliminates the product of the generated ketone compound by reduction. The present invention utilizes cheap and readily available keto acid and pyridinium salt as raw materials, and uses them in the synergistic action of metal and photocatalysis to prepare organic ketone compounds with potential biological activity in synthetic applications, and has the value of developing functional ketone compounds that can be used for industrial synthesis.

Description

Technical Field

[0001] The invention relates to a method for preparing an organic ketone compound, in particular to a method for preparing an organic ketone compound by catalysis of light and metal synergy. Background Art

[0002] Organic ketones are an important class of functional organic molecules, which are widely found in natural products, drug design and functional materials research. In addition, the carbonyl functional group in organic ketones is an important biologically active group, and a variety of different chemical transformations can be achieved by the carbonyl group. Therefore, the synthesis of functional organic ketones is one of the research focuses of chemical synthesis.

[0003] Free radical reaction is an important organic synthesis method with advantages such as mild conditions, high functional group tolerance, and a wide range of substrate applications. Using cheap and easy-to-prepare keto acids as raw materials, photocatalytic keto acid decarboxylation radical acylation reaction is an atomic step economical, green and efficient synthesis strategy for the synthesis of organic ketones. However, acyl radicals are often highly active and difficult to control the reaction selectivity. The key to keto acid decarboxylation radical acylation is to select suitable carbon radical precursors to couple with acyl radicals produced by keto acids. In the past, people used borides, chlorides and olefins to react with keto acids to generate organic ketones, but these methods often require high temperatures and strong oxidants to achieve, and the scope of application of the reaction is often limited.

[0004] Photocatalytic reaction is a green synthesis method that is expected to overcome the shortcomings brought by transition metals. Therefore, it is of great practical significance to develop new methods for synthesizing organic ketones with mild conditions and simple operation. Pyridinium tetrafluoroborate is an easy-to-prepare, cheap and readily available carbon radical precursor, which is widely used in photocatalytic free radical reactions. The synthesis of functional organic ketones by photocatalytic reaction of pyridinium tetrafluoroborate and ketoacid is expected to provide an effective synthetic route for the synthesis of ketones. In the past, the synthesis method of organic ketones under high temperature and strong oxidant conditions was highly efficient, but it required the use of strong oxidants. The high temperature conditions had harsh requirements on the reaction equipment, which did not meet the requirements of the development of modern green chemical industry and failed to be widely used in industry. The synthesis of organic ketones by photocatalytic ketoacids and pyridinium salts is expected to achieve greater breakthroughs in the preparation of ketones. In addition, based on this, it is very necessary to provide a new method for preparing organic ketone compounds catalyzed by light and metal synergy. Summary of the invention

[0005] Purpose of the invention: The present invention aims to provide a novel method for preparing organic ketone compounds by light and metal synergistic catalysis, utilizing a photocatalyst to realize keto acid decarboxylation and pyridinium salt reduction, and further realizing cross-coupling of acyl radicals produced by keto acid decarboxylation and carbon radicals produced by pyridinium salt reduction under the synergistic action of metal relay, thereby generating a green synthesis of organic ketone functional molecules.

[0006] Technical solution: The method for preparing an organic ketone compound by light and metal synergistic catalysis of the present invention comprises the following steps: adding keto acid, pyridinium tetrafluoroborate, a photocatalyst, a metal catalyst, a base and a ligand into an organic solvent, and reacting under light, the reaction formula is as follows:

[0007]

[0008] In the formula, R1 is selected from one of hydrogen, halogen, hydroxyl, and C1-C6 alkyl; R2 is selected from one of hydrogen, aryl, tert-butyl, halogen, halogen-substituted C1-C6 alkyl, methoxy, or cyano.

[0009] Preferably, R1 is selected from one of hydrogen, halogen, hydroxyl, methyl or ethyl; R2 is selected from one of hydrogen, aryl, tert-butyl, halogen, -CF3, methoxy or cyano.

[0010] In the above technical scheme, a photocatalyst is used to oxidize keto acid for decarboxylation to generate acyl radicals and a reduced photocatalyst. The generated reduced photocatalyst simultaneously reduces pyridinium salt to generate carbon radicals. Then, under the conditions of metal synergistic catalysis, the acyl radicals and carbon radicals generated by the photocatalysis are captured by the metal catalyst to generate a metal complex. The generated metal complex is reduced and eliminated to generate a ketone product, and the metal catalysis realizes a regeneration cycle.

[0011] Preferably, the photocatalyst is selected from 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile or (4,4'-di-tert-butyl-2,2'-bipyridyl)bis[3,5-difluoro-2-[5-trifluoromethyl-2-pyridyl]phenyl]iridium(III) hexafluorophosphate.

[0012] Preferably, the metal catalyst is selected from one of chromium dichloride, chromium trichloride, nickel dichloride, diacetyl nickel or nickel dibromide.

[0013] Preferably, the base is selected from one of sodium acetate, potassium carbonate, sodium methoxide or dipotassium hydrogen phosphate. The ligand is selected from one of 2,2'-bipyridine, 4,4-dimethyl-2,2-bipyridine, 4,4-di-tert-butyl-2,2-bipyridine or 4,4-dimethoxy-2,2-bipyridine.

[0014] Preferably, the light source in the reaction is a blue light source of 450 to 455 nm, and the power of the light source is 8 to 40 watts.

[0015] Preferably, the keto acid is selected from one of p-benzoylformic acid, p-fluorophenyloxalic acid, 2-(4-bromophenyl)-2-oxoacetic acid, 2-(4-hydroxyphenyl)-2-oxoacetic acid or 2-(4-ethylphenyl)-2-oxoacetic acid.

[0016] Preferably, the pyridinium tetrafluoroborate is selected from 1-benzyl-2,4,6-triphenylpyridine tetrafluoroborate, 1-(4-tert-butyl)benzyl-2,4,6-triphenylpyridine tetrafluoroborate, 1-(4-iodo)benzyl-2,4,6-triphenylpyridine tetrafluoroborate, 1-(4-trifluoromethyl)benzyl-2,4,6-triphenylpyridine tetrafluoroborate or 1-(4-cyano)benzyl-2,4,6-triphenylpyridine tetrafluoroborate.

[0017] Preferably, the organic solvent is selected from one of acetonitrile, tetrahydrofuran, ethyl acetate or dichloromethane, wherein tetrahydrofuran has the best effect and the highest yield of the product.

[0018] Preferably, the molar ratio of pyridinium tetrafluoroborate, keto acid, photocatalyst, metal catalyst, ligand and base is 1:1-2:0.02-0.1:0.02-0.1:0.02-0.1:1-2.

[0019] Preferably, the reaction temperature is 20-30°C and the reaction time is 20-48 hours. Preferably, the reaction temperature is room temperature and the reaction time is 24 hours, which can obtain a higher yield; the reaction is carried out under the protection of inert gas.

[0020] Preferably, the organic ketone compound has any of the following compound structural formulas:

[0021]

[0022] In the above technical scheme, keto acid, pyridinium tetrafluoroborate, photocatalyst, metal catalyst and its ligand, and base are used as starting materials to react and synthesize organic ketones, and this method is further used in the post-modification of the synthesis of functional organic ketone molecules with biologically active groups such as hydroxyl groups and halogens.

[0023] The present invention uses keto acid, pyridinium tetrafluoroborate, photocatalyst, metal catalyst and its ligand, and base as starting materials, and the reaction obtains the product of organic ketone compound. The preparation method utilizes photocatalyst to oxidize keto acid for decarboxylation, generates acyl radical and reduced photocatalyst, and the generated reduced photocatalyst simultaneously reduces pyridinium salt to generate carbon radical, and then under the metal synergistic catalytic conditions, the acyl radical and carbon radical generated by photocatalysis are captured by the metal catalyst to generate metal complex, and the generated metal complex is reduced and eliminated to generate the corresponding ketone compound product, and the metal catalysis realizes the regeneration cycle at the same time. The organic ketone compound with potential biological activity is synthesized, and the reaction is compatible with drug active groups such as hydroxyl groups, which can be used for post-modification transformation of functional organic molecules, and has the value of developing new methods for industrial synthesis of organic ketone compound functional molecules.

[0024] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: it solves the reliance on high reaction temperature and the use of strong oxidants in traditional synthesis routes, avoids the harsh reaction conditions and environmental unfriendliness caused by the use of high temperature and strong oxidants, and the method has mild reaction conditions and is easy to achieve industrial-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The following is the reaction scheme of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0027] like Figure 1 As shown, the present invention provides a method for preparing an organic ketone compound by light and metal coordinated catalysis, wherein the method utilizes a photocatalyst to oxidize and decarboxylate keto acids to generate acyl radicals and a reduced photocatalyst, wherein the generated reduced photocatalyst simultaneously reduces pyridinium salts to generate carbon radicals, and then under metal coordinated catalytic conditions, the acyl radicals and carbon radicals generated by the photocatalysis are captured by the metal catalyst to generate a metal complex, and the generated metal complex is reduced and eliminated to generate the corresponding ketone product.

[0028]

[0029] In the formula, R1 is independently selected from hydrogen, halogen, hydroxyl, methyl, ethyl; R2 is independently selected from hydrogen, aryl, tert-butyl, halogen, methoxy, cyano;

[0030] In an organic solvent, keto acid, pyridinium tetrafluoroborate, a photocatalyst, a metal catalyst and its ligand, and a base are used as starting materials, and an organic ketone compound is prepared by reaction under the synergistic effect of light and metal.

[0031] The present invention relates to the synthesis of the following known compounds:

[0032]

[0033] Example 1

[0034] Diphenylacetone, the structural formula is:

[0035]

[0036] Its synthesis method is:

[0037] Take p-benzoylformic acid (60 mg, 0.4 mmol, 2.0 equiv.), 1-benzyl-2,4,6-triphenylpyridine tetrafluoroborate (97 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 30.5 mg of Example 1 compound with a yield of 78%.

[0038] Its structure was confirmed by NMR examination; 1 H NMR (CDCl3, 400MHz): δ7.98-7.95(m,2H),7.52-7.47(m,1H),7.42-7.37(m,2H),7.30-7.25(m,2H),7.23-7.15(m,3H),4.23(s,2H)ppm. 13 C{ 1 H}NMR (100MHz, CDCl3): δ197.7,136.7,134.6,133.2,129.5,128.7,128.7,128.7,126.9,45.5ppm.

[0039] Example 2

[0040] 4'-Fluoro-2-phenylacetophenone, the structural formula is:

[0041]

[0042] Its synthesis method is:

[0043] Take p-fluorophenyl oxalic acid (67.2 mg, 0.4 mmol, 2.0 equiv.), 1-benzyl-2,4,6-triphenylpyridine tetrafluoroborate (97 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 26.1 mg of Example 2 compound with a yield of 61%.

[0044] Its structure was confirmed by NMR examination; 1 H NMR (CDCl 3, 400MHz): δ8.05-8.00(m,2H),7.37-7.29(m,2H),7.28-7.20(m,3H),7.14-7.07(m,2H),4.17(s,2H)ppm. 13 C{ 1 H}NMR (100MHz, CDCl3): δ196.1,165.8(d,J C-F =255.1Hz),134.4,133.1,133.0,131.3(d,J C-F =9.2Hz),129.5,128.8,127.1,115.8(d,J C-F =21.9Hz),45.6ppm. 19 F NMR (CDCl3, 376MHz) δ-104.9ppm.

[0045] Example 3

[0046] 4'-Bromo-2-phenylacetophenone, the structural formula is:

[0047]

[0048] Its synthesis method is:

[0049] Take 2-(4-bromophenyl)-2-oxoacetic acid (91.6 mg, 0.4 mmol, 2.0 equiv.), 1-benzyl-2,4,6-triphenylpyridine tetrafluoroborate (97 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 43.4 mg of Example 3 compound in a yield of 79%.

[0050] Its structure was confirmed by NMR examination; 1 H NMR (CDCl 3, 400MHz): δ7.89-7.85(m,2H),7.63-7.56(m,2H),7.38-7.30(m,2H),7.26-7.20(m,3H),4.25(s,2H)ppm. 13 C{ 1 H}NMR (100MHz, CDCl3): δ196.7,135.3,134.2,132.0,130.2,129.4,128.8,128.4,127.1,45.6ppm.

[0051] Example 4

[0052] 4'-Hydroxy-2-phenylacetophenone, the structural formula is:

[0053]

[0054] Its synthesis method is:

[0055] Take 2-(4-hydroxyphenyl)-2-oxoacetic acid (66.4 mg, 0.4 mmol, 2.0 equiv.), 1-benzyl-2,4,6-triphenylpyridine tetrafluoroborate (97 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 31.4 mg of Example 4 compound with a yield of 74%.

[0056] Its structure was confirmed by NMR examination; 1 H NMR (CDCl 3, 400MHz): δ8.02-7.94(m,2H),7.43-7.32(m,2H),7.32-7.21(m,3H),6.93-6.85(m,2H),6.03(br,1H,-OH),4.24(s,2H),1.31(br,1H). 13 C{ 1 H}NMR (100MHz, CDCl3): δ196.9,160.4,134.9,131.4,129.7,129.5,128.8,127.0,115.6,45.3ppm.

[0057] Example 5

[0058] 4'-Ethyl-2-phenylacetophenone, the structural formula is:

[0059]

[0060] Its synthesis method is:

[0061] Take 2-(4-ethylphenyl)-2-oxoacetic acid (71.2 mg, 0.4 mmol, 2.0 equiv.), 1-benzyl-2,4,6-triphenylpyridine tetrafluoroborate (97 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 31.4 mg of Example 5 compound with a yield of 70%.

[0062] Its structure was confirmed by NMR examination; 1 H NMR (CDCl 3, 400MHz): δ7.97-7.94(m,2H),7.38-7.21(m,7H),4.27(s,2H),2.71(q,J=7.6Hz,2H),1.26(t,J=7.6Hz,3H)ppm. 13 C{ 1 H}NMR (100MHz, CDCl3): δ197.4,150.2,134.9,134.4,129.5,128.9,128.7,128.2,126.9,45.5,29.0,15.2ppm. 19 F NMR (376MHz, CDCl3) δ-109.0ppm.

[0063] Example 6

[0064] 4-tert-Butylbenzylphenylketone, the structural formula is:

[0065]

[0066] Its synthesis method is:

[0067] Take p-benzoylformic acid (60 mg, 0.4 mmol, 2.0 equiv.), 1-(4-tert-butyl)benzyl-2,4,6-triphenylpyridine tetrafluoroborate (108.3 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 35.3 mg of Example 6 compound with a yield of 70%.

[0068] Its structure was confirmed by NMR examination; 1 H NMR (CDCl 3, 400MHz): δ8.08-8.01(m,2H),7.50-7.44(m,2H),7.38-7.35(m,2H),7.24-7.20(m,2H),4.27(s,2H),1.32(s,9H)ppm. 13 C{ 1 H}NMR (100MHz, CDCl3): δ197.9,149.8,136.8,133.2,131.5,130.0,129.2,128.7,125.7,45.0,34.5,31.4ppm.

[0069] Example 7

[0070] 4-iodobenzyl phenyl ketone, the structural formula is:

[0071]

[0072] Its synthesis method is:

[0073] Take p-benzoylformic acid (60 mg, 0.4 mmol, 2.0 equiv.), 1-(4-iodo)benzyl-2,4,6-triphenylpyridine tetrafluoroborate (122.2 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 46.3 mg of Example 7 compound with a yield of 72%.

[0074] Its structure was confirmed by NMR examination; 1 H NMR (CDCl 3, 400MHz): δ8.02-7.97(m,2H),7.69-7.61(m,2H),7.57(t,J=7.4Hz,1H),7.49-7.43(m,2H),7.03-6.99(m,2H),4.22(s,2H)ppm. 13 C{ 1 H}NMR (100MHz, CDCl3): δ197.1,137.8,136.5,134.2,133.5,131.6,128.8,128.6,92.5,45.0ppm.

[0075] Example 8

[0076] 4-Trifluoromethylbenzylphenyl ketone, the structural formula is:

[0077]

[0078] Its synthesis method is:

[0079] Take p-benzoylformic acid (60 mg, 0.4 mmol, 2.0 equiv.), 1-(4-trifluoromethyl)benzyl-2,4,6-triphenylpyridine tetrafluoroborate (110.6 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 36.9 mg of Example 8 compound with a yield of 70%.

[0080] Its structure was confirmed by NMR examination; 1 H NMR (CDCl 3, 400MHz): δ8.04-8.00(m,2H),7.63-7.56(m,3H),7.53-7.45(m,2H),7.41-7.36(m,2H),4.36(s,2H)ppm. 13 C{ 1 H}NMR (100MHz, CDCl3): δ196.7,138.6,136.4,135.0,133.6,130.1,129.1,128.9,128.6,125.6(q,J=3.9Hz),45.1ppm. 19 F NMR (376MHz, CDCl3) δ-62.5ppm.

[0081] Example 9

[0082] 4-Cyanomethylphenyl ketone, the structural formula is:

[0083]

[0084] Its synthesis method is:

[0085] Take p-benzoylformic acid (60 mg, 0.4 mmol, 2.0 equiv.), 1-(4-cyano)benzyl-2,4,6-triphenylpyridine tetrafluoroborate (102.0 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 24.3 mg of Example 9 compound with a yield of 55%.

[0086] Its structure was confirmed by NMR examination; 1 H NMR (CDCl 3, 400MHz): δ8.02-7.98(m,2H),7.66-7.56(m,3H),7.52-7.47(m,2H),7.39-7.36(m,2H),4.36(s,2H)ppm. 13 C{ 1 H}NMR (100MHz, CDCl3): δ196.2,140.1,136.3,133.8,132.4,130.6,128.9,128.5,118.9,111.0,45.3ppm.

[0087] Example 10

[0088] 4-phenylmethyl phenyl ketone, the structural formula is:

[0089]

[0090] Its synthesis method is:

[0091] Take p-benzoylformic acid (60 mg, 0.4 mmol, 2.0 equiv.), 1-(4-phenyl)benzyl-2,4,6-triphenylpyridine tetrafluoroborate (112.2 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 38.1 mg of Example 10 compound with a yield of 70%.

[0092] Its structure was confirmed by NMR examination; 1 H NMR (CDCl 3, 400MHz): δ8.09-8.02(m,2H),7.60-7.54(m,5H),7.50-7.41(m,4H),7.37-7.32(m,3H),4.34(s,2H)ppm. 13 C{ 1 H}NMR (100MHz, CDCl3): δ197.7,140.9,140.0,136.7,133.6,133.3,130.0,128.8,128.8,128.7,127.5,127.3,127.2,45.2ppm.

[0093] Embodiment 11

[0094] In this embodiment, the synthesis conditions are changed, and the synthesis method is as follows:

[0095] Take p-benzoylformic acid (46 mg, 0.3 mmol, 1.5 equiv.), 1-(4-cyano)benzyl-2,4,6-triphenylpyridine tetrafluoroborate (102.0 mg, 0.2 mmol, 1.0 equiv.), sodium acetate (24.6 mg, 0.3 mmol, 1.5 equiv.), chromium dichloride (10 mol%, 2.5 mg, 0.02 mmol), 4,4-di-tert-butyl-2,2-bipyridine (5.4 mg, 0.02 mmol, 10 mol%), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), tetrahydrofuran (1.0 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain Example 9 compound with a yield of 50%.

Claims

1. A method for preparing an organic ketone compound by light and metal synergistic catalysis, characterized in that: The method comprises the following steps: adding keto acid, pyridinium tetrafluoroborate, a photocatalyst, a metal catalyst, a base and a ligand into an organic solvent, and reacting under light, and the reaction formula is as follows: , wherein R1 is selected from one of hydrogen, halogen, hydroxyl, and C1~C6 alkyl; R2 is selected from one of hydrogen, aryl, tert-butyl, halogen, halogen-substituted C1~C6 alkyl, methoxy, or cyano; the photocatalyst is 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile, the metal catalyst is chromium dichloride, and the ligand is selected from one of 2,2'-bipyridine, 4,4-dimethyl-2,2-bipyridine, 4,4-di-tert-butyl-2,2-bipyridine, or 4,4-dimethoxy-2,2-bipyridine.

2. The method for preparing organic ketones by light and metal synergistic catalysis according to claim 1, characterized in that: The base is selected from one of sodium acetate, potassium carbonate, sodium methoxide or dipotassium hydrogen phosphate.

3. The method for preparing organic ketones by light and metal synergistic catalysis according to claim 1, characterized in that: The light source in the reaction is a blue light source of 450~455 nm, and the light source power is 8~40 watts.

4. The method for preparing organic ketones by light and metal synergistic catalysis according to claim 1, characterized in that: The keto acid is selected from one of p-benzoylformic acid, p-fluorophenyloxalic acid, 2-(4-bromophenyl)-2-oxoacetic acid, 2-(4-hydroxyphenyl)-2-oxoacetic acid or 2-(4-ethylphenyl)-2-oxoacetic acid.

5. The method for preparing organic ketones by light and metal synergistic catalysis according to claim 1, characterized in that: The pyridinium tetrafluoroborate is selected from 1-benzyl-2,4,6-triphenylpyridine tetrafluoroborate, 1-(4-tert-butyl)benzyl-2,4,6-triphenylpyridine tetrafluoroborate, 1-(4-iodo)benzyl-2,4,6-triphenylpyridine tetrafluoroborate, 1-(4-trifluoromethyl)benzyl-2,4,6-triphenylpyridine tetrafluoroborate or 1-(4-cyano)benzyl-2,4,6-triphenylpyridine tetrafluoroborate.

6. The method for preparing organic ketones by light and metal synergistic catalysis according to claim 1, characterized in that: The organic solvent is selected from at least one of acetonitrile, tetrahydrofuran, ethyl acetate or dichloromethane.

7. The method for preparing organic ketones by light and metal synergistic catalysis according to claim 1, characterized in that: The molar ratio of the tetrafluoroborate pyridinium salt, keto acid, photocatalyst, metal catalyst, ligand and base is 1:1-2:0.02-0.1:0.02-0.1:0.02-0.1:1-2.

8. The method for preparing organic ketones by light and metal synergistic catalysis according to claim 1, characterized in that: The reaction temperature is 20-30°C, the reaction time is 20-48 hours, and the reaction is carried out under the protection of an inert gas.

9. The method for preparing organic ketones by light and metal synergistic catalysis according to claim 1, characterized in that: The organic ketone compound has any of the following compound structural formulas: .

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