A process for the oxidative cleavage of olefins to carbonyl compounds

Abstract

The application discloses a method for producing carbonyl compounds by olefin oxidative cleavage, which comprises the following steps: reacting olefins under the action of a catalyst and hydrazine in the presence of water and in an air atmosphere at room temperature to obtain carbonyl compounds. The method provides a new alternative method for cleavage of C=C bonds, and has the advantages of green and environmental protection, use of H2O as a solvent and use of oxygen in air as an oxidant, no need of high temperature and pure oxygen, simple reaction operation, safety, wide substrate adaptability, and suitability for industrial production and market promotion and application.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for the oxidative cracking of olefins in water and air catalyzed by phenylhydrazine to produce carbonyl compounds. This provides a new alternative method for the cracking of C=C bonds, and synthesizes derivatives such as benzophenones or acetophenones. Background Technology

[0002] Oxidative cracking of olefins has a wide range of applications in organic synthesis, pharmaceuticals, fragrances, agrochemicals and materials. Among them, carbonyl compounds produced by the oxidative cracking of C=C bonds are very useful in organic synthesis because they introduce oxygen-containing functional groups into inexpensive olefin feedstocks. For example, it can undergo nucleophilic addition reactions (the carbonyl group can add to nucleophiles centered on carbon atoms: Grignard reagents, HCN, sodium acetylation, etc.; the carbonyl group can add to nucleophiles centered on nitrogen atoms: ammonia and its derivatives; the carbonyl group can also add to nucleophiles centered on oxygen atoms: H2O, ROH, etc.), oxidation reactions (Baeyer-Villger reaction (Chem. Ges., 1899, 32, 3625.; Chem. Ges., 1900, 33, 858.)), and reduction reactions (catalytic hydrogenation, Wolff-Kishner-Huang Minglong reduction (Chem. Soc., 1911, 43, 582.; J. Am. Chem. Soc., 1946, 68.)). Reduction reactions such as αH reactions (Claisen-Schmidt reaction (Ber., 1881, 14, 2460; Ber., 1881, 14, 1459), Mannich reaction (Arch. Pharm, 1917, 255, 261)) and other types of reactions (Perkin reaction (J. Chem. Soc., 1877, 31, 388), Knoevenagel reaction (Ber., 1894, 27, 2345; Ber., 1896, 29, 172), Wittig reaction (Ber., 1954, 87, 1318)). Therefore, scientists have conducted numerous studies on methods for the oxidative cleavage of C=C to produce carbonyl compounds. Methods for the oxidative cracking of olefins to produce carbonyl compounds can be broadly classified into two categories: traditional oxidation theory systems and catalytic oxidation theory systems. In traditional oxidation theory systems, ozone decomposition using O3 as an oxidant remains a commonly used method; however, this method presents serious safety issues. Therefore, scientists have developed methods that use oxidants such as KMnO4, H2O2, TBHP, PhIO / HBF4, m-CPBA, and OsO4 instead of O3 for decomposition. However, these methods use oxidants in amounts exceeding stoichiometry, leading to significant resource waste.In the theoretical system of catalytic oxidation, catalysts such as TBADT, PEGDME, Cu, Fe, Ni, AIBN, B2pin2, TEMPO, and Acid Red 94 have been reported for the oxidative cracking of olefins to produce carbonyl compounds (Angew. Chem. Int. Ed., 2017, 56, 832.; RSC Adv., 2021, 11, 13848.; Org. Lett., 2021, 23, 4705.; Tetrahedron Letters, 2021, 80, 153321.). For example, in 2019, Cheng's group reported a method for the oxidative cracking of olefins to carbonyl compounds using B2pin2 as a catalyst and NMP as both a solvent and a Lewis base. The advantage of this method is that it does not require transition metal catalysis and develops a novel catalytic oxidation system, but the disadvantages are that the reaction temperature is too high and the reaction time is too long (Org. Chem. Front., 2019, 6, 841.). In 2021, Wang's group reported a convenient and practical method for converting terminal olefins to carbonyl compounds using iron-sulfur complexes generated in situ from K₂S and FeCl₃. The advantage of this method lies in the development of a novel metal catalyst, while the disadvantages include the need for oxygen conditions and excessively high reaction temperatures (Org. Lett., 2021, 23, 4705). Also in 2021, Xie's group reported a method for oxidatively cracking olefins to carbonyl compounds under light irradiation using TBADT as a photocatalyst. This scheme uses H₂O as a solvent and air as the oxidant at room temperature, without transition metal catalysts, which is highly consistent with the principles of green chemistry (Green Chem., 2021, 23, 5936). Despite significant progress in olefin oxidative cracking, few safe, simple, and environmentally friendly methods have been reported. Therefore, developing a safer, simpler, and more environmentally friendly method for olefin oxidative cracking is highly desirable. Summary of the Invention

[0003] This invention provides a method for the copper-catalyzed, phenylhydrazine-promoted oxidative cracking of olefins to produce carbonyl compounds in the presence of water and air, offering a new alternative for the cracking of C=C bonds. The reaction conditions are relatively green, using H2O as a solvent and oxygen in the air as an oxidant, eliminating the need for high temperatures and pure oxygen. The reaction is simple and safe to operate, and the method has broad substrate adaptability, making it suitable for large-scale synthesis.

[0004] The specific steps of the method of the present invention are as follows:

[0005] (1) Add the catalyst, hydrazine, and olefin to a reactor containing water and react at room temperature for 4-14 h, wherein the molar ratio of hydrazine to olefin is 1-3:1 and the molar ratio of catalyst to olefin is 0.03-0.35:1.

[0006] The structural formula of the olefin is shown below:

[0007]

[0008] The catalyst is cuprous thiophene-2-carboxylate (CuTc);

[0009] The hydrazine is one of phenylhydrazine, ethyl hydrazine carbamate, tert-butyl hydrazine carbamate, benzoyl hydrazine, dihydrazide carbonate, 2-hydrazinepyridine, hydrazine hydrate, cyclohexylhydrazine hydrochloride, 1,3-diaminoguanidine hydrochloride, 4-(trifluoromethyl)phenylhydrazine, 2,4,6-trichlorophenylhydrazine, and (2-aminobenzoyl)hydrazine.

[0010] (2) The reaction product of step (1) was extracted with an organic solvent, the organic solvent phase was collected and concentrated under reduced pressure, and the carbonyl compound was obtained after separation and purification by column chromatography.

[0011] The structural formulas of carbonyl compounds are shown in formulas I-VIII:

[0012]

[0013] The positions of the substituents on the benzene ring are not fixed, R 1 Selected from hydrogen, methyl, methoxy, halogen; R 2 Selected from hydrogen, methyl; R 3 Selected from hydrogen, methyl, methoxy, ethyl, cyclohexyl, phenyl, halogen, nitro, cyano, and methoxyformyl.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] The method of this invention has green and environmentally friendly reaction conditions, using H2O as a solvent and oxygen in the air as an oxidant. It does not require high temperature or pure oxygen, and the reaction operation is simple and safe. The method provided has broad substrate adaptability and is suitable for large-scale synthesis. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited to the contents described. Unless otherwise specified, the methods in the embodiments are conventional methods, and the reagents used are commercially available or prepared by conventional methods unless otherwise specified.

[0017] Example 1: Synthesis of benzophenone (2a)

[0018] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (1a), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:200) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 44.3 mg of benzophenone (2a), with a yield of 81%. The reaction equation is as follows:

[0019]

[0020] The NMR data of the compound are as follows:

[0021] 1 H NMR (600MHz, CDCl3) δ7.81 (d, J = 7.8Hz, 4H), 7.58 (t, J = 7.2Hz, 2H), 7.47 (t, J = 7.8Hz, 4H). 13 C NMR (126MHz, CDCl3) δ196.80,137.73,132.50,130.15,128.38.

[0022] Example 2: Synthesis of 4-methylbenzophenone (2b)

[0023] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (1b), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (1:100 v / v) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 32.5 mg of 4-methylbenzophenone (2b), with a yield of 55%. The reaction equation is as follows:

[0024]

[0025] The NMR data of the compound are as follows:

[0026] 1H NMR (600MHz, CDCl3) δ7.79(d,J=7.2Hz,2H),7.73(d,J=8.4Hz,2H),7.57(t,J=7.2Hz,1H),7.47(t,J=7.8Hz,2H),7.29(d,J=8.4Hz,2H),2.44(s,3H). 13 C NMR (126MHz, CDCl3) δ196.59,143.34,138.11,135.04,132.26,130.42,130.04,129.09,128.32,21.76.

[0027] Example 3: Synthesis of 4-methoxybenzophenone (2c)

[0028] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (1c), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:60) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 34.7 mg of 4-methoxybenzophenone (2c), with a yield of 55%. The reaction equation is as follows:

[0029]

[0030] The NMR data of the compound are as follows:

[0031] 1 H NMR (600MHz, CDCl3) δ7.84(d,J=9.0Hz,2H),7.76(d,J=7.8Hz,2H),7.57(t,J=7.2Hz,1H),7.47(t,J=7.8Hz,2H),6.97(d,J=8.4Hz,2H),3.88(s,3H). 13 C NMR (126MHz, CDCl3) δ195.63,163.35,138.43,132.65,131.98,130.29,129.82,128.29,113.68,55.59.

[0032] Example 4: Synthesis of 4,4'-dimethylbenzophenone (2d)

[0033] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (1 d), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:80) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 42.5 mg of the product 4,4'-dimethylbenzophenone (2 d), with a yield of 67%. The reaction equation is as follows:

[0034]

[0035] The NMR data of the compound are as follows:

[0036] 1 H NMR (600MHz, CDCl3) δ7.71 (d, J = 8.4Hz, 4H), 7.27 (d, J = 7.8Hz, 4H), 2.43 (s, 6H). 13 C NMR (126MHz, CDCl3) δ196.34,143.01,135.36,130.29,129.01,21.72.

[0037] Example 5: Synthesis of 4-fluorobenzophenone (2e)

[0038] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (1e), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:80) as the eluent. The eluent was collected and concentrated under reduced pressure at 35 °C to obtain 33.7 mg of 4-fluorobenzophenone (2e), with a yield of 56%. The reaction equation is as follows:

[0039]

[0040] The NMR data of the compound are as follows:

[0041] 1H NMR (600MHz, CDCl3) δ7.86-7.83(m,2H),7.78(d,J=7.8Hz,2H),7.59(t,J=7.8Hz,1H),7.49(t,J=7.8Hz,2H),7.16(t,J=9.0Hz,2H). 13 C NMR (126MHz, CDCl3) δ195.37, 166.54 (d, J = 254.5Hz), 137.67, 133.98 (d, J = 3 .1Hz), 132.83 (d, J = 9.1Hz), 132.59, 130.00, 128.49, 115.67 (d, J = 21.8Hz).

[0042] Example 6: Synthesis of 2-bromobenzophenone (2f)

[0043] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (1f), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:80) as the eluent. The eluent was collected and concentrated under reduced pressure at 40 °C to obtain 32.9 mg of the product 2-bromobenzophenone (2f), with a yield of 42%. The reaction equation is as follows:

[0044]

[0045] The NMR data of the compound are as follows:

[0046] 1 H NMR (600MHz, CDCl3) δ7.83(d,J=8.4Hz,2H),7.66(d,J=7.8Hz,1H),7.62(q,J =7.2Hz,1H),7.47(t,J=7.2Hz,2H),7.42(t,J=7.8Hz,1H),7.37-7.34(m,2H). 13 C NMR (126MHz, CDCl3) δ198.08,149.49,139.47,134.27,133.34,131.62,129.21,128.43,120.09,118.98,118.58.

[0047] Example 7: Synthesis of acetophenone (4a)

[0048] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3a), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:60) as the eluent. The eluent was collected and concentrated under reduced pressure at 35 °C to obtain 15 mg of acetophenone (4a), with a yield of 42%. The reaction equation is as follows:

[0049]

[0050] The NMR data of the compound are as follows:

[0051] 1 H NMR (500MHz, CDCl3) δ7.97-7.95(m,2H),7.58-7.55(m,1H),7.48-7.45(m,2H),2.61(s,3H). 13 C NMR (126MHz, CDCl3) δ198.26,137.32,133.23,128.71,128.45,26.73.

[0052] Example 8: Synthesis of 2-methoxyacetophenone (4b)

[0053] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3b), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:60) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 27.0 mg of the product 2-methoxyacetophenone (4b), with a yield of 60%. The reaction equation is as follows:

[0054]

[0055] The NMR data of the compound are as follows:

[0056] 1 H NMR (600MHz, CDCl3) δ7.74 (dd, J=1.2, 1.8Hz, 1H), 7.48-7.45 (m, 1H), 7.00-6.96 (m, 2H), 3.90 (s, 3H), 2.61 (s, 3H).13 C NMR (126MHz, CDCl3) δ199.89,158.99,133.71,130.39,128.38,120.61,111.67,55.54,31.87.

[0057] Example 9: Synthesis of 3-methoxyacetophenone (4c)

[0058] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3c), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:60) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 22.0 mg of the product 3-methoxyacetophenone (4c), with a yield of 49%. The reaction equation is as follows:

[0059]

[0060] The NMR data of the compound are as follows:

[0061] 1 H NMR (600MHz, CDCl3) δ7.55(d,J=7.2Hz,1H),7.49(s,1H),7.38(t,J=7.8Hz,1H),7.13-7.11(m,1H),3.86(s,3H),2.61(s,3H). 13 C NMR (126MHz, CDCl3) δ197.99,159.93,138.62,129.65,121.20,119.67,112.49,55.51,26.77.

[0062] Example 10: Synthesis of 4-methoxyacetophenone (4d)

[0063] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3d), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:60) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 25.0 mg of 4-methoxyacetophenone (4d), with a yield of 56%. The reaction equation is as follows:

[0064]

[0065] The NMR data of the compound are as follows:

[0066] 1 H NMR (600MHz, CDCl3) δ7.95 (d, J = 9.0Hz, 2H), 6.95 (d, J = 8.4Hz, 2H), 3.87 (s, 3H), 2.56 (s, 3H). 13 C NMR (126MHz, CDCl3) δ196.89,163.63,130.71,130.51,113.82,55.58,26.44.

[0067] Example 11: Synthesis of 4-methylacetophenone (4e)

[0068] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3e), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:80) as the eluent. The eluent was collected and concentrated under reduced pressure at 35 °C to obtain 13.6 mg of 4-methylacetophenone (4e), with a yield of 34%. The reaction equation is as follows:

[0069]

[0070] The NMR data of the compound are as follows:

[0071] 1 H NMR (600MHz, CDCl3) δ7.87 (d, J = 7.8 Hz, 2H), 7.27 (d, J = 7.8 Hz, 2H), 2.58 (s, 3H), 2.41 (s, 3H). 13 C NMR (126MHz, CDCl3) δ197.97,144.00,134.90,129.38,128.58,26.64,21.75.

[0072] Example 12: Synthesis of 4-ethylacetophenone (4f)

[0073] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3f), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:80) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 20.2 mg of 4-ethylacetophenone (4f), with a yield of 46%. The reaction equation is as follows:

[0074]

[0075] The NMR data of the compound are as follows:

[0076] 1 H NMR (600MHz, CDCl3) δ7.90 (d, J = 8.4Hz, 2H), 7.29 (d, J = 7.8Hz, 2H), 2.73 (q, J = 7.2Hz, 2H), 2.59 (s, 3H), 1.26 (t, J = 7.8Hz, 3H). 13 C NMR (126MHz, CDCl3) δ197.90,150.14,135.10,128.65,128.16,29.03,26.60,15.27.

[0077] Example 13: Synthesis of 4-cyclohexylacetophenone (4g)

[0078] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3 g), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:80) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 39.2 mg of 4-cyclohexylacetophenone (4 g), with a yield of 65%. The reaction equation is as follows:

[0079]

[0080] The NMR data of the compound are as follows:

[0081] 1H NMR (600MHz, CDCl3) δ7.90 (d, J = 7.8Hz, 2H), 7.30 (d, J = 8.4Hz, 2H), 2.58 (s, 4H), 1.88-1.84 (m, 4H), 1.77 (d, J = 12.6Hz, 1H), 1.46 -1.36(m,4H),1.30-1.23(m,1H). 13 CNMR (126MHz, CDCl3) δ197.87,153.82,135.20,128.63,127.12,44.79,34.21,26.83,26.58,26.14.

[0082] Example 14: Synthesis of 4-phenylacetophenone (4h)

[0083] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3 h), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (1:60 v / v) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 30.7 mg of 4-phenylacetophenone (4 h), with a yield of 52%. The reaction equation is as follows:

[0084]

[0085] The NMR data of the compound are as follows:

[0086] 1 H NMR (500MHz, CDCl3) δ8.04-8.01(m,2H),7.69-7.67(m,2H),7.63-7.61(m,2H),7.48-7.45(m,2H),7.41-7.38(m,1H),2.63(s,3H). 13 C NMR (126MHz, CDCl3) δ197.80,145.88,139.99,135.99,129.07,129.02,128.34,127.38,127.32,26.75.

[0087] Example 15: Synthesis of 4-fluoroacetophenone (4i)

[0088] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3i), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:40) as the eluent. The eluent was collected and concentrated under reduced pressure at 35 °C to obtain 22.7 mg of the product 4-fluoroacetophenone (4i), with a yield of 55%. The reaction equation is as follows:

[0089]

[0090] The NMR data of the compound are as follows:

[0091] 1 H NMR (600MHz, CDCl3) δ8.00-7.98 (m, 2H), 7.14 (t, J = 8.4Hz, 2H), 2.60 (s, 3H). 13 C NMR (126MHz, CDCl3) δ196.33, 166.73 (d, J = 254.9Hz), 133.63 (d, J = 3.0Hz), 130.95 (d, J = 9.3Hz), 115.66 (d, J = 21.9Hz), 26.40.

[0092] Example 16: Synthesis of 4-chloroacetophenone (4j)

[0093] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3j), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:40) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 20.3 mg of 4-chloroacetophenone (4j), with a yield of 44%. The reaction equation is as follows:

[0094]

[0095] The NMR data of the compound are as follows:

[0096] 1 H NMR (600MHz, CDCl3) δ7.91 (d, J = 8.4Hz, 2H), 7.45 (d, J = 8.4Hz, 2H), 2.60 (s, 3H).13 C NMR (126MHz, CDCl3) δ196.87,139.68,135.60,129.84,129.00,26.63.

[0097] Example 17: Synthesis of 4-bromoacetophenone (4k)

[0098] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3k), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (1:100 v / v) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 23.5 mg of the product 4-bromoacetophenone (4k), with a yield of 40%. The reaction equation is as follows:

[0099]

[0100] The NMR data of the compound are as follows:

[0101] 1 H NMR (600MHz, CDCl3) δ7.83 (d, J = 8.4Hz, 2H), 7.62 (d, J = 8.4Hz, 2H), 2.59 (s, 3H). 13 C NMR (126MHz, CDCl3) δ197.10,135.99,132.03,129.97,128.43,26.65.

[0102] Example 18: Synthesis of 4-nitroacetophenone (4l)

[0103] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3 L), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:40) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 26.5 mg of 4-nitroacetophenone (4 L), with a yield of 54%. The reaction equation is as follows:

[0104]

[0105] The NMR data of the compound are as follows:

[0106] 1 H NMR (600MHz, CDCl3) δ8.34 (d, J = 9.0 Hz, 2H), 8.13 (d, J = 8.4 Hz, 2H), 2.70 (s, 3H). 13 C NMR (126MHz, CDCl3) δ196.39,150.55,141.56,129.44,124.00,27.09.

[0107] Example 19: Synthesis of 4-cyanoacetophenone (4m)

[0108] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3m), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:15) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 12.9 mg of the product 4-cyanoacetophenone (4m), with a yield of 30%. The reaction equation is as follows:

[0109]

[0110] The NMR data of the compound are as follows:

[0111] 1 H NMR (600MHz, CDCl3) δ8.06 (d, J = 8.4Hz, 2H), 7.80 (d, J = 7.8Hz, 2H), 2.66 (s, 3H). 13 C NMR (126MHz, CDCl3) δ196.61,140.10,132.65,128.83,118.04,116.59,26.86.

[0112] Example 20: Synthesis of methyl 4-acetylbenzoate (4n)

[0113] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3n), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:40) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 30.1 mg of methyl 4-acetylbenzoate (4n), with a yield of 56%. The reaction equation is as follows:

[0114]

[0115] The NMR data of the compound are as follows:

[0116] 1 H NMR (500MHz, CDCl3) δ8.13-8.12(m,2H),8.02-8.00(m,2H),3.95(s,3H),2.64(s,3H). 13 C NMR (126MHz, CDCl3) δ197.59,166.33,140.40,134.05,129.95,128.32,52.55,26.96.

[0117] Example 21: Synthesis of 4-phenyl-2-butanone (4o)

[0118] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3°), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:80) as the eluent. The eluent was collected and concentrated under reduced pressure at 35 °C to obtain 22.2 mg of the product 4-phenyl-2-butanone (4°), with a yield of 50%. The reaction equation is as follows:

[0119]

[0120] The NMR data of the compound are as follows:

[0121] 1H NMR (600MHz, CDCl3) δ7.29(t,J=7.8Hz,2H),7.21-7.18(m,3H),2.90(t,J=7.8Hz,2H),2.77(t,J=7.8Hz,2H),2.15(s,3H). 13 C NMR (126MHz, CDCl3) δ207.93,141.12,128.61,128.40,126.22,45.26,30.14,29.87.

[0122] Example 22: Synthesis of 2-naphthyl ethylone (4p)

[0123] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3p), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:60) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 28.7 mg of the product 2-naphthyl ethylone (4p), with a yield of 56%. The reaction equation is as follows:

[0124]

[0125] The NMR data of the compound are as follows:

[0126] 1 H NMR (500MHz, CDCl3) δ8.45(d,J=1.0Hz,1H),8.03(dd,J=1.5,8.5Hz,1H),7.96(d,J=8.0Hz,1H),7.88-7.85(m,2H),7.61-7.53(m,2H),2.71(s,3H). 13 C NMR (126MHz, CDCl3) δ198.15,135.70,134.62,132.63,130.28,129.65,128.56,128.52,127.89,126.87,124.00,26.76.

[0127] Example 23: Synthesis of 3-acetylpyridine (4q)

[0128] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3q), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:5) as the eluent. The eluent was collected and concentrated under reduced pressure at 35 °C to obtain 10.0 mg of 3-acetylpyridine (4q), with a yield of 28%. The reaction equation is as follows:

[0129]

[0130] The NMR data of the compound are as follows:

[0131] 1 H NMR (600MHz, CDCl3) δ9.18 (s, 1H), 8.80 (d, J = 4.2Hz, 1H), 8.26-8.24 (m, 1H), 7.46 (q, J = 4.8Hz, 1H), 2.66 (s, 3H). 13 C NMR (126MHz, CDCl3) δ196.71,153.56,149.97,135.43,132.30,123.62,26.71.

[0132] Example 24: Synthesis of Cyclopropylphenyl ketone (4r)

[0133] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3r), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:200) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 15.6 mg of the product cyclopropylphenyl ketone (4r), with a yield of 36%. The reaction equation is as follows:

[0134]

[0135] The NMR data of the compound are as follows:

[0136] 1H NMR (600MHz, CDCl3) δ8.03(d,J=7.2Hz,2H),7.57(t,J=7.2Hz,1H),7.48(t,J=7.2Hz,2H),2.71-2.67(m,1H),1.26-1.24(m,2H),1.07-1.04(m,2H). 13 C NMR (126MHz, CDCl3) δ200.34,137.90,132.59,128.38,127.87,16.98,11.45.

[0137] Example 25: Synthesis of 1-Tetrahydronaphthol (4S)

[0138] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3s), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (1:100 v / v) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 22.6 mg of the product 1-tetrahydronaphthol (4s), with a yield of 52%. The reaction equation is as follows:

[0139]

[0140] The NMR data of the compound are as follows:

[0141] 1 H NMR(600MHz, CDCl3)δ8.04(d,J=7.8Hz,1H),7.49-7.46(m,1H),7.31(t,J=7.2Hz,1H), 7.27(d,J=8.4Hz,1H),2.97(t,J=6.0Hz,2H),2.66(t,J=6.6Hz,2H),2.17-2.12(m,2H). 13 C NMR (126MHz, CDCl3) δ198.35,144.55,133.44,132.72,128.84,127.22,126.68,39.23,29.77,23.36.

[0142] Example 26: Synthesis of 6-methyl-1-indanone (4t)

[0143] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (3 t), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (1:100 v / v) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 18.5 mg of 6-methyl-1-indanone (4 t), with a yield of 42%. The reaction equation is as follows:

[0144]

[0145] The NMR data of the compound are as follows:

[0146] 1 H NMR (600MHz, CDCl3) δ7.55(s,1H),7.41(dd,J=7.8,7.8Hz,2H),3.09(t,J=5.4Hz,2H),2.68(t,J=6.0Hz,2H),2.40(s,3H). 13 C NMR (126MHz, CDCl3) δ207.12,152.57,137.32,137.23,135.89,126.41,123.68,36.63,25.48,21.10.

[0147] Example 27: Synthesis of benzophenone (2a)

[0148] 0.025 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (1a), and 0.9 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:200) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 39.9 mg of benzophenone (2a), with a yield of 73%. The reaction equation is as follows:

[0149]

[0150] The NMR data of the compound are as follows:

[0151] 1H NMR (600MHz, CDCl3) δ7.81 (d, J = 7.8Hz, 4H), 7.58 (t, J = 7.2Hz, 2H), 7.47 (t, J = 7.8Hz, 4H). 13 C NMR (126MHz, CDCl3) δ196.80,137.73,132.50,130.15,128.38.

[0152] Example 28: Synthesis of benzophenone (2a)

[0153] 0.10 mmol CuTc, 2 mL H2O, 0.3 mmol olefin (1a), and 0.6 mmol phenylhydrazine were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:200) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 38.2 mg of benzophenone (2a), with a yield of 70%. The reaction equation is as follows:

[0154]

[0155] The NMR data of the compound are as follows:

[0156] 1 H NMR (600MHz, CDCl3) δ7.81 (d, J = 7.8Hz, 4H), 7.58 (t, J = 7.2Hz, 2H), 7.47 (t, J = 7.8Hz, 4H). 13 C NMR (126MHz, CDCl3) δ196.80,137.73,132.50,130.15,128.38.

[0157] Example 29: Synthesis of benzophenone (2a)

[0158] 0.025 mmol CuTc, 2 mL H2O, 0.6 mmol benzoylhydrazine, and 0.3 mmol olefin (1a) were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:200) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 6 mg of benzophenone (2a), with a yield of 11%. The reaction equation is as follows:

[0159]

[0160] The NMR data of the compound are as follows:

[0161] 1 H NMR (600MHz, CDCl3) δ7.81 (d, J = 7.8Hz, 4H), 7.58 (t, J = 7.2Hz, 2H), 7.47 (t, J = 7.8Hz, 4H). 13 C NMR (126MHz, CDCl3) δ196.80,137.73,132.50,130.15,128.38.

[0162] Example 30: Synthesis of benzophenone (2a)

[0163] 0.025 mmol CuTc, 2 mL H2O, 0.6 mmol ethyl hydrazine carbamate, and 0.3 mmol olefin (1a) were added sequentially to a 10 mL thick-walled test tube. The mixture was stirred for 12 hours at room temperature under air atmosphere. After the reaction was complete, ethyl acetate was added to the system for extraction. The extraction was repeated three times, and the combined ethyl acetate phases were collected and concentrated under reduced pressure at 45 °C to obtain the crude product. The crude product was purified by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether mixture (volume ratio 1:200) as the eluent. The eluent was collected and concentrated under reduced pressure at 45 °C to obtain 17 mg of benzophenone (2a), with a yield of 31%. The reaction equation is as follows:

[0164]

[0165] The NMR data of the compound are as follows:

[0166] 1 H NMR (600MHz, CDCl3) δ7.81 (d, J = 7.8Hz, 4H), 7.58 (t, J = 7.2Hz, 2H), 7.47 (t, J = 7.8Hz, 4H). 13 C NMR (126MHz, CDCl3) δ196.80, 137.73, 132.50, 130.15, 128.38.

Claims

1. A method for oxidative cracking of olefins to produce carbonyl compounds, characterized in that, Carbonyl compounds are prepared by reacting olefins with a catalyst and hydrazine in the presence of water, air atmosphere and at room temperature. The catalyst is cuprous thiophene-2-carboxylate; The structural formula of olefins is shown below: ； In the formula: R 1 Selected from hydrogen, methyl, methoxy, halogen; R 2 Selected from hydrogen, methyl; R 3 Selected from hydrogen, methyl, methoxy, ethyl, cyclohexyl, phenyl, halogen, nitro, cyano, and methoxyformyl; The hydrazine is one of the following: phenylhydrazine, ethyl hydrazine carbamate, tert-butyl hydrazine carbamate, benzoyl hydrazine, dihydrazide carbonate, 2-hydrazinepyridine, hydrazine hydrate, cyclohexylhydrazine hydrochloride, 1,3-diaminoguanidine hydrochloride, 4-(trifluoromethyl)phenylhydrazine, 2,4,6-trichlorophenylhydrazine, and (2-aminobenzoyl)hydrazine.

2. The method for producing carbonyl compounds by oxidative cracking of olefins according to claim 1, characterized in that, The structural formulas of carbonyl compounds are shown in formulas I-VIII: ； In the formula: R 1 Selected from hydrogen, methyl, methoxy, halogen; R 2 Selected from hydrogen, methyl; R 3 Selected from hydrogen, methyl, methoxy, ethyl, cyclohexyl, phenyl, halogen, nitro, cyano, and methoxyformyl.

3. The method for producing carbonyl compounds by oxidative cracking of olefins according to claim 1, characterized in that: The catalyst, hydrazine, and olefin were added to water and reacted at room temperature in an air atmosphere for 4-14 h. The mixture was then extracted with an organic solvent, the organic solvent phase was collected and concentrated, and the carbonyl compound was obtained by column chromatography separation and purification. The molar ratio of hydrazine to olefin was 1-3:1, and the molar ratio of catalyst to olefin was 0.03-0.35:1.

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