A process for the preparation of 2-aryl-3-carbonyl substituted tetrahydrofurans and tetrahydropyrans

Abstract

The present application relates to a kind of 2-aryl-3-carbonyl-substituted tetrahydrofuran and tetrahydropyran compound preparation method, its reaction general formula is as follows: the present application is prepared by one-pot method under photocatalytic condition 2-aryl-3-carbonyl-substituted tetrahydrofuran and tetrahydropyran compound of unsaturated alcohol, alkyl or aryl acyl oxime ester.The starting material of this method is cheap and easy to obtain, simple operation, mild reaction condition, avoid using the dosage of oxidizing agent and additional reagent, provide a kind of green and efficient preparation method for 2-aryl-3-carbonyl-substituted tetrahydrofuran and tetrahydropyran compound.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis, specifically relating to a method for preparing 2-aryl-3-carbonyl-substituted tetrahydrofuran and tetrahydropyran compounds. Background Technology

[0002] Five- and six-membered oxygen-containing heterocycles are a prevalent and advantageous backbone in drug molecules and bioactive natural product molecules. Examples include the macrocyclic lactone Amphidinolide C1, which inhibits cancer cell proliferation; the anticancer drug Eribulin; and the hepatitis C treatment drug Sofosbuvir, all of which contain tetrahydrofuran or tetrahydropyran structural units. They are also important synthetic intermediates in the manufacture of pharmaceuticals and fine chemicals. 2-aryl-3-carbonyl-substituted tetrahydrofuran and tetrahydropyran molecules are very special oxygen-containing heterocyclic compounds. The aryl and carbonyl substituents in these heterocyclic structures can further expand the biological properties of the parent molecule and its synthetic applications. Currently, there are few reported methods for synthesizing 2-aryl-3-carbonyl-substituted tetrahydrofurans and tetrahydropyrans. Existing synthetic methods mainly include the following categories: (1) preparation by γ or δ chloroketones and aryl aldehydes under low temperature conditions. This method has a low yield, few successfully synthesized product molecules, and the low temperature reaction conditions further limit its synthetic application (Synthesis, 2006, 7, 1190 and Synthesis, 2007, 8, 1209); (2) acyl-substituted... Cyclopropane reacts with titanium tetrachloride to prepare an intermediate for cyclopropane ring opening. The intermediate generated in situ reacts with aryl aldehydes at -78 degrees Celsius to prepare related heterocyclic molecules in low yield (Tetrahedron, 2001, 57, 987); (3) It is prepared by intramolecular hydrogen alkylation of electron-deficient inner alkenes containing benzyloxy and acetyl groups under the action of boron trifluoride diethyl ether. The substrate preparation of this method is relatively complicated, and only one 2-aryl-3-carbonyl-substituted tetrahydropyran molecule has been reported so far (Journal of the American Chemical Society, 2005, 127, 12180). This invention creatively prepares 2-aryl-3-carbonyl-substituted tetrahydrofuran and pyran compounds in a one-pot process with unsaturated alcohols and alkyl or aryl-substituted acyl oxime esters under photocatalytic conditions. This method utilizes inexpensive and readily available starting materials, employs mild reaction conditions, avoids the use of large doses of redox reagents and additional reaction additives, and is simple to operate. It provides a green and efficient method for the preparation of 2-aryl-3-carbonyl-substituted tetrahydrofurans and tetrahydropyrans. Therefore, this invention possesses high innovation and practical value, providing important reference for the process development of similar compounds and downstream products. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing synthetic techniques and provide a method for preparing 2-aryl-3-carbonyl-substituted tetrahydrofurans and tetrahydropyrans that uses readily available starting materials, is simple to operate, has mild reaction conditions, and is universally applicable. The technical solution of this invention is: a method for preparing 2-aryl-3-carbonyl-substituted tetrahydrofurans and tetrahydropyrans, characterized by the sequential addition of an unsaturated alcohol, an alkyl or aryl acyl oxime ester, a photocatalyst, and a solvent to a reaction flask equipped with a stir bar, and the one-pot preparation of 2-aryl-3-carbonyl-substituted tetrahydrofurans and tetrahydropyrans under light irradiation, as shown in the following reaction formula:

[0004]

[0005] in:

[0006] (1) Ar is phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butoxyphenyl, 3,4-dimethoxyphenyl, 3,5-dimethoxyphenyl, 3,4,5-trimethoxyphenyl, 3-chloro-4-methoxyphenyl, 3-bromo-4-methoxyphenyl, 3-bromophenyl, 4-bromophenyl, 4-chlorophenyl, 4-fluorophenyl, 4-trifluoromethylphenyl, 4-iodophenyl, 4-cyanophenyl, 2-naphthyl, 2-furanyl;

[0007] (2) R is phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 4-bromophenyl, 4-chlorophenyl, 4-fluorophenyl, 4-trifluoromethylphenyl, 3-chlorophenyl, 2-fluorophenyl, 2-furanyl, 2-thienyl, methyl, ethyl, n-propyl, isopropyl, n-butyl.

[0008] In the above method, the photocatalyst used is selected from tris(2-phenylpyridine)iridium, bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate), 2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile, [4,4'-bis(1,1-dimethylethyl)-2,2'-bipyridine]bis[3,5-difluoro-2-(5-fluoro-2-pyridyl)phenyl]iridium hexafluorophosphate, dichlorotris(2,2'-dipyridine)ruthenium(II) hexahydrate, tris(2,2'-bipyridine)ruthenium di(hexafluorophosphate), tris(2,2'-bipyridine)ruthenium di(tetrafluoroborate), eosin Y, thioxanone, and rhodamine B, preferably tris(2-phenylpyridine)iridium.

[0009] In the above scheme, the light source used is selected from blue light, white light, violet light and red light, with blue light being preferred.

[0010] In the above scheme, the solvent used is selected from acetonitrile, methanol, dichloromethane, tetrahydrofuran, ethyl acetate, acetone, N,N-dimethylformamide, dimethyl sulfoxide and hexafluoroisopropanol, with tetrahydrofuran being preferred.

[0011] In the above scheme, the heating temperature is 0-50℃, preferably 25℃; the reaction time is 4-36 hours, preferably 24 hours; and the gas atmosphere is selected from nitrogen and argon, preferably argon.

[0012] In the above scheme, the molar ratio of each substance in the reaction is: unsaturated alcohol substrate: alkyl or aryl acyl oxime ester: photocatalyst = 1:1-5:0.001-0.2. Preferably, the ratio of unsaturated alcohol substrate: alkyl or aryl acyl oxime ester: photocatalyst = 1:3:0.01. Detailed Implementation

[0013] The present invention will be further described below through specific embodiments, but it should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments. All technologies implemented based on the above content of the present invention fall within the scope of the present invention.

[0014] Example

[0015] Using (E)-4-phenyl-3-buten-1-ol as an olefin substrate and benzoyl oxime ester as an acylation reagent, 2-aryl-3-acyl-substituted tetrahydrofuran molecules were prepared (reaction formula 1).

[0016]

[0017] 4-Phenylacetyl-3-buten-1-ol substrate (29.6 mg, 0.2 mmol), (E)-2-(acetoxyimino)-1-phenyl-1-propanone (123.1 mg, 0.6 mmol), and tris(2-phenylpyridinium)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W of blue light at room temperature for 24 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a light yellow oily liquid (dr > 20:1, 33.8 mg, yield = 67%).

[0018] The product test data are as follows:

[0019] 1H NMR (400MHz, CDCl3) δ7.83(d,J=7.5Hz,2H),7.54(t,J=7.4Hz,1H),7.41(t,J=7.7Hz,2H),7.36–7.28(m,4H),7.27–7.23(m,1 H),5.27(d,J=7.1Hz,1H),4.31–4.23(m,1H),4.08(q,J=7.9Hz,1H),3.97–3.89(m,1H),2.53–2.42(m,1H),2.37–2.26(m,1H).

[0020] 13 C NMR (101MHz, CDCl3) δ199.9,141.6,136.5,133.5,128.7,128.60,128.57,127.8,126.0,83.2,68.6,54.9,32.3

[0021] HRMS(ESI,Q-TOF)m / z:[M+Na] + Calcd for C 17 H 16 NaO2, 275.1043. Found: 275.1045

[0022] Using (E)-4-(3',4'-dimethoxy)phenyl-3-buten-1-ol as a substrate and benzoyl oxime ester as an acylation reagent, 2-aryl-3-acyl-substituted tetrahydrofuran molecules were prepared (reaction formula 2).

[0023]

[0024] (E)-4-(3,4-dimethoxy)phenyl-3-buten-1-ol substrate (41.7 mg, 0.2 mmol), (E)-2-(acetoxyimino)-1-phenyl-1-propanone (123.1 mg, 0.6 mmol), and tris(2-phenylpyridine)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W of blue light at room temperature for 12 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a brown oily liquid (dr > 20:1, 47.4 mg, yield = 76%).

[0025] The product test data are as follows: 1H NMR (400MHz, CDCl3) δ7.81(d,J=7.8Hz,2H),7.54(t,J=7.4Hz,1H),7.41(t,J=7.7Hz,2H),6.89–6.84(m,2H),6.78(d,J=8.7Hz,1H),5.15(d, J=7.5Hz,1H),4.29–4.23(m,1H),4.07(q,J=7.8Hz,1H),3.94–3.89(m,1H),3.85(s,3H),3.82(s,3H),2.51–2.41(m,1H),2.38–2.29(m,1H).

[0026] 13 C NMR (101MHz, CDCl3) δ200.2,149.0,148.6,136.7,133.9,133.5,128.8,128.6,118.3,111.1,109.0,83.5,68.6,56.0,55.9,54.9,32.3.

[0027] HRMS(ESI,Q-TOF)m / z:[M+Na] + Calcd for C 19 H 20 NaO4,335.1254.Found:335.1253 Using (E)-4-p-trifluoromethylphenyl-3-buten-1-ol as a substrate and benzoyl oxime ester as an acylation reagent, 2-aryl-3-acyl-substituted tetrahydrofuran molecules were prepared (reaction 3).

[0028]

[0029] (E)-4-(3,4-dimethoxy)phenyl-3-buten-1-ol substrate (41.7 mg, 0.2 mmol), (E)-2-(acetoxyimino)-1-phenyl-1-propanone (123.1 mg, 0.6 mmol), and tris(2-phenylpyridine)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W of blue light at room temperature for 24 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a brown oily liquid (dr > 20:1, 40.4 mg, yield = 63%).

[0030] The product test data are as follows: 1H NMR(400MHz, CDCl3) δ7.84(d,J=7.5Hz,2H),7.60–7.53(m,3H),7.49–7.40(m,4H),5.38(d,J=7.2Hz ,1H),4.32–4.24(m,1H),4.10(q,J=7.7Hz,1H),3.90–3.82(m,1H),2.51(m,1H),2.34–2.24(m,1H).

[0031] 13 C NMR(101MHz, CDCl3)δ199.5,145.9,136.4,133.8,131.6(q,J=300.3Hz),130.0( q,J=32.2Hz),128.9,128.6,126.2,125.6(q,J=3.8Hz),82.2,68.7,55.1,32.5. 19 FNMR (376MHz, CDCl3) δ -62.53.

[0032] HRMS(ESI,Q-TOF)m / z:[M+H]+Calcd for C 18 H 16 F3O2, 321.1097. Found: 321.1096.

[0033] Using (E)-p-bromophenyl-3-buten-1-ol as a substrate and benzoyl oxime ester as an acylation reagent, 2-aryl-3-acyl-substituted tetrahydrofuran molecules were prepared (reaction formula 4).

[0034]

[0035] (E)-4-p-bromophenyl-3-buten-1-ol substrate (45.4 mg, 0.2 mmol), (E)-2-(acetoxyimino)-1-phenyl-1-propanone (123.1 mg, 0.6 mmol), and tris(2-phenylpyridine)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W of blue light at room temperature for 24 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a brown oily liquid (dr > 20:1, 40.4 mg, yield = 61%).

[0036] The product test data are as follows:

[0037] 1H NMR (400MHz, CDCl3) δ7.83(d,J=7.5Hz,2H),7.56(t,J=7.4Hz,1H),7.45–7.40(m,4H),7.22(d,J=8.3Hz,2H),5.25( d,J=7.4Hz,1H),4.28–4.22(m,1H),4.06(q,J=7.7Hz,1H),3.88–3.81(m,1H),2.53–2.43(m,1H),2.32–2.24(m,1H).

[0038] 13 C NMR (101MHz, CDCl3) δ199.6,140.7,136.4,133.7,131.7,128.8,128.6,127.7,121.6,82.4,68.6,55.0,32.4.

[0039] HRMS(ESI,Q-TOF)m / z:[M+Na]+Calcd for C 17 H 15 BrNaO2,353.0148.Found:353.0144.

[0040] Using (E)-o-methylphenyl-3-buten-1-ol as a substrate and benzoyl oxime ester as an acylation reagent, 2-aryl-3-acyl-substituted tetrahydrofuran molecules were prepared (reaction 5).

[0041]

[0042] (E)-4-o-methylphenyl-3-buten-1-ol substrate (32.4 mg, 0.2 mmol), (E)-2-(acetoxyimino)-1-phenyl-1-propanone (123.1 mg, 0.6 mmol), and tris(2-phenylpyridine)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W of blue light at room temperature for 12 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a white solid (dr > 20:1, 42.6 mg, yield = 80%).

[0043] The product test data are as follows:

[0044] 1H NMR (400MHz, CDCl3) δ7.82(d,J=7.6Hz,2H),7.53(t,J=8.8Hz,2H),7.40(t,J=7.4Hz,2H),7.27–7.21(m,1H),7.17(t,J=7.2Hz,1H),7.06(d,J=7. 3Hz,1H),5.50(d,J=6.2Hz,1H),4.33–4.26(m,1H),4.04(q,J=7.8Hz,1H ),3.99–3.91(m,1H),2.52–2.42(m,1H),2.33–2.25(m,1H),2.14(s,3H).

[0045] 13 C NMR (101MHz, CDCl3) δ200.0,140.0,136.3,135.3,133.5,130.6,128.7,128.6,127.6,126.4,125.7,80.2,68.6,54.0,32.4,19.5.

[0046] HRMS(ESI,Q-TOF)m / z:[M+Na]+Calcd for C 18 H 18 NaO2, 289.1199. Found: 289.1192.

[0047] Using 4-(4-butoxy)phenyl-3-buten-1-ol as a substrate and (E)-2-(acetoxyimino)-1-(4-methoxyphenyl)prop-1-one as an acylation reagent, a 2-aryl-3-acyl-substituted tetrahydrofuran molecule was synthesized (reaction 6).

[0048]

[0049] 4-(4-butoxy)phenyl-3-buten-1-ol substrate (44.1 mg, 0.2 mmol), (E)-2-(acetoxyimino)-1-(4-methoxyphenyl)prop-1-one (141 mg, 0.6 mmol), and tris(2-phenylpyridine)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W of blue light at room temperature for 24 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a yellow oily liquid (dr > 20:1, 51.0 mg, 72%).

[0050] The product test data are as follows:

[0051] 1 H NMR (400MHz, CDCl3) δ7.77(d,J=8.9Hz,2H),7.23(d,J=8.6Hz,2H),6.82(t,J =9.3Hz,4H),5.11(d,J=7.3Hz,1H),4.25–4.18(m,1H),4.02(q,J=7.8Hz,1H), 3.90(t,J=6.5Hz,2H),3.86–3.81(m,1H),3.80(s,3H),2.45–2.35(m,1H),2. 34–2.25(m,1H),1.76–1.67(m,2H),1.50–1.40(m,2H),0.94(t,J=7.4Hz,3H).

[0052] 13 C NMR (101MHz, CDCl3) δ198.5,163.6,158.7,133.3,130.9,129.6,127.3,114.4,113.7,83.3,68.4,67.7,55.5,54.4,32.2,31.3,19.3,13.9.

[0053] HRMS(ESI,Q-TOF)m / z:[M+H] + Calcd for C 22 H 27 O4,355.1904.Found:355.1906

[0054] Using (E)-p-butoxyphenyl-3-buten-1-ol as a substrate and an oxime ester containing a furan-2-formyl group as an acylation reagent, 2-aryl-3-acyl-substituted tetrahydrofuran molecules were prepared (reaction formula 7).

[0055]

[0056] (E)-4-butoxyphenyl-3-buten-1-ol substrate (44.1 mg, 0.2 mmol), furan-2-formyl oxime ester (117.1 mg, 0.6 mmol), and tris(2-phenylpyridine)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W of blue light at room temperature for 12 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a white solid (dr > 20:1, 54.7 mg, yield = 87%). The product detection data are as follows:

[0057] 1 H NMR (400MHz, CDCl3) δ7.54 (s, 1H), 7.24 (d, J = 8.4Hz, 2H), 6.98 (d, J = 3.4Hz, 1H) ,6.83(d,J=8.4Hz,2H),6.46(d,J=3.5Hz,1H),5.07(d,J=7.4Hz,1H),4.26–4.1 9(m,1H),4.07(q,J=7.7Hz,1H),3.93(t,J=6.5Hz,2H),3.71(q,J=7.8Hz,1H),2 .42–2.35(m,2H),1.78–1.70(m,2H),1.51–1.42(m,2H),0.96(t,J=7.4Hz,3H).

[0058] 13 C NMR (101MHz, CDCl3) δ188.7,158.9,152.6,147.0,133.1,127.3,118.4,114.5,112.5,83.3,68.6,67.8,55.3,31.5,31.4,19.4,14.0.

[0059] HRMS(ESI,Q-TOF)m / z:[M+Na]+Calcd for C 19 H 22 NaO4, 337.1410. Found: 337.1410

[0060] Using (E)-p-butoxyphenyl-3-buten-1-ol as a substrate and a formyl-containing oxime ester as an acylation reagent, a 2-aryl-3-acyl-substituted tetrahydrofuran molecule was prepared (reaction formula 8).

[0061]

[0062] (E)-4-butoxyphenyl-3-buten-1-ol substrate (44.1 mg, 0.2 mmol), furan-2-carboxyl oxime ester (85.8 mg, 0.6 mmol), and tris(2-phenylpyridine)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W of blue light at room temperature for 12 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a light yellow oily liquid (dr > 20:1, 29.4 mg, yield = 56%).

[0063] The product test data are as follows:

[0064] 1 H NMR (400MHz, CDCl3) δ7.24(d,J=8.5Hz,2H),6.85(d,J=8.5Hz,2H),4.85(d,J=7.6Hz,1H),4.12(q,J=8.0Hz,1H),3.98–3.90 (m,3H),3.12(q,J=8.1Hz,1H),2.28–2.22(m,2H),2.07(s,3H),1.77–1.70(m,2H),1.52–1.42(m,2H),0.95(t,J=7.4Hz,3H).

[0065] 13 C NMR (101MHz, CDCl3) δ208.0,159.0,133.0,127.4,114.6,82.7,68.2,67.8,60.2,31.4,30.5,30.3,19.3,14.0.

[0066] HRMS(ESI,Q-TOF)m / z:[M+H]+Calcd for C 16 H 23 O3,263.1642.Found:263.1645.

[0067] Using (E)-5-phenyl-4-penten-1-ol as a substrate and (E)-2-(acetoxyimino)-1-phenyl-1-propanone as an acylation agent, 2-aryl-3-acyl-substituted tetrahydropyran molecules were prepared (reaction formula 9).

[0068]

[0069] (E)-5-phenyl-4-penten-1-ol substrate (32.4 mg, 0.2 mmol), (E)-2-(acetoxyimino)-1-phenyl-1-propanone (123.1 mg, 0.6 mmol), and tris(2-phenylpyridine)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W blue light at room temperature for 24 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a white solid (dr > 20:1, 39.4 mg, 74%).

[0070] The product test data are as follows:

[0071] 1 H NMR (400MHz, CDCl3) δ7.67(d,J=7.5Hz,2H),7.45(t,J=7.3Hz,1H),7.36–7.29(m,4H),7.19(t,J=7.4Hz,2H),7.15–7.10(m,1H),4.71 (d,J=10.0Hz,1H),4.23–4.17(m,1H),3.77–3.68(m,2H),2.31–2.27(m,1H),2.15–2.09(m,1H),1.94–1.90(m,1H),1.79–1.73(m,1H).

[0072] 13 C NMR (101MHz, CDCl3) δ202.3,140.8,136.6,133.1,129.7,128.6,128.4,128.1,127.1,81.9,68.7,50.9,28.9,25.3.

[0073] HRMS(ESI,Q-TOF)m / z:[M+H] + Calcd for C 18 H 19 O2,267.1380.Found:267.1385

[0074] Using 5-p-bromophenyl-4-penten-1-ol as a substrate and (E)-2-(acetoxyimino)-1-phenyl-1-propanone as an acylation agent, 2-aryl-3-acyl-substituted tetrahydropyran molecules were prepared (reaction formula 10).

[0075]

[0076] 5-p-bromophenyl-4-penten-1-ol substrate (48.2 mg, 0.2 mmol), (E)-2-(acetoxyimino)-1-phenyl-1-propanone (123.1 mg, 0.6 mmol), and tris(2-phenylpyridine)iridium (1.2 mg, 0.002 mmol) were sequentially added to a Schlenk tube equipped with a stir bar. The Schlenk tube was purged with argon three times, and ultra-dry tetrahydrofuran (2 mL) was added to the Schlenk tube under argon countercurrent. The Schlenk tube was then sealed and irradiated with 14 W blue light at room temperature for 24 hours. After the reaction was completed, the reaction system was extracted, dried, concentrated, and subjected to silica gel column chromatography to obtain a white solid (dr > 20:1, 51.7 mg, 72%).

[0077] The product test data are as follows: 1 H NMR (400MHz, CDCl3) δ7.73(d,J=7.7Hz,2H),7.56(t,J=7.4Hz,1H),7.45–7.37(m,4H),7.23(d,J=8.4Hz,2H ),5.73(d,J=10.0Hz,1H),3.93(q,J=9.0Hz,1H),2.91–2.82(m,1H),2.75–2.67(m,1H),2.30–2.19(m,2H). 13 C NMR (101MHz, CDCl3) δ199.3,170.7,137.0,135.5,134.2,131.9,129.1,128.7,128.4,122.9,81.5,47.4,28.7,24.1.

[0078] HRMS(ESI,Q-TOF)m / z:[M+Na]+Calcd for C 18 H 15 BrNaO3,381.0097.Found:381.0099.

Claims

1. A method for preparing a 2-aryl-3-carbonyl-substituted tetrahydrofuran or tetrahydropyran compound, characterized in that an unsaturated alcohol, an alkyl or aryl acyl oxime ester, a photocatalyst, and a solvent are sequentially added to a reaction flask equipped with a stir bar, and the 2-aryl-3-carbonyl-substituted tetrahydrofuran or tetrahydropyran compound is prepared in a one-pot reaction under a 14-watt blue light source, as shown in the following reaction formula: in: 1) Ar represents phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butoxyphenyl, 3,4-dimethoxyphenyl, 3,5-dimethoxyphenyl, 3,4,5-trimethoxyphenyl, 3-chloro-4-methoxyphenyl, 3-bromo-4-methoxyphenyl, 3-bromophenyl, 4-bromophenyl, 4-chlorophenyl, 4-fluorophenyl, 4-trifluoromethylphenyl, 4-iodophenyl, 4-cyanophenyl, and 2-naphthyl; 2) R is phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 4-bromophenyl, 4-chlorophenyl, 4-fluorophenyl, 4-trifluoromethylphenyl, 3-chlorophenyl, 2-fluorophenyl, 2-furanyl, 2-thienyl, methyl, ethyl, n-propyl, isopropyl, n-butyl; The photocatalyst is selected from tris(2-phenylpyridine)iridium, bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate), and [4,4'-bis(1,1-dimethylethyl)-2,2'-bipyridine]bis[3,5-difluoro-2-(5-fluoro-2-pyridyl)phenyl]iridium hexafluorophosphate.

2. The method for preparing a 2-aryl-3-carbonyl-substituted tetrahydrofuran or tetrahydropyran compound according to claim 1, characterized in that the solvent used is selected from acetonitrile, methanol, dichloromethane, tetrahydrofuran, ethyl acetate, acetone, etc. N , N - Dimethylformamide, dimethyl sulfoxide, and hexafluoroisopropanol.

3. The method for preparing a 2-aryl-3-carbonyl-substituted tetrahydrofuran or tetrahydropyran compound according to claim 1, characterized in that: The reaction temperature is 0-50℃; the reaction time is 4-36 hours; the gas atmosphere is selected from nitrogen and argon.

4. The method for preparing a 2-aryl-3-carbonyl-substituted tetrahydrofuran or tetrahydropyran compound according to claim 1, characterized in that the molar ratio of each substance in the reaction is: unsaturated alcohol substrate: alkyl or aryl acyl oxime ester: photocatalyst = 1:1-5:0.001-0.2.

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