Method for preparing cyclopentane [c] quinoline by using visible light / molecular iodine dual catalysis

Abstract

The invention discloses a method for preparing cyclopentane [c] quinoline by using visible light / molecular iodine dual catalysis, and relates to the technical field of chemical synthesis. Specifically, diazoacetate compounds and 1, 7-eneyne are used as substrates, fac-Ir (planar-tri (2-phenylpyridine) iridium complex) and molecular iodine are used as catalysts, CH3CN is used as a solvent, and a cyclopentane [c] quinoline skeleton is synthesized under the protection of nitrogen atmosphere and irradiation of a 15w LED blue light lamp. The preparation method provided by the invention has very excellent substrate compatibility, can also be well compatible with diazoacetate compounds modified by natural products, enriches the diversity of substrates synthesized by a cyclopentane [c] quinoline skeleton, and provides a new way for preparation of the cyclopentane [c] quinoline skeleton.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical synthesis, and particularly relates to a method for preparing cyclopentane c quinoline by dual catalysis of visible light / molecular iodine. Background Art

[0002] Diazoacetate compounds are an important synthetic structural unit with a wide range of uses. Since the second half of the 19th century, they have been widely used in organic synthesis. For example, diazoacetate compounds can be converted into metal carbenes, followed by X-H insertion reactions. In addition, diazoacetate compounds can also be used as 1,3-dipoles, C-nucleophiles, etc. for various cycloaddition and homologation reactions. In recent years, the rapid development of visible light-driven technology has injected new vitality into the development of new reaction modes of diazoacetate compounds. Specifically, under visible light catalysis, diazoacetate compounds can be converted into alkyl radicals through the PCET (proton-coupled electron transfer) pathway, followed by a series of radical-type reactions. For example: 1) In 20, the Li Pan research group at Henan University used diazoacetate compounds under visible light catalysis to undergo a difunctionalization reaction between the alkyl radicals generated through PCET (proton-coupled electron transfer) and alkenes (Org. Lett. 2022, 24, 6834-6838). 2) In 2023, the Li Huaifeng research group in chemistry at Guangxi Normal University was the first to report a new method for synthesizing indoles mediated by alkyl radicals generated through PCET (proton-coupled electron transfer) from diazoacetate compounds under visible light catalysis (Org Lett, 2023, 25, 3778-3783). 3) The Xuan Jun research group in chemistry at Anhui University successfully developed a photocatalytic radical cascade cyclization reaction using diazoacetate compounds as substrates in 2024 (Org Lett, 2024, 26, 1393-1398.). Despite these advances in radical reactions, unfortunately, in the current reactions of diazoacetate compounds as radical precursors, the newly generated carbon radicals cannot achieve an intermolecular radical cascade cyclization reaction with 1,7-enynes to construct the cyclopentane c quinoline skeleton. Based on the cyclopentane c quinoline skeleton is an important nitrogen-containing heterocycle and has a wide range of applications in the fields of medicine and pesticides. Its efficient construction is one of the hot topics in the field of organic synthesis. Therefore, it is very meaningful to develop an efficient and mild method to construct the cyclopentane c quinoline skeleton from structurally diverse diazoacetate compounds. Summary of the Invention

[0003] The object of the present invention is to provide a method for preparing cyclopentane by dual catalysis of visible light / molecular iodinec Method for preparing quinoline, enriching cyclopentane c Preparation pathway of quinoline skeleton.

[0004] To achieve the above object, the present invention provides a method for preparing cyclopentane c quinoline by dual catalysis of visible light / molecular iodine. Specifically, diazoacetate compounds and 1,7-enynes are used as substrates, fac-Ir and molecular iodine as the catalyst, CH3CN as the solvent. Under the protection of a nitrogen atmosphere, cyclopentane c quinoline is synthesized by irradiation with an LED blue light, wherein fac-Ir is fac-tris(2-phenylpyridine)iridium complex.

[0005] The present invention provides a method for preparing cyclopentane c quinoline by dual catalysis of visible light / molecular iodine, which specifically comprises the following steps: (1) Mix diazoacetate compounds and 1,7-enynes as substrates, fac-Ir and molecular iodine, add the solvent CH3CN, mix evenly, place under an LED blue light for irradiation, and carry out a stirring-assisted reaction; (2) After the reaction is completed, collect the organic phase, wash it with saturated brine, extract it with ethyl acetate, and combine the extracted organic phases for drying; (3) Distill off the solvent from the dried product under reduced pressure, and then purify the remaining organic residue to obtain cyclopentane c quinoline product.

[0006] Preferably, in the above method, the molar ratio of diazoacetate compounds to 1,7-enynes is 5:1.

[0007] Preferably, in the above method fac-Ir and 1,7-enynes is 1:50.

[0008] Preferably, in the above method, the molar ratio of molecular iodine to 1,7-enynes is 1:5.

[0009] Preferably, the LED blue light in the above method is 15W.

[0010] Preferably, the reaction in step (1) above is carried out at room temperature under a nitrogen atmosphere, more preferably at room temperature for 24 h.

[0011] Preferably, the completion of the reaction in step (2) of the above method is to monitor the reaction process by thin layer chromatography until the substrate reaction is complete and the product spots no longer change; the drying can be carried out by adding anhydrous sodium sulfate.

[0012] Preferably, the purification in the above method is silica gel column chromatography purification, and the eluent for purification is preferably a mixed solvent of petroleum ether and ethyl acetate. Especially when the volume ratio of petroleum ether to ethyl acetate is 10:1, the purification efficiency is the best.

[0013] The present invention has the following advantages: The present invention provides an efficient visible light / molecular iodine dual catalytic reaction strategy to obtain cyclopentane c quinoline compounds. Through the single electron transfer process of the diiodo compound generated by molecular iodine and diazoacetate compounds with the photocatalyst fac-Ir to generate iodoalkyl radicals. It is worth noting that this radical can efficiently undergo an intermolecular radical cascade cyclization reaction with 1,7-enynes to obtain cyclopentane c quinoline compounds. In addition, the preparation method provided by the present invention shows good substrate compatibility, and various diazoacetate compounds modified with natural products can also participate in the reaction, greatly enriching the synthetic diversity of cyclopentane c quinoline compounds. Detailed implementation manners

[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0015] Note: The experimental methods in the following embodiments are all conventional methods unless otherwise specified, and are carried out according to the technologies or conditions described in the literature in this field or according to the product specifications. The materials, reagents, etc. used in the following embodiments can be obtained from commercial channels unless otherwise specified.

[0016] To overcome the defect that the alkyl radicals generated by diazoacetate compounds through the photoinduced PCET (proton-coupled electron transfer) pathway are incompatible with 1,7-enynes, the present invention provides an efficient method based on visible light / molecular iodine dual catalysis, using diazoacetate compounds and 1,7-enynes as substrates, fac-Ir and molecular iodine as the catalyst, CH3CN as the solvent, and synthesizing the cyclopentane c quinoline skeleton under the irradiation of a 15w LED blue light, specifically as follows: Example 1 Add ethyl diazoacetate (1.0 mmol), 1,7-enyne (0.2 mmol) to a 25 mL Schlenk tube, fac- Ir(Face-tris(2-phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol), and 3 mL of CH3CN were mixed thoroughly and stirred under nitrogen atmosphere under 15W LED blue light for 24 hours. The reaction progress was monitored by thin-layer chromatography (TLC). The reaction was stopped when the substrate reaction was complete and the product point no longer changed. The specific reaction equation is shown in Equation 1 below. The reaction mixture was washed with saturated brine (50 mL) and extracted with EtOAc (50 mL x 3) in three portions. The organic layers were combined. The organic phase (the combined organic layers) was dried over anhydrous sodium sulfate. After removing the solvent by distillation under reduced pressure, the crude product was purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 90%.

[0017] (Formula 1) In the above preparation method, the extraction agent ethyl acetate used for extraction can also be replaced by other solvents that are immiscible with water and have a low boiling point, such as dichloromethane, diethyl ether, etc.

[0018] The obtained product was subjected to NMR characterization test, and the obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the formula.

[0019] 1 H NMR (400 MHz, CDCl3) δ 7.29–7.21 (m, 6H), 7.10–7.01 (m, 2H), 6.80 (t, J = 7.6 Hz, 1H), 4.19 (dd, J = 10.0, 7.6 Hz, 1H), 3.90 (dd, J = 15.6, 7.2 Hz, 2H), 3.42 (s, 3H), 2.74 (dd, J = 13.2, 10.0 Hz, 1H), 2.48 (dd, J = 13.2, 7.6 Hz, 1H),1.25 (s, 3H), 0.90 (t, J = 7.2 Hz, 3H). 1313C NMR (100 MHz, CDCl3) δ 174.6, 173.2, 140.2, 136.5, 136.3, 135.4, 128.9, 128.3, 128.1, 127.7, 127.5, 122.3, 120.5, 115.2, 60.5, 53.4, 52.8, 38.6, 29.8, 23.1, 13.8. Example 2 Add diazoacetic acid estradiol benzoate (1.0 mmol), 1,7 - enyne (0.2 mmol), fac-Ir (fac - tris(2 - phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol) and 3 mL of CH3CN into a 25 mL Schlenk tube. After mixing the mixture evenly, place it under nitrogen protection and irradiate it with a 15 w blue LED light for 24 hours. Monitor the reaction process using thin - layer chromatography (TLC). When the substrate reaction is complete and the product spots no longer change, stop the reaction. The specific reaction equation is shown in Equation 2 below. Add saturated brine (50 mL) to the reactants for washing, and then extract three times with EtOAc (50 mL * 3). Combine the organic layers. Add anhydrous sodium sulfate to dry the organic phase (combined organic layers). After removing the solvent by reduced - pressure distillation, purify the crude product by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 86%.

[0020] (Equation 2) Perform NMR characterization tests on the obtained product. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the formula.

[0021] 1 1H NMR (400 MHz, CDCl3) δ 8.20 (d, J J = 7.6 Hz, 2H), 7.63 (t, J J = 7.6 Hz, 1H), 7.51 (t, J J = 7.6 Hz, 2H), 7.33 (d, J J = 8.4 Hz, 1H), 7.29 (d, J J = 3.2 Hz, 5H), 7.18 (ddd, J J = 7.6, 3.6, 1.2 Hz, 1H), 7.04 (d, J J = 8.4 Hz, 1H), 6.98 (dd, J= 8.4, 2.0 Hz, 1H), 6.93 (d, J = 2.0 Hz, 1H), 6.83 (td, J = 7.6, 2.4 Hz, 1H), 4.80 (dt, J = 26.8, 8.4 Hz, 1H), 3.81 (dt, J = 10.8, 2.0 Hz, 1H), 3.42 (s, 3H), 3.01 (ddd, J = 14.0, 10.8, 6.8 Hz, 1H), 2.94–2.84 (m, 2H), 2.35–2.30 (m, 2H), 2.28 (dd, J = 4.4, 1.6 Hz, 1H), 1.98–1.75 (m, 3H), 1.66–1.47 (m, 5H), 1.42 (d, J = 4.0 Hz, 4H), 1.38–1.30 (m, 2H), 0.79 (d, J = 7.6 Hz, 3H). 13 C NMR (101 MHz, CDCl3) δ 175.35, 175.27, 165.43, 148.68, 140.00, 139.97, 138.18, 137.80, 136.31, 136.16, 136.05, 133.45, 130.11, 129.67, 128.93, 128.50, 128.40, 128.08, 127.72, 126.43, 122.49, 121.60, 121.12, 118.68, 114.98, 83.31, 77.32, 77.00, 76.68, 55.26, 55.08, 54.38, 49.83, 43.96, 43.10, 42.89, 38.15, 29.96, 29.49, 27.58, 27.00, 26.05, 24.89, 23.26, 12.13. Example 3 Add trimethylsilyl diazoacetate (1.0 mmol), 1,7 - enyne (0.2 mmol) to a 25 mL Schlenk tube, fac-Ir(fac - tris(2 - phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol), and 3 mL of CH3CN were mixed well and placed under nitrogen protection. They were irradiated with a 15 w blue LED lamp for 24 hours. The reaction process was monitored using thin - layer chromatography (TLC). When the substrate reaction was complete and the product spots no longer changed, the reaction was stopped. The specific reaction equation is shown in Equation 3 below. Saturated brine (50 mL) was added to the reactants for washing, and then extracted three times with EtOAc (50 mL * 3). The organic layers were combined. Anhydrous sodium sulfate was added to the organic phase (combined organic layers) for drying. After removing the solvent by vacuum distillation, the crude product was separated and purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 89%.

[0022] (Equation 3) The obtained product was characterized by NMR. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the equation.

[0023] 1 H NMR (400 MHz, CDCl3) δ 7.25–7.17 (m, 6H), 7.07 (dd, J J = 7.6, 1.2 Hz,1H), 6.99 (d, J J = 8.0 Hz, 1H), 6.76 (t, J J = 7.6 Hz, 1H), 4.21 (ddd, J J = 11.2, 6.0,2.0 Hz, 2H), 3.70 (dd, J J = 10.8, 1.6 Hz, 1H), 3.37 (s, 3H), 2.93 (dd, J J = 14.0,10.8 Hz, 1H), 2.22 (dd, J J = 14.0, 2.0 Hz, 1H), 1.36 (s, 3H), 0.96 (dt, J J = 19.2,8.8 Hz, 2H), 0.00 (s, 9H). 1313C NMR (100 MHz, CDCl3) δ 176.9, 176.8, 141.5, 139.4, 138.0, 137.7, 130.4, 129.9, 129.6, 129.2, 123.9, 122.5, 116.5, 78.8, 78.5, 78.2, 64.9, 56.7, 55.9, 39.6, 31.5, 26.7, 18.8, -0.00. Example 4 Cyclohexyl diazoacetate (1.0 mmol), 1,7 - enyne (0.2 mmol), fac-Ir (fac - tris(2 - phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol) and 3 mL of CH3CN were added to a 25 mL Schlenk tube. After mixing the mixture evenly, it was placed under nitrogen protection and irradiated with a 15 w blue LED light for 24 hours. The reaction process was monitored by thin - layer chromatography (TLC). When the substrate reaction was complete and the product spots no longer changed, the reaction was stopped. The specific reaction equation is shown in Equation 4 below. Saturated brine (50 mL) was added to the reaction mixture for washing, and then extracted three times with EtOAc (50 mL * 3). The organic layers were combined. Anhydrous sodium sulfate was added to the organic phase (combined organic layers) for drying. After removing the solvent by vacuum distillation, the crude product was purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 85%.

[0024] (Equation 4) The obtained product was characterized by NMR. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the equation.

[0025] 1 1H NMR (400 MHz, CDCl3) δ 7.30–7.23 (m, 6H), 7.14 (d, J J = 7.6 Hz, 1H), 7.03 (d, J J = 8.4 Hz, 1H), 6.82 (t, J J = 7.6 Hz, 1H), 4.86 (td, J J = 8.8, 4.0 Hz, 1H), 3.75 (d, J J = 9.2 Hz, 1H), 3.41 (s, 3H), 2.98 (dd, J J = 14.0, 10.8 Hz, 1H), 2.27(dd,J = 14.0, 1.6 Hz, 1H), 1.89 (t, J = 12.4 Hz, 2H), 1.72 (t, J = 10.4 Hz, 2H), 1.65–1.42 (m, 3H), 1.40 (s, 3H), 1.38–1.28 (m, 2H), 1.27–1.23 (m, 1H). 13 C NMR(100 MHz, CDCl3) δ 175.4, 174.6, 140.0, 137.7, 136.4, 136.3, 128.9, 128.5, 128.4, 128.1, 127.7, 122.4, 121.1, 114.9, 73.4, 55.4, 54.4, 38.3, 31.5, 29.9, 25.3, 25.1, 23.7. Example 5 Add diazoacetic allyl methyl ester (1.0 mmol), 1,7 - enyne (0.2 mmol), fac-Ir (facial - tris(2 - phenylpyridine)iridium complex) (0.004 mmol) and iodine (0.04 mmol) and 3 mL of CH3CN into a 25 mL Schlenk tube. After mixing the mixture evenly, place it under nitrogen protection and irradiate it with a 15 w LED blue light for 24 hours. Monitor the reaction process using thin - layer chromatography (TLC). When the substrate reaction is complete and the product spots no longer change, stop the reaction. The specific reaction equation is shown in Equation 5 below. Add saturated brine (50 mL) to the reactants for washing, and then extract three times with EtOAc (50 mL * 3). Combine the organic layers. Add anhydrous sodium sulfate to dry the organic phase (combined organic layers). After removing the solvent by rotary evaporation under reduced pressure, purify the crude product by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with a total yield of 55%.

[0026] (Equation 5) Perform NMR characterization tests on the obtained product. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the equation.

[0027] 1 H NMR (400 MHz, CDCl3) δ 7.31–7.26 (m, 3H), 7.25–7.20 (m, 3H), 7.12(dd, J = 7.6, 1.2 Hz, 1H), 7.03 (d, J= 8.4 Hz, 1H), 6.81 (t, J = 7.6 Hz, 1H), 4.96(d, J = 20.0 Hz, 2H), 4.65–4.55 (m, 2H), 3.82 (dd, J = 10.8, 1.6 Hz, 1H), 3.42(s, 3H), 3.00 (dd, J = 14.0, 10.8 Hz, 1H), 2.30 (dd, J = 14.4, 2.0 Hz, 1H), 1.74(s, 3H), 1.40 (s, 3H). 13 C NMR (100 MHz, CDCl3) δ 175.3, 174.9, 140.0, 139.6,138.1, 136.3, 136.0, 128.9, 128.45, 128.42, 128.1, 127.7, 122.5, 121.0,115.0, 113.6, 68.4, 55.0, 54.4, 38.2, 30.0, 25.1, 19.6. Example 6 Add ethyl adamantyl diazoacetate (1.0 mmol), 1,7 - enyne (0.2 mmol), fac-Ir (fac - tris(2 - phenylpyridine)iridium complex) (0.004 mmol) and iodine (0.04 mmol) and 3 mL of CH3CN into a 25 mL Schlenk tube. After mixing the mixture evenly, place it under nitrogen protection and irradiate it with a 15 w LED blue light for 24 hours. Monitor the reaction process using thin - layer chromatography (TLC). When the substrate reaction is complete and the product spots no longer change, stop the reaction. The specific reaction equation is shown in Equation 6 below. Add saturated brine (50 mL) to wash the reactants, and then extract three times with EtOAc (50 mL * 3). Combine the organic layers. Add anhydrous sodium sulfate to dry the organic phase (combined organic layers). After removing the solvent by vacuum distillation, purify the crude product by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 55%.

[0028] (Equation 6) Perform NMR characterization tests on the obtained product. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the formula.

[0029] 11H NMR (400 MHz, CDCl3) δ 7.28 (dd, J J = 5.2, 2.0 Hz, 3H), 7.25–7.20 (m,3H), 7.11 (dd, J J = 7.6, 1.6 Hz, 1H), 7.03 (d, J J = 8.0 Hz, 1H), 6.81 (dd, J J = 10.8,4.4 Hz, 1H), 4.29–4.17 (m, 2H), 3.75 (dd, J J = 10.8, 2.0 Hz, 1H), 3.41 (s, 3H),2.97 (dd, J J = 14.0, 10.8 Hz, 1H), 2.27 (dd, J J = 14.0, 2.0 Hz, 1H), 1.93 (s, 3H),1.69 (d, J J = 12.0 Hz, 3H), 1.60 (d, J J = 10.8 Hz, 4H), 1.51 (d, J J = 2.0 Hz, 6H),1.43 (d, J J = 7.2 Hz, 1H), 1.40 (s, 3H). 13 13C NMR (100 MHz, CDCl3) δ 175.3, 140.0,137.8, 136.4, 136.1, 128.9, 128.43, 128.41, 128.1, 127.7, 122.4, 121.1,115.0, 61.6, 55.2, 54.4, 42.5, 42.3, 38.1, 37.0, 31.8, 29.9, 28.5, 25.1. Example 7 Add tert-butyl diazoacetate (1.0 mmol), 1,7-enyne (0.2 mmol) to a 25 mL Schlenk tube, fac- Ir(Fac - tris(2 - phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol), and 3 mL of CH3CN. After mixing the mixture evenly, it was placed under nitrogen protection and irradiated with a 15 w LED blue light for 24 hours. The reaction process was monitored by thin - layer chromatography (TLC). When the substrate reaction was complete and the product spots no longer changed, the reaction was stopped. The specific reaction equation is shown in Equation 7 below. Saturated brine (50 mL) was added to the reactants for washing, and then extracted three times with EtOAc (50 mL * 3). The organic layers were combined. Anhydrous sodium sulfate was added to the organic phase (combined organic layers) for drying. After removing the solvent by vacuum distillation, the crude product was separated and purified by silica gel column chromatography using a mixed solution of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 75%.

[0030] (Equation 7) The obtained product was characterized by NMR. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the equation.

[0031] 1 H NMR (400 MHz, CDCl3) δ 7.30–7.22 (m, 6H), 7.16 (dd, J J = 7.6, 1.6 Hz,1H), 7.03 (d, J J = 8.0 Hz, 1H), 6.81 (td, J J = 7.6, 0.8 Hz, 1H), 3.67 (dd, J J = 10.8,2.0 Hz, 1H), 3.41 (s, 3H), 2.95 (dd, J J = 14.0, 10.8 Hz, 1H), 2.25 (dd, J J = 14.0,2.0 Hz, 1H), 1.49 (s, 9H), 1.39 (s, 3H). 13 C NMR (100 MHz, CDCl3) δ 175.4,174.4, 140.0, 137.4, 136.6, 128.8, 128.5, 128.3, 128.1, 127.6, 122.4, 121.2,114.9, 81.0, 56.2, 54.3, 38.3, 29.9, 28.0, 25.1. Example 8 Add cholesteryl diazoacetate (1.0 mmol), 1,7 - enyne (0.2 mmol) to a 25 mL Schlenk tube,fac-Ir (Face - tris(2 - phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol) and 3 mL of CH3CN. After mixing the mixture evenly, it was placed under nitrogen protection and irradiated with a 15 w blue LED light for 24 hours. The reaction process was monitored by thin - layer chromatography (TLC). When the substrate reaction was complete and the product spots no longer changed, the reaction was stopped. The specific reaction equation is shown in Equation 8 below. Saturated brine (50 mL) was added to the reactants for washing, and then extracted three times with EtOAc (50 mL * 3). The organic layers were combined. Anhydrous sodium sulfate was added to the organic phase (combined organic layers) for drying. After removing the solvent by vacuum distillation, the crude product was separated and purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 85%.

[0032] (Equation 8) The obtained product was characterized by NMR. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the equation.

[0033] 1 H NMR (400 MHz, CDCl3) δ 7.31–7.27 (m, 3H), 7.23 (ddd, J J = 5.6, 4.4,1.6 Hz, 3H), 7.15–7.11 (m, 1H), 7.03 (d, J J = 8.0 Hz, 1H), 6.81 (t, J J = 7.6 Hz,1H), 5.40 (d, J J = 4.8 Hz, 1H), 4.76–4.65 (m, 1H), 3.74 (dd, J J = 10.4, 1.6 Hz,1H), 3.41 (s, 3H), 2.97 (dd, J J = 14.0, 10.8 Hz, 1H), 2.39–2.25 (m, 3H), 2.07–1.99 (m, 2H), 1.90–1.84 (m, 2H), 1.62–1.48 (m, 7H), 1.40 (s, 3H), 1.33 (s,3H), 1.26 (s, 5H), 1.12 (dd, J J = 18.8, 12.8 Hz, 7H), 1.01 (s, 3H), 0.92 (d, J J =6.4 Hz, 3H), 0.87 (d, J= 1.6 Hz, 3H), 0.86 (d, J = 1.6 Hz, 3H), 0.68 (s, 3H). 13 C NMR (100 MHz, CDCl3) δ 175.4, 174.6, 140.0, 139.6, 139.4, 137.8, 136.5,136.3, 128.9, 128.5, 128.4, 128.1, 127.7, 122.9, 122.5, 121.1, 115.0, 74.7,56.7, 56.1, 55.4, 54.4, 50.0, 42.3, 39.7, 39.5, 38.3, 38.0, 37.0, 36.6, 36.2,35.8, 31.9, 30.0, 29.7, 28.3, 28.0, 27.7, 25.2, 24.3, 23.8, 22.8, 22.6, 19.3,18.7, 11.9. Example 9 Add cyclopropyl diazoacetate (1.0 mmol), 1,7 - enyne (0.2 mmol), fac- Ir (fac - tris(2 - phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol) and 3 mL of CH3CN into a 25 mL Schlenk tube. After mixing the mixture evenly, place it under nitrogen protection and irradiate it with a 15 w blue LED light for 24 hours. Monitor the reaction process using thin - layer chromatography (TLC). When the substrate reaction is complete and the product spots no longer change, stop the reaction. The specific reaction equation is shown in Equation 9 below. Add saturated brine (50 mL) to wash the reactants, and then extract with EtOAc (50 mL * 3) three times. Combine the organic layers. Add anhydrous sodium sulfate to dry the organic phase (combined organic layers). After removing the solvent by vacuum distillation, purify the crude product by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 90%.

[0034] (Equation 9) Perform NMR characterization tests on the obtained product. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the equation.

[0035] 1 H NMR (400 MHz, CDCl3) δ 7.31–7.27 (m, 3H), 7.25–7.18 (m, 3H), 7.10(dd, J= 7.6, 1.6 Hz, 1H), 7.03 (d, J = 8.0 Hz, 1H), 6.81 (td, J = 7.6, 0.8 Hz,1H), 4.24 (dq, J = 9.6, 3.2 Hz, 1H), 3.73 (dd, J = 10.8, 2.0 Hz, 1H), 3.41 (s,3H), 2.96 (dd, J = 14.4, 10.8 Hz, 1H), 2.24 (dd, J = 14.4, 2.0 Hz, 1H), 1.39 (s,3H), 0.78–0.71 (m, 2H), 0.71–0.65 (m, 2H). 13 C NMR (100 MHz, CDCl3) δ 176.1,175.2, 140.0, 138.0, 136.3, 135.9, 128.9, 128.44, 128.40, 128.1, 127.8,122.5, 120.9, 115.0, 54.9, 54.4, 49.4, 38.0, 29.9, 25.2, 5.1, 5.0. Example 10 Add hexyl diazoacetate (1.0 mmol), 1,7 - enyne (0.2 mmol), fac-Ir (fac - tris(2 - phenylpyridine)iridium complex) (0.004 mmol) and iodine (0.04 mmol) and 3 mL of CH3CN into a 25 mL Schlenk tube. After mixing the mixture evenly, place it under nitrogen protection and irradiate it with a 15 w LED blue light for 24 hours. Monitor the reaction process using thin - layer chromatography (TLC). When the substrate reaction is complete and the product spots no longer change, stop the reaction. The specific reaction equation is shown in Equation 10 below. Add saturated brine (50 mL) to wash the reactants, and then extract three times with EtOAc (50 mL * 3). Combine the organic layers. Add anhydrous sodium sulfate to dry the organic phase (combined organic layers). After removing the solvent by reduced - pressure distillation, purify the crude product by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with a total yield of 56%.

[0036] (Equation 10) Perform NMR characterization tests on the obtained product. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the formula.

[0037] 1 1H NMR (400 MHz, CDCl3) δ 7.29–7.22 (m, 6H), 7.17–7.11 (m, 1H), 7.03 (d, J J = 8.4 Hz, 1H), 6.82 (t, J J = 7.6 Hz, 1H), 5.05–4.94 (m, 1H), 3.75 (dt, J J = 10.4, 2.0 Hz, 1H), 3.41 (s, 3H), 2.98 (ddd, J J = 14.0, 10.8, 1.6 Hz, 1H), 2.25 (ddd, J J = 14.0, 4.0, 2.0 Hz, 1H), 1.62–1.43 (m, 2H), 1.40 (s, 3H), 1.31 (ddd, J J = 10.4, 5.6, 2.8 Hz, 3H), 1.27–1.25 (m, 3H), 1.23 (d, J J = 6.4 Hz, 1H), 0.88 (t, J J = 6.8 Hz, 3H). 13 13C NMR (100 MHz, CDCl3) δ 175.4, 174.90, 174.89, 140.0, 137.8, 136.5, 136.3, 128.9, 128.5, 128.41, 128.38, 128.1, 127.7, 122.5, 121.1, 115.0, 71.9, 71.8, 55.4, 55.3, 54.4, 38.3, 35.6, 35.5, 30.0, 27.5, 25.1, 25.0, 22.54, 22.50, 19.92, 19.87, 14.0. Example 11 Add 2-fluorobenzyl diazoacetate (1.0 mmol), 1,7-enyne (0.2 mmol) to a 25 mL Schlenk tube, fac-Ir(Face-tris(2-phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol), and 3 mL of CH3CN were mixed thoroughly and placed under nitrogen. Irradiation was performed with a 15W LED blue light for 24 hours. The reaction progress was monitored by thin-layer chromatography (TLC). The reaction was stopped when the substrate reaction was complete and the product point stopped changing. The specific reaction equation is shown in Equation 11 below. The reaction mixture was washed with saturated brine (50 mL) and extracted with EtOAc (50 mL x 3) in three portions. The organic layers were combined. The organic phase (combined organic layers) was dried over anhydrous sodium sulfate. After removing the solvent by distillation under reduced pressure, the crude product was purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 71%.

[0038] (Equation 11) The obtained product was subjected to NMR characterization test, and the obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the formula.

[0039] 1 H NMR (400 MHz, CDCl3) δ 7.34 (dt, J = 8.0, 6.8 Hz, 2H), 7.26 (s, 1H), 7.23 (d, J = 7.2 Hz, 3H), 7.15 (dd, J = 7.6, 2.0 Hz, 3H), 7.09 (d, J = 8.0 Hz, 2H),7.03 (d, J = 8.4 Hz, 1H), 6.80 (t, J = 7.6 Hz, 1H), 5.28 (s, 2H), 3.81 (dd, J =10.4, 1.6 Hz, 1H), 3.41 (s, 3H), 2.97 (dd, J = 14.0, 10.8 Hz, 1H), 2.28 (dd, J =14.4, 1.6 Hz, 1H), 1.35 (s, 3H). 1313C NMR (100 MHz, CDCl3) δ 175.3, 174.9, 140.0, 138.2, 136.2, 135.9, 131.0, 130.9, 130.45, 130.37, 129.0, 128.45, 128.40, 128.2, 127.7, 124.1, 122.5, 121.0, 115.7, 115.4, 115.0, 60.8, 54.9, 54.5, 38.1, 30.0, 25.0. Example 12 Add cyclododecyl diazoacetate (1.0 mmol), 1,7-enyne (0.2 mmol), fac-Ir (fac-tris(2-phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol) and 3 mL of CH3CN into a 25 mL Schlenk tube. After mixing the mixture evenly, place it under nitrogen protection and irradiate it with a 15 w LED blue light for 24 hours. Monitor the reaction process using thin layer chromatography (TLC). When the substrate reaction is complete and the product spots no longer change, stop the reaction. The specific reaction equation is shown in Equation 12 below. Add saturated brine (50 mL) to the reactants for washing, and then extract three times with EtOAc (50 mL * 3). Combine the organic layers. Add anhydrous sodium sulfate to dry the organic phase (combined organic layers). After removing the solvent by vacuum distillation, purify the crude product by silica gel column chromatography using a mixed solution of petroleum ether and ethyl acetate to obtain a colorless liquid with a total yield of 36%.

[0040] (Equation 12) Perform NMR characterization tests on the obtained product. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the equation.

[0041] 1 1H NMR (400 MHz, CDCl3) δ 7.31–7.24 (m, 5H), 7.24–7.21 (m, 1H), 7.14 (dd, J J = 7.6, 1.2 Hz, 1H), 7.03 (d, J J = 8.0 Hz, 1H), 6.82 (dd, J J = 11.2, 4.0 Hz, 1H), 5.14–5.07 (m, 1H), 3.74 (dd, J J = 10.8, 1.6 Hz, 1H), 3.41 (s, 3H), 2.97 (dd, J= 14.0, 10.8 Hz, 1H), 2.25 (dd, J = 14.0, 2.0 Hz, 1H), 1.79–1.64 (m, 3H), 1.53 (dd, J = 12.4, 7.2 Hz, 2H), 1.47 (dd, J = 14.0, 7.2 Hz, 2H), 1.40 (s, 7H), 1.34 (d, J = 4.8 Hz, 11H). 13 C NMR (100 MHz, CDCl3) δ 175.4, 174.9, 140.0, 137.7, 136.4, 136.2, 128.8, 128.4, 128.3, 128.1, 127.7, 122.4, 121.1, 114.9, 73.0, 55.3, 54.4, 38.3, 29.9, 29.07, 29.05, 25.1, 24.01, 23.97, 23.8, 23.4, 23.2, 21.0, 20.9. Example 13 Add diazoacetic acid 2-methylphenethyl ester (1.0 mmol), 1,7-enyne (0.2 mmol), fac-Ir (fac-tris(2-phenylpyridine)iridium complex) (0.004 mmol) and iodine (0.04 mmol) and 3 mL of CH3CN to a 25 mL Schlenk tube. After mixing the mixture evenly, place it under nitrogen protection and irradiate it with a 15 w LED blue light for 24 hours. Monitor the reaction process using thin layer chromatography (TLC). When the substrate reaction is complete and the product spot no longer changes, stop the reaction. The specific reaction equation is shown in Equation 13 below. Add saturated brine (50 mL) to the reactants for washing, and then extract three times with EtOAc (50 mL * 3). Combine the organic layers. Add anhydrous sodium sulfate to dry the organic phase (combined organic layers). After removing the solvent by vacuum distillation, the crude product is separated and purified by silica gel column chromatography using a mixed solution of petroleum ether and ethyl acetate to obtain a colorless liquid with a total yield of 53%.

[0042] (Equation 13) Perform NMR characterization tests on the obtained product. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the formula.

[0043] 11H NMR (400 MHz, CDCl3) δ 7.20–7.14 (m, 4H), 7.10–7.01 (m, 7H), 6.95 (d, J = 8.0 Hz, 1H), 6.74 (t, J = 7.6 Hz, 1H), 4.36–4.23 (m, 2H), 3.69 (dd, J = 10.8, 1.6 Hz, 1H), 3.33 (s, 3H), 2.92–2.84 (m, 3H), 2.26 (s, 3H), 2.16 (dd, J = 14.4, 2.0 Hz, 1H), 1.27 (s, 3H). 13 13C NMR (100 MHz, CDCl3) δ 175.2, 175.1, 139.9, 137.9, 136.4, 136.3, 136.0, 135.5, 130.3, 129.5, 128.9, 128.4, 128.3, 128.1, 127.7, 126.8, 126.1, 122.4, 120.9, 114.9, 64.5, 55.0, 54.4, 38.0, 32.3, 29.9, 25.1, 19.4. Example 14 Add 2-trifluoromethylbenzyl diazoacetate (1.0 mmol), 1,7-enyne (0.2 mmol), fac-Ir (fac-tris(2-phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol) and 3 mL of CH3CN into a 25 mL Schlenk tube. After mixing the mixture evenly, place it under nitrogen protection and irradiate it with a 15 w LED blue light for 24 hours. Monitor the reaction process using thin layer chromatography (TLC). When the substrate reaction is complete and the product spots no longer change, stop the reaction. The specific reaction equation is shown in Equation 14 below. Add saturated brine (50 mL) to the reactants for washing, and then extract three times with EtOAc (50 mL * 3). Combine the organic layers. Add anhydrous sodium sulfate to dry the organic phase (combined organic layers). After removing the solvent by vacuum distillation, purify the crude product by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with a total yield of 25%.

[0044] (Equation 14) Perform NMR characterization tests on the obtained product. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the formula.

[0045] 1 1H NMR (400 MHz, CDCl3) δ 7.62 (d, J J = 6.0 Hz, 2H), 7.56–7.48 (m, 2H), 7.27 (dd, J J = 15.2, 7.2 Hz, 4H), 7.19–7.10 (m, 3H), 7.05 (d, J J = 8.4 Hz, 1H), 6.83 (t, J J = 7.6 Hz, 1H), 5.31–5.22 (m, 2H), 3.87 (dd, J J = 10.8, 1.6 Hz, 1H), 3.44 (d, J J = 4.8 Hz, 3H), 3.03 (dd, J J = 14.4, 10.8 Hz, 1H), 2.30 (dd, J J = 14.4, 2.0 Hz, 1H), 1.39 (s, 3H). 13 13C NMR (100 MHz, CDCl3) δ 175.1, 174.8, 139.9, 138.2, 136.6, 136.1, 135.7, 131.6, 131.5, 131.2, 130.8, 130.5, 129.1, 129.0, 128.4, 128.3, 128.0, 127.8, 125.22, 125.18, 125.14, 125.10, 125.06, 125.03, 124.99, 122.5, 120.8, 115.0, 65.9, 54.9, 54.5, 37.9, 29.9, 25.1. Example 15 Add cyclobutyl diazoacetate (1.0 mmol), 1,7 - enyne (0.2 mmol) to a 25 mL Schlenk tube, fac-Ir(fac - Tris(2 - phenylpyridine)iridium complex) (0.004 mmol), iodine (0.04 mmol) and 3 mL of CH3CN were mixed well and placed under nitrogen protection. It was irradiated with a 15 w LED blue light for 24 hours. The reaction process was monitored by thin - layer chromatography (TLC). When the substrate reaction was complete and the product spots no longer changed, the reaction was stopped. The specific reaction equation is shown in Equation 15 below. Saturated brine (50 mL) was added to the reactants for washing, and then extracted three times with EtOAc (50 mL * 3). The organic layers were combined. Anhydrous sodium sulfate was added to the organic phase (combined organic layers) for drying. After removing the solvent by vacuum distillation, the crude product was separated and purified by silica gel column chromatography using a mixture of petroleum ether and ethyl acetate to obtain a colorless liquid with an overall yield of 35%.

[0046] (Equation 15) The obtained product was characterized by NMR. The obtained characterization results are as follows. It can be seen that the compound structure of the obtained product is consistent with the structural formula in the equation.

[0047] 1 H NMR (400 MHz, CDCl3) δ 7.29 (dd, J = 7.2, 3.6 Hz, 3H), 7.25–7.19 (m,3H), 7.11 (d, J = 7.6 Hz, 1H), 7.03 (d, J = 8.4 Hz, 1H), 6.81 (t, J = 7.6 Hz, 1H),5.08 (d, J = 7.5 Hz, 1H), 3.74 (dd, J = 10.4, 1.6 Hz, 1H), 3.41 (s, 3H), 2.97(dd, J = 14.0, 10.8 Hz, 1H), 2.43–2.33 (m, 2H), 2.27 (dd, J = 14.0, 1.6 Hz, 1H),2.11–2.02 (m, 2H), 1.81 (q, J = 10.4 Hz, 1H), 1.67 (dd, J = 14.4, 6.4 Hz, 1H),1.40 (s, 3H). 1313C NMR (100 MHz, CDCl3) δ 175.3, 174.6, 140.0, 137.9, 136.4, 136.1, 128.9, 128.43, 128.41, 128.1, 127.7, 122.5, 121.0, 115.0, 69.3, 55.0, 54.4, 38.1, 30.2, 30.1, 29.9, 25.1, 13.6. In summary, the present invention provides a method for synthesizing cyclopentane fac-Ir quinoline by using diazoacetate compounds and 1,7-enynes as substrates, c molecular iodine as a catalyst, CH3CN as a solvent, and under the protection of a nitrogen atmosphere, through irradiation with an LED blue light. fac-Ir quinoline, wherein c is fac-tris(2-phenylpyridine)iridium complex. The preparation method provided by the present invention has very excellent substrate compatibility and can also be well compatible with diazoacetate compounds modified by natural products, enriching the substrate diversity for the synthesis of the cyclopentane c quinoline skeleton, and at the same time providing a new approach for the preparation of the cyclopentane

[0048] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. After those skilled in the art have read the above content, various modifications and alternatives to the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

1. A method for preparing cyclopentane c quinoline by dual catalysis of visible light / molecular iodine, characterized in that The method uses diazoacetate compounds and 1,7-enynes as substrates, fac-Ir and molecular iodine as the catalyst, CH3CN as the solvent, and under the protection of a nitrogen atmosphere, cyclopentane c quinoline is synthesized by irradiation with an LED blue light, where the fac-Ir is fac-tris(2-phenylpyridine)iridium complex.

2. The method according to claim 1, wherein The method comprises the following steps: (1)Mix a diazoacetate compound and 1,7-enyne as substrates, fac-Ir with molecular iodine, add the solvent CH3CN, mix evenly, place it under a blue LED lamp for irradiation, and carry out a stirring-assisted reaction; (2) After the reaction is completed, collect the organic phase, wash it with saturated brine, extract it with ethyl acetate, and combine the extracted organic phases for drying; (3) The solvent is removed from the dried product by vacuum distillation, and the remaining organic residue is purified to obtain cyclopentane. c quinoline product.

3. The method according to claim 2, wherein The molar ratio of the diazoacetate compound to the 1,7-enyne is 5:

1.

4. The method according to claim 2, wherein The fac-Ir has a molar ratio of 1:50 with the 1,7-enyne.

5. The method according to claim 2, characterized in that, The molar ratio of the molecular iodine to the 1,7-enyne is 1:

5.

6. The method according to claim 2, wherein The LED blue light is 15 W.

7. The method according to claim 2, characterized in that The reaction in step (1) is carried out at room temperature under a nitrogen atmosphere.

8. The method according to claim 2, wherein The completion of the reaction is to monitor the reaction process by thin-layer chromatography until the substrate reaction is complete and the product spots no longer change.

9. The method according to claim 2, characterized in that, The purification is purification by silica gel column chromatography.

10. The method according to claim 9, characterized in that, The eluent for the silica gel column chromatography purification is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio of the petroleum ether to the ethyl acetate is 10:1.

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