Preparation method and application of photocatalytic synthesis of azaheteroarene compounds
The photocatalytic synthesis method solves the problem of synthesizing different functionalized nitrogen-containing aromatic compounds, providing a simple and sustainable synthesis route that enables the efficient generation of various nitrogen-containing aromatic compounds, suitable for organic light-emitting materials and other applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTH CHINA UNIV OF TECH
- Filing Date
- 2024-09-04
- Publication Date
- 2026-05-19
AI Technical Summary
There are few existing methods for synthesizing nitrogen-containing aromatic compounds with different functionalizations, and there is a lack of novel, simple and sustainable synthetic routes.
A photocatalytic synthesis method was used to react isonitrile compounds, alkylboronic acid reagents, photosensitizers and base reagents under visible light irradiation to generate nitrogen-containing aromatic compounds, including indole/pyrrolo[1,2-a]quinoxaline compounds, phenanthridine compounds and benzothiazole compounds.
The synthesis of aza-aromatic compounds with different substituents has been achieved. It has the advantages of readily available raw materials, simple operation, mild reaction, and wide substrate applicability, and has good application prospects in the synthesis of organic light-emitting materials and other analogs.
Smart Images
Figure CN119219641B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic synthesis technology, specifically to a method for preparing and applying photocatalytic synthesis of nitrogen-containing aromatic compounds. Background Technology
[0002] Aromatic hydrocarbons exhibit rich pharmacological properties in pharmaceutical fields such as anticancer, antidiabetic, and antituberculosis treatments. Their derivatives also show promising prospects in electronic and optical applications. However, there are few reports on the synthesis of aromatic hydrocarbons with different functionalizations. Therefore, developing a novel, simple, and sustainable synthetic route for the synthesis of this class of compounds is of significant research importance. Summary of the Invention
[0003] The purpose of this invention is to provide a method for preparing and applying photocatalytic synthesis of nitrogen-containing aromatic compounds; the nitrogen-containing aromatic compounds include indole / pyrrolo[1,2-a]quinoxaline compounds, phenanthridine compounds, and benzothiazole compounds.
[0004] The technical solution adopted in this invention is:
[0005] A method for photocatalytic synthesis of nitrogen-containing aromatic compounds includes the following steps:
[0006] A mixture of isonitrile compound, alkylboronic acid reagent, photosensitizer, base reagent and solvent is reacted under visible light to obtain aza-aromatic compounds.
[0007] The structural formula of the isonitrile compound is as follows:
[0008]
[0009] The structural formula of the alkylboronic acid reagent is as follows:
[0010]
[0011] The structural formula of the nitrogen-containing aromatic compounds is as follows:
[0012]
[0013] In the formula, R 1 Selected from one of hydrogen, alkyl, alkoxy, halogen, and cyano groups, Ar 1 and Ar 2 Each of the substituents is independently selected from one or two of hydrogen, alkyl, alkoxy, halogen, and cyano groups, X is selected from C and N, and R is selected from alkyl groups.
[0014] Preferably, R 1 Ar 1 and Ar2 In the substituents, the alkyl group (including straight-chain, branched and cycloalkyl) has 1 to 6 carbon atoms, the alkoxy group has 1 to 6 carbon atoms (the alkyl group in the alkoxy group includes straight-chain, branched and cycloalkyl), and the halogen is fluorine, chlorine, bromine or iodine.
[0015] Preferably, in R, the alkyl group is a straight-chain alkyl group, a branched alkyl group, or a cycloalkyl group, wherein the straight-chain alkyl group has 1 to 6 carbon atoms, the branched alkyl group has 3 to 6 carbon atoms, and the cycloalkyl group has 3 to 8 carbon atoms.
[0016] Preferably, the structural formula of the isonitrile compound is as follows:
[0017]
[0018] The structural formula of the alkylboronic acid reagent is as follows:
[0019]
[0020] The structural formula of the nitrogen-containing aromatic compounds is as follows:
[0021]
[0022] In the formula, Ar 1 and Ar 2 The substituents are each independently selected from one or two of H, Me, MeO, F, Cl, CN, X is selected from C, N, and R is selected from cyclohexyl, cyclopentyl, n-butyl.
[0023] Preferably, the alkylboronic acid reagent is either chain-like or cyclic.
[0024] Preferably, the molar ratio of the isonitrile compound, alkylboronic acid reagent, photosensitizer, and alkaline reagent is 1:1 to 5:0.01 to 0.10:1 to 3.
[0025] Preferably, the concentration of the isonitrile compound is 50–100 mM.
[0026] Preferably, the photosensitizer is at least one of the following: 3,6-di-tert-butyl-9-trimethyl-10-phenylacridine perchlorate, 2,4,5,6-tetra(carbazole-9-yl)-1,3-dicyanobenzene, 2',4',5',7'-tetrabromo-3',6'-dihydroxy-3H-spiro[isobenzofuran-1,9'-oxanthracene]-3-one, 2',4',5',7'-tetrabromo-3-oxo-3H-spirocyclic[isobenzofuran-1,9'-oxanthracene]-3',6'-bis(phenol) disodium salt, and bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium hexafluorophosphate;
[0027] Preferably, the alkaline reagent is at least one selected from sodium carbonate, sodium acetate, potassium carbonate, cesium carbonate, potassium phosphate, DBU, and triethylamine;
[0028] Preferably, the solvent is at least one selected from tetrahydrofuran, acetonitrile, toluene, dichloroethane, methanol, dimethyl sulfoxide, and dioxane.
[0029] Preferably, the wavelength of the visible light is at least one of 380 to 525 nm.
[0030] More preferably, the visible light wavelength is at least one of 380nm-390nm, 440nm-445nm, 450nm-455nm, and 515nm-525nm.
[0031] Preferably, the reaction temperature is 10℃~80℃ and the reaction time is 8h~18h.
[0032] Preferably, the reaction is carried out at a stirring speed of 300 rpm to 700 rpm.
[0033] Preferably, the reaction products are further separated and purified after the reaction is completed.
[0034] More preferably, the specific operations of separation and purification are as follows: the reaction solution is extracted with ethyl acetate, dried with anhydrous Na2SO4, and distilled under reduced pressure. The crude product obtained by reduced pressure distillation is then purified by column chromatography.
[0035] More preferably, the eluent used in the column chromatography is composed of petroleum ether and ethyl acetate in a volume ratio of 3 to 50:1.
[0036] The above-described preparation method yields a nitrogen-containing aromatic hydrocarbon compound.
[0037] The above-mentioned aza-aromatic compounds are used as luminescent materials or in the preparation of imaging reagents. The structural formula of the aza-aromatic compounds is as follows (indole / pyrrolo[1,2-a]quinoxaline compound):
[0038]
[0039] In the formula, Ar 1 and Ar 2 Each of the substituents is independently selected from one or two of hydrogen, alkyl, alkoxy, halogen, and cyano groups, X is selected from C and N, and R is selected from alkyl groups.
[0040] The principle of this invention is as follows: Under visible light irradiation, the interaction between the base and the photocatalyst generates an intermediate of free radical cation, which then interacts with alkylboronic acid to form an alkyl free radical. Subsequently, it undergoes a free radical tandem cyclization process with various aryl isonitriles to generate the final nitrogen-containing aromatic compounds.
[0041] The beneficial effects of this invention are: it synthesizes a series of nitrogen-containing aromatic compounds and drug molecules with different substituents. The synthetic method has advantages such as readily available raw materials, simple operation, mild reaction, and wide substrate applicability, and shows great promise for the synthesis of organic light-emitting materials and other similar compounds. Attached Figure Description
[0042] Figure 1 , Figure 2 The images shown are the proton and carbon spectra of the target product obtained in Example 1.
[0043] Figure 3 , Figure 4 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 2.
[0044] Figure 5 , Figure 6 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 3, respectively.
[0045] Figure 7 , Figure 8 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 5.
[0046] Figure 9 , Figure 10 The images shown are the proton and carbon spectra of the target product obtained in Example 6.
[0047] Figure 11 , Figure 12 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 7.
[0048] Figure 13 , Figure 14 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 8.
[0049] Figure 15 , Figure 16 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 9.
[0050] Figure 17 , Figure 18 , Figure 19 The images shown are the hydrogen spectrum, carbon spectrum, and fluorine spectrum of the target product obtained in Example 10.
[0051] Figure 20 , Figure 21The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 11.
[0052] Figure 22 , Figure 23 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 12, respectively.
[0053] Figure 24 , Figure 25 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 13, respectively.
[0054] Figure 26 , Figure 27 , Figure 28 The images shown are the hydrogen spectrum, carbon spectrum, and fluorine spectrum of the target product obtained in Example 14.
[0055] Figure 29 , Figure 30 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 15.
[0056] Figure 31 , Figure 32 The images shown are the hydrogen spectrum and carbon spectrum of the target product obtained in Example 16, respectively.
[0057] Figure 33 The fluorescence emission spectra of the target products indole / pyrrolo[1,2-a]quinoxaline compounds in Examples 4, 5, 6, 7 and 8 are shown. Detailed Implementation
[0058] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings, but the scope of protection and implementation of the present invention are not limited thereto.
[0059] Example 1:
[0060] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0061] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 50:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 94%).
[0062] The proton and carbon spectra of the target product in this embodiment are as follows: Figure 1 As shown and as Figure 2 As shown, the spectral data is as follows:
[0063] 1 H NMR (400MHz, CDCl3) δ8.50–8.47(m,2H),8.03(d,J=7.6Hz,1H),7.98(d,J=8.0Hz,1H),7.57(dt,J=14.4,7.2Hz,2H),7.45(q,J=7.6Hz,2H),7.26 (s,1H),3.31–3.25(m,1H),2.13(d,J=13.2Hz,2H),1.99(d,J=14.8Hz,2 H),1.90(dd,J=24.8,12.8Hz,3H),1.62–1.55(m,2H),1.52–1.43(m,1H).
[0064] 13 C NMR (100MHz, CDCl3) δ162.4,132.9,130.1,129.9,129.2,129.0,127.6,123.9,122.5,122.5,114.6,114.5,99.2,43.3,31.2,26.6,26.1.
[0065] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0066] IR(KBr) Vmax :2927,2851,2361,1743,1532,1447,1401,1241,1048,744cm -1 .
[0067] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0068] HRMS (APCI) calcd for C 21 H 21 N2[M+H] + :301.1699,Found:301.1696.
[0069] In summary, the structural formula of the target product in this embodiment is as follows:
[0070] Example 2:
[0071] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0072] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 50:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 89%).
[0073] The proton and carbon spectra of the target product in this embodiment are as follows: Figure 3 As shown and as Figure 4 As shown, the spectral data is as follows:
[0074] 1 H NMR (400MHz, CDCl3) δ8.42–8.38(m,1H),8.22(d,J=8.7Hz,1H),7.96(dd,J=7.9,1.5Hz,1H),7.52–7.47(m,1H),7.40–7.34( m,2H),7.18(d,J=8.8Hz,2H),3.29–3.21(m,1H),2.70(s,3H),2.09(d,J=15.2Hz,2H),1.98–1.82(m,5H),1.60–1.39(m,3H).
[0075] 13 C NMR (100MHz, CDCl3) δ162.3,136.2,132.7,131.9,130.1,129.8,129.0,128.7, 127.4,124.0,123.8,122.4,114.5,112.1,97.4,43.2,31.2,26.6,26.1,19.0.
[0076] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0077] IR(KBr) Vmax :2925,2853,2361,1804,1533,1454,1400,1316,1208,746cm -1 .
[0078] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0079] HRMS (APCI) calcd for C 22 H 23 N2, [M+H] + :315.1856,Found:315.1854.
[0080] In summary, the structural formula of the target product in this embodiment is as follows:
[0081] Example 3:
[0082] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0083] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 90%).
[0084] The proton and carbon spectra of the target product in this embodiment are as follows: Figure 5 As shown and as Figure 6 As shown, the spectral data is as follows:
[0085] 1 H NMR (400MHz, CDCl3) δ8.39–8.37(m,1H),8.32(d,J=9.2Hz,1H),8.02–8.00(m,1H),7.54(t,J=8.4Hz,1H),7.41(t,J=8.0Hz,1H),7.3 1(d,J=2.8Hz,1H),7.18–7.14(m,2H),3.95(s,3H),3.28–3.21(m,1H),2.13(d,J=13.2Hz,2H),2.02–1.86(m,5H),1.62–1.43(m,3H).
[0086] 13 C NMR (100MHz, CDCl3) δ161.8,155.5,136.0,130.0,129.9,129.8,129.6,128.1, 127.4,123.6,115.5,114.9,114.1,102.2,98.5,55.5,43.3,31.2,26.6,26.1.
[0087] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0088] IR(KBr) Vmax :2919,2850,2359,1618,1531,1456,1214,1031,832,744cm -1 .
[0089] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0090] HRMS (APCI) calcd for C 22 H 23 N₂O, [M+H] + :331.1805,Found:331.1803.
[0091] In summary, the structural formula of the target product in this embodiment is as follows:
[0092] Example 4:
[0093] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0094] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 72%).
[0095] The spectral data of the proton and carbon spectra of the target product in this embodiment are as follows:
[0096] 1 H NMR (400MHz, CDCl3) δ8.36(d,J=8.0Hz,1H),8.00–7.97(m,1H),7.87–7.83(m,2H),7.5–7.53(m,1H),7.41(t,J=7.6Hz,1H),7.18(s,1H),7. 14(dd,J=8.8,2.0Hz,1H),4.03(s,3H),3.26–3.18(m,1H),2.10(d,J=13.6Hz,2H),2.00–1.96(m,2H),1.93–1.84(m,3H),1.60–1.42(m,3H).
[0097] 13 C NMR (100MHz, CDCl3) δ162.5,157.5,136.3,133.5,130.1,129.8,128.8,127.1 ,123.8,123.4,123.1,114.2,113.1,99.3,97.7,55.9,43.3,31.2,26.6,26.1
[0098] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0099] IR(KBr) Vmax :2928,2852,2361,1604,1531,1492,1443,1260,1221,744cm -1 .
[0100] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0101] HRMS (APCI) calcd for C 22 H 23 N₂O, [M+H] + :331.1805,Found:331.1801.
[0102] In summary, the structural formula of the target product in this embodiment is as follows:
[0103] Example 5:
[0104] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0105] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 50:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 88%).
[0106] The proton and carbon spectra of the target product in this embodiment are as follows: Figure 9 As shown and as Figure 10 As shown, the spectral data is as follows:
[0107] 1 H NMR (400MHz, CDCl3) δ8.39(s,1H),8.28(d,J=8.4Hz,1H),7.99–7.97(m,1H),7.82(d,J=8.4Hz,1H),7.58–7.54(m,1H),7.44–7.40(m,1H),7. 37(dd,J=8.4,1.6Hz,1H),7.15(s,1H),3.25–3.17(m,1H),2.11(d,J=12.0Hz,2H),2.01–1.98(m,2H),1.95–1.85(m,3H),1.61–1.42(m,3H).
[0108] 13 C NMR (100MHz, CDCl3) δ162.2,136.1,132.7,130.0,129.7,129.5,129.5,127 .7,127.3,124.2,123.2,123.1,114.4,114.3,99.0,43.3,31.2,26.5,26.1.
[0109] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0110] IR(KBr) Vmax :2922,2359,1628,1472,1433,1396,1358,1085,814,743cm -1 .
[0111] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0112] HRMS (APCI) calcd for C 21 H 20 ClN2,[M+H] + :335.1310,Found:335.1307.
[0113] In summary, the structural formula of the target product in this embodiment is as follows:
[0114] Example 6:
[0115] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0116] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 86%).
[0117] The proton and carbon spectra of the target product in this embodiment are as follows: Figure 11 As shown and as Figure 12 As shown, the spectral data is as follows:
[0118] 1 H NMR (400MHz, CDCl3) δ8.69(s,1H),8.27(d,J=8.4Hz,1H),7.99(d,J=8.0Hz,1H),7.95(d,J=8.4Hz,1H),7.62–7.56(m,2H),7.46(t,J =7.6Hz,1H),7.19(s,1H),3.23–3.16(m,1H),2.08(d,J=12.4Hz,2H),1.97(d,J=13.2Hz,2H),1.91–1.81(m,3H),1.58–1.38(m,3H).
[0119] 13 C NMR (100MHz, CDCl3) δ161.9,136.2,131.7,131.6,131.4,130.6,129.2,128.5, 125.0,124.6,123.3,120.2,119.7,114.4,105.9,99.3,43.4,31.2,26.5,26.0.
[0120] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0121] IR(KBr)Vmax :2925,2851,2363,2223,1631,1438,1395,1351,814,745cm -1 .
[0122] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0123] HRMS (APCI) calcd for C 22 H 20 N3, [M+H] + :326.1652,Found:326.1649.
[0124] In summary, the structural formula of the target product in this embodiment is as follows:
[0125] Example 7:
[0126] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0127] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 50:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 74%).
[0128] The proton and carbon spectra of the target product in this embodiment are shown in Figure 13 and Figure 14. Figure 14 As shown, the spectral data is as follows:
[0129] 1H NMR(400MHz, CDCl3)δ8.49(s,1H),8.23(d,J=8.0Hz,1H),7.97–7.95(m,2H),7.56(t,J=7.4Hz,1H),7.42(t,J=7.4Hz,1H), 7.06(s,1H),3.16(t,J=11.6Hz,1H),2.07(d,J=12.4Hz,2H),1.96(d,J=12.4Hz,2H),1.90–1.84(m,3H),1.56–1.38(m,3H).
[0130] 13 C NMR (100MHz, CDCl3) δ161.9,136.0,131.0,130.4,130.2,129.1,128.3,127 .9,127.4,126.6,124.5,122.8,115.8,114.0,98.1,43.2,31.1,26.5,26.1.
[0131] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0132] IR(KBr) Vmax :2930,2851,2363,1615,1469,1443,1394,1362,1111,750cm -1 .
[0133] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0134] HRMS (APCI) calcd for C 22 H 23 N2, [M+H] + :369.0920,Found:369.0918.
[0135] In summary, the structural formula of the target product in this embodiment is as follows:
[0136] Example 8:
[0137] A pyrrolo[1,2-a]quinoxaline compound, the preparation method of which includes the following steps:
[0138] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 62%).
[0139] The proton and carbon spectra of the target product in this embodiment are shown in Figure 15 and Figure 16. Figure 16 As shown, the spectral data is as follows:
[0140] 1 H NMR (400MHz, CDCl3) δ9.90(s,1H),8.55(s,1H),8.44(d,J=8.4Hz,1H),8.05(d,J=7.2Hz,1H),7.83(d,J=4.8Hz,1H),7.66(t,J=7.4Hz,1H),7 .50(t,J=7.6Hz,1H),7.18(s,1H),3.30–3.22(m,1H),2.12(d,J=12.4Hz,2H),1.99(d,J=13.2Hz,2H),1.94–1.85(m,3H),1.60–1.41(m,3H).
[0141] 13 C NMR (100MHz, CDCl3) δ161.8,140.4,137.3,136.0,133.2,131.1,130.4,129.2,128.5,124.7,116.0,115.0,97.6,43.4,31.1,26.5,26.0.
[0142] The infrared test data of the pyrrolo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0143] IR(KBr) Vmax :2927,2852,2360,1631,1467,1441,1396,1352,821,749cm -1 .
[0144] The mass spectrometry data of the pyrrolo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0145] HRMS (APCI) calcd for C 20 H 20 N3, [M+H] + :302.1652,Found:302.1647.
[0146] In summary, the structural formula of the target product in this embodiment is as follows:
[0147] Example 9:
[0148] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0149] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 50:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 91%).
[0150] The proton and carbon spectra of the target product in this embodiment are shown in Figure 17 and Figure 18. Figure 18 As shown, the spectral data is as follows:
[0151] 1 H NMR (400MHz, CDCl3) δ8.41–8.39(m,1H),8.22(d,J=8.8Hz,1H),7.96(dd,J=7.6,1.2Hz,1H),7.52–7.47(m,1H),7.39–7.34(m,2H),7 .19–7.17(m,2H),3.29–3.21(m,1H),2.70(s,3H),2.09(d,J=15.2Hz,2H),1.98–1.94(m,2H),1.91–1.82(m,3H),1.60–1.39(m,3H).
[0152] 13 C NMR (100MHz, CDCl3) δ162.3,136.2,132.7,131.9,130.1,129.8,129.0,128.7, 127.4,124.0,123.8,122.4,114.5,112.1,97.4,43.2,31.2,26.6,26.1,19.0.
[0153] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0154] IR(KBr) Vmax :2920,2361,1613,1527,1495,1449,1422,1398,1303,747cm -1 .
[0155] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0156] HRMS (APCI) calcd for C 22 H 23 N2, [M+H] + :315.1856,Found:315.1853.
[0157] In summary, the structural formula of the target product in this embodiment is as follows:
[0158] Example 10:
[0159] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0160] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 50:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 43%).
[0161] The proton, carbon, and fluorine spectra of the target product in this embodiment are shown in Figures 19, 20, and 21, respectively. Figure 21 As shown, the spectral data is as follows:
[0162] 1 H NMR (400MHz, CDCl3) δ8.31(d,J=8.4Hz,1H),8.20(s,1H),7.96(d,J=7.6Hz,1H),7.57(t,J=7.6Hz,1H),7.47(t,J=7.4Hz ,1H),7.28(s,1H),7.20–7.18(m,1H),3.29–3.23(m,1H),2.11(d,J=13.2Hz,2H),2.00–1.84(m,5H),1.60–1.42(m,3H).
[0163] 13 C NMR (100MHz, CDCl3) δ162.8, 159.6, 157.0, 132.8, 132.5 (d, J = 12.4Hz), 131.5 (d, J = 4.2Hz), 129.1, 128. 8,124.7,123.2,122.7,114.3,111.5(d,J=23.9Hz),110.5(d,J=4.0Hz),100.7,43.6,31.1,26.5,26.0.
[0164] 19 F NMR (376MHz, CDCl3) δ-118.79 (d, J=9.4Hz).
[0165] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0166] IR(KBr) Vmax:2919,2850,2356,1612,1538,1446,1399,1275,807,741cm -1 .
[0167] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0168] HRMS (APCI) calcd for C 21 H 19 ClFN2,[M+H] + :353.1215,Found:353.1212.
[0169] In summary, the structural formula of the target product in this embodiment is as follows:
[0170] Example 11:
[0171] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0172] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 50:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 60%).
[0173] The proton and carbon spectra of the target product in this embodiment are shown in Figure 22 and Figure 23. Figure 23 As shown, the spectral data is as follows:
[0174] 1H NMR (400MHz, CDCl3) δ8.45(d,J=8.4Hz,1H),8.21(s,1H),7.95(d,J=7.6Hz,1H),7.78(s,1H),7.52(t,J=7.6Hz,1H),7.43(t,J=7. 4Hz,1H),7.20(s,1H),3.29–3.23(m,1H),2.50(s,3H),2.40(s,3H),2.15(d,J=12.4Hz,2H),2.03–1.87(m,5H),1.63–1.45(m,3H).
[0175] 13 C NMR (100MHz, CDCl3) δ161.2,136.5,134.3,132.6,132.3,130.2,129.2,128.9,12 7.9,123.3,122.3,122.1,115.2,114.5,98.4,43.2,31.2,26.6,26.1,20.4,19.2.
[0176] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0177] IR(KBr) Vmax :2926,2852,2358,1649,1529,1485,1449,1397,1278,738cm -1 .
[0178] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0179] HRMS (APCI) calcd for C 23 H 25 N2, [M+H] + :329.2012,Found:329.2010.
[0180] In summary, the structural formula of the target product in this embodiment is as follows:
[0181] Example 12:
[0182] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0183] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 50:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 88%).
[0184] The proton and carbon spectra of the target product in this embodiment are shown in Figure 24 and Figure 25. Figure 25 As shown, the spectral data is as follows:
[0185] 1 H NMR(400MHz, CDCl3)δ8.48–8.45(m,2H),8.00(dd,J=15.2,8.0Hz,2H),7.59–7.53(m,2H),7.48–7.4 1(m,2H),7.22(s,1H),3.78–3.70(m,1H),2.31–2.17(m,4H),2.03–1.92(m,2H),1.88–1.78(m,2H).
[0186] 13 C NMR (100MHz, CDCl3) δ161.4,136.0,132.8,130.1,129.9,129.8,129.0,127.5,123.8,123.8,122.5,122.4,114.5,114.5,99.5,44.2,31.4,26.1.
[0187] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0188] IR(KBr) Vmax :2952,2867,2360,1612,1531,1474,1448,1401,1205,745cm -1 .
[0189] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0190] HRMS (APCI) calcd for C20 H 19 N2[M+H] + :287.1543,Found:287.1540.
[0191] In summary, the structural formula of the target product in this embodiment is as follows:
[0192] Example 13:
[0193] A method for preparing an indo[1,2-a]quinoxaline compound includes the following steps:
[0194] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 50:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 73%).
[0195] The proton and carbon spectra of the target product in this embodiment are shown in Figure 26 and Figure 27, respectively. Figure 27 As shown, the spectral data is as follows:
[0196] 1 H NMR (400MHz, CDCl3) δ8.45(t,J=7.6Hz,2H),8.01–7.96(m,2H),7.56(dt,J=14.8,8.0Hz,2H),7.44(q,J=7. 6Hz,2H),7.19(s,1H),3.12(t,J=7.6Hz,2H),2.01–1.93(m,2H),1.63–1.53(m,2H),1.05(t,J=7.2Hz,3H).
[0197] 13C NMR (100MHz, CDCl3) δ156.0,135.9,132.8,130.2,129.7,129.5,129.0,127 .6,124.0,123.9,122.6,122.5,114.5,114.5,99.7,35.7,30.3,22.9,14.0.
[0198] The infrared test data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0199] IR(KBr) Vmax :2956,2361,1535,1473,1449,1398,1330,1294,1205,744cm -1 .
[0200] The mass spectrometry data of the indo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0201] HRMS (APCI) calcd for C 19 H 19 N2[M+H] + :275.1543,Found:275.1540.
[0202] In summary, the structural formula of the target product in this embodiment is as follows:
[0203] Example 14:
[0204] A pyrrolo[1,2-a]quinoxaline compound, the preparation method of which includes the following steps:
[0205] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using petroleum ether and ethyl acetate in a volume ratio of 30:1 to obtain indo[1,2-a]quinoxaline compounds (yield: 72%).
[0206] The proton, carbon, and fluorine spectra of the target product in this embodiment are shown in Figures 28, 29, and 20, respectively. Figure 30 As shown, the spectral data is as follows:
[0207] 1 H NMR (400MHz, CDCl3) δ8.27(s,1H),8.03(d,J=7.2Hz,1H),7.95(d,J=7.6Hz,1H),7.84(d,J=8.0Hz,1H),7.63–7.55(m,2H),7.23(t,J=8.2Hz,1H),7 .10(d,J=7.6Hz,1H),3.77–3.70(m,1H),2.15(d,J=12.4Hz,2H),1.94(d, J=13.2Hz,2H),1.88–1.78(m,3H),1.70–1.60(m,2H),1.43–1.32(m,1H).
[0208] 13 C NMR (100MHz, CDCl3) δ159.5,144.0,140.7,136.2,131.4(t,J=181.9Hz),130.3,128.8,128.4,127 .0,125.4,124.3,123.8,122.6,116.3,115.2,114.3,114.0,109.4,86.5,42.1,31.5,26.0,25.9.
[0209] 19 F NMR (376MHz, CDCl3) δ -49.27.
[0210] The infrared test data of the pyrrolo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0211] IR(KBr) Vmax : 3461,3420,3351,3285,2922,1646,1350,1254,1122,746.
[0212] The mass spectrometry data of the pyrrolo[1,2-a]quinoxaline compounds in this embodiment are as follows:
[0213] HRMS(APCI): calcd for C 25 H 20 F₂N₃O₂,[M+H] + :432.1518,Found:432.1516.
[0214] In summary, the structural formula of the target product in this embodiment is as follows:
[0215] Example 15:
[0216] A phenanthridine compound, the preparation method of which includes the following steps:
[0217] 0.1 mmol 0.5 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using a column chromatography eluent composed of petroleum ether and ethyl acetate in a volume ratio of 30:1 to obtain phenanthridine compounds (yield: 87%).
[0218] The proton, carbon, and fluorine spectra of the target product in this embodiment are shown in Figure 31 and Figure 32. Figure 32 As shown, the spectral data is as follows:
[0219] 1 H NMR (400MHz, CDCl3) δ8.66(d,J=8.4Hz,1H),8.56(d,J=8.0Hz,1H),8.35(d,J=8.0Hz,1H),8.22(d,J=8.4Hz,1H),7.82(t,J=8.0Hz,1H),7.7 7–7.69(m,2H),7.66–7.62(m,1H),3.70–3.63(m,1H),2.15(d,J=10.8Hz,2H),2.07–1.97(m,4H),1.91(d,J=12.4Hz,1H),1.68–1.48(m,3H).
[0220] 13 C NMR (100MHz, CDCl3) δ165.2,143.8,132.9,129.9,129.8,128.3,127.0,126.0,125.5,124.6,123.3,122.5,121.7,41.9,32.2,26.8,26.3.
[0221] The infrared test data of the phenanthridine compounds in this embodiment are as follows:
[0222] IR(KBr) Vmax : 3429,2926,2850,2357,1627,1388,1352,1120,752,622.
[0223] The mass spectrometry data of the phenanthridine compounds in this embodiment are as follows:
[0224] HRMS(APCI): calcd for C 19 H 20 N[M+H] + :262.1590,Found:262.1587.
[0225] In summary, the structural formula of the target product in this embodiment is as follows:
[0226] Example 16:
[0227] A benzothiazole compound, the preparation method of which includes the following steps:
[0228] 0.1 mmol 0.4 mmol 0.002 mmol of bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate) (abbreviated as Ir[dF(CF3)ppy]2(dtbbpy)PF6) and 0.2 mmol of DBU were dispersed in 2 mL of dioxane and reacted at room temperature for 12 h under visible light at a wavelength of 450 nm to 455 nm with stirring at 500 rpm. The reaction solution was extracted three times with ethyl acetate, and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was subjected to vacuum distillation. The crude product obtained by vacuum distillation was purified by column chromatography using a column chromatography eluent composed of petroleum ether and ethyl acetate in a volume ratio of 30:1 to obtain benzothiazole compounds (yield: 81%).
[0229] The proton, carbon, and fluorine spectra of the target product in this embodiment are shown in Figure 31 and Figure 32. Figure 32 As shown, the spectral data is as follows:
[0230] 1H NMR (400MHz, CDCl3) δ7.97(d,J=8.0Hz,1H),7.84(d,J=8.0Hz,1H),7.46–7.42(m,1H),7.35–7.31(m,1H),3.15–3.07(m, 1H),2.22–2.19(m,2H),1.91–1.86(m,2H),1.79–1.74(m,1H),1.69–1.59(m,2H),1.50–1.39(m,2H),1.37–1.29(m,1H).
[0231] 13 C NMR (100MHz, CDCl3) δ177.6,153.0,134.5,125.8,124.5,122.5,121.5,43.4,33.4,26.0,25.7.
[0232] The infrared test data of the benzothiazole compounds in this embodiment are as follows:
[0233] IR(KBr) Vmax : 3483,2925,2352,1667,1520,1400,1328,1248,1084,747.
[0234] The mass spectrometry data of the benzothiazole compounds in this embodiment are as follows:
[0235] HRMS(APCI): calcd for C 13 H 16 NS[M+H] + :218.0998,Found:218.0997.
[0236] In summary, the structural formula of the target product in this embodiment is as follows: Application testing:
[0237] The target products indole / pyrrolo[1,2-a]quinoxaline compounds from Examples 4, 5, 6, 7, and 8 were prepared in 10 mL solutions with a concentration of 10... -3 M was prepared as a dichloromethane solution. Then, 20 μL of the target product solution was mixed thoroughly with 2 mL of dichloromethane. The mixture was then subjected to fluorescence testing, and the corresponding fluorescence emission spectrum of the target product was obtained as shown below. Figure 33 As shown.
[0238] Depend on Figure 33It can be seen that the indole / pyrrolo[1,2-a]quinoxaline compounds in Examples 4, 5, 6, 7 and 8 all have excellent fluorescence properties. Among them, the products with electron-donating MeO substitution show a significant decrease in fluorescence intensity, while the other substituents do not show a significant decrease in intensity, indicating that electronic effects may affect the fluorescence absorption and fluorescence emission of the products.
[0239] Tests have shown that the indole / pyrrolo[1,2-a]quinoxaline compounds in other embodiments also exhibit excellent fluorescence properties, and the preparation method of this invention can be applied to the synthesis of fluorescent materials.
[0240] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A method for preparing nitrogen-containing aromatic compounds by photocatalytic synthesis, characterized in that, Includes the following steps: A mixture of isonitrile compound, alkylboronic acid reagent, photosensitizer, base reagent and solvent is reacted under visible light to obtain aza-aromatic compounds. The structural formula of the isonitrile compound is as follows: , , or ; The structural formula of the alkylboronic acid reagent is as follows: , or ; The structural formula of the nitrogen-containing aromatic compounds is as follows: , , or ; In the formula, R 1 Selected from one of hydrogen or cyano groups, Ar 1 and Ar 2 The substituents are each independently selected from one or two of hydrogen, methyl, methoxy, fluorine, chlorine, and cyano; X is selected from C and N; and R is selected from cyclohexyl, cyclopentyl, and n-butyl. The photosensitizer is bis[2-(2,4-difluorophenyl)-5-trifluoromethylpyridine][2-2'-bi(4-tert-butylpyridine)]iridium di(hexafluorophosphate); and the base reagent is DBU.
2. The preparation method according to claim 1, characterized in that, The molar ratio of the isonitrile compound, alkylboronic acid reagent, photosensitizer, and base reagent is 1:1~5:0.01~0.10:1~3; The concentration of the isonitrile compound is 50~100 mM.
3. The preparation method according to claim 1, characterized in that, The solvent is at least one selected from tetrahydrofuran, acetonitrile, toluene, dichloroethane, methanol, dimethyl sulfoxide, and dioxane.
4. The preparation method according to claim 1, characterized in that, The wavelength of the visible light is at least one of 380 to 525 nm.
5. The preparation method according to claim 1, characterized in that, The reaction temperature is 10 ℃ to 80 ℃, and the reaction time is 8 h to 18 h.
6. The preparation method according to claim 1, characterized in that, The reaction was carried out at a stirring speed of 300 rpm to 700 rpm; After the reaction was completed, the reaction products were separated and purified.
7. The preparation method according to claim 6, characterized in that, The specific operations for separation and purification are as follows: the reaction solution is extracted with ethyl acetate, dried with anhydrous Na2SO4, and distilled under reduced pressure. The crude product obtained by reduced pressure distillation is then purified by column chromatography. The column chromatography eluent consists of petroleum ether and ethyl acetate in a volume ratio of 3 to 50:1.