Method for activating alkane C (sp3)-H bond through photocatalysis and constructing C-C bond with aza-aromatic hydrocarbon

Abstract

The invention provides a method for activating an alkane C (sp3)-H bond through photocatalysis and constructing a C-C bond with aza-aromatic hydrocarbon. The method comprises the following steps: adding an aza-aromatic compound, an alkyl compound and acid into a solvent to obtain a solution A; and irradiating the solution A with visible light in an oxygen-containing atmosphere to obtain the photocatalyst. According to the method, the C (sp3)-H bond of the alkyl compound is successfully activated by utilizing a photochemical method under the condition of no introduction of a metal catalyst, a photocatalyst and a strong oxidant, the C-C bond construction of the alkyl compound and the aza-aromatic hydrocarbon compound is realized, the whole process is simple and efficient, the reaction conditions are mild, the preparation way of the alkyl-substituted aza-aromatic hydrocarbon compound is expanded, and the method is suitable for industrial production. The method is very favorable for popularizing the synthetic route of the coupling reaction of the alkane C (sp3)-H bond and aza-aromatic hydrocarbon.

Description

Technical Field

[0001] The present invention belongs to the field of photocatalysis technology and specifically comprises a photocatalytic alkane C(sp 3 )-H bond activation and CC bond construction with nitrogen heteroaromatic hydrocarbons. Background Art

[0002] Alkyl-substituted nitrogen aromatic compounds have unique physiological activities and functions and are widely present in functional molecules such as medicines, pesticides, functional materials and fine chemicals. 3 )-H bond activation and subsequent nitrogen heteroarylation to synthesize alkyl-substituted nitrogen heteroarenes boasts a reduced number of steps, atom economy, and simple operation. Transition metal catalysis is an effective strategy for achieving this reaction in the prior art. However, this catalytic technology requires the use of noble metal catalysts, specially designed ligands, and alkane substrates with directing groups, placing high demands on the reaction.

[0003] The strategy of hydrogen atom transfer assisted by visible light is the C(sp 3 For example, in 2018, David WC MacMillan's group used polytungstate TBADT as a hydrogen atom transfer reagent and photocatalyst to achieve the catalytic conversion of alkane C(sp 3 In the same year, Gong Chen's group used the strategy of combining photocatalyst Ru(bpy)3Cl2 with high-valent iodine oxide PFBI-OH to realize the arylation reaction of alkane C(sp 3 )-H bond with nitrogen heteroaromatics; in 2019, Wu Lizhu's group used stoichiometric K2S2O8 as oxidant and Ir(ppy)2(dtbbpy)PF6 as photocatalyst to realize the arylation reaction of alkanes with nitrogen heteroaromatics under visible light irradiation; in 2021, Li Chaojun's group used cobalt oxime catalyst and chlorine radical synergistic catalysis to realize the arylation reaction of alkanes C(sp 3 )-H bond coupling reaction with nitrogen heteroaromatic hydrocarbons. However, due to the alkane C (sp 3 )-H bond has low acidity, high bond dissociation energy and lacks π-system coordinated with transition metals. 3 Most methods for synthesizing alkyl-substituted nitrogen-heteroaromatic compounds through )-H bonds require the use of metal catalysts, photocatalysts, and stoichiometric strong oxidants, which greatly limits the application and promotion of this technology. It has always been a challenge to achieve such reactions under mild conditions. Summary of the Invention

[0004] In view of the above problems existing in the prior art, the present invention aims to provide a photocatalytic alkane C (sp 3 )-H bond activation and the construction of CC bond of nitrogen heteroaromatic hydrocarbon. This method uses photochemical method to convert alkyl compound C(sp 3 )-H bond activation to achieve CC bond construction with nitrogen-heteroarene compounds. With the introduction of metal-free catalysts, photocatalysts and strong oxidants, the cross-coupling reaction of the two substrates was successfully achieved for the first time. The whole process is simple, efficient and economical, and the reaction conditions are mild.

[0005] To achieve the above objectives, the technical solutions adopted by the present invention include:

[0006] The present invention discloses a method for photocatalytically constructing a CC bond, comprising the following steps:

[0007] Adding an azoaromatic compound, an alkyl compound and an acid to a solvent to obtain a solution A;

[0008] In an oxygen-containing atmosphere, solution A is irradiated with visible light to obtain the product.

[0009] Furthermore, the acid is selected from a mixture of one or more of formic acid, acetic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, trifluoroacetic acid and benzoic acid.

[0010] Furthermore, the nitrogen heteroaromatic compound is selected from one or more of the following structures:

[0011]

[0012] Wherein, the R1-R 20 may be the same or different and each independently represent any one of H, OCH3, CH3CH2, (CH3)2CH, (CH3)3C, CH2OH, COOCH3, COOCH2CH3, CF3, F, Cl, Br, NH2, OH, CN, NO2, OCH2Ph, Ph; illustratively, the azaaromatic compound may be selected from isoquinoline, 4-chloroisoquinoline, 5-chloroisoquinoline, 6-chloroisoquinoline, 4-bromoisoquinoline, 5-bromoisoquinoline, 6-bromoisoquinoline, 4-phenylisoquinoline, 5-phenylisoquinoline, 5-nitroisoquinoline, 6-cyanoisoquinoline, 3-ethylformiisoquinoline, 3-methylisoquinoline, 6-methylisoquinoline, 5-methoxyisoquinoline, 6-methoxyisoquinoline, 5-benzyloxyisoquinoline, 5-benzoylisoquinoline, 4-chloroquinoline, 4,7-dichloroquinoline, phenanthidine, and the like.

[0013] Furthermore, the alkyl compound is selected from one or more of straight-chain alkanes with carbon atoms of C5-C12, branched-chain alkanes with carbon atoms of C5-C12, and cycloalkanes with carbon atoms of C5-C12; the cycloalkanes may be spirocycloalkanes, condensed cycloalkanes, or bridged cycloalkanes; illustratively, the alkyl compound may be selected from n-pentane, cyclohexane, n-heptane, n-octane, cyclopentane, cycloheptane, norbornane, cyclooctane, cyclododecane, and the like.

[0014] Furthermore, the solvent is selected from one or more of acetonitrile, acetone, dimethyl sulfoxide, ethyl acetate, dichloromethane, and 1,2-dichloroethane.

[0015] Furthermore, the reaction system provided by the present invention can react as long as there is oxygen. When the oxygen content is low (lower than 20.9%, that is, lower than the proportion of oxygen in the air), the reaction atmosphere will affect the reaction rate. When the oxygen content reaches 20.9% or more, it can be considered that the reaction atmosphere has no effect on the reaction rate; the oxygen-containing atmosphere is an air atmosphere or a mixed atmosphere of an inert gas and oxygen in any other proportion.

[0016] Furthermore, the concentration of the alkyl compound in solution A is from 0.001 mol / L to saturation concentration.

[0017] Furthermore, the concentration of the nitrogen heteroaromatic compound in solution A is from 0.001 mol / L to saturation concentration.

[0018] Furthermore, the concentration of the acid in solution A is from 0.001 mol / L to saturation concentration.

[0019] Furthermore, the light source of visible light is selected from one of LED, xenon lamp, mercury lamp and sunlight.

[0020] Furthermore, the wavelength range of the visible light is 300-800 nm.

[0021] Furthermore, the visible light irradiation time is 1-48 hours.

[0022] Beneficial effects of the present invention:

[0023] The present invention discloses a photocatalytic alkane C (sp 3 The method of activating the )-H bond and constructing a CC bond with nitrogen heteroaromatic hydrocarbons has the following advantages compared to the existing technology:

[0024] 1. This method successfully achieved the cross-coupling reaction between alkyl compounds and nitrogen-heteroaromatic compounds for the first time under the introduction of metal-free catalysts, photocatalysts and strong oxidants.

[0025] 2. This method uses photochemical methods to convert C(sp 3)-H bond activation, and then reacting with nitrogen heteroaromatic compounds to achieve the construction of a CC bond between the two substrates.

[0026] 3. The whole process is simple, efficient, economical, and the reaction conditions are mild, which expands the preparation route of alkyl-substituted nitrogen heteroaromatic compounds, which is of great significance for promoting the synthesis of alkane C(sp 3 The synthetic route of the coupling reaction of )-H bond with nitrogen heteroarene is very favorable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] Figure 1 1-cyclohexylisoquinoline prepared in Example 1 1 H NMR spectrum;

[0029] Figure 2 1-cyclohexylisoquinoline prepared in Example 1 13 C NMR spectrum;

[0030] Figure 3 1-(pentan-2-yl)isoquinoline and 1-(pentan-3-yl)isoquinoline prepared in Example 2 1 H NMR spectrum;

[0031] Figure 4 1-(pentan-2-yl)isoquinoline and 1-(pentan-3-yl)isoquinoline prepared in Example 2 13 C NMR spectrum;

[0032] Figure 5 1-(heptane-2-yl)isoquinoline, 1-(heptane-3-yl)isoquinoline and 1-(heptane-4-yl)isoquinoline prepared in Example 3 1 H NMR spectrum;

[0033] Figure 6 1-(heptane-2-yl)isoquinoline, 1-(heptane-3-yl)isoquinoline and 1-(heptane-4-yl)isoquinoline prepared in Example 3 13 C NMR spectrum;

[0034] Figure 7 1-(Octane-2-yl)isoquinoline, 1-(Octane-3-yl)isoquinoline and 1-(Octane-4-yl)isoquinoline prepared in Example 4 1 H NMR spectrum;

[0035] Figure 8 1-(Octane-2-yl)isoquinoline, 1-(Octane-3-yl)isoquinoline and 1-(Octane-4-yl)isoquinoline prepared in Example 4 13 C NMR spectrum;

[0036] Figure 9 1-cyclopentylisoquinoline prepared in Example 5 1 H NMR spectrum;

[0037] Figure 10 1-cyclopentylisoquinoline prepared in Example 5 13 C NMR spectrum;

[0038] Figure 11 1-cycloheptylisoquinoline prepared in Example 6 1 H NMR spectrum;

[0039] Figure 12 1-cycloheptylisoquinoline prepared in Example 6 13 C NMR spectrum;

[0040] Figure 13 1-((1R,2S,4S)-bicyclo[2.2.1]hept-2-yl)isoquinoline prepared in Example 7 1 H NMR spectrum;

[0041] Figure 14 1-((1R,2S,4S)-bicyclo[2.2.1]hept-2-yl)isoquinoline prepared in Example 7 13 C NMR spectrum;

[0042] Figure 15 1-cyclooctylisoquinoline prepared in Example 8 1 H NMR spectrum;

[0043] Figure 16 1-cyclooctylisoquinoline prepared in Example 8 13 C NMR spectrum;

[0044] Figure 17 1-cyclododecylisoquinoline prepared in Example 9 1 H NMR spectrum;

[0045] Figure 18 1-cyclododecylisoquinoline prepared in Example 9 13 C NMR spectrum;

[0046] Figure 19 4-chloro-1-cyclohexylisoquinoline prepared in Example 10 1 H NMR spectrum;

[0047] Figure 20 4-chloro-1-cyclohexylisoquinoline prepared in Example 10 13 C NMR spectrum;

[0048] Figure 21 5-chloro-1-cyclohexylisoquinoline prepared in Example 11 1 H NMR spectrum;

[0049] Figure 22 5-chloro-1-cyclohexylisoquinoline prepared in Example 11 13 C NMR spectrum;

[0050] Figure 23 6-chloro-1-cyclohexylisoquinoline prepared in Example 12 1 H NMR spectrum;

[0051] Figure 24 6-chloro-1-cyclohexylisoquinoline prepared in Example 12 13 C NMR spectrum;

[0052] Figure 25 4-Bromo-1-cyclohexylisoquinoline prepared in Example 13 1 H NMR spectrum;

[0053] Figure 26 4-Bromo-1-cyclohexylisoquinoline prepared in Example 13 13 C NMR spectrum;

[0054] Figure 27 5-Bromo-1-cyclohexylisoquinoline prepared in Example 14 1 H NMR spectrum;

[0055] Figure 28 5-Bromo-1-cyclohexylisoquinoline prepared in Example 14 13 C NMR spectrum;

[0056] Figure 29 6-Bromo-1-cyclohexylisoquinoline prepared in Example 15 1 H NMR spectrum;

[0057] Figure 30 6-Bromo-1-cyclohexylisoquinoline prepared in Example 15 13 C NMR spectrum;

[0058] Figure 31 1-cyclohexyl-4-phenylisoquinoline prepared in Example 16 1 H NMR spectrum;

[0059] Figure 32 1-cyclohexyl-4-phenylisoquinoline prepared in Example 16 13 C NMR spectrum;

[0060] Figure 331-cyclohexyl-5-phenylisoquinoline prepared in Example 17 1 H NMR spectrum;

[0061] Figure 34 1-cyclohexyl-5-phenylisoquinoline prepared in Example 17 13 C NMR spectrum;

[0062] Figure 35 1-cyclohexyl-5-nitroisoquinoline prepared in Example 18 1 H NMR spectrum;

[0063] Figure 36 1-cyclohexyl-5-nitroisoquinoline prepared in Example 18 13 C NMR spectrum. DETAILED DESCRIPTION

[0064] To more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. It should be understood that the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0065] In addition, unless otherwise specified, the raw materials used in the present invention can be obtained commercially, and any range recorded in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0066] Example 1

[0067]

[0068] To 2.5 mL of acetonitrile, 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of trifluoroacetic acid were added to obtain solution A;

[0069] Solution A was irradiated with a 415 nm LED at room temperature under air for 6 hours. After the reaction, a 1 M aqueous sodium hydroxide solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. The crude product was separated by silica gel column chromatography (elution with petroleum ether / ethyl acetate = 10:1) to obtain the product, 1-cyclohexylisoquinoline, in a yield of 95%.

[0070] 1H NMR (400MHz, CDCl3) δ8.48(d,J=5.8Hz,1H),8.21(d,J=8.3Hz,1H),7.78(d,J=7.9Hz,1H),7.63(t,J=7.5Hz,1H),7.56(t,J=7.7Hz,1H),7.46( d,J=5.7Hz,1H),3.56(t,J=11.8Hz,1H),1.96(t,J=17.7Hz,4H),1.84(q,J=11.7,10.2Hz,3H),1.53(q,J=13.2Hz,2H),1.40(t,J=12.1Hz,1H).

[0071] Comparative Example 1

[0072]

[0073] To 2.5 mL of acetone, add 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of trifluoroacetic acid to obtain solution A;

[0074] Solution A was irradiated with a 415 nm LED at room temperature under air for 6 hours. After the reaction, the reaction solution was treated with a 1 M aqueous sodium hydroxide solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. The crude product was then separated by silica gel column chromatography (petroleum ether / ethyl acetate = 10:1) to provide 1-cyclohexylisoquinoline with a yield of 44%.

[0075] Comparative Example 2

[0076] Add 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of trifluoroacetic acid to 2.5 mL of methanol to obtain solution A;

[0077] Solution A was irradiated at room temperature for 6 hours with a 415 nm LED in an air atmosphere. After the reaction was completed, 1 M sodium hydroxide aqueous solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. 0.1 mmol of diphenylacetonitrile was added to the crude product as an internal standard and tested. 1 H NMR showed that no 1-cyclohexylisoquinoline was produced.

[0078] Comparative Example 3

[0079] To 2.5 mL of isopropanol, add 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of trifluoroacetic acid to obtain solution A;

[0080] Solution A was irradiated at room temperature for 6 hours with a 415 nm LED in an air atmosphere. After the reaction was completed, 1 M sodium hydroxide aqueous solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. 0.1 mmol of diphenylacetonitrile was added to the crude product as an internal standard and tested. 1 H NMR showed that no 1-cyclohexylisoquinoline was produced.

[0081] Comparative Example 4

[0082] 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of trifluoroacetic acid were added to 2.5 mL of N,N-dimethylformamide to obtain solution A;

[0083] Solution A was irradiated at room temperature for 6 hours with a 415 nm LED in an air atmosphere. After the reaction was completed, 1 M sodium hydroxide aqueous solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. 0.1 mmol of diphenylacetonitrile was added to the crude product as an internal standard and tested. 1 H NMR showed that no 1-cyclohexylisoquinoline was produced.

[0084] Comparative Example 5

[0085]

[0086] To 2.5 mL of acetonitrile, 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of trifluoroacetic acid were added to obtain solution A;

[0087] Solution A was irradiated at room temperature with a 400 nm LED under air atmosphere for 6 hours. After the reaction was completed, 1 M sodium hydroxide aqueous solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. 0.1 mmol of diphenylacetonitrile was added to the crude product as an internal standard and tested. 1 H NMR gave 1-cyclohexylisoquinoline in 66% yield.

[0088] Comparative Example 6

[0089]

[0090] To 2.5 mL of acetonitrile, 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmmol of concentrated hydrochloric acid were added to obtain solution A;

[0091] Solution A was irradiated at room temperature for 6 hours under air atmosphere with a 415 nm LED. After the reaction was completed, 1 M sodium hydroxide aqueous solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. 0.1 mmol of diphenylacetonitrile was added to the crude product as an internal standard and tested. 1 H NMR gave 1-cyclohexylisoquinoline in 94% yield.

[0092] Comparative Example 7

[0093]

[0094] To 2.5 mL of acetonitrile, 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmmol of glacial acetic acid were added to obtain solution A;

[0095] Solution A was irradiated at room temperature for 6 hours under air atmosphere with a 415 nm LED. After the reaction was completed, 1 M sodium hydroxide aqueous solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. 0.1 mmol of diphenylacetonitrile was added to the crude product as an internal standard and tested. 1 H NMR gave 1-cyclohexylisoquinoline in 18% yield.

[0096] Comparative Example 8

[0097]

[0098] To 2.5 mL of acetonitrile, 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of benzoic acid were added to obtain solution A;

[0099] Solution A was irradiated at room temperature for 6 hours under air atmosphere with a 415 nm LED. After the reaction was completed, 1 M sodium hydroxide aqueous solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. 0.1 mmol of diphenylacetonitrile was added to the crude product as an internal standard and tested. 1 H NMR gave 1-cyclohexylisoquinoline in <5% yield.

[0100] Comparative Example 9

[0101] 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of trifluoroacetic acid were added to 2.5 mL of acetonitrile to obtain solution A;

[0102] The reaction was carried out in an air atmosphere at room temperature in the dark for 6 hours. After the reaction was completed, 1M sodium hydroxide aqueous solution was added to the reaction solution and extracted with ethyl acetate three times. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. 0.1 mmol of diphenylacetonitrile was added to the crude product as an internal standard and tested. 1 H NMR showed that no 1-cyclohexylisoquinoline was produced.

[0103] Comparative Example 10

[0104]

[0105] To 2.5 mL of acetonitrile, 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of trifluoroacetic acid were added to obtain solution A;

[0106] Under a high-purity argon atmosphere, solution A was irradiated with a 415 nm LED at room temperature for 6 hours. After the reaction, the reaction solution was treated with 1 M aqueous sodium hydroxide solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain 1-cyclohexylisoquinoline with a yield of <5%. This was probably due to the presence of trace oxygen in the reaction tube.

[0107] Comparative Example 11

[0108] Comparative Example 10 was repeated, and the introduction of oxygen was strictly controlled.

[0109] To 2.5 mL of acetonitrile, 0.1 mmol of isoquinoline, 5 mmol of cyclohexane, and 0.12 mmol of trifluoroacetic acid were added to obtain solution A;

[0110] Under a high-purity argon atmosphere, solution A was irradiated at room temperature for 6 hours by a 415 nm LED. After the reaction was completed, 1 M sodium hydroxide aqueous solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure to obtain a crude product. 0.1 mmol of diphenylacetonitrile was added to the crude product as an internal standard and tested. 1 H NMR showed no formation of 1-cyclohexylisoquinoline, demonstrating that the reaction did not occur under an inert atmosphere.

[0111] Examples 2-9

[0112] In Examples 2-9, the operating steps are exactly the same as those in Example 1, except that the type of alkane compound and the reaction time are changed. Other reaction conditions remain the same as those in Example 1. Please see Table 1 for details.

[0113] Table 1 Experimental summary of Examples 2-9

[0114]

[0115] As shown in Table 1, excellent yields can be obtained by adopting this method for both straight-chain alkanes of different chain lengths and cycloalkanes of different molecular weights, indicating that the method provided by the present invention has a wide range of substrate selection.

[0116] Examples 10-29

[0117] In Examples 10-29, the operating steps are exactly the same as those in Example 1, except that the type of nitrogen heteroaromatic compound and the reaction time are changed. Other reaction conditions remain the same as those in Example 1. See Table 2 for details.

[0118] Table 2 Experimental summary of Examples 10-29

[0119] Example Nitrogen heteroaromatic compounds Response time / hour Yield / % product 10 4-Chloroisoquinoline 12 39 4-Chloro-1-cyclohexylisoquinoline 11 5-Chloroisoquinoline 12 46 5-Chloro-1-cyclohexylisoquinoline 12 6-Chloroisoquinoline 12 63 6-Chloro-1-cyclohexylisoquinoline 13 4-Bromoisoquinoline 7 67 4-Bromo-1-cyclohexylisoquinoline 14 5-Bromoisoquinoline 24 45 5-Bromo-1-cyclohexylisoquinoline 15 6-Bromoisoquinoline 12 59 6-Bromo-1-cyclohexylisoquinoline 16 4-Phenylisoquinoline 20 29 1-Cyclohexyl-4-phenylisoquinoline 17 5-Phenylisoquinoline 20 48 1-Cyclohexyl-5-phenylisoquinoline 18 5-Nitroisoquinoline 20 29 1-Cyclohexyl-5-nitroisoquinoline 19 6-Cyanoisoquinoline 24 26 1-cyclohexylisoquinolin-6-cyano 20 3-Ethylisoquinolinecarboxylate 20 14 1-Cyclohexylisoquinolin-3-yl ethyl ester 21 3-Methylisoquinoline 20 38 1-cyclohexyl-3-methylisoquinoline 22 6-Methylisoquinoline 20 55 1-cyclohexyl-6-methylisoquinoline 23 5-Methoxyisoquinoline 20 21 1-cyclohexyl-5-methoxyisoquinoline 24 6-Methoxyisoquinoline 20 16 1-cyclohexyl-6-methoxyisoquinoline 25 5-Benzyloxyisoquinoline 20 22 5-Benzyloxy-1-cyclohexylisoquinoline 26 5-Benzylisoquinoline 20 56 5-Benzoyl-1-cyclohexylisoquinoline 27 4-Chloroquinoline 24 46 4-Chloro-2-cyclohexylquinoline 28 4,7-Dichloroquinoline 24 60 4,7-Dichloro-2-cyclohexylquinoline 29 phenidine 20 43 6-Cyclohexylmorphine

[0120] Table 2 shows that isoquinolines containing bromine or chlorine substituents at the C4, C5, and C6 positions can be converted into the corresponding C-H heteroaromatic products in high yields. When isoquinolines are substituted with electron-poor groups (such as phenyl, nitro, cyano, and ester groups), electron-rich groups (such as methyl, benzyloxy, and -OCOPh), or relatively neutral alkyl groups, they can also react with alkanes to provide C-H heteroaromatic products, but the yields are relatively low.

[0121] Example 30 (Amplification reaction)

[0122]

[0123] In a 150 mL custom-made Pyrex glass light tube (5.0 cm inner diameter, 18 cm length) equipped with a magnet, isoquinoline (900 μL, 7.5 mol), cyclohexane (20 mL, 25 equiv.), trifluoroacetic acid (900 μL, 1.2 equiv.) and acetonitrile (70 mL) were added to obtain solution A.

[0124] Solution A was irradiated with a blue LED (λ = 415 nm) at room temperature for 26 hours under an air atmosphere. After the reaction, a 1M aqueous sodium hydroxide solution was added to the reaction solution and extracted three times with ethyl acetate. The organic phases were combined and the solvent was removed by rotary evaporation under reduced pressure. The crude product was purified by silica gel column chromatography (eluted with petroleum ether / ethyl acetate) to obtain 1-cyclohexylisoquinoline in a yield of 60% (0.95 g).

[0125] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for photocatalytically constructing CC bonds, characterized in that: The steps include: Adding an azaaromatic compound, an alkyl compound and an acid into a solvent to obtain a solution A; In an oxygen-containing atmosphere, solution A is irradiated with visible light to obtain.

2. The method according to claim 1, characterized in that The acid is selected from one or more of formic acid, acetic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, trifluoroacetic acid and benzoic acid.

3. The method according to claim 1, characterized in that The nitrogen heteroaromatic compound is selected from one or more of the following structures: Among them, the R1-R 20 They may be the same or different and each independently represents any one of H, OCH3, CH3CH2, (CH3)2CH, (CH3)3C, CH2OH, COOCH3, COOCH2CH3, CF3, F, Cl, Br, NH2, OH, CN, NO2, OCH2Ph, and Ph.

4. The method according to claim 1, characterized in that: The alkyl compound is selected from one or more of straight-chain alkanes with carbon atoms of C5-C12, branched-chain alkanes with carbon atoms of C5-C12, and cycloalkanes with carbon atoms of C5-C12.

5. The method according to claim 1, characterized in that The solvent is selected from one or more of acetonitrile, acetone, dimethyl sulfoxide, ethyl acetate, dichloromethane, and 1,2-dichloroethane.

6. The method according to claim 1, characterized in that The concentration of the alkyl compound in solution A is from 0.001 mol / L to saturation concentration.

7. The method according to claim 1, characterized in that The concentration of the nitrogen heteroaromatic compound in solution A is from 0.001 mol / L to saturation concentration.

8. The method according to claim 1, characterized in that The concentration of the acid in solution A is from 0.001 mol / L to saturation concentration.

9. The method according to claim 1, characterized in that: The light source of the visible light is selected from one of LED, xenon lamp, mercury lamp and sunlight.

10. The method according to claim 1, characterized in that The illumination time of the visible light is 1-48 hours.

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