Method for preparing hydrogen / deuterated aromatic compound by photo-initiation of nitro hydrogen / deuteration removal of nitro aromatic hydrocarbon

Abstract

The invention discloses a method for preparing a hydrogen / deuterated aromatic compound by photo-initiating nitro hydrogen / deuteration removal of nitro aromatic hydrocarbon, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: mixing nitro-aromatic hydrocarbon and hydroboron / boron deuteride in an organic solvent, and reacting at 25-75 DEG C under the irradiation of light with the wavelength of 365-450 nm to obtain the hydrogen / deuterated aromatic compound. According to the present invention, the denitrification hydrogenation or deuterization of the nitro-aromatic compound is achieved through the photo-initiation, the reaction conditions are simple, the used raw material reagent is less, the step economy and the atom economy are provided, the compatibility of the substrate functional group is good, and the further conversion of the product into the complex functional molecule is easily achieved.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogenation / deuteration of nitroaromatic hydrocarbons. Background Art

[0002] Nitroaromatics are a class of abundant chemical raw materials with a wide range of sources and low prices. They can be synthesized through aromatic electrophilic nitration. Nitroaromatics not only exist in functional materials, but are also a widely used synthetic intermediate. Nitroaromatics can be reduced, diazotized and halogenated to obtain halogenated aromatics, which facilitates the subsequent synthesis of complex functional molecules. In 2017, the Nakao research group realized the cross-coupling reaction of non-activated nitrobenzene, and the construction of carbon-carbon bonds, carbon-nitrogen bonds and carbon-hydrogen bonds of nitrobenzene catalyzed by palladium was reported by the research group. However, there are few studies on the direct conversion of nitro groups into corresponding CH(D) bonds without precious metal catalysis to prepare hydrogen / deuterated aromatic compounds.

[0003] At present, there are two traditional conversion methods for aromatic nitro compounds to other aromatic compounds: one is to reduce nitrobenzene to obtain aromatic amines, and then construct carbon-carbon bonds or carbon-heteroatom bonds through diazotization and Sandmeyer reaction; the other is to convert nitro compounds containing electron-withdrawing groups into other aromatic compounds through aromatic nucleophilic substitution (S N The nitro group can be converted to other groups by the reaction of Ar). Of the two traditional conversions mentioned above, the former requires the handling of diazonium salts with explosion hazards during the reaction, and the reaction steps are relatively cumbersome, while the latter has drastic reaction conditions, poor functional group compatibility, and the substrate must contain at least one electron-withdrawing group. Summary of the invention

[0004] In view of the above deficiencies in the prior art, the present invention provides a method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogenation / deuteration of nitroaromatic hydrocarbons, which is used to solve the problems of complicated steps and narrow substrate application range in the prior art.

[0005] To achieve the above purpose, the specific technical solutions of the present invention are as follows:

[0006] A method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogenation / deuteration of nitroaromatic hydrocarbons, wherein the hydrogenated aromatic compounds are prepared by the following method: materials including nitroaromatic hydrocarbons I and borohydride are mixed in an organic solvent, and reacted under irradiation with light having a wavelength of 365 nm to 450 nm to obtain hydrogenated aromatic compounds II. The specific reaction equation is as follows:

[0007] ;

[0008] The deuterated aromatic compound is prepared by the following method: materials including nitroaromatic I and deuterated boron are mixed in an organic solvent, and reacted under light irradiation with a wavelength of 365 nm to 450 nm to obtain a deuterated aromatic compound III. The specific reaction equation is as follows:

[0009] ;

[0010] The aromatic hydrocarbon in the nitroaromatic hydrocarbon I is one of substituted / unsubstituted aromatic groups and substituted / unsubstituted heteroaromatic groups (that is, Ar in the reaction equation is one of substituted aromatic groups, unsubstituted aromatic groups, substituted heteroaromatic groups and unsubstituted heteroaromatic groups).

[0011] Preferably, the borohydride is selected from NaBH 4 , LiBH 4 , NaBH 3 CN、NaBHEt 3 One or more of the .

[0012] Further preferably, the borohydride is NaBH 4 .

[0013] Preferably, the borodeuteride is selected from NaBD 4 、LiBD 4 , NaBD 3 CN、NaBDEt 3 One or more of the .

[0014] Further preferably, the deuterated boron is NaBD 4 .

[0015] Preferably, the substituents in the aromatic or heteroaromatic group are selected from one or more of halogen, cyano, hydroxyl, trifluoromethyl, alkyl, alkoxy, aryloxy, acyloxy, ester, acyl, thienyl, oxazolyl, phenyl, and amide.

[0016] Preferably, the aromatic group is selected from one of phenyl, styryl, and condensed ring aromatic groups; the heteroaromatic group is selected from one of furyl, pyridyl, benzopyridyl, pyrazole, benzoxazolyl, benzofuranyl, dibenzofuranyl, isoquinolyl, and quinolyl.

[0017] Preferably, the nitroarene I is selected from one of the following structures:

[0018] .

[0019] Preferably, in the method for preparing the hydrogenated aromatic compound or the method for preparing the deuterated aromatic compound, the material further includes an oxidant, and the molar ratio of the oxidant to the nitroaromatic hydrocarbon I is (0.35-3):1.

[0020] More preferably, the oxidant is potassium peroxosulfate (oxone).

[0021] Preferably, in the method for preparing the hydrogenated aromatic compound or the method for preparing the deuterated aromatic compound, the material further comprises water, and the molar ratio of the water to the nitroaromatic hydrocarbon I is (0.35-3):1.

[0022] Preferably, the reaction temperature is 25-75 °C.

[0023] More preferably, the reaction temperature is 25-55°C.

[0024] Preferably, the molar ratio of the nitroarene I to the borohydride is 1:(0.8-3).

[0025] Preferably, the molar ratio of the nitroarene I to the borodeuteride is 1:(0.8-3).

[0026] Preferably, the organic solvent is acetonitrile.

[0027] Compared with the prior art, the present invention is beneficial in that:

[0028] The present invention uses nitroaromatics and borohydrides / borodeuterides as main raw materials, and realizes denitration hydrogenation / deuteration of nitro compounds through photoinitiation. The reaction conditions are mild, the raw materials and reagents used are small, and the process has step economy and atom economy. In addition, the substrate functional groups have good compatibility, which is conducive to further converting the products into complex functional molecules. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the reaction mechanism diagram for preparing deuterated 1,1'-biphenyl by denitration in Example 16. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The present invention provides a method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogenation / deuteration of nitroaromatic hydrocarbons. The hydrogenated aromatic compounds are prepared by the following method: materials including nitroaromatic hydrocarbons I and borohydride are mixed in an organic solvent, and reacted under light irradiation with a wavelength of 365 nm to 450 nm to obtain hydrogenated aromatic compounds II. The specific reaction equation is as follows:

[0032] ;

[0033] The deuterated aromatic compound is prepared by the following method: materials including nitroaromatic I and deuterated boron are mixed in an organic solvent, and reacted under light irradiation with a wavelength of 365 nm to 450 nm to obtain a deuterated aromatic compound III. The specific reaction equation is as follows:

[0034] ;

[0035] The aromatic hydrocarbon in the nitroaromatic hydrocarbon I is one of substituted / unsubstituted aromatic groups and substituted / unsubstituted heteroaromatic groups (that is, Ar in the reaction equation is selected from one of substituted aromatic groups, unsubstituted aromatic groups, substituted heteroaromatic groups and unsubstituted heteroaromatic groups).

[0036] In some examples, the borohydride is selected from NaBH 4 , LiBH 4 , NaBH 3 CN、NaBHEt 3 One or more of the .

[0037] In some examples, the deuterated boron is selected from NaBD 4 、LiBD 4 , NaBD 3 CN、NaBDEt 3 One or more of the .

[0038] In some examples, the substituents in the aromatic or heteroaromatic group are selected from one or more of halogen, cyano, hydroxyl, trifluoromethyl, alkyl, alkoxy, aryloxy, acyloxy, ester, acyl, thienyl, oxazolyl, phenyl, and amide.

[0039] In some examples, the aromatic group is selected from one of phenyl, styryl, and condensed ring aromatic groups; the heteroaromatic group is selected from one of furanyl, pyridyl, benzopyridyl, pyrazole, benzoxazolyl, benzofuranyl, dibenzofuranyl, isoquinolyl, and quinolyl.

[0040] In the following specific embodiments, the nitroarene I is selected from one of the following structures:

[0041] ;

[0042] Accordingly, the hydrogenated aromatic compound II is selected from one of the following structures:

[0043] ;

[0044] Accordingly, the deuterated aromatic compound III is selected from one of the following structures:

[0045] .

[0046] In some examples, in the method for preparing the hydrogenated aromatic compound or the method for preparing the deuterated aromatic compound, the material further includes an oxidant, and the molar ratio of the oxidant to the nitroaromatic hydrocarbon I is (0.35~3):1.

[0047] In some examples, in the method for preparing the hydrogenated aromatic compound or the method for preparing the deuterated aromatic compound, the material further includes water, and the molar ratio of the water to the nitroaromatic hydrocarbon I is (0.35~3):1.

[0048] In some examples, the reaction temperature is 25-75 °C.

[0049] In some examples, the molar ratio of the nitroarene I to the borohydride is 1:(0.8-3).

[0050] In some examples, the molar ratio of the nitroarene I to the borodeuteride is 1:(0.8-3).

[0051] In the following specific examples, all materials used are commercially available.

[0052] Example 1

[0053] Preparation of 2-phenylthiophene

[0054] The specific reaction formula is as follows:

[0055]

[0056] The specific preparation process is as follows:

[0057] In an argon atmosphere, 2-nitro-5-phenylthiophene (20.5 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxodisulfate (123.0 mg, 2.0 equivalents), NaBH 4(8.0 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 2-phenylthiophene (7.7 mg, yield 48%).

[0058] On a silica gel thin layer plate using n-hexane-ethyl acetate as the developing solvent (the volume ratio of n-hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.4.

[0059] The structural characterization data of the product are as follows:

[0060] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.88 – 7.87 (m, 2H), 7.65 – 7.54 (m, 5H), 7.35 – 7.34 (m, 1H) ppm.

[0061] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 144.8, 143.8, 129.2, 128.4, 127.8,126.3, 125.2, 123.4 ppm.

[0062] HRMS-EI(m / z) calc'd for C 10 H 9 S + [M+H] + , 161.0419; found, 161.0421.

[0063] Example 2

[0064] Preparation of Deuterated 2-Phenylthiophene

[0065]

[0066] The specific preparation process is as follows:

[0067] In an argon atmosphere, 2-nitro-5-phenylthiophene (20.5 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxydisulfate (123.0 mg, 2.0 equivalents), NaBD 4(8.4 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product deuterated 2-phenylthiophene (6.6 mg, yield 48%, of which the deuteration rate was 97%).

[0068] On a silica gel thin layer plate using n-hexane-ethyl acetate as the developing solvent (the volume ratio of n-hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.4.

[0069] The structural characterization data of the product are as follows:

[0070] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.67 – 7.65 (m, 2H), 7.44 – 7.40 (m, 4H), 7.13 – 7.11 (m, 1H) ppm.

[0071] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 134.4, 128.9, 128.0, 127.9, 127.5,126.0, 124.8, 123.1 ppm.

[0072] HRMS-EI(m / z) calc'd for C 10 H 8 DS + [M+H] + , 162.0482; found, 162.0482.

[0073] Example 3

[0074] Preparation of 3-fluoro-1,1'-biphenyl

[0075] The specific reaction formula is as follows:

[0076]

[0077] The specific preparation process is as follows:

[0078] In an argon atmosphere, 3-fluoro-4-nitro-1,1'-biphenyl (21.7 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxodisulfate (123.0 mg, 2.0 equivalents), NaBH 4 (8.0 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 3-fluoro-1,1'-biphenyl (12.0 mg, yield 70%).

[0079] On a silica gel thin layer plate using n-hexane-ethyl acetate as the developing solvent (the volume ratio of n-hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.3.

[0080] The structural characterization data of the product are as follows:

[0081] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.63 – 7.62 (m, 2H), 7.52 – 7.43(m, 5H), 7.35 – 7.30 (m, 1H), 7.11 – 7.07 (m, 1H) ppm.

[0082] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 163.2 (d, J = 244.0 Hz), 143.6,140.0, 130.2 (d, J = 8.4 Hz), 128.9, 127.9, 127.1, 122.8 (d, J = 2.8 Hz),114.2, 114.0, 113.9 ppm.

[0083] 19 F NMR (376 MHz, CDCl 3 , 25 ℃, δ): – 113.1, – 113.2 (m) ppm.

[0084] HRMS-EI(m / z) calc'd for C 13 H9 F + [M] + , 172.0683; found, 172.0687.

[0085] Example 4

[0086] Preparation of Deuterated 3-Fluoro-1,1'-Biphenyl

[0087] The specific reaction formula is as follows:

[0088]

[0089] The specific preparation process is as follows:

[0090] In an argon atmosphere, 3-fluoro-4-nitro-1,1'-biphenyl (20.5 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxodisulfate (123.0 mg, 2.0 equivalents), NaBD 4 (8.4 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product deuterated 3-fluoro-1,1'-biphenyl (12.5 mg, yield 72%, of which the deuteration rate was 99%).

[0091] On a silica gel thin layer plate using n-hexane-ethyl acetate as the developing solvent (the volume ratio of n-hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.3.

[0092] The structural characterization data of the product are as follows:

[0093] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.63 – 7.62 (m, 2H), 7.55 – 7.43(m, 5H), 7.35 – 7.30 (m, 1H) ppm.

[0094] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 163.2 (q, J = 244.0 Hz), 143.6,140.0, 130.2 (d, J= 8.4 Hz), 128.9, 127.9, 127.1, 122.8 (d, J = 2.8 Hz),114.2, 113.9 ppm.

[0095] 19 F NMR (376 MHz, CDCl 3 , 25 °C, δ): – 113.4 ppm.

[0096] HRMS-EI(m / z) calc'd for C 12 H 7 DF + [MH] + , 172.0642; found, 172.0641.

[0097] Example 5

[0098] Preparation of 2-methylnaphthalene

[0099] The specific reaction formula is as follows:

[0100]

[0101] The specific preparation process is as follows:

[0102] In an argon atmosphere, 2-methyl-1-nitronaphthalene (21.7 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxodisulfate (123.0 mg, 2.0 equivalents), NaBH 4 (8.0 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 2-methylnaphthalene (9.5 mg, yield 67%).

[0103] On a silica gel thin layer plate using n-hexane-ethyl acetate as the developing solvent (the volume ratio of n-hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.3.

[0104] The structural characterization data of the product are as follows:

[0105] 1 H NMR (400 MHz, CDCl 3, 25 ℃, δ): 7.93 – 7.86 (m, 3H), 7.73 (s, 1H), 7.59 – 7.51 (m, 2H), 7.43 (d, J = 8.4 Hz, 1H), 2.57 (s, 3H) ppm.

[0106] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 135.6, 133.8, 131.8, 128.2, 127.8,127.7, 127.4, 127.0, 126.0, 125.1, 21.9 ppm.

[0107] HRMS-EI(m / z) calc'd for C 11 H 10 + [M] + , 142.0783; found, 142.0784.

[0108] Example 6

[0109] Preparation of Deuterated 2-Methylnaphthalene

[0110]

[0111] The specific preparation process is as follows:

[0112] In an argon atmosphere, 2-methyl-1-nitronaphthalene (20.5 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxydisulfate (123.0 mg, 2.0 equivalents), NaBD 4 (8.4 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product deuterated 2-methylnaphthalene (8.6 mg, yield 60%, of which the deuteration rate was 96%).

[0113] On a silica gel thin layer plate using n-hexane-ethyl acetate as the developing solvent (the volume ratio of n-hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.3.

[0114] The structural characterization data of the product are as follows:

[0115] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.86 – 7.79 (m, 3H), 7.51 – 7.44(m, 2H), 7.37 (d, J = 8.4 Hz, 1H), 2.57 (s, 3H) ppm.

[0116] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 135.4, 133.6, 131.7, 128.2, 127.7,127.6, 127.2, 125.9, 124.9, 21.7 ppm.

[0117] HRMS-EI(m / z) calc'd for C 11 H 9 D + [M] + , 143.0840; found, 143.0839.

[0118] Example 7

[0119] Preparation of 9H-fluorene

[0120] The specific reaction formula is as follows:

[0121]

[0122] The specific preparation process is as follows:

[0123] In an argon atmosphere, 2-nitro-9H-fluorene (21.1 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxydisulfate (123.0 mg, 2.0 equivalents), NaBH 4 (8.0 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 9H-fluorene (12.6 mg, yield 76%).

[0124] On a silica gel thin layer plate using hexane-ethyl acetate as the developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.4.

[0125] The structural characterization data of the product are as follows:

[0126] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.85 (d, J = 7.6 Hz, 2H), 7.60 (d, J =7.6 Hz, 2H), 7.44 (t, J = 7.6 Hz, 2H), 7.37 (d, J = 7.6 Hz, 2H), 3.96 (s, 2H)ppm.

[0127] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 143.3, 141.7, 126.8, 126.7, 125.1,119.9, 36.9 ppm.

[0128] HRMS-EI(m / z) calc'd for C 13 H 10 + [M] + , 166.0777; found, 166.0772.

[0129] Example 8

[0130] Preparation of Deuterated 9H-Fluorene

[0131] The specific reaction formula is as follows:

[0132]

[0133] The specific preparation process is as follows:

[0134] In an argon atmosphere, 2-nitro-9H-fluorene (21.1 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxydisulfate (123.0 mg, 2.0 equivalents), NaBD 4(8.4 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product deuterated 9H-fluorene (yield 14.0 mg, yield 84%, of which the deuteration rate was 99%).

[0135] On a silica gel thin layer plate using hexane-ethyl acetate as the developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.3.

[0136] The structural characterization data of the product are as follows:

[0137] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.81 (d, J = 7.6 Hz, 2H), 7.57 (m,2H), 7.40 (m, 2H), 7.32 (d, J = 7.2 Hz, 1H), 3.92 (s, 2H) ppm.

[0138] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 143.3, 141.8, 126.8, 126.7, 126.6,125.1, 124.9, 119.9, 36.9 ppm.

[0139] HRMS-EI(m / z) calc'd for C 13 H 7 D + [M-2H] + , 165.0699; found, 165.0694.

[0140] Example 9

[0141] Preparation of 1,2-diphenylacetylene

[0142]

[0143] The specific preparation process is as follows:

[0144] In an argon atmosphere, 1-nitro-4-phenylethynylbenzene (22.3 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxodisulfate (123.0 mg, 2.0 equivalents), NaBH 4 (8.0 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 1,2-diphenylacetylene (12.8 mg, yield 72%).

[0145] On a silica gel thin layer plate using hexane-ethyl acetate as the developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.3.

[0146] The structural characterization data of the product are as follows:

[0147] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.65 – 7.62 (m, 4H), 7.48 – 7.41 (m, 6H) ppm.

[0148] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 131.7, 128.5, 128.4, 123.4, 89.5ppm.

[0149] HRMS-EI(m / z) calc'd for C 14 H 11 + [M+H] + , 179.0855; found, 179.0855.

[0150] Example 10

[0151] Preparation of Deuterated 1,2-Diphenylacetylene

[0152] The specific reaction formula is as follows:

[0153]

[0154] In an argon atmosphere, 1-nitro-4-phenylethynylbenzene (22.3 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxydisulfate (123.0 mg, 2.0 equivalents), NaBD 4 (8.4 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product deuterated 1,2-diphenylacetylene (11.6 mg, yield 65%, of which the deuteration rate was 99%).

[0155] On a silica gel thin layer plate using hexane-ethyl acetate as the developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.3.

[0156] The structural characterization data of the product are as follows:

[0157] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.61 – 7.59 (m, 4H), 7.41 – 7.40 (m, 5H) ppm.

[0158] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 131.6, 128.4, 128.3, 123.3, 89.4ppm.

[0159] HRMS-EI(m / z) calc'd for C 14 H 9 D + [M] + , 179.0840; found, 179.0839.

[0160] Embodiment 11

[0161] Preparation of 9-(p-Tolyl)-9H-fluorene

[0162] The specific reaction formula is as follows:

[0163]

[0164] The specific preparation process is as follows:

[0165] In an argon atmosphere, 2-nitro-9-(p-tolyl)-9H-fluorene (30.1 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxodisulfate (123.0 mg, 2.0 equivalents), NaBH 4 (8.0 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 9-(p-tolyl)-9H-fluorene (18.2 mg, yield 71%).

[0166] Hexane-ethyl acetate was used as the developing solvent on a silica gel thin layer plate (the volume ratio of hexane to ethyl acetate was 100:1), and the Rf of the product was measured to be 0.2.

[0167] The structural characterization data of the product are as follows:

[0168] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.86 (d, J = 7.6 Hz, 2H), 7.46 – 7.30(m, 6H), 7.14 (d, J = 7.6 Hz, 2H), 7.05 (d, J = 7.6 Hz, 2H), 5.09 (s, 1H), 2.38(s, 3H) ppm.

[0169] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 148.2, 141.0, 138.6, 136.4, 129.4,128.3, 127.3, 127.2, 125.4, 119.9, 54.1, 21.1 ppm.

[0170] HRMS-EI(m / z) calc'd for C 19 H 14 + [M] + , 256.1247; found, 256.1250.

[0171] Example 12

[0172] Preparation of Deuterated 9-(p-Tolyl)-9H-fluorene

[0173] The specific reaction formula is as follows:

[0174]

[0175] The specific preparation process is as follows:

[0176] In an argon atmosphere, 2-nitro-9-(p-tolyl)-9H-fluorene (30.1 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxydisulfate (123.0 mg, 2.0 equivalents), NaBD 4 (8.4 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product deuterated 9-(p-tolyl)-9H-fluorene (19.5 mg, yield 76%, of which the deuteration rate was 99%).

[0177] On a silica gel thin layer plate using hexane-ethyl acetate as the developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.2.

[0178] The structural characterization data of the product are as follows:

[0179] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.86 (d, J = 7.6 Hz, 2H), 7.46 – 7.30(m, 5H), 7.15 (d, J = 7.6 Hz, 2H), 7.05 (d, J = 7.6 Hz, 2H), 5.09 (s, 1H), 2.38(s, 3H) ppm.

[0180] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 148.2, 141.0, 138.6, 136.4, 129.5,128.3, 127.3, 127.2, 125.4, 125.2, 119.9, 54.1, 21.1 ppm.

[0181] HRMS-EI(m / z) calc'd for C 20 H 14 D + [MH] + , 256.1232; found, 256.1231.

[0182] Embodiment 13

[0183] Preparation of methyl 2-(2-fluoro-1,1'-biphenyl-4-yl)propionate

[0184] The specific reaction formula is as follows:

[0185]

[0186] The specific preparation process is as follows:

[0187] In an argon atmosphere, methyl 2-(2-fluoro-4'-nitro-1,1'-biphenyl-4-yl)propanoate (30.3 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxodisulfate (123.0 mg, 2.0 equivalents), NaBH 4 (8.0 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 2-(2-fluoro-1,1'-biphenyl-4-yl) propionic acid methyl ester (14.2 mg, yield 55%).

[0188] On a silica gel thin layer plate using hexane-ethyl acetate as the developing solvent (the volume ratio of hexane to ethyl acetate was 30:1), the Rf of the product was measured to be 0.3.

[0189] The structural characterization data of the product are as follows:

[0190] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.59 – 7.58 (m, 2H), 7.51 – 7.39 (m, 4H), 7.21 – 7.16 (m, 2H), 3.84 – 3.79 (m, 1H), 3.75 (d, J = 2.0 Hz, 3H),1.58 (dd,J = 2.0 Hz, 7.2 Hz, 3H) ppm.

[0191] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 174.5, 159.7 (d, J = 247.0 Hz),141.8 (d, J = 7.0 Hz), 135.5, 130.8 (d, J = 3.0 Hz), 128.9 (d, J = 3.0 Hz), 128.5,127.7, 123.6 (d, J = 3.0 Hz), 115.3 (d, J = 24.0 Hz), 52.3, 45.0, 18.5 ppm.

[0192] 19 F NMR (376 MHz, CDCl 3 , 25 ℃, δ): –117.6 (m) ppm.

[0193] HRMS-EI(m / z) calc'd for C 16 H 16 FO 2 + [M+H] + , 259.1129; found, 259.1126.

[0194] Embodiment 14

[0195] Preparation of deuterated methyl 2-(2-fluoro-1,1'-biphenyl-4-yl)propionate

[0196] The specific reaction formula is as follows:

[0197]

[0198] The specific preparation process is as follows:

[0199] In an argon atmosphere, methyl 2-(2-fluoro-4'-nitro-1,1'-biphenyl-4-yl)propanoate (30.3 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxodisulfate (123.0 mg, 2.0 equivalents), NaBD 4(8.4 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product, deuterated 2-(2-fluoro-1,1'-biphenyl-4-yl) propionic acid methyl ester (11.9 mg, yield 46%, of which the deuteration rate was 98%).

[0200] On a silica gel thin layer plate using hexane-ethyl acetate as the developing solvent (the volume ratio of hexane to ethyl acetate was 30:1), the Rf of the product was measured to be 0.3.

[0201] The structural characterization data of the product are as follows:

[0202] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.59 – 7.57 (m, 2H), 7.49 – 7.41(m, 3H), 7.20 – 7.15 (m, 2H), 3.83 – 3.78 (m, 1H), 3.75 (d, J = 2.0 Hz, 3H),1.58 (d, J = 7.2 Hz, 3H) ppm.

[0203] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 174.5, 159.7 (d, J = 247.0 Hz),141.8 (q, J = 8.0 Hz), 135.5, 130.8 (q, J = 4.0 Hz), 128.9, 128.4, 123.6 (q, J =3.0 Hz), 115.3 (q, J = 23.0 Hz), 52.3, 45.0, 18.5 ppm.

[0204] 19 F NMR (376 MHz, CDCl 3 , 25 ℃, δ): –117.6 (m) ppm.

[0205] HRMS-EI(m / z) calc'd for C 16 H 13 DO 2 F + [MH] + , 258.1046; found, 258.1046.

[0206] Embodiment 15

[0207] Preparation of 1,1'-biphenyl

[0208]

[0209] In an argon atmosphere, 4-nitro-1,1'-biphenyl (19.9 mg, 0.10 mmol, 1.0 equivalent), NaBH 4 (8.0 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 1,1'-biphenyl (4.1 mg, yield 27%).

[0210] On a silica gel thin layer plate using hexane-ethyl acetate as the developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.4.

[0211] The structural characterization data of the product are as follows:

[0212] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.62– 7.54 (m, 4H), 7.49 – 7.41 (m, 4H), 7.36 – 7.28 (m, 2H) ppm.

[0213] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 141.3, 128.8, 127.3, 127.2 ppm.

[0214] Example 16

[0215] Preparation of Deuterated 1,1'-Biphenyl

[0216]

[0217] In an argon atmosphere, 4-nitro-1,1'-biphenyl (19.9 mg, 0.10 mmol, 1.0 equivalent), water (2.2 equivalents), potassium peroxodisulfate (123.0 mg, 2.0 equivalents), NaBD 4 (8.4 mg, 0.20 mol, 2.0 equivalents), and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was placed under 390 nm LEDs and stirred at room temperature for 12 hours. The mixture was transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product deuterated 1,1'-biphenyl (12.9 mg, yield 84%, of which the deuteration rate was 98%).

[0218] On a silica gel thin layer plate using hexane-ethyl acetate as the developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), the Rf of the product was measured to be 0.4.

[0219] The structural characterization data of the product are as follows:

[0220] 1 H NMR (400 MHz, CDCl 3 , 25 ℃, δ): 7.67 – 7.57 (m, 4H), 7.52 – 7.41 (m, 4H), 7.39 – 7.33 (m, 1H) ppm.

[0221] 13 C NMR (100 MHz, CDCl 3 , 25 ℃, δ): 141.4, 128.9,128.8, 127.4, 127.3ppm.

[0222] HRMS-EI(m / z) calc'd for C 12 H 10 D + [MH] + , 156.0918; found, 156.0917.

[0223] The inventors studied the reaction mechanism of preparing deuterated biphenyl by denitration in Example 16 by DFT calculation (reaction mechanism as shown in Figure 1 As shown in the figure, the results show that nitrobenzene is excited by ultraviolet light with a wavelength of 365-390 nm, and forms a triplet biradical active intermediate T1 through intersystem crossing. T1 combines with sodium deuterated borohydride to form an intermediate3 C D ,because 3 C D The carbon in the benzene ring has certain carbon cation properties, so it will react with BD 4 Negative ions combine to form a Mesenheimier intermediate 3 D D BD bond breaking and BO bond formation then occur synergistically. This step is the rate-determining step with a reaction barrier of 14.8 kcal / mol. After the reaction, an intermediate is formed. 3 E D , the Ar-N bond is activated and broken, forming an intermediate 3 F D , the reaction is then quenched back to the ground state, removing NaNO 2 BD 3 , and obtain the deuterated product. Figure 1 The green line in the figure is the ground state path, in which only cooperative S N Ar reaction, and the energy barrier is as high as 54.8 kcal / mol, so the reaction cannot occur without light.

[0224] Embodiment 17

[0225] Preparation of 1,1'-biphenyl, the preparation method is basically the same as that of Example 15, the only difference is that NaBH 4 Replaced with an equal molar amount of LiBH 4 The yield of 1,1'-biphenyl was 28%.

[0226] Embodiment 18

[0227] The preparation method of 1,1'-biphenyl is basically the same as that of Example 15, except that water (2.2 equivalents) is added to the reaction, and the yield of 1,1'-biphenyl is 49%.

[0228] Embodiment 19

[0229] The preparation method of 1,1'-biphenyl is basically the same as that of Example 15, except that water (2.2 equivalents) and potassium persulfate (2.0 equivalents) are also added to the reaction, and the yield of 1,1'-biphenyl is 72%.

[0230] Embodiment 20

[0231] The preparation method of 1,1'-biphenyl is basically the same as that of Example 15, except that the wavelength of the LEDs irradiation lamp in the reaction is 425 nm, and the yield of 1,1'-biphenyl is 20%.

[0232] Comparative Example 1

[0233] The preparation method of 1,1'-biphenyl is basically the same as that of Example 15, except that the wavelength of the LEDs irradiation lamp in the reaction is 520 nm, and the yield of 1,1'-biphenyl is 0%.

[0234] Comparative Example 2

[0235] The preparation method of 1,1'-biphenyl is basically the same as that of Example 15, except that no LEDs are used in the reaction, and the yield of 1,1'-biphenyl is 0%.

[0236] The above specific embodiments describe the implementation of the present invention in detail, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the claims and technical concept of the present invention, the technical solution of the present invention can be modified and changed in many simple ways, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. A method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogenation / deuteration of nitroaromatic hydrocarbons, characterized in that: The hydrogenated aromatic compound is prepared by the following method: materials including nitroaromatic hydrocarbon I and borohydride are mixed in an organic solvent, and reacted under light irradiation with a wavelength of 365 nm to 450 nm to obtain the hydrogenated aromatic compound II. The specific reaction equation is as follows: ； The deuterated aromatic compound is prepared by the following method: materials including nitroaromatic I and deuterated boron are mixed in an organic solvent, and reacted under light irradiation with a wavelength of 365 nm to 450 nm to obtain a deuterated aromatic compound III. The specific reaction equation is as follows: ； The aromatic hydrocarbon in the nitro aromatic hydrocarbon I is one of a substituted / unsubstituted aromatic group and a substituted / unsubstituted heteroaromatic group.

2. The method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogen / deuteration of nitroaromatic hydrocarbons according to claim 1, characterized in that: The borohydride is selected from one or more of NaBH4, LiBH4, NaBH3CN, and NaBHEt3.

3. The method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogen / deuteration of nitroaromatic hydrocarbons according to claim 2, characterized in that: The borohydride is NaBH4.

4. The method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogen / deuteration of nitroaromatic hydrocarbons according to claim 1, characterized in that: The boron deuteride is selected from one or more of NaBD4, LiBD4, NaBD3CN, and NaBDEt3.

5. The method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogen / deuteration of nitroaromatic hydrocarbons according to claim 1, characterized in that: The boron deuteride is NaBD4.

6. The method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogen / deuteration of nitroaromatic hydrocarbons according to claim 1, characterized in that: The substituents in the aromatic or heteroaromatic group are selected from one or more of halogen, cyano, hydroxyl, trifluoromethyl, alkyl, alkoxy, aryloxy, acyloxy, ester, acyl, thienyl, oxazolyl, phenyl, and amide.

7. The method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogen / deuteration of nitroaromatic hydrocarbons according to claim 1, characterized in that: The aromatic group is selected from one of phenyl, styryl, and condensed ring aromatic groups; the heteroaromatic group is selected from one of furyl, pyridyl, benzopyridyl, pyrazole, benzoxazolyl, benzofuranyl, dibenzofuranyl, isoquinolyl, and quinolyl.

8. The method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogen / deuteration of nitroaromatic hydrocarbons according to claim 1, characterized in that: The nitroarene I is selected from one of the following structures: 。 9. The method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogen / deuteration of nitroaromatic hydrocarbons according to claim 1, characterized in that: In the method for preparing the hydrogenated aromatic compound or the method for preparing the deuterated aromatic compound, the material further comprises an oxidant, and the molar ratio of the oxidant to the nitroaromatic hydrocarbon is (0.35-3):

1.

10. The method for preparing hydrogen / deuterated aromatic compounds by photoinduced denitration hydrogen / deuteration of nitroaromatic hydrocarbons according to claim 1, characterized in that: In the method for preparing the hydrogenated aromatic compound or the method for preparing the deuterated aromatic compound, the material further comprises water, and the molar ratio of the water to the nitroaromatic hydrocarbon is (0.35-3):1.

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