Synthesis method of photocatalytic organic germanide

Abstract

The invention discloses a method for synthesizing a photocatalytic organic germanide, which is characterized in that green synthesis of the organic germanide is realized by taking alkyl hydrogen germanide, olefin and aryl cyanide as raw materials under an illumination condition. Under illumination, the photocatalyst / alkali synergistically activates alkyl hydrogen germanide to generate corresponding germanium free radicals, and meanwhile, the generated photocatalyst in a reduction state reduces aryl cyanide into anion free radicals. And finally, the generated germanium free radicals and aryl cyanide anion free radicals are sequentially subjected to addition and reaction with olefin, and a 1.2-germanium arylation product of the olefin is prepared after a cyano group removal process. According to the invention, cheap raw materials are utilized and are applied to preparation of organic germanide with potential biological activity under the photocatalytic condition, and the method has the value of developing the germanide which can be used for industrial synthesis of the functional germanide.

Description

Technical Field

[0001] The invention relates to a method for synthesizing an organic germanium compound, in particular to a method for synthesizing a photocatalytic organic germanium compound. Background Art

[0002] Organic germanium compounds are an important class of functional organic molecules, which are widely used in drug molecules, organic synthesis and functional materials research. In particular, in recent years, scientists have found that organic germanium compounds can be used as an important synthon in various carbon-carbon and carbon-hetero cross-couplings. Therefore, the development of the synthesis method of organic germanium compounds has received great attention from the academic community.

[0003] Photocatalytic synthesis methods have the advantages of mild conditions, high functional group tolerance, and a wide range of substrate applications. They are an important organic synthesis method. Using cheap and readily available germanium hydrogen, olefins, and aromatic cyanides as raw materials, photocatalytic selective synthesis of highly functional group organic germanium compounds is an atomic step-economical, green and efficient synthesis strategy. However, it is usually difficult to selectively control the three-component reaction, and the traditional metal-catalyzed coupling process is not easy to achieve. In the past, organic germanium compounds were mainly prepared by direct cross-coupling of germanium compounds with another species catalyzed by organometallic reagents, transition metal catalysts, or Lewis acids. However, these methods often have shortcomings such as low functional group compatibility and harsh conditions, which often limit the scope of application of the reaction.

[0004] As a green synthesis method, photocatalytic reaction is expected to overcome the shortcomings of traditional transition metals. Therefore, it is of great practical significance to develop new methods for synthesizing organic germanium compounds with mild conditions and simple operation. The activation strategy of photocatalysis and hydrogen transfer is expected to achieve the activation of multiple substrates at the same time, which is suitable for multi-component reactions and is expected to become an effective way to synthesize high-functionality organic germanium compounds. In the past, the hydrogenation reaction of germanium hydrogen and olefins was realized based on the photo-hydrogen transfer dual catalytic strategy, but the new reaction of olefin germanium arylation has not been reported using this strategy. Considering that the synthesis of organic germanium compounds mainly relied on transition metals and metal organic reagents in the past, although the efficiency was high, it did not meet the requirements of the development of modern green chemical industry and it was difficult to achieve large-scale industrial application. The synthesis of organic germanium compounds with diverse structures by the three-component synthesis of germanium hydrogen, olefins and aryl cyanides through photo-hydrogen transfer dual catalysis is expected to achieve a greater breakthrough in the preparation of germanium compounds. In addition, based on this, it is very necessary to provide a new method for the preparation of photocatalytic organic germanium compounds. Summary of the invention

[0005] Purpose of the invention: The present invention aims to provide a method for synthesizing photocatalytic organic germanium compounds, which solves the problems of dependence on transition metals, low compatibility, narrow application range, and single product structure in traditional synthesis routes.

[0006] Technical solution: The method for synthesizing the photocatalytic organic germanium compound of the present invention comprises the following steps: adding alkyl hydrogen germanium, olefin, aryl cyanide, photocatalyst, base and hydrogen transfer reagent into an organic solvent, and reacting under light, the reaction formula is as follows:

[0007]

[0008] In the formula, R1 is selected from aryl; R2 is selected from one of hydrogen, C1-C6 alkyl or C1-C6 cycloalkyl; R3, R4, R5 are all selected from one of C1-C6 alkyl or phenyl; R6 is selected from hydrogen or C1-C6 alkyl; X is N or C; R7 is selected from hydrogen or -CN; n=0 or 1.

[0009] The present invention utilizes photocatalytic activation of aryl cyanide to generate aryl cyanide anion free radicals. Synchronously, based on the hydrogen transfer strategy, the germanium hydrogen bond in the germanide is activated to generate germanium free radicals. The generated germanium free radicals and aryl cyanide anion free radicals sequentially add to the olefin double bond, and then the reaction undergoes a decyanation process to generate organic germanium compounds with diverse structures.

[0010] Preferably, R1 is selected from phenyl, pyridyl, substituted phenyl or substituted pyridyl, and the substituent is C1-C6 alkyl, C1-C6 alkoxy, methylthio or -CO2Me.

[0011] Preferably, the photocatalyst is selected from one of 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile, tris(2-phenylpyridine)iridium or (4,4'-di-tert-butyl-2,2'-bipyridine)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate.

[0012] Preferably, the hydrogen transfer agent is selected from one of ethyl thioglycolate or triisopropylsilanethiol; and the base is selected from potassium phosphate.

[0013] Preferably, the light source in the reaction is a blue light source of 450 to 455 nm, and the power of the light source is 8 to 40 watts.

[0014] Preferably, the alkylgermanide is selected from one of triethylgermanide, tributylgermanide, triphenylgermanide, dimethylphenylgermanide or diphenylmethylgermanide.

[0015] Preferably, the olefin is selected from styrene or α-methyl substituted styrene. The aryl cyanide is selected from one of tetracyanopyridine, p-phenylenedicyanide or 2,6-dimethyl-4-cyanopyridine.

[0016] Preferably, the organic solvent is selected from at least one of acetonitrile, tetrahydrofuran, dimethyl sulfoxide or N,N-dimethylformamide.

[0017] Preferably, the molar ratio of the alkyl hydrogengermanide, olefin, aryl cyanide, photocatalyst, base and hydrogen transfer agent is 1-2:1:1-2:0.001-0.05:1-2:0.02-0.1.

[0018] Preferably, the reaction temperature is 20-30° C., the reaction time is 20-48 hours, and the reaction is carried out under the protection of an inert gas.

[0019] Preferably, the organic germanium compound has the structural formula of any of the following compounds:

[0020]

[0021] In the above technical scheme, alkyl hydrogengermanide, olefin, aryl cyanide, photocatalyst, base and hydrogen transfer reagent are used as starting materials to react and synthesize organic germanium compounds, and this method is further used in the post-modification of synthesizing functional organic germanium compounds with potential activity.

[0022] The present invention uses alkyl germanium hydrogen, olefin, aryl cyanide, photocatalyst, base, and hydrogen transfer reagent as starting materials, and the reaction obtains an organic germanium compound product. The preparation method uses a photocatalyst to oxidize a hydrogen transfer reagent to generate a reduced photocatalyst and a sulfur free radical of a hydrogen transfer reagent, and the generated reduced photocatalyst simultaneously reduces the aryl cyanide to generate an aryl anion free radical, and then the sulfur free radical of the generated hydrogen transfer reagent captures the hydrogen atom in the germanium hydrogen to generate a germanium free radical. As the reaction proceeds, the germanium free radical and the aromatic cyanide anion free radical are respectively added to the olefin, and an organic germanium compound is generated after undergoing decyanation aromatization. The reaction is compatible with a variety of functional groups and can be used for post-modification transformation of functional organic molecules, and has the value of developing a new method for industrial synthesis of organic germanium compound functional molecules.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: it solves the shortcomings of traditional synthesis routes such as dependence on transition metals, low compatibility, narrow application range, and single product structure. The method has mild reaction conditions and is easy to achieve industrial-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The following is the reaction scheme of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0026] The present invention relates to the synthesis of the following compounds:

[0027]

[0028] Example 1

[0029] 4-(1-phenyl-2-(triethylgermanium)benzonitrile, the structural formula is:

[0030]

[0031] Its synthesis method is:

[0032] Styrene (20.8 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridyl)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), sealed under nitrogen protection, irradiated with blue light (wavelength 455 nm, power 40 W), reacted at room temperature for 24 h, cooled, filtered, recovered the solvent under reduced pressure, and separated by column chromatography to obtain 49 mg of Example 1 compound in a yield of 67%.

[0033] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ7.55(d,J=8.2Hz,2H),7.40(d,J=8.1Hz,2H),7.31-7.20(m,5H),4. 13(t,J=8.1Hz,1H),1.62-1.49(m,2H),0.91(t,J=8.0Hz,9H),0.54(q,J=7.9Hz,6H)ppm. 13 C NMR (100MHz, CDCl3) δ153.0,145.5,132.3,128.7,128.3,127.5,126.7,119.1,109.8,48.3,19.0,8.9,4.2ppm.

[0034] Example 2

[0035] 4-(1-(p-tolyl)-2-(triethylgermanium)ethyl)benzonitrile, the structural formula is:

[0036]

[0037] Its synthesis method is:

[0038] 4-Methylstyrene (24.0 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridyl)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), sealed under nitrogen protection, irradiated with blue light (wavelength 455 nm, power 40 W), reacted at room temperature for 24 h, cooled, filtered, recovered the solvent under reduced pressure, and separated by column chromatography to obtain 42.6 mg of Example 2 compound in a yield of 56%.

[0039] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ7.54(d,J=8.3Hz,2H),7.38(d,J=8.3Hz,2H),7.14(d,J=8.2Hz,2H),7.09(d,J=8.0Hz, 2H), 4.09 (t, J = 8.1Hz, 1H), 2.30 (s, 3H), 1.59-1.47 (m, 2H), 0.91 (t, J = 7.9Hz, 9H), 0.53 (q, J = 7.9Hz, 6H) ppm. 13 C NMR (100MHz, CDCl3) δ153.3,142.5,136.3,132.3,129.4,128.2,127.4,119.2,109.7,47.9,21.1,19.0,8.9,4.2ppm.

[0040] Example 3

[0041] 4-(1-(p-tert-butylphenyl)-2-(triethylgermanium)ethyl)benzonitrile, the structural formula is:

[0042]

[0043] Its synthesis method is:

[0044] Take 4-tert-butylstyrene (32.0 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridine)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm, power 40 W), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 58.2 mg of Example 3 compound in a yield of 69%.

[0045] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ7.57-7.53(m,2H),7.46-7.38(m,2H),7.30(d,J=8.4Hz,2H),7.23-7.14(m,2H),4 .10(t,J=8.1Hz,1H),1.60-1.48(m,2H),1.29(s,9H),0.90(t,J=7.9Hz,9H),0.53(q,J=8.0Hz,6H)ppm. 3 C NMR (100MHz, CDCl3) δ153.1,149.6,142.6,132.3,128.4,127.0,125.5,119.2,109.8,47.8,34.4,31.4,19.1,8.9,4.2ppm.

[0046] Example 4

[0047] 4-(1-(2-methoxyphenyl)-2-(triethylgermanium)ethyl)benzonitrile, the structural formula is:

[0048]

[0049] Its synthesis method is:

[0050] Take 3-methoxystyrene (26.8 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridyl)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm, power 40 W), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 44.8 mg of Example 4 compound with a yield of 53%.

[0051] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ7.39-7.35(m,2H),7.28-7.23(m,2H),7.16-7.11(m,1H),7.06-7.00(m,1H),6.80-6.74(mn,1H),6.67-6.63(m,1H),4.4 6(t,J=8.2Hz,1H),3.63(s,3H),1.41(dd,J=13.7,8.6Hz,1H),1.29(dd,J=13.7,7.8Hz,1H),0.76(t,J=7.9Hz,9H),0.38(q,J=7.9Hz,6H)ppm. 3 C NMR (100MHz, CDCl3) δ156.5,153.1,133.9,132.0,128.6,127.7,127.4,120.6,119.4,110.6,109.4,55.3,40.0,18.1,8.9,4.2ppm.

[0052] Example 5

[0053] 4-(1-(-methoxyphenyl)-2-(triethylgermanium)ethyl)benzonitrile, the structural formula is:

[0054]

[0055] Its synthesis method is:

[0056] Take 2-methoxystyrene (26.8 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridyl)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), seal the mixture under nitrogen protection, irradiate with blue light (wavelength 455 nm, power 40 W), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 54.6 mg of Example 5 compound in a yield of 69%.

[0057] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ7.62-7.57(m,2H),7.48-7.42(m,2H),7.28-7.23(m,1H),6.93-6.88(m,1H),6.86-6.83(m,1H),6. 81-6.76(m,1H),4.15(t,J=8.1Hz,1H),3.84(s,3H),1.65-1.51(m,2H),0.97(t,J=7.9Hz,9H),0.60(q,J=7.9Hz,6H)ppm. 3 C NMR (100MHz, CDCl3) δ159.8,152.8,147.1,132.3,129.7,128.3,120.0,119.1,113.8,111.4,109.9,55.3,48.3,18.0,8.9,4.2ppm.

[0058] Example 6

[0059] 4-(2-phenyl-1-(triethylgermanium)propyl-2-yl)benzonitrile, the structural formula is:

[0060]

[0061] Its synthesis method is:

[0062] Take α-methylstyrene (23.6 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridine)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm, power 40 W), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 54.7 mg of Example 6 compound in a yield of 72%.

[0063] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ7.47-7.41(m,2H),7.29-7.23(m,2H),7.20-7.09(m,5H),1 .70-1.62(m,2H),1.59(s,3H),0.79(t,J=7.9Hz,9H),0.38(q,J=8.1Hz,6H)ppm. 3 C NMR (100MHz, CDCl3) δ157.6,149.9,131.8,128.2,127.8,126.9,126.2,119.2,109.4,46.0,30.1,27.5,8.9,5.2ppm.

[0064] Example 7

[0065] Methyl-3-(1-(4-cyanophenyl)-2-(triethylgermanium)ethyl)benzoate, the structural formula is:

[0066]

[0067] Its synthesis method is:

[0068] Take 4-vinyl-benzoic acid methyl ester (32.4 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridine)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), under nitrogen protection, seal, blue light (wavelength 455 nm, power 40 W) at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 52.9 mg of Example 7 compound in a yield of 77%.

[0069] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ7.97-7.94(m,1H),7.89-7.84(m,1H),7.57-7.53(m,2H),7.46-7.34(m,4H),4.18(t, J=8.1Hz,1H),3.90(s,3H),1.55(tt,J=13.7,6.5Hz,2H),0.90(t,J=7.9Hz,9H),0.52(q,J=7.9Hz,6H)ppm. 3 C NMR (100MHz, CDCl3) δ167.0,152.3,145.9,132.4,132.2,130.5,128.8,128.5,128.2,128.0,119.0,110.1,52.2,48.1,18.9,8.8,4.2ppm.

[0070] Example 8

[0071] 4-(1-cyclobutyl-1-phenyl-2-(triethylgermanium)ethyl)benzonitrile, the structural formula is:

[0072]

[0073] Its synthesis method is:

[0074] Take 1-cyclobutylvinylbenzene (31.6 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridyl)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), seal the mixture under nitrogen protection, irradiate with blue light (wavelength 455 nm, power 40 W), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 40.3 mg of Example 8 compound with a yield of 48%.

[0075] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ7.53-7.49(m,2H),7.26-7.16(m,5H),7.08-7.03(m,2H),3.22-3.09(m,1H),1.99-1.88(m,2H),1 .72-1.62(m,1H),1.58(s,2H),1.54-1.44(m,2H),1.31-1.19(m,1H),0.82(t,J=7.9Hz,9H),0.36(q,J=7.7Hz,6H)ppm. 3 C NMR (100MHz, CDCl3) δ154.9,147.6,131.2,130.0,128.9,127.7,126.2,119.3,109.5,52.2,43.1,25.0,24.8,24.1,17.6,8.9,5.1ppm.

[0076] Example 9

[0077] 4-(2-(4-(methylthio)phenyl)-1-(triethylgermanium)propyl-2-yl)benzonitrile, the structural formula is:

[0078]

[0079] Its synthesis method is:

[0080] Take 1-(1-methylvinyl)-4-(methylthio)benzene (32.8 mg, 0.2 mmol, 1.0 equiv.), 1,4-dicyanophenyl (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridyl)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl thioglycolate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), under nitrogen protection, sealed, irradiated with blue light (wavelength 455 nm, power 40 W), reacted at room temperature for 24 h, cooled, filtered, and the solvent was recovered under reduced pressure. 70.7 mg of Example 9 compound was separated by column chromatography, and the yield was 83%.

[0081] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ7.55-7.51(m,2H),7.36-7.33(m,2H),7.17-7.10(m,4H),2.45(s ,3H),1.74-1.67(m,2H),1.66(s,3H),0.88(t,J=7.9Hz,9H),0.48(q,J=7.9Hz,6H)ppm. 13 C NMR (100MHz, CDCl3) δ157.3,147.0,136.0,131.8,127.8,127.4,126.5,119.1,109.5,45.6,30.05,27.5,16.0,8.9,5.3ppm.

[0082] Example 10

[0083] 4-(2-pyridinyl-3-yl)-1-(triethylgermanium)propyl-2-yl)benzonitrile, the structural formula is:

[0084]

[0085] Its synthesis method is:

[0086] Take α-methyl-3-pyridylethylene (23.8 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), (4,4'-di-tert-butyl-2,2'-bipyridyl)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate (2 mol%, 3.7 mg, 0.004 mmol), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), seal the mixture under nitrogen protection, irradiate with blue light (wavelength 455 nm, power 40 W), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 53.3 mg of Example 10 compound in a yield of 70%.

[0087] Its structure was confirmed by NMR examination; 1 H NMR (400MHz, CDCl3) δ8.52-8.47(m,1H),8.44(d,J=4.1Hz,1H),7.57-7.54(m,2H),7.50-7.45(m,1H),7.35-7.32 (m,2H),7.21-7.16(m,1H),1.73(d,J=3.1Hz,2H),1.70(s,3H),0.87(t,J=7.9Hz,9H),0.46(q,J=7.9Hz,6H)ppm. 3 CNMR (100MHz, CDCl3) δ156.0,148.6,147.5,145.3,134.4,132.1,127.8,123.1,118.9,109.9,44.9,29.8,27.3,8.8,5.3ppm.

[0088] Embodiment 11

[0089] Based on Example 2, the photocatalyst is changed and the synthesis method is as follows:

[0090] Take 4-methylstyrene (24.0 mg, 0.2 mmol, 1.0 equiv.), 1,4-phenylenedicyanide (51 mg, 0.4 mmol, 2.0 equiv.), triethylgermanium hydrogen (64.3 mg, 0.4 mmol, 2.0 equiv.), 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile (2 mol%, 3.2 mg), ethyl mercaptoacetate (10 mol%, 2.4 mg, 0.02 mmol), potassium phosphate (84.9 mg, 0.4 mmol, 2.0 equiv.), anhydrous acetonitrile (2 mL), under nitrogen protection, seal, irradiate with blue light (wavelength 455 nm, power 40 W), react at room temperature for 24 h, cool, filter, recover the solvent under reduced pressure, and separate by column chromatography to obtain 38.0 mg of Example 11 compound with a yield of 50%.

Claims

1. A method for synthesizing a photocatalytic organic germanium compound, characterized in that: The following steps are involved: Alkyl germanium hydrogen, olefin, aryl cyanide, photocatalyst, base and hydrogen transfer reagent are added to an organic solvent and reacted under light. The reaction formula is as follows: In the formula, R1 is selected from aryl or substituted aryl, the substituent is C1-C6 alkyl, C1-C6 alkoxy, methylthio or -CO2Me; R2 is selected from one of hydrogen, C1-C6 alkyl or C1-C6 cycloalkyl; R3, R4, R5 are all selected from C1-C6 alkyl or phenyl; R6 is selected from hydrogen or C1-C6 alkyl; X is N or C; R7 is selected from hydrogen or -CN; n=0 or 1.

2. The method for synthesizing a photocatalytic organic germanium compound according to claim 1, characterized in that: The aryl group is selected from phenyl or pyridyl.

3. The method for synthesizing the photocatalytic organic germanium compound according to claim 1, characterized in that: The photocatalyst is selected from 2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile, tris(2-phenylpyridine)iridium or (4,4'-di-tert-butyl-2,2'-bipyridine)bis[(2-pyridyl)phenyl]iridium(III) hexafluorophosphate, and the alkylgermanide is selected from one of triethylgermanide, tributylgermanide, triphenylgermanide, dimethylphenylgermanide or diphenylmethylgermanide.

4. The method for preparing a photocatalytic organic germanium compound according to claim 1, characterized in that: The hydrogen transfer agent is selected from ethyl thioglycolate or triisopropylsilanethiol; and the base is selected from potassium phosphate.

5. The method for synthesizing a photocatalytic organic germanium compound according to claim 1, characterized in that: The light source in the reaction is a blue light source of 450 to 455 nm, and the power of the light source is 8 to 40 watts.

6. The method for synthesizing a photocatalytic organic germanium compound according to claim 1, characterized in that: The olefin is selected from styrene or α-methyl substituted styrene, and the aryl cyanide is selected from one of tetracyanopyridine, p-phenylenedicyanide or 2,6-dimethyl-4-cyanopyridine.

7. The method for synthesizing a photocatalytic organic germanium compound according to claim 1, characterized in that: The organic solvent is selected from at least one of acetonitrile, tetrahydrofuran, dimethyl sulfoxide or N,N-dimethylformamide.

8. The method for synthesizing a photocatalytic organic germanium compound according to claim 1, characterized in that: The molar ratio of the alkylgermanide, olefin, aryl cyanide, photocatalyst, base and hydrogen transfer reagent is 1-2:1:1-2:0.001-0.05:1-2:0.02-0.

1.

9. The method for synthesizing a photocatalytic organic germanium compound according to claim 1, characterized in that: The reaction temperature is 20-30° C., the reaction time is 20-48 hours, and the reaction is carried out under the protection of an inert gas.

10. The method for synthesizing a photocatalytic organic germanium compound according to claim 1, characterized in that: The organic germanium compound has the structural formula of any of the following compounds:

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