A method for photocatalytic dehalogenation coupling of halogenated compounds

Abstract

The present application relates to the technical field of synthesis of symmetrical molecular compounds, and particularly relates to a method for photocatalytic dehalogenation coupling of halogenated compounds. The halogenated compound, alkali, sacrificial agent, solvent and catalyst are mixed and placed in a photocatalytic reactor, the atmosphere in the reactor is replaced with inert gas and then sealed, and then the dehalogenation coupling reaction occurs under irradiation of an external light source to generate a coupling product. The method of the present application can realize efficient conversion of the halogenated compound under mild conditions, and the yield of the coupling product is 77% to 99%. The catalyst is easy to separate after the reaction and can be repeatedly used. The obtained coupling product can be used to synthesize precursors, supramolecular compounds, polymers and the like, and has wide application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of synthesis of symmetrical molecular compounds, and particularly relates to a method for photocatalytic dehalogenation coupling of halogenated compounds. BACKGROUND

[0002] C-C coupling of halides is a common method for synthesizing precursors, supramolecular compounds, polymers, etc. in pharmaceutical and chemical industry applications. Current research mainly focuses on the reaction of aryl or alkenyl electrophiles, such as Suzuki coupling, Heck reaction, Sonogashira coupling, etc. The cleavage of carbon-halogen bond (C-X) mainly relies on Pd, and the radical intermediates are stabilized on the Pd catalyst, thereby diverting the selectivity to C-C coupling. However, this method of carbon-carbon coupling is not suitable for halogenated compounds, mainly due to two factors: the C-X bond of halogenated compounds is stronger, and the alkyl radical after dehalogenation is more prone to hydrogenation. Halogenated compound coupling not only requires a higher activation energy, but also easily produces a large amount of side reactions such as hydrogenation due to the inability of the organometallic catalyst to well selectively stabilize the alkane group.

[0003] Photocatalysis provides such activation energy and a method for distinguishing alkane groups for the control of bond cleavage and product selectivity. A mature approach is to combine photocatalysis with organometallic chemistry to achieve the reduction of C-X bond and the stabilization of C-C bond coupling radical. For example, MacMillan et al. developed a strategy for constructing C-C bonds by combining photooxidation and transition metal catalysis, using Ir[dF(CF3)ppy]2(dtbbpy)PF6 and NiCl2·dtbppy as catalysts to construct C-C bonds (J. Am. Chem. Soc. 2016, 138, 8084-8087). The principle of this photocatalytic scheme is to reduce the cleaved C-X bond by the excited state photocatalyst with high reducing ability. At the same time, the organometallic catalyst stabilizes the alkane radical to prevent it from being hydrogenated. Halogenated compound coupling can also be unified on a metal-semiconductor heterojunction. In a recent work, Su et al. reported photocatalytic reduction coupling of halogenated benzyl using Cu / TiO2 (ACS Catal. 2021, 11, 4338-4348), obtaining a high yield of biphenyl (95%). However, current work using semiconductors is limited to generating stable benzyl radicals, which is not suitable for halogenated compounds.

[0004] The traditional halogenated compound coupling reaction technology has disadvantages such as harsh reaction conditions, low reaction selectivity, poor substrate universality, etc., and therefore there is an urgent need to develop a new method for photocatalytic dehalogenation coupling of halogenated compounds. SUMMARY

[0005] Based on this, the purpose of the present application is to provide a method for photocatalytic dehalogenation coupling of halogenated compounds, which has mild reaction conditions and can realize efficient conversion of halogenated compounds, and the yield of the coupling product is 77%-99%. In order to solve the above technical problems of the present application, the present application provides the following technical scheme:

[0006] The present application provides a method for photocatalytic dehalogenation coupling of halogenated compounds, which comprises mixing halogenated compounds, base, sacrificial agent, solvent and catalyst in a photocatalytic reactor, replacing the atmosphere in the reactor with inert gas, and then sealing the reactor, and then dehalogenation coupling reaction occurs under the irradiation of an external light source to generate a coupling product.

[0007] Further, the halogenated compound is one or more of halogenated alkanes, halogenated alkenes, halogenated ethers, and halogenated esters.

[0008] The halogen element contained in the halogenated compound is one or both of Br and I.

[0009] Further, the catalyst is metal-loaded titanium dioxide (M / TiO2), wherein the metal (M) is one or more of Ag, Au, Ni, Co, Pd, Ru, and Pt, the titanium dioxide (TiO2) is at least one of TiO2-R (anatase phase), TiO2-A (rutile phase), and TiO2-P25 (anatase phase and rutile phase in a mass ratio of about 8:2), and the loading amount of the metal is 0.1-10.0wt.%.

[0010] Preferably, the titanium dioxide (TiO2) is TiO2-P25 (anatase phase and rutile phase in a mass ratio of about 8:2), the metal (M) is Ag or Au, and the optimal loading amount of the metal is 1.0-5.0wt.%.

[0011] Further, the sacrificial agent is at least one of methanol, ethanol, propanol, and isopropanol.

[0012] The solvent is one or more of acetonitrile, cyclohexane, tetrahydrofuran, and dimethyl sulfoxide.

[0013] Preferably, the solvent is acetonitrile or cyclohexane.

[0014] Further, the base is one or more of potassium carbonate, cesium carbonate, sodium hydroxide, and ethylenediamine.

[0015] Further, the inert gas is one or more of nitrogen and argon.

[0016] The external light source is at least one of an LED (central wavelength 365nm, 10W) and a xenon lamp (150W).

[0017] Further, the concentration of the halogenated compound in the initial reaction system is 1-100 g / L; the solvent accounts for 10%-90% of the total volume of the reaction system, and the sacrificial agent accounts for 10%-90% of the total volume of the reaction system.

[0018] Further, the concentration of the halogenated compound in the initial reaction system is 1-100 g / L; the solvent accounts for 10%-90% of the total volume of the reaction system, and the sacrificial agent accounts for 10%-90% of the total volume of the reaction system.

[0019] Further, the temperature of the dehalogenation coupling reaction is 10-40℃, and the time is 10 min-10 h.

[0020] Further, the temperature of the dehalogenation coupling reaction is 10-40℃, and the time is 10 min-10 h.

[0021] Advantages of the present application:

[0022] 1. The present application designs a simple metal-loaded semiconductor photocatalyst, which realizes efficient dehalogenation coupling of halogenated compounds. The addition of alkali can assist the reduction of C-X bond rupture, thereby reducing the conduction band potential required for the reduction of C-X bond rupture, and can avoid the poisoning of the catalyst by halogen elements, overcoming the shortcomings of ordinary catalysts, such as poor effect and easy poisoning.

[0023] 2. The reaction conditions of the present application are mild, and the use of expensive noble metals as catalysts can realize efficient conversion of halogenated compounds, and the yield of the coupling product is 77%-99%. The obtained coupling product can be used to synthesize precursors, supramolecular compounds, polymers, etc., and has wide application value.

[0024] 3. The catalyst used in the present application has high activity, simple preparation, and good stability, and can be recycled multiple times after simple separation and washing. The metal-loaded semiconductor photocatalyst has good resistance to halogenated compounds, and has important significance for the synthesis of symmetrical molecular compounds. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0026] Figure 1 The gas chromatogram of the product of Example 1 is shown in the figure.

[0027] Figure 2 The gas chromatogram of the product of Example 17 is shown in the figure. DETAILED DESCRIPTION

[0028] In order to make the purposes, technical solutions and points of the embodiments of the present application clearer, the technical solutions of the present application will be described clearly and completely below in conjunction with the drawings and specific embodiments in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0029] The experimental methods in the following embodiments are all conventional methods unless otherwise specified. The reagents or instruments involved in the present application are all ordinary commercially available products and can be purchased on the market.

[0030] In the present application, the yield of quantitative analysis is determined by a gas chromatograph (Agilent 7890B), and the chromatographic column is an Agilent HP-5 capillary column (30 m*32 μm*0.25 μm). Qualitative analysis is determined by a gas mass spectrometer (Thermo scientific TRACE1310), and the chromatographic column is a Thermoscientific TG-MS capillary column (30 m*32 μm*0.25 μm).

[0031] Example 1:

[0032] In a photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading amount of metal Ag is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging five times, and irradiation was performed at 25°C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 89%. The gas chromatogram of the obtained product is shown in Figure 1 .

[0033] Example 2:

[0034] In a photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Au / TiO2-P25 (the loading amount of metal Au is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging five times, and irradiation was performed at 20°C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 87%.

[0035] Example 3:

[0036] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 30°C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 87%.

[0037] Example 4:

[0038] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Au / TiO2-P25 (the loading of metal Au is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 20°C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 83%.

[0039] Example 5:

[0040] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 35°C for 20 min under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 77%.

[0041] Example 6:

[0042] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 25°C for 2 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 89%.

[0043] Example 7:

[0044] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of sodium hydroxide, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 25°C for 1 h under 365 nm LED; after the completion of the dehalogenation coupling reaction, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 80%.

[0045] Example 8:

[0046] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1 wt.%) catalyst, 0.9 mL of methanol and 0.1 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 25°C for 1 h under 365 nm LED; after the completion of the dehalogenation coupling reaction, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 83%.

[0047] Example 9:

[0048] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of potassium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 30°C for 1 h under 365 nm LED; after the completion of the dehalogenation coupling reaction, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 81%.

[0049] Example 10:

[0050] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1 wt.%) catalyst, 0.2 mL of methanol and 0.8 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 32°C for 1 h under 365 nm LED; after the completion of the dehalogenation coupling reaction, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 80%.

[0051] Example 11:

[0052] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / Ti02-P25 (the loading of metal Ag is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of cyclohexane solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging five times, and irradiated at 25 °C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 85%.

[0053] Example 12:

[0054] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / Ti02-P25 (the loading of metal Ag is 1 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and argon purging five times, and irradiated at 25 °C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 87%.

[0055] Example 13:

[0056] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / Ti02-P25 (the loading of metal Ag is 2.5 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging five times, and irradiated at 25 °C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 88%.

[0057] Example 14:

[0058] In the photocatalytic reactor, 21.6 mg of 1-iodohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / Ti02-P25 (the loading of metal Ag is 5.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging five times, and irradiated at 25 °C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 89%.

[0059] Example 15:

[0060] In the photocatalytic reactor, 30.0 mg of 1-bromohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiated at 25°C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 88%.

[0061] Example 16:

[0062] In the photocatalytic reactor, 30.0 mg of 1-bromohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiated at 25°C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 88%.

[0063] Example 17:

[0064] In the photocatalytic reactor, 30.0 mg of 1-bromohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiated at 25°C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 88%. Figure 2 .

[0065] Example 18:

[0066] In the photocatalytic reactor, 30.0 mg of 1-bromohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiated at 25°C for 1 h under 365 nm LED; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 88%.

[0067] Example 19:

[0068] In the photocatalytic reactor, 30.0 mg of 2-bromohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiated at 365 nm LED for 1 h at 26°C; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 86%.

[0069] Example 20:

[0070] In the photocatalytic reactor, 30.0 mg of 2-bromohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiated at 365 nm LED for 1 h at 26°C; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 86%.

[0071] Example 21:

[0072] In the photocatalytic reactor, 15.0 mg of 3-iodopropene, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiated at 365 nm LED for 1 h at 25°C; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 99%.

[0073] Example 22:

[0074] In the photocatalytic reactor, 30.0 mg of iodocyclohexane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiated at 365 nm LED for 1 h at 25°C; after the dehalogenation coupling reaction was completed, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 89%.

[0075] Example 23:

[0076] In the photocatalytic reactor, 30.0 mg of 1-iodo-2-methoxyethane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading amount of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 30°C for 1 h under 365 nm LED. After the completion of the dehalogenative coupling reaction, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 93%.

[0077] Example 24:

[0078] In the photocatalytic reactor, 30.0 mg of 1-iodo-2-methoxyethane, 32.5 mg of cesium carbonate, 5.0 mg of Ag / TiO2-P25 (the loading amount of metal Ag is 1.0 wt.%) catalyst, 0.1 mL of methanol and 0.9 mL of acetonitrile solvent were added, the atmosphere of the reaction tube was replaced by continuous vacuum pumping and nitrogen purging for five times, and irradiation was carried out at 30°C for 1 h under 365 nm LED. After the completion of the dehalogenative coupling reaction, the product was analyzed by GC, and the molar yield of the coupling product was calculated to be 93%.

[0079] The above detailed description of the preferred embodiments of the present patent, but the patent is not limited to the above-mentioned embodiments, within the scope of knowledge possessed by those skilled in the art, other different forms of changes or variations can also be made. Here it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement, etc. within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for photocatalytic dehalogenation coupling of halogenated compounds, characterized in that: A halogenated compound, a base, a sacrificial agent, a solvent, and a catalyst are mixed and placed in a photocatalytic reactor. The atmosphere in the reactor is replaced with an inert gas and then sealed. Under the irradiation of an external light source, a dehalogenation coupling reaction occurs to generate coupling products. The catalyst is titanium dioxide supported on a metal, wherein the metal is one or more of Ag and Au, the titanium dioxide is TiO2-P25, and the metal loading is 1.0-5.0 wt.%. The halogenated compound is one or more of halogenated alkanes, halogenated alkenes, halogenated ethers, and halogenated esters; The halogenated compound contains one or two of the halogen elements Br and I. The sacrificial agent is at least one of methanol, ethanol, propanol, and isopropanol; The solvent is one or more of acetonitrile and cyclohexane; The alkali is one or more of cesium carbonate and sodium hydroxide; The concentration of the halogenated compound in the initial reaction system is 15-25 g / L; the solvent accounts for 10%-90% of the total volume of the reaction system, and the sacrificial agent accounts for 10%-90% of the total volume of the reaction system. The dehalogenation coupling reaction is carried out at a temperature of 10-40℃ for 10 min-10 h.

2. The method according to claim 1, characterized in that: The inert gas is one or more of nitrogen and argon; The external light source is at least one of LED and xenon lamp.

3. The method according to claim 1, characterized in that: The sacrificial agent accounts for 10% of the total volume of the reaction system.

4. The method according to claim 1, characterized in that: The dehalogenation coupling reaction is carried out at a temperature of 20-30℃ for 30 min-2 h.

Images