A mechanical redox dehalogenation process for organic halides

Abstract

The application discloses a mechanical oxidation-reduction dehalogenation method of organic halides, and comprises the following steps: mixing organic halides, a mechanical oxidation-reduction catalyst and tris(trimethylsilyl)silane to obtain a mixture under an inert gas environment, and applying mechanical stress to the mixture so that the organic halides are subjected to mechanical oxidation-reduction dehalogenation reaction to obtain corresponding alkanes; the organic halides are alkyl halides or aryl halides. The application successfully realizes the treatment of the organic halides under the action of mechanical force by using the mechanical oxidation-reduction catalyst and the tris(trimethylsilyl)silane, does not use solvents which pollute the environment, and can realize the reaction under the condition of no solvent or a small amount of solvent, so that the organic halides are treated in a short time, and the monomer conversion rate is relatively high. The mechanical oxidation-reduction dehalogenation method can be used for the alkyl halides and the relatively stable aryl halides, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of mechanical oxidation-reduction technology, and specifically to a mechanical oxidation-reduction dehalogenation method for organic halides. Background Technology

[0002] Mechanochemistry, a branch of chemistry that utilizes mechanical forces to induce chemical reactions, has been widely applied in inorganic synthesis and materials science since its development in 1887, but its application in organic synthesis is relatively recent. Hydrogenation dehalogenation reactions have been carried out using other methods, such as metal-halogen substitution reactions, metal-mediated reduction, photochemical reduction, and radical reductive dehalogenation. Some of these reactions inevitably present problems, such as the use of toxic and explosive reagents, the generation of stoichiometric metal waste, poor selectivity, and susceptibility to degradation due to low functional group tolerance. In the development of novel radical-based synthetic methods, photoredox catalysis has been used to efficiently utilize the potential reactivity of carbon-halogen bonds. To date, the photocatalytic conversion of CX bonds containing iodine, bromine, chlorine, and fluorine has been well documented; however, the cost of photocatalysis, the use of organic solvents, and light penetration issues hinder its practical application.

[0003] Ball milling is a common tool in mechanochemistry. It utilizes the mechanical energy released by the collision of balls and reactants to achieve efficient mixing of reagents in a solvent-free environment, thereby accelerating chemical reactions. Currently, mechanochemistry has been widely applied in organocatalysis and metal-catalyzed transformations, such as Suzuki-Miyaura coupling, olefin metathesis, and CH activation. However, compared to the tremendous success of photoredox catalysis, the field of mechanochemical redox reactions is still in its early stages, and the direct activation of stable organohalides through mechanical force remains challenging.

[0004] Using highly polarized piezoelectric materials as mechanochemical catalysts is an alternative approach to breaking chemical bonds through mechanical force. When subjected to stress, the non-centrosymmetric nature of piezoelectric crystals leads to strain-induced piezoelectric potentials, allowing charges to cross the piezoelectric / solution interface and trigger redox reactions that are typically inert under conventional mechanochemical conditions. Over the past decade, this concept has expanded dramatically from water splitting reactions to other catalytic reactions aimed at addressing environmental pollution. In synthetic chemistry research, mechanochemical oxidation catalysis was first applied to regulate radical polymerization. Subsequently, the Ito group pioneered the mechanochemical arylation and borylation of aryl diazonium salts using ball milling and piezoelectric BaTiO3, reporting radical chain reactions with polymers as radical initiators under mechanochemical conditions. This reaction requires additional heating besides ball milling and is primarily applicable to organic iodides.

[0005] Currently, the substrate scope of mechanical redox reactions mainly targets relatively unstable chemical bonds. For more stable carbon-halogen bonds, especially stable carbon-bromine and carbon-chlorine bonds, it is difficult to effectively convert them. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a mechanical oxidation-reduction dehalogenation method for organohalides.

[0007] This invention is achieved through the following technical solution:

[0008] A mechanical redox dehalogenation method for organohalides includes the following steps:

[0009] In an inert gas environment, an organohalide, a mechanical redox catalyst, and tris(trimethylsilyl)silane are mixed to obtain a mixture. Mechanical stress is applied to the mixture to cause the organohalide to undergo a mechanical redox dehalogenation reaction to obtain the corresponding alkane.

[0010] The organohalides are alkyl halides or aryl halides.

[0011] Furthermore, the mechanical redox catalyst is zinc oxide nanoparticles, barium titanate nanoparticles, or titanium dioxide nanoparticles, and the zinc oxide nanoparticles are preferably mesoporous zinc oxide nanoparticles.

[0012] In the mechanical redox dehalogenation method of this invention, mesoporous zinc oxide nanoparticles (m-ZnO) with excellent catalytic performance activate carbon-halogen bonds to form carbon free radicals, which react with tris(trimethylsilyl)silane (TTMSS) via hydrogen atom transfer (HAT) and subsequent halogen atom transfer (XAT) mechanisms to produce the desired reduction product. This invention uses inexpensive and recyclable mesoporous zinc oxide nanoparticles as a mechanical redox catalyst, successfully achieving the treatment of organohalides under mechanical force. It avoids the use of environmentally polluting solvents and allows for reactions under solvent-free or very low-solvent conditions, ensuring that organohalides are treated quickly while maintaining a relatively high monomer conversion rate. This mechanical redox dehalogenation method can be used for both alkyl halides and relatively stable aryl halides, two typical monomer classes, and has broad application prospects.

[0013] Furthermore, the inert gas is nitrogen or argon.

[0014] Furthermore, the alkyl halide is RX, where X is a halogen, and the carbon atom attached to the halogen is on the carbon chain rather than on the benzene ring. RX can be...

[0015] Furthermore, the structural formula of the aryl halide Ar-X is as follows: R1 is selected from one or more of cyano, ester, acyl, carboxyl, nitro, alkyl, phenyl, amide, acyloxy, amino, hydroxyl and alkoxy, and X is a halogen.

[0016] Furthermore, the mixture also includes an inorganic salt, which is sodium bromide or potassium bromide.

[0017] Mechanical redox dehalogenation of alkyl halides can be performed without the addition of inorganic salts, while mechanical redox dehalogenation of aryl halides preferably requires the addition of inorganic salts.

[0018] Furthermore, the molar ratio of the organohalide, tris(trimethylsilyl)silane, and inorganic salt is 1:2:(1-2).

[0019] Furthermore, the mass fraction of the mechanical redox catalyst in the mixture is 5% to 15%.

[0020] Furthermore, the pore size of the mesoporous zinc oxide nanoparticles is 2–50 nm.

[0021] Furthermore, the mechanical oxidation-reduction dehalogenation reaction takes 3 to 8 hours.

[0022] Furthermore, mechanical stress is applied by ball milling or ultrasound.

[0023] In a specific implementation, the ball milling operation is as follows: in an inert gas environment, the mixture is added to a stainless steel ball mill jar, stainless steel grinding beads are placed in it, the ball mill jar is tightened and placed on a ball mill, the reaction frequency is set to 15-30Hz, and the reaction time is 3-4h.

[0024] In a specific implementation, the ultrasonic operation is as follows: in an inert gas environment, the mixture is added to an ampoule, the system is degassed and deoxygenated through a double-row tube, and then immersed in an ultrasonic bath (30-35℃, 40-50kHz, 100-110W) for 7-8 hours.

[0025] Furthermore, the reaction also includes a step of dissolving the product in an organic solvent and then extracting it after the reaction is complete.

[0026] In a specific embodiment, after the reaction is completed, the product is dissolved in an organic solvent, the supernatant is centrifuged and extracted with ethyl acetate / water to separate the lower aqueous phase, and the upper organic phase is subjected to a rotary evaporator to remove excess solvent. The dehalogenated alkanes of the organic halides are obtained by column chromatography.

[0027] Furthermore, the organic solvent is selected from one or more of N,N-dimethylformamide (DMF), N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylaniline and 1,4-dioxane.

[0028] The beneficial effects of this invention are:

[0029] This invention utilizes an inexpensive and recyclable mechanical redox catalyst to successfully treat organohalides under mechanical force. It avoids the use of environmentally polluting solvents and allows for reactions with little or no solvent, ensuring rapid treatment of organohalides while maintaining relatively high monomer conversion rates. This mechanical redox dehalogenation method is applicable to both alkyl halides and relatively stable aryl halides, demonstrating broad application prospects. Attached Figure Description

[0030] Figure 1 This is a scanning electron microscope image of mesoporous zinc oxide nanoparticles.

[0031] Figure 2 This is a transmission electron microscope (TEM) image of mesoporous zinc oxide nanoparticles.

[0032] Figure 3 This is an energy dispersive spectra of mesoporous zinc oxide nanoparticles.

[0033] Figure 4 The image shows the X-ray diffraction pattern of mesoporous zinc oxide nanoparticles.

[0034] Figure 5 The diagrams show the specific surface area and porosity of mesoporous zinc oxide nanoparticles; where (a) is the specific surface area diagram and (b) is the porosity analysis diagram.

[0035] Figure 6 The reaction kinetics curve of benzyl bromoacetate in Example 1 is shown.

[0036] Figure 7 The benzyl acetate separated after the reaction of benzyl bromoacetate in Example 1. 1 H-NMR spectrum.

[0037] Figure 8 The benzyl acetate separated after the reaction of benzyl bromoacetate in Example 1. 13 C-NMR spectrum.

[0038] Figure 9 This is a reaction kinetic curve of methyl bromobenzoate in Example 2.

[0039] Figure 10 The methyl benzoate separated after the reaction of methyl bromobenzoate in Example 2 1 H-NMR spectrum.

[0040] Figure 11 The methyl benzoate separated after the reaction of methyl bromobenzoate in Example 2 13 C-NMR spectrum.

[0041] Figure 12 The image shows a transmission electron microscope comparison of the m-ZnO recovered after the reaction in Example 3 and the m-ZnO before the reaction.

[0042] Figure 13 The image shows a comparison of X-ray diffraction patterns of the m-ZnO recovered after the reaction in Example 3 and the m-ZnO before the reaction.

[0043] Figure 14 The diagram shows the specific surface area and porosity of the m-ZnO recovered after the reaction in Example 3. Detailed Implementation

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0046] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available.

[0047] In the following examples, mesoporous zinc oxide nanoparticles (m-ZnO) were synthesized using a hydrothermal method, specifically prepared by the following method:

[0048] At room temperature, 0.025 mol Zn(CH3COO)·2H2O and 0.5 mol CO(NH2)2 were dissolved in 150 mL of deionized water to obtain a mixed solution. A template agent, polyoxyethylene-polyoxypropylene ether triblock copolymer (F-127), was added to the mixed solution, and the mixture was stirred continuously to obtain a transparent solution. After stirring for another 2 hours, the transparent solution was transferred to a sealed stainless steel high-pressure reactor lined with polytetrafluoroethylene and hydrothermally treated at 90 °C for 24 hours. After the reaction was completed, the mixture was naturally cooled to room temperature, and the resulting product was washed several times with deionized water until neutral, and then dried overnight in ambient air at 80 °C. Finally, the template agent was removed by calcination in static air at 400 °C for 2 hours to obtain mesoporous zinc oxide nanoparticles.

[0049] Figure 1 This is a scanning electron microscope image of mesoporous zinc oxide nanoparticles.

[0050] Figure 2This is a transmission electron microscope (TEM) image of mesoporous zinc oxide nanoparticles.

[0051] Figure 3 This is an energy dispersive spectra of mesoporous zinc oxide nanoparticles.

[0052] Figure 4 The image shows the X-ray diffraction pattern of mesoporous zinc oxide nanoparticles.

[0053] Figure 5 The diagrams show the specific surface area and porosity of mesoporous zinc oxide nanoparticles; where (a) is the specific surface area diagram and (b) is the porosity analysis diagram.

[0054] Example 1

[0055] A mechanical redox dehalogenation method for alkyl halides includes the following steps:

[0056] In a glove box, 0.4 mmol of alkyl halide RX, m-ZnO (15 wt%), and 0.8 mmol of TTMSS were mixed to obtain a mixture. This mixture was then added to a 1.5 mL stainless steel ball mill jar, along with a 5 mm diameter stainless steel grinding bead. The jar was then tightened in the glove box. The tightened jar was placed on a ball mill, and the reaction frequency was set to 30 Hz for 3 h. After the reaction, the jar was opened, and the product was dissolved using 1 mL of DMF. The product was transferred from the jar to a centrifuge tube, centrifuged, and the supernatant was extracted with ethyl acetate / water. The lower aqueous phase was separated, and the upper organic phase was subjected to rotary evaporation to remove excess solvent. The resulting organic phase was then subjected to column chromatography to obtain the corresponding alkane RH.

[0057] The reaction equation for the mechanical redox dehalogenation of alkyl halides in Example 1 is as follows:

[0058]

[0059] The conversion rates were calculated using NMR spectroscopy. Table 1 shows the alkyl halides, corresponding alkanes, and conversion rates of a to h in Example 1.

[0060] Table 1

[0061]

[0062]

[0063] Figure 6 The reaction kinetics curve of benzyl bromoacetate in Example 1 is shown.

[0064] Figure 7 The benzyl acetate separated after the reaction of benzyl bromoacetate in Example 1. 1 H-NMR spectrum.

[0065] Figure 8 The benzyl acetate separated after the reaction of benzyl bromoacetate in Example 1. 13 C-NMR spectrum.

[0066] The data from Example 1 show that alkyl halides have high reactivity and can be efficiently dehalogenated in a short time without the addition of inorganic salts.

[0067] Example 2

[0068] A mechanical redox dehalogenation method for aryl bromides includes the following steps:

[0069] In a glove box, 0.4 mmol of aryl bromide Ar-Br, m-ZnO (5 wt%), 0.8 mmol of TTMSS, and 0.4 mmol of sodium bromide were mixed to obtain a mixture. This mixture was then added to a 1.5 mL stainless steel ball mill jar, along with a 5 mm diameter stainless steel grinding bead. The jar was then tightened in the glove box. The tightened jar was placed on a ball mill, and the reaction frequency was set to 30 Hz for 4 h. After the reaction, the jar was opened, and the product was dissolved in 1 mL of NMP. The product was transferred from the jar to a centrifuge tube, centrifuged, and the supernatant was extracted with ethyl acetate / water. The lower aqueous phase was separated, and the upper organic phase was subjected to rotary evaporation to remove excess solvent. The resulting organic phase was then subjected to column chromatography to obtain the corresponding alkane Ar-H.

[0070] The reaction equation for the mechanical redox dehalogenation of aryl bromides in Example 2 is as follows:

[0071]

[0072] The aryl bromides, corresponding alkanes, and conversion rates of a to h in Example 2 are shown in Table 2:

[0073] Table 2

[0074]

[0075] Figure 9 This is a reaction kinetic curve of methyl bromobenzoate in Example 2.

[0076] Figure 10 The methyl benzoate separated after the reaction of methyl bromobenzoate in Example 2 1 H-NMR spectrum.

[0077] Figure 11 The methyl benzoate separated after the reaction of methyl bromobenzoate in Example 2 13 C-NMR spectrum.

[0078] Data from Example 2 show that aryl halides also exhibit high reactivity under conditions of added inorganic salts, enabling efficient dehalogenation in a short time.

[0079] Example 3

[0080] A mechanical redox dehalogenation method for methyl p-bromobenzoate includes the following steps:

[0081] In a glove box, 0.4 mmol of methyl p-bromobenzoate, m-ZnO (5 wt%), 0.8 mmol of TTMSS, and 0.4 mmol of sodium bromide were mixed to obtain a mixture. This mixture was then added to a 1.5 mL stainless steel ball mill jar, along with a 5 mm diameter stainless steel grinding bead. The jar was then tightened in the glove box. The tightened jar was placed on a ball mill, and the reaction frequency was set to 30 Hz for 4 h. After the reaction was complete, the jar was opened, and the product was dissolved using 1 mL of DMF. The product was transferred from the jar to a centrifuge tube, centrifuged, and the supernatant was extracted with ethyl acetate / water. The lower aqueous phase was separated, and the upper organic phase was subjected to rotary evaporation to remove excess solvent. Methyl benzoate was obtained by column chromatography.

[0082] The precipitate after centrifugation is washed with water multiple times to recover m-ZnO, which can be reused after drying.

[0083] Figure 12 The image shows a transmission electron microscope comparison of the m-ZnO recovered after the reaction in Example 3 and the m-ZnO before the reaction.

[0084] Figure 13 The image shows a comparison of X-ray diffraction patterns of the m-ZnO recovered after the reaction in Example 3 and the m-ZnO before the reaction.

[0085] Figure 14 The diagram shows the specific surface area and porosity of the m-ZnO recovered after the reaction in Example 3.

[0086] Test results showed that the specific surface area (BET) of m-ZnO before and after the reaction did not differ significantly, and even increased slightly, while the pore size remained within the mesoporous range. Morphology analysis also revealed that the morphology of m-ZnO was destroyed during ball milling, but its performance was not significantly affected. This further demonstrates that the recycled m-ZnO can achieve a high conversion rate in the cyclic experiment, thus realizing the recyclability of the catalyst.

[0087] Example 4

[0088] A mechanical redox dehalogenation method for methyl p-bromobenzoate is basically the same as that in Example 3, except that sodium bromide is not added.

[0089] Example 5

[0090] A mechanical redox dehalogenation method for methyl p-bromobenzoate is basically the same as that in Example 3, except that sodium bromide is replaced with potassium bromide.

[0091] Example 6

[0092] A mechanical redox dehalogenation method for methyl p-bromobenzoate is basically the same as that in Example 3, except that sodium bromide is replaced with lithium bromide.

[0093] The inorganic salts added in Examples 3-6 and their conversion rates are shown in Table 3:

[0094] Table 3

[0095] 3 Sodium bromide 31％ 4 No additions <10％ 5 Potassium bromide 22％ 6 lithium bromide <10％

[0096] Examples 3-6 show that methyl bromobenzoate has different reactivity under different inorganic salt conditions. Through screening of inorganic salts, sodium bromide was found to be the optimal choice for efficient dehalogenation in a short time.

[0097] Example 7

[0098] A mechanical redox dehalogenation method for (2-bromoethyl)benzene includes the following steps:

[0099] In a glove box, 0.4 mmol of (2-bromoethyl)benzene, m-ZnO (15 wt%), and 0.8 mmol of TTMSS were mixed to obtain a mixture. This mixture was then added to a 1.5 mL stainless steel ball mill jar, along with a 5 mm diameter stainless steel grinding bead. The jar was then tightened in the glove box. The tightened jar was placed on a ball mill, and the reaction frequency was set to 30 Hz for 3 h. After the reaction was complete, the jar was opened, and the product was dissolved using 1 mL of DMF. The product was transferred from the jar to a centrifuge tube, centrifuged, and the supernatant was extracted with ethyl acetate / water. The lower aqueous phase was separated, and the upper organic phase was subjected to rotary evaporation to remove excess solvent. Ethylbenzene was obtained by column chromatography.

[0100] Comparative Example 1

[0101] A mechanical redox dehalogenation method for (2-bromoethyl)benzene is basically the same as that in Example 7, except that TTMSS is replaced with dimethylchlorosilane.

[0102] Comparative Example 2

[0103] A mechanical redox dehalogenation method for (2-bromoethyl)benzene is basically the same as that in Example 7, except that TTMSS is replaced with triethylsilane.

[0104] Comparative Example 3

[0105] A mechanical redox dehalogenation method for (2-bromoethyl)benzene is basically the same as that in Example 7, except that TTMSS is replaced with 1,1,1,3,5,5,5-heptamethyltrisiloxane.

[0106] Comparative Example 4

[0107] A mechanical redox dehalogenation method for (2-bromoethyl)benzene is basically the same as that in Example 7, except that TTMSS is replaced with triphenylsilane.

[0108] The silane reactants and conversion rates of Examples 7 and Comparative Examples 1-4 are shown in Table 4:

[0109] Table 4

[0110]

[0111] The data in Table 4 show that the reactivity of bromoethylbenzene is greatly affected by the addition of different silanes. Through screening of silane types, tris(trimethylsilyl)silane was found to be the optimal choice for efficient dehalogenation in a short time.

[0112] Example 8

[0113] A mechanical redox dehalogenation method for 2-bromo-2-acetylnaphthalene includes the following steps:

[0114] In a glove box, 0.4 mmol of 2-bromo-2-acetylnaphthalene, m-ZnO (15 wt%), and 0.8 mmol of TTMSS were mixed to obtain a mixture. This mixture was then added to a 1.5 mL stainless steel ball mill jar, along with a 5 mm diameter stainless steel grinding bead. The jar was then tightened in the glove box. The tightened jar was placed on a ball mill, and the reaction frequency was set to 30 Hz for 3 h. After the reaction was complete, the jar was opened, and the product was dissolved using 1 mL of DMF. The product was transferred from the jar to a centrifuge tube, centrifuged, and the supernatant was extracted with ethyl acetate / water. The lower aqueous phase was separated, and the upper organic phase was subjected to rotary evaporation to remove excess solvent. 2-acetylnaphthalene was obtained by column chromatography.

[0115] Example 9

[0116] A mechanical redox dehalogenation method for 2-bromo-2-acetylnaphthalene is basically the same as that in Example 8, except that the reaction frequency of the ball mill is 15 Hz.

[0117] Example 10

[0118] A mechanical redox dehalogenation method for 2-bromo-2-acetylnaphthalene is basically the same as that in Example 8, except that the reaction frequency of the ball mill is 20 Hz.

[0119] Example 11

[0120] A mechanical redox dehalogenation method for 2-bromo-2-acetylnaphthalene is basically the same as that in Example 8, except that m-ZnO is replaced with zinc oxide nanoparticles.

[0121] Example 12

[0122] A mechanical redox dehalogenation method for 2-bromo-2-acetylnaphthalene is basically the same as that in Example 8, except that m-ZnO is replaced with titanium dioxide nanoparticles.

[0123] Comparative Example 5

[0124] A mechanical redox dehalogenation method for 2-bromo-2-acetylnaphthalene is basically the same as that in Example 8, except that the reaction frequency of the ball mill is 0 Hz.

[0125] Comparative Example 6

[0126] A mechanical redox dehalogenation method for 2-bromo-2-acetylnaphthalene is basically the same as that in Example 8, except that m-ZnO is not added.

[0127] The mechanical redox catalysts, reaction frequencies, and conversion rates of Examples 8-12 and Comparative Examples 5-6 are shown in Table 5.

[0128] Table 5

[0129]

[0130] The data in Table 5 show that the addition of different mechanical redox catalysts and different reaction frequencies have a great influence on the reactivity of 2-bromo-2-acetylnaphthalene. Through screening of mechanical redox catalyst types and mechanical frequencies, it was found that m-ZnO as a mechanical redox catalyst and a mechanical frequency of 30Hz are the optimal choices for efficient dehalogenation in a short time.

[0131] Example 13

[0132] A mechanical redox dehalogenation method for alkyl bromides includes the following steps:

[0133] In a glove box, 0.4 mmol of alkyl bromide R-Br, m-ZnO (15 wt%), and 0.8 mmol of TTMSS were mixed to obtain a mixture. The mixture was added to an ampoule, and the system was degassed and deoxygenated using a double-row tube. The mixture was then immersed in an ultrasonic bath (33 °C, 40 kHz, 110 W) for 8 h. After the reaction was complete, the product was dissolved in 1 mL of DMF. The product was transferred from the ampoule to a centrifuge tube, centrifuged, and the supernatant was extracted with ethyl acetate / water. The lower aqueous phase was separated, and the upper organic phase was subjected to rotary evaporation to remove excess solvent. The corresponding alkane RH was obtained by column chromatography.

[0134] The alkyl bromides, corresponding alkanes, and conversion rates of 1–14 in Example 11 are shown in Table 6.

[0135] Table 6

[0136]

[0137]

[0138] Example 12

[0139] A mechanical redox dehalogenation method for aryl bromides includes the following steps:

[0140] In a glove box, 0.4 mmol of aryl bromide Ar-Br, m-ZnO (5 wt%), 0.8 mmol of TTMSS, and 0.4 mmol of sodium bromide were mixed to obtain a mixture. The mixture was added to an ampoule, and the system was degassed and deoxygenated using a double-row tube. The mixture was then immersed in an ultrasonic bath (33℃, 40 kHz, 110 W) for 8 h. After the reaction was complete, the product was dissolved in 1 mL of DMF. The product was transferred from the ampoule to a centrifuge tube, centrifuged, and the supernatant was extracted with ethyl acetate / water. The lower aqueous phase was separated, and the upper organic phase was subjected to rotary evaporation to remove excess solvent. The corresponding alkane Ar-H was obtained by column chromatography.

[0141] The aryl bromides, corresponding alkanes, and conversion rates of 1–10 in Example 12 are shown in Table 7.

[0142] Table 7

[0143]

[0144] The data in Tables 6 and 7 show that different mechanical redox methods have a significant impact on the reactivity of organohalides. Under liquid-phase mechanochemical conditions, organohalides can also be effectively dehalogenated, but compared to solid-phase mechanochemical conditions, more solvent and a longer reaction time are required.

[0145] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art should understand that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A mechanical redox dehalogenation method for organohalides, characterized in that, Includes the following steps: In an inert gas environment, an organohalide, a mechanical redox catalyst, and tris(trimethylsilyl)silane are mixed to obtain a mixture. Mechanical stress is applied to the mixture to cause the organohalide to undergo a mechanical redox dehalogenation reaction to obtain the corresponding product. The organic halide is an alkyl halide or an aryl halide; the mechanical redox catalyst is zinc oxide nanoparticles; the mechanical stress is applied by ball milling or ultrasound. The alkyl halide is , , , , , , , , , , , , , , or X is a halogen; When the organic halide is an aryl halide, an inorganic salt is added to the mixture, wherein the inorganic salt is sodium bromide or potassium bromide.

2. The mechanical redox dehalogenation method for organohalides according to claim 1, characterized in that, The structural formula of the aryl halide is as follows: R1 is selected from one or more of cyano, ester, acyl, carboxyl, nitro, alkyl, phenyl, amide, acyloxy, amino, hydroxyl and alkoxy, and X is a halogen.

3. The mechanical redox dehalogenation method for organohalides according to claim 1, characterized in that, The molar ratio of the aryl halide, tris(trimethylsilyl)silane, and inorganic salt is 1:2:(1~2).

4. The mechanical redox dehalogenation method for organohalides according to claim 1, characterized in that, The mass fraction of the mechanical redox catalyst in the mixture is 5% to 15%.

5. The mechanical redox dehalogenation method for organohalides according to claim 1, characterized in that, The reaction also includes steps of dissolving the product in an organic solvent and extracting it after the reaction is complete.

6. The mechanical redox dehalogenation method for organohalides according to claim 5, characterized in that, The organic solvent is selected from one or more of N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylaniline, and 1,4-dioxane.

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