Method for catalyzing hydrodehalogenation of halogenated hydrocarbon by using bidentate nitrogen ligand palladium complex

Abstract

The invention belongs to the technical field of catalysis, and relates to a method for catalyzing hydrodehalogenation of halogenated hydrocarbon by using a bidentate nitrogen ligand palladium complex. The method comprises the following steps: dissolving halogenated hydrocarbon in an organic solvent in a hydrogen atmosphere in the presence of a bidentate nitrogen ligand palladium complex, and efficiently catalyzing the halogenated hydrocarbon for hydrodehalogenation at a certain temperature to obtain a dehalogenation product. The method disclosed by the invention has a very wide application range, can be applied to most common halides and mixtures thereof, and is a green, safe and practical synthesis method and environmental pollutant treatment method for efficiently reducing the halides.

Description

Technical Field

[0001] The invention belongs to the field of organic synthesis and relates to a method for catalyzing the hydrogenation and dehalogenation of halogenated hydrocarbons by a bidentate nitrogen ligand palladium complex. Background Art

[0002] As a common chemical and pharmaceutical intermediate material, halogenated hydrocarbons have been used more and more widely in recent years. They are present in large quantities in industrial wastewater and waste materials. Most of them are easily volatile in the air and are highly irritating to the human eyes, skin, respiratory tract and other parts. They are also carcinogenic. Therefore, the treatment of halogenated hydrocarbons is extremely important, but they are not easy to remove in actual chemical production.

[0003] Hydrogenation and dehalogenation of halogenated hydrocarbons is a method for reusing halogenated hydrocarbons. Traditionally, halogenated hydrocarbons are reduced using a large amount of metal hydrides such as sodium hydride, sodium borohydride and lithium aluminum hydride catalysts. For example, Zhang et al. (CN1051984C[P].2000-05-03) used sodium hydride to reduce benzyl chloride at 80°C. The reaction conversion rate was high, but the reaction time was long and the amount of catalyst used was large. However, heterogeneous catalysts such as palladium-carbon generally require higher temperatures and pressures to effectively reduce halogenated hydrocarbons. For example, C. Fernandez-Ruiz et al. (Industrial & Engineering Chemistry Research 58 (2019) 20592-20600) used a bimetallic catalyst of zinc and palladium supported on activated carbon to reduce chloroform at 300°C, with a high conversion rate, but the reaction temperature required was high; Ji et al. (CN 100465140C[P]. 2009-03-04) used an encapsulated palladium chloride catalyst to reduce benzyl chloride at 0.1 MPa hydrogen and 60°C, with good conversion rate and selectivity, but a kettle reaction was required. Recently, metal complex catalysts are increasingly used. In 2014, Guillermo et al. (ChemSusChem Volume 8, Issue 3 February (2015) 495-503) used rhodium-nitrogen-heterocyclic carbene catalyst to reduce benzyl chloride at 120°C with triethylsilane as hydrogen source and 1,4-dioxane as solvent. The conversion rate and selectivity were very good, but the hydrogen source used was silane, which is relatively expensive and carries negative hydrogen, which has the ability to reduce itself. Based on this, the present invention is proposed, which newly proposes a method for dehalogenation and hydrogenation of halogenated hydrocarbons catalyzed by bidentate nitrogen ligand palladium complex. The method of the present invention has a very wide range of application and can be applied to most commonly used halides. It is a green, safe and practical synthesis method for efficiently reducing halides and a method for treating environmental pollutants. Summary of the invention

[0004] The purpose of the present invention is to solve the above technical problems and provide a method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex. The method is simple to operate, has mild reaction conditions, good substrate applicability, and has good yield and selectivity.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A method for hydrogenating and dehalogenating halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex, wherein the method comprises dissolving the halogenated hydrocarbon in an organic solvent in the presence of a bidentate nitrogen ligand palladium complex under a hydrogen atmosphere, and reacting at a certain temperature to obtain a dehalogenated compound. Preferably, the presence of the bidentate nitrogen ligand palladium complex means that: the palladium source and the bidentate nitrogen ligand are directly added to the reaction system respectively and the bidentate nitrogen ligand palladium complex is generated in the system; or the palladium source and the bidentate nitrogen ligand are first reacted to generate the bidentate nitrogen ligand palladium complex and then added to the reaction system.

[0007] Preferably, the reaction formula of the method is as shown in the following formula (I):

[0008]

[0009] In formula (I), X 1 is bromine, chlorine or iodine;

[0010] Ar is an aromatic group containing an aromatic ring, wherein the aromatic ring is a 5-13-membered aromatic ring containing or not containing a heteroatom, wherein the heteroatom is at least one of N, S, and O; more preferably, the aromatic group is selected from one of phenyl, benzyl, biphenyl, naphthyl, diphenyl ketone, pyridyl, pyrazinyl, carbazolyl, quinolyl, thienyl, furyl, and the like;

[0011] R 1 It is a substituent at any position on the aromatic ring of the aromatic group, the number of substituents is at least one, and the substituents include but are not limited to at least one of hydrogen, C1-C6 alkyl, C1-C6 alkoxy, cyano, amino, aldehyde, hydroxyl, nitro, and halogen groups, and the halogen group includes at least one of fluorine, chlorine, bromine, and iodine; more preferably, when the substituent on the aromatic ring is not hydrogen, the number of substituents is 1-3.

[0012] Preferably, the structure of the bidentate nitrogen ligand palladium complex used in the present invention is as shown in the following formula (II):

[0013]

[0014] In formula (II),

[0015] R1 is at least one of hydrogen and methyl,

[0016] R2 is at least one of hydrogen, bromine and phenyl,

[0017] R3 is at least one of hydrogen, bromine, hydroxyl, phenyl, and 4-bromophenyl.

[0018] R4 is at least one of hydrogen and oxygen.

[0019] Preferably, the bidentate nitrogen ligand of the bidentate nitrogen ligand palladium complex is selected from at least one of the following formulas:

[0020]

[0021] In the above method,

[0022] Preferably, the pressure range of hydrogen is 0.01-25 bar.

[0023] Preferably, the molar ratio of the halogenated hydrocarbon to the bidentate nitrogen ligand palladium complex is 1:(0.05-0.001); more preferably 1:0.005.

[0024] Preferably, when the palladium source and the bidentate nitrogen ligand are directly put into the reaction without coordination, the palladium source is preferably at least one of palladium dichloride and palladium acetate, and more preferably palladium dichloride. Preferably, the molar ratio of the palladium source to the bidentate nitrogen ligand phenanthroline compound is 1:2.5.

[0025] Preferably, the organic solvent is one of methanol, ethanol, isopropanol, N,N-dimethylformamide (DMF), acetonitrile or a mixed solvent of two or more in any proportion; more preferably methanol. Preferably, the mass ratio of the halogenated hydrocarbon to the organic solvent is 1:(1-50); more preferably 1:(8-12).

[0026] Preferably, the reaction may further include the addition of a base, preferably at least one of triethylamine, N,N-isopropylethylamine, and potassium tert-butoxide; more preferably N,N-isopropylethylamine. More preferably, the molar ratio of the base to the halogenated hydrocarbon is 1:(0.5:3); more preferably 1:2.

[0027] Preferably, the reaction temperature is 20-150°C; more preferably 25-140°C.

[0028] Preferably, the reaction time is not less than 1 h; more preferably 5-10 h.

[0029] Preferably, the synthesis method of the bidentate nitrogen ligand palladium complex is as follows: a palladium source and a bidentate nitrogen ligand phenanthroline compound are added to an alcohol, and the mixture is heated to reflux to obtain the bidentate nitrogen ligand palladium complex. The reaction formula is as follows:

[0030]

[0031] In formula (III),

[0032] R1 is at least one of hydrogen and methyl,

[0033] R2 is at least one of hydrogen, bromine and phenyl,

[0034] R3 is at least one of hydrogen, bromine, hydroxyl, phenyl, and 4-bromophenyl.

[0035] R4 is at least one of hydrogen and oxygen.

[0036] Preferably, the palladium source is at least one of palladium dichloride and palladium acetate, and more preferably palladium dichloride.

[0037] Preferably, the alcohol is at least one of methanol, ethanol and isopropanol, preferably anhydrous ethanol.

[0038] Preferably, the molar ratio of the palladium source to the bidentate nitrogen ligand phenanthroline compound is 1:2.5.

[0039] Preferably, the reaction time is 24 hours.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) The hydrodehalogenation system developed by the present invention has a wide range of substrate applicability and can efficiently achieve dehalogenation and hydrogenation of three halogens: chlorine, bromine, and iodine.

[0042] (2) The hydrodehalogenation system developed by the present invention has mild reaction conditions, sp 3 Halogenated hydrocarbons can be dehalogenated by hydrogenation under normal pressure, and no base is required for the dehalogenation reaction of benzyl chloride and benzyl bromide; 2 Halogenated hydrocarbons can be dehalogenated by hydrodehalogenation at relatively low hydrogen pressure.

[0043] (3) The hydrodehalogenation system developed by the present invention can catalyze the hydrodehalogenation of halogenated hydrocarbon mixtures and efficiently degrade environmental pollutants.

[0044] The method of the present invention has a very wide application range and can be applied to most commonly used halides and mixtures thereof. It is a green, safe and practical synthesis method for efficiently reducing halides and a method for treating environmental pollutants. DETAILED DESCRIPTION

[0045] In order to better clarify and understand the purpose, process scheme and advantages of the present invention, the technical scheme and implementation method of the present invention are further described clearly, completely and in detail through specific examples. It should be noted that the embodiments described in the present invention are implemented on the premise of the technical scheme of the present invention, and detailed implementation methods and specific operation processes are given, but they are only part of the embodiments of the present invention, not all of the embodiments. The specific implementation methods described are limited to explaining and interpreting the present invention, and do not limit the present invention. Based on the embodiments in the present invention, all other implementation methods obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0046] The experimental methods and conditions used in the embodiments of the present invention are conventional methods and conventional conditions unless otherwise specified. The materials, reagents or instruments used in the embodiments, unless otherwise specified, can be obtained from commercial sources or prepared by conventional methods. The reaction conditions embodied in the content of the invention of the present invention can achieve the reaction and obtain the product of the expected effect. Due to space limitations, some embodiments are listed below to further illustrate the advantages of the technical solution of the present invention.

[0047] Example 1

[0048]

[0049] Benzyl chloride (300 mg) was added to a two-necked bottle equipped with a stirrer, and bidentate nitrogen ligand palladium complex catalyst (5 mg), dodecane (70 mg) as an internal standard, and solvent (5 mL) were added. After the addition, the reaction system was replaced with a hydrogen atmosphere (hydrogen balloon), and the reaction was heated at 25° C. for a certain period of time. After the reaction was completed, a sample was taken for detection by GC. The specific reaction conditions and yields are shown in Table 1.

[0050] Table 1. Reaction and yield under different conditions

[0051]

[0052]

[0053] Note: a is the gas phase internal standard yield, b The palladium source and the ligand are directly put into the reaction without coordination, and the molar ratio of the palladium source and the ligand is 1:2.5. The reaction pressure is 0.01-0.03 bar (hydrogen balloon), 300 mg of benzyl chloride, 5 mg of catalyst, 5 mL of solvent, the reaction temperature is 25°C, and the molar ratio of halogenated hydrocarbon: catalyst = 1:0.005.

[0054] The ligand structure is shown below:

[0055]

[0056]

[0057] Benzyl chloride obtained 1 H NMR data characterize as follows: 1 HNMR (400MHz, Chloroform-d)δ

[0058] 7.24-7.13 (m, 5H), 2.34 (s, 3H).

[0059] Example 2

[0060]

[0061] Benzyl bromide (171 mg) was added to a two-necked flask equipped with a stirrer, and palladium complex Pd-2 (5 mg) and ethanol (3 mL) were added. After the addition of the materials, the reaction system was replaced with a hydrogen atmosphere (hydrogen balloon), and the reaction was stirred at 25° C. for 2 h. After the reaction was completed, a sample was taken for GC detection, and the gas phase yield was 99%.

[0062] The product obtained 1 H NMR data characterize as follows: 1 HNMR(400MHz,Chloroform-d)δ7.24-7.13(m,5H),2.34(s,3H).

[0063] Example 3

[0064]

[0065] 4-Cyanobenzyl bromide (196 mg) was added to a two-necked flask equipped with a stirrer, and palladium complex Pd-2 (5 mg), N,N-diisopropylethylamine (258 mg), and ethanol (3 mL) were added. After the addition of the materials, the reaction system was replaced with a hydrogen atmosphere (hydrogen balloon), and the reaction was stirred at 25°C for 6 hours. After the reaction was completed, a sample was taken for detection by GC, and the gas phase yield was 99%.

[0066] The product obtained 1 H NMR data characterize as follows: 1 H NMR (400MHz, Chloroform-d) δ7.52 (d, J = 8.2 Hz, 2H), 7.26 (d, J = 8.2 Hz, 2H), 2.41 (s, 3H).

[0067] Example 4

[0068]

[0069] 2,3-Difluorobenzyl chloride (162 mg) was added to a two-necked bottle equipped with a stirrer, and palladium complex Pd-2 (5 mg), N,N-diisopropylethylamine (258 mg), and ethanol (3 mL) were added. After the addition of the materials, the reaction system was replaced with a hydrogen atmosphere (hydrogen balloon), and the reaction was stirred at 50° C. for 10 hours. After the reaction was completed, a sample was taken for detection by GC, and the gas phase yield was 67%.

[0070] The product obtained 1 H NMR data characterize as follows: 1 H NMR (400MHz, Chloroform-d) δ7.2-6.91 (m, 3H), 2.31 (s, 3H).

[0071] Example 5

[0072]

[0073] Add p-nitrobenzyl bromide (216 mg) to a two-necked bottle equipped with a stirrer, and add palladium complex Pd-2 (5 mg), N,N-diisopropylethylamine (258 mg), and ethanol (3 mL). After adding the materials, replace the reaction system with a hydrogen atmosphere (hydrogen balloon), and stir the reaction at 70°C for 10 hours. After the reaction is completed, take a sample and detect it with GC, and the gas phase yield is 29%.

[0074] The product obtained 1 H NMR data characterize as follows: 1 H NMR (400MHz, Chloroform-d) δ8.12(d,J=6.8Hz,1H),7.32(d,J=6.8Hz,1H),7.17(d,J=5.7Hz,2H),2.35(s,3H).

[0075] Example 6

[0076]

[0077] Add p-methylbenzyl chloride (140 mg) to a two-necked bottle equipped with a stirrer, and add palladium complex Pd-2 (5 mg), N,N-diisopropylethylamine (258 mg), and ethanol (3 mL). After adding the materials, replace the reaction system with a hydrogen atmosphere (hydrogen balloon), and stir the reaction at 25°C for 4 hours. After the reaction is completed, take a sample and detect it with GC, and the gas phase yield is 99%.

[0078] The product obtained 1 The HNMR data are characterized as follows: 1 H NMR(400MHz,Chloroform-d)δ7.12(m,4H)2.36(s,6H).

[0079] Example 7

[0080]

[0081] 3-Methylbenzyl chloride (140 mg) was added to a two-necked bottle equipped with a stirrer, and palladium complex Pd-2 (5 mg), N, N-diisopropylethylamine (258 mg), and ethanol (3 mL) were added. After the addition of the materials, the reaction system was replaced with a hydrogen atmosphere (hydrogen balloon), and the reaction was stirred at 25°C for 4 hours. After the reaction was completed, a sample was taken for detection by GC, and the gas phase yield was 99%.

[0082] The product obtained 1 The H NMR data are characterized as follows: 1 H NMR(400MHz,Chloroform-d)δ6.76–6.99(m,4H),2.23(s,6H).

[0083] Example 8

[0084]

[0085] Add tert-butylbenzyl bromide (227 mg) to a two-necked bottle equipped with a stirrer, and add palladium complex Pd-2 (5 mg), N,N-diisopropylethylamine (258 mg), and ethanol (3 mL). After adding the materials, replace the reaction system with a hydrogen atmosphere (hydrogen balloon), and stir the reaction at 25°C for 6 hours. After the reaction is completed, take a sample and detect it with GC, and the gas phase yield is 99%.

[0086] The product obtained 1 The H NMR data are characterized as follows: 1 H NMR(400MHz,Chloroform-d)δ7.34(d,J=8.2Hz,2H),7.27(d,J=7.9Hz,2H),2.47(s,3H),1.47(s,9H).'

[0087] Example 9

[0088]

[0089] Add o-methylbenzyl chloride (140 mg) to a two-necked bottle equipped with a stirrer, and add palladium complex Pd-2 (5 mg), N,N-diisopropylethylamine (258 mg), and ethanol (3 mL). After adding the materials, replace the reaction system with a hydrogen atmosphere (hydrogen balloon), and stir the reaction at 25°C for 4 hours. After the reaction is completed, take a sample and detect it with GC, and the gas phase yield is 99%.

[0090] The product obtained 1 The H NMR data are characterized as follows: 1H NMR(400MHz,Chloroform-d)δ7.13-7.07(m,4H),2.25(s,6H).

[0091] Example 10

[0092]

[0093] 4-Chlorotoluene (127 mg) was added to a 5 mL bottle equipped with a stirrer, and palladium complex Pd-5 (5 mg), N, N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL) were added. The 5 mL bottle was placed in a 100 mL autoclave, and the autoclave was tightened to replace hydrogen 5 times, and the pressure was adjusted to 2.0 MPa, and heated at 120 ° C for 6 h. After the reaction was completed, ice water bath was placed for 2 h, and samples were taken for GC detection. The gas phase yield was 99%.

[0094] The product obtained 1 The H NMR data are characterized as follows: 1 HNMR(400MHz,Chloroform-d)δ7.24-7.13(m,5H),2.34(s,3H).

[0095] Embodiment 11

[0096]

[0097] 4-Chloroaniline (128 mg) was added to a 5 mL bottle equipped with a stirrer, and palladium complex Pd-2 (5 mg), N, N-diisopropylethylamine (194 mg), and solvent ethanol (3 mL) were added. The 5 mL bottle was placed in a 100 mL autoclave, and the autoclave was tightened to replace hydrogen 5 times, and the pressure was adjusted to 2.0 MPa, and heated at 120 ° C for 8 h. After the reaction was completed, ice water bath was placed for 2 h, and samples were taken for GC detection. The gas phase yield was 96%.

[0098] The product obtained 1 The HNMR data are characterized as follows: 1 HNMR(400MHz,Chloroform-d)δ7.20(t,J=12.0Hz,2H),6.80(t,J=12.0Hz,1H),6.72(d,J=12.0Hz,2H),3.64(s,2H).

[0099] Example 12

[0100]

[0101] 4-Chlorobenzaldehyde (143 mg) was added to a 5 mL bottle equipped with a stirrer, and palladium complex Pd-2 (5 mg), N, N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL) were added. The 5 mL bottle was placed in a 100 mL autoclave, and the autoclave was tightened to replace hydrogen 5 times, and the pressure was adjusted to 2.2 MPa, and heated at 140 ° C for 8 h. After the reaction was completed, ice water bath was placed for 2 h, and samples were taken for GC detection. The gas phase yield was 80%.

[0102] The product obtained 1 H NMR data characterize as follows: 1 H NMR (400MHz, Chloroform-d) δ10.02(s,1H),7.88(m,J=8.0Hz,2H),7.63(m,J=8.0Hz,1H),7.51(m,J=8.0Hz,2H).

[0103] Example 13

[0104]

[0105] 3-Bromopyridine (158 mg) was added to a 5 mL bottle equipped with a stirrer, and palladium complex Pd-2 (5 mg), N, N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL) were added. The 5 mL bottle was placed in a 100 mL autoclave, and the autoclave was tightened to replace hydrogen 5 times, and the pressure was adjusted to 2.2 MPa, and heated at 140 ° C for 8 h. After the reaction was completed, ice water bath was placed for 2 h, and samples were taken for GC detection. The gas phase yield was 99%.

[0106] The product obtained 1 H NMR data characterize as follows: 1 H NMR (400MHz, Chloroform-d) δ8.61(m,2H),7.67(tt,J=7.5,J=1.0Hz,1H),7.27(m,2H).

[0107] Embodiment 14

[0108]

[0109] 4-Bromophenol (173 mg) was added to a 5 mL bottle equipped with a stirrer, and palladium complex Pd-2 (5 mg), N, N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL) were added. The 5 mL bottle was placed in a 100 mL autoclave, and the autoclave was tightened to replace hydrogen 5 times, and the pressure was adjusted to 2.2 MPa, and heated at 140 ° C for 8 h. After the reaction was completed, ice water bath was placed for 2 h, and samples were taken for LC detection. The liquid phase yield was 96%.

[0110] The product obtained1 The H NMR data are characterized as follows: 1 H NMR (400MHz, Chloroform-d) δ7.26 (t, J = 5.2 Hz, 2H), 6.94 (t, J = 6.0 Hz, 2H), 6.85 (d, J = 5.3 Hz, 2H).

[0111] Embodiment 15

[0112]

[0113] 1-Bromocarbazole (246 mg) was added to a 5 mL bottle equipped with a stirrer, and palladium complex Pd-2 (5 mg), N, N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL) were added. The 5 mL bottle was placed in a 100 mL autoclave, and the autoclave was tightened to replace hydrogen 5 times, and the pressure was adjusted to 2.2 MPa, and heated at 140 ° C for 8 h. After the reaction was completed, ice water bath was added for 2 h, and samples were taken for LC detection. The liquid phase yield was 96%.

[0114] The product obtained 1 The H NMR data are characterized as follows: 1 HNMR(400MHz,Chloroform-d)δ8.07–8.09(m,2H),8.04(s,1H),7.39–7.44(m,4H),7.22–7.26(m,2H).

[0115] Example 16

[0116]

[0117] Add 3,4-dimethyl iodobenzene (232 mg) to a 5 mL bottle equipped with a stirrer, and add palladium complex Pd-2 (5 mg), N,N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL). Place the 5 mL bottle in a 100 mL autoclave, tighten the autoclave to replace hydrogen 5 times, adjust the pressure to 2.0 MPa, and heat at 120 ° C for 8 hours. After the reaction is completed, place in an ice water bath for 2 hours, and take samples for GC detection. The gas phase yield is 78%.

[0118] The product obtained 1 The H NMR data are characterized as follows: 1 H NMR(400MHz,Chloroform-d)δ7.13–7.07(m,4H),2.25(s,6H).

[0119] Embodiment 17

[0120]

[0121] Add 2-bromo-1,3,5-trimethylbenzene (199 mg) to a 5 mL bottle equipped with a stirrer, and add palladium complex Pd-2 (5 mg), N,N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL). Place the 5 mL bottle in a 100 mL autoclave, tighten the autoclave to replace hydrogen 5 times, adjust the pressure to 2.0 MPa, and heat at 120 ° C for 8 hours. After the reaction is completed, place in an ice water bath for 2 hours, and take samples for GC detection. The gas phase yield is 99%.

[0122] The product obtained 1 The H NMR data are characterized as follows: 1 H NMR(400MHz,Chloroform-d)δ6.90(s,3H),2.43(s,9H).

[0123] Embodiment 18

[0124]

[0125] Add 4-tert-butyl bromobenzene (213 mg) to a 5 mL bottle equipped with a stirrer, and add palladium complex Pd-2 (5 mg), potassium tert-butoxide (224 mg), and solvent ethanol (3 mL). Place the 5 mL bottle in a 100 mL autoclave, tighten the autoclave to replace hydrogen 5 times, adjust the pressure to 2.0 MPa, and heat at 140 ° C for 8 hours. After the reaction is completed, place in an ice water bath for 2 hours, and take samples for GC detection. The gas phase yield is 94%.

[0126] The product obtained 1 The H NMR data are characterized as follows: 1 H NMR (400MHz, Chloroform-d) δ7.39 (dt, J = 6.6, 1.3Hz, 2H), 7.34-7.28 (m, 2H), 7.20-7.14 (m, 1H), 1.33 (s, 9H).

[0127] Embodiment 19

[0128]

[0129] 4-Chloroanisole (143 mg) was added to a 5 mL bottle equipped with a stirrer, and palladium complex Pd-2 (5 mg), potassium tert-butoxide (224 mg), and solvent ethanol (3 mL) were added. The 5 mL bottle was placed in a 100 mL autoclave, and the autoclave was tightened to replace hydrogen 5 times, and the pressure was adjusted to 2.0 MPa, and heated at 140 ° C for 8 h. After the reaction was completed, ice water bath was added for 2 h, and samples were taken for GC detection. The gas phase yield was 54%.

[0130] The product obtained 1 The H NMR data are characterized as follows: 1H NMR (400MHz, Chloroform-d) δ7.30–7.25(m,2H),6.95–6.89(m,3H),3.79(s,3H).

[0131] Embodiment 20

[0132]

[0133] Add 6-iodoquinoline (255 mg) to a 5 mL bottle equipped with a stirrer, and add palladium complex Pd-8 (5 mg), N, N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL). Place the 5 mL bottle in a 100 mL autoclave, tighten the autoclave to replace hydrogen 5 times, adjust the pressure to 2.0 MPa, and heat at 120 ° C for 8 hours. After the reaction is completed, place in an ice water bath for 2 hours, and take a sample for LC detection. The liquid phase yield is 85%.

[0134] The product obtained 1 The H NMR data are characterized as follows: 1 H NMR(400MHz,Chloroform-d)δ8.93(q,1H),8.16(d,J=8.3Hz,1H),8.12(d,J=8 .6Hz,1H),7.82(d,J=8.1Hz,1H),7.72(m,1H),7.58-7.52(m,1H),7.40(q,1H).

[0135] Embodiment 21

[0136]

[0137] Add 6-bromoquinoline (208 mg) to a 5 mL bottle equipped with a stirrer, and add palladium complex Pd-8 (5 mg), N, N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL). Place the 5 mL bottle in a 100 mL autoclave, tighten the autoclave to replace hydrogen 5 times, adjust the pressure to 2.0 MPa, and heat at 120 ° C for 8 hours. After the reaction is completed, place in an ice water bath for 2 hours, and take a sample for LC detection. The liquid phase yield is 70%.

[0138] The product obtained 1 The H NMR data are characterized as follows: 1 H NMR(400MHz,Chloroform-d)δ8.94(q,1H),8.18(d,J=8.3Hz,1H),8.13(d,J=8 .6Hz,1H),7.82(d,J=8.1Hz,1H),7.71(m,1H),7.59-7.51(m,1H),7.42(q,1H).

[0139] Embodiment 22

[0140]

[0141] 5-Bromo-8-hydroxyquinoline (224 mg) was added to a 5 mL bottle equipped with a stirrer, and palladium complex Pd-8 (5 mg), N, N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL) were added. The 5 mL bottle was placed in a 100 mL autoclave, and the autoclave was tightened to replace hydrogen 5 times, and the pressure was adjusted to 2.0 MPa, and heated at 120 ° C for 8 h. After the reaction was completed, ice water bath was added for 2 h, and samples were taken for LC detection. The liquid phase yield was 98%.

[0142] The product obtained 1 The H NMR data are characterized as follows: 1 H NMR (400MHz, DMSO-d6) δ10.41 (s, 1H), 8.78 (d, J = 4.2Hz, 1H), 8.44 (d, J = 8.4Hz, 1H), 7.49 (t, J = 8.4Hz, 1H), 7.42-7.3 (m, 2H), 6.8 (d, J = 7.5Hz, 1H).

[0143] Embodiment 23

[0144]

[0145] Add 2-bromothiophene (163 mg) to a 5 mL bottle equipped with a stirrer, and add palladium complex Pd-8 (5 mg), N, N-diisopropylethylamine (258 mg), and solvent ethanol (3 mL). Place the 5 mL bottle in a 100 mL autoclave, tighten the autoclave to replace hydrogen 5 times, adjust the pressure to 2.0 MPa, and heat at 120 ° C for 8 hours. After the reaction is completed, place in an ice water bath for 2 hours, and take a sample for LC detection. The liquid phase yield is 99%.

[0146] The product obtained 1 The HNMR data are characterized as follows: 1 H NMR (400MHz, CD3OD) δ7.39(d,2H),7.09(d,2H).

[0147] Embodiment 24

[0148]

[0149] 4-Chlorotoluene (127 mg), benzyl chloride (127 mg), benzyl bromide (171 mg) were added to a 100 mL autoclave, and palladium complex Pd-2 (15 mg), N, N-diisopropylethylamine (774 mg), and solvent ethanol (10 mL) were added. The autoclave was tightened to replace hydrogen 5 times, the pressure was adjusted to 2.0 MPa, and heated at 120 ° C for 8 h. After the reaction was completed, ice water bath was added for 2 h, and samples were taken for GC detection. The gas phase yield was 99%.

[0150] The product obtained 1 The H NMR data are characterized as follows: 1 H NMR(400MHz,Chloroform-d)δ7.23-7.13(m,5H),2.34(s,3H).

[0151] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A method for the hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex, characterized in that: The method is to dissolve a halogenated hydrocarbon in an organic solvent in the presence of a bidentate nitrogen ligand palladium complex under a hydrogen atmosphere, and react at a certain temperature to obtain a dehalogenated compound; the reaction formula of the method is shown in the following formula (I): In formula (I), X 1 is bromine, chlorine or iodine; Ar is an aromatic group containing an aromatic ring, wherein the aromatic ring is a 5-membered to 13-membered aromatic ring containing or not containing a heteroatom, wherein the heteroatom is at least one of N, S, and O; R 1 It is a substituent at any position on the aromatic ring of the aromatic group, the number of substituents is at least one, and the substituent includes but is not limited to at least one of hydrogen, C1-C6 alkyl, C1-C6 alkoxy, cyano, amino, aldehyde, hydroxyl, nitro, and halogen groups, and the halogen group includes at least one of fluorine, chlorine, bromine, and iodine.

2. The method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex according to claim 1, characterized in that: The structural formula of the bidentate nitrogen ligand palladium complex is shown in the following formula (II): In formula (II), R1 is at least one of hydrogen and methyl, R2 is at least one of hydrogen, bromine, and phenyl, R3 is at least one of hydrogen, bromine, hydroxyl, phenyl, and 4-bromophenyl. R4 is at least one of hydrogen and oxygen.

3. The method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex according to claim 2, characterized in that: The bidentate nitrogen ligand of the palladium complex is selected from at least one of the following formulae:

4. The method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex according to claim 1, characterized in that: The existence of bidentate nitrogen ligand palladium complex means that: the palladium source and the bidentate nitrogen ligand are directly added to the reaction system and generate bidentate nitrogen ligand palladium complex in the system; or the palladium source and the bidentate nitrogen ligand react to generate bidentate nitrogen ligand palladium complex and then added to the reaction system.

5. The method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex according to claim 1, characterized in that: The aromatic group is selected from one of phenyl, benzyl, biphenyl, naphthyl, pyridyl, pyrazinyl, carbazolyl, quinolyl, thienyl and furyl.

6. The method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex according to claim 1, characterized in that: The pressure range of hydrogen is 0.01-25 bar.

7. The method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex according to claim 1, characterized in that: The molar ratio of the halogenated hydrocarbon to the bidentate nitrogen ligand palladium complex is 1:(0.05-0.001).

8. The method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex according to claim 1, characterized in that: The organic solvent is one of methanol, ethanol, isopropanol, N,N-dimethylformamide, acetonitrile or a mixed solvent of two or more in any proportion, and the mass ratio of the halogenated hydrocarbon to the organic solvent is 1:(1-50).

9. The method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex according to claim 1, characterized in that: The reaction further adds a base, which is at least one of triethylamine, N,N-isopropylethylamine and potassium tert-butoxide, and the molar ratio of the base to the halogenated hydrocarbon is 1:(0.5:3).

10. The method for hydrodehalogenation of halogenated hydrocarbons catalyzed by a bidentate nitrogen ligand palladium complex according to claim 1, characterized in that: The reaction temperature is 20-150° C., and the reaction time is not less than 1 hour.

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