Preparation method of an iridium dimer catalyst

Abstract

The present invention discloses a preparation method of an iridium dimer catalyst, and the iridium dimer catalyst is Ir2Cl2C 16 H 24 dimer, comprising: dissolving an iridium-containing and chlorine-containing compound in distilled water and injecting it into a raw material tube to obtain solution A; mixing cyclooctadiene and a reducing agent acid and injecting them into another raw material tube to obtain solution B; slowly injecting solutions A and B into a continuous reactor simultaneously for cyclic reaction. The method of the present invention abandons the conventionally used reactants (alcohols and aldehydes), uses a novel reactant (acid), and adopts a continuous flow reaction, which can shorten the reaction time and obtain high-purity Ir2Cl2C 16 H 24 dimer with a yield as high as 97%; and potassium permanganate is used to neutralize the mercury catalyst during the waste liquid treatment process to generate a mercury complex precipitate from the excess cyclooctadiene in the waste liquid, greatly reducing the environmental pollution of the waste liquid and facilitating batch industrialization. The present invention reduces the dosage of cyclooctadiene, reduces waste liquid treatment, and lowers the production cost.

Description

Technical Field

[0001] The present invention relates to a method for batch preparation of noble metal catalysts, a method for preparation of an iridium dimer catalyst, and specifically relates to a method for batch preparation of Ir2Cl2C 16 H 24 dimer, belonging to the field of chemical engineering and chemistry. Background Art

[0002] Ir2Cl2C 16 H 24 Dimer is a platinum group metal homogeneous catalytic complex, which has the advantages of a wide range of applicable substrates and high enantioselectivity. It is an important catalyst for alkylation reaction, oxidation reaction, hydrogenation reaction, cycloaddition reaction, and has been widely used in the synthesis of chemical drugs and fine chemical products. At the same time, it also serves as a catalyst precursor for various iridium complexes and has been widely used in industrial production. In the industrial production process of S-metolachlor, the catalyst for the key asymmetric hydrogenation reaction is exactly Ir2Cl2C 16 H 24 as the precursor.

[0003] Winkhaus and Singer et al. (Chemische Berichte, 1966, 99, 11) mixed NaIrCl6·6H2O, cyclooctadiene, distilled water, ethanol, etc. in a flask and refluxed for 8 - 12 h. The orange-yellow crystals after stopping the reaction had a yield of 45%.

[0004] Bezman et al. (Inorganic Chemistry, 1980, 19.12) added IrCl3·3H2O, hydroquinone, 1,5-cyclooctadiene, ethanol, distilled water, etc. to a round-bottom flask. Before the reaction, nitrogen was bubbled for 0.5 h, and then the mixture was stirred and refluxed for 6 h. After the reaction stopped, the solution in the flask was concentrated. Orange-yellow solid precipitated after cooling, filtered, and dried in vacuum to obtain the product with a yield of 59%.

[0005] Crabtree et al. (Organometallics, 1984, 3.5) used H2IrCl6 as the raw material, and the synthesis was carried out in two steps. In the first step, H2IrCl6, 1,5-cyclooctadiene, and isopropanol were used as the reaction solvent and refluxed for 6 h. After the reaction stopped, the solvent was evaporated at 60 °C, and then washed with n-hexane twice to obtain a white solid [IrH(COD)Cl2]2. In the second step, the obtained white solid was added to a saturated sodium acetate solution to remove the coordinated HCl, and finally recrystallized with dichloromethane / ethanol to obtain brick-red crystals. The yield was 90% - 95%, but the reaction process was complex, and the raw materials and reagents used in the reaction were expensive, and hydroquinone was highly toxic.

[0006] Cotton et al. (Inorganica Chimica Acta, 1986, 120, 2) mixed IrC13·3H2O, 1,5-cyclooctadiene (1,5-COD), isopropanol, and distilled water in a flask. It was heated to 65 - 70 °C in an argon atmosphere and reacted for 40 h. The resulting red crystals were filtered, washed with ice methanol, and dried, with a yield of 75%.

[0007] Choudhury and Walter et al. (Journal of the American Chemical Society, 2005, 127, 17 and Journal of the American Chemical Society, 1998, 120, 34) added IrCl3·3H2O, isopropanol, 1,5-cyclooctadiene, and distilled water to a round-bottom flask and refluxed the reaction for 18 h in an argon atmosphere. The reaction solution changed from brown to dark red. After the reaction stopped, the reaction solution was concentrated to 50% of its original volume. Brick-red crystals precipitated out after cooling, were filtered, and washed with cold methanol. After vacuum drying, the product was obtained with a yield of 81%.

[0008] US6399804B2 discloses a preparation method of [(COD)IrCl]2. The reaction process is that iridium trichloride or iridium tetrachloride is refluxed with an alcohol (with 3 - 9 carbon atoms) for 19 h. The reaction time is long, and when the number of carbon atoms of the alcohol is greater than 4 in this preparation method, it is difficult for the alcohol to be miscible with distilled water. Adding a large amount of alcohol (the volume ratio of alcohol to water is 2:1 - 1:1) is meaningless and brings post-treatment problems.

[0009] In the preparation method of [(COD)IrCl]2 disclosed in JP2006045089A, the molar amount of 1,5-cyclooctadiene used is 7 - 9 times that of IrCl3. The purity of the [(COD)IrCl]2 obtained is relatively low. In order to remove impurities 1,3-cyclooctadiene and 1,4-cyclooctadiene, a large amount of water is added at the end of the reaction, and then the product is precipitated. This method cannot obtain a high-purity product. Using a large amount of 1,5-cyclooctadiene causes subsequent environmental protection problems, and the use of a large amount of water brings great pressure to the treatment of wastewater.

[0010] Therefore, there is an urgent need to develop a batch preparation method of Ir2Cl2C 16 H 24 dimer with less usage of cyclooctadiene and solvent, short reaction time, high product purity and yield. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to overcome the above deficiencies and provide an Ir2Cl2C 16 H24 A method for preparing a dimer, which can overcome the disadvantages of high cost and difficult waste liquid treatment existing in the prior art, and at the same time has the advantages of environmental friendliness, simple waste liquid treatment, reduced sewage discharge, reduced cost, and being suitable for industrial batch production. The iridium dimer prepared by this method shows excellent catalytic effects in reaction processes such as the alkylation reaction of allyl derivatives, the hydrogenation reaction of carbon-carbon double bonds, carbon-oxygen double bonds, and carbon-nitrogen double bonds, the carbonylation reaction of β,γ-unsaturated esters, the oxidation reaction for synthesizing alcohols, ketones, acid anhydrides, and epoxides, and the cycloaddition reaction of α,ω-diyne.

[0012] The technical solution of the present invention is as follows:

[0013] A batch preparation method of an Ir2Cl2C 16 H 24 dimer, comprising the following steps:

[0014] Step (1), under an argon atmosphere, dissolve an iridium-containing and chlorine-containing compound in an appropriate amount of distilled water, inject it into a raw material tube, heat and circulate to mix evenly to obtain solution A;

[0015] Step (2), under an argon atmosphere, mix cyclooctadiene and a reducing agent acid evenly and inject them into another raw material tube, circulate at room temperature to mix evenly to obtain solution B;

[0016] Step (3), slowly inject the above solutions A and B into a continuous reaction flow reactor at the same time, heat and carry out a cyclic reaction. After the reaction is completed, cool to room temperature to obtain a monovalent iridium solution, remove most of the solvent, filter, wash the filter cake with ice methanol, and dry it under vacuum to obtain an Ir2Cl2C 16 H 24 dimer;

[0017] Step (4), transfer the filtrate to a sealed reaction bottle, add an appropriate amount of potassium permanganate and a mercury catalyst, generate a mercury complex precipitate from the cyclooctadiene in the waste liquid, and reduce the environmental pollution caused by cyclooctadiene. Filter, transfer the filtrate to a waste liquid recovery barrel for recycling into metallic iridium.

[0018] Its preparation route is as Figure 1 shown.

[0019] Furthermore, in step (1), the iridium-containing and chlorine-containing compound is selected from iridium tetrachloride hydrate, iridium trichloride hydrate, or chloroiridic acid.

[0020] Furthermore, in step (2), the acid is formic acid, acetic acid, propionic acid, or oxalic acid.

[0021] Furthermore, in step (3), the removal of most of the solvent means removing two-thirds of the solvent.

[0022] Further, in step (4), the cyclooctadiene in the waste liquid is in excess and is precipitated with a mercury catalyst complex to reduce environmental pollution.

[0023] Advantages of the present invention

[0024] The present invention uses a novel raw material acid to replace traditional alcohols and aldehydes, adopts a continuous reaction flow method, reduces the usage amount of solvents and cyclooctadiene, and simultaneously uses a mercury catalyst complex to precipitate cyclooctadiene in the waste liquid, reducing environmental pollution, lowering costs, and having few steps, being easy to operate, having a high yield, and being easy to realize industrial promotion. The iridium dimer prepared by the method of the present invention exhibits excellent catalytic effects in reaction processes such as the alkylation reaction of allyl derivatives, the hydrogenation reaction of carbon-carbon double bonds, carbon-oxygen double bonds, and carbon-nitrogen double bonds, the carbonylation reaction of β,γ-unsaturated esters, the oxidation reaction for synthesizing alcohols, ketones, acid anhydrides, and epoxides, and the cycloaddition reaction of α,ω-diyne. Description of the drawings

[0025] The drawings are used to provide a further understanding of the products of the invention and constitute a part of the specification. Together with the following specific implementation modes, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0026] Figure 1 : Schematic diagram of the preparation route of the preparation method of the present invention.

[0027] Figure 2 : 1H NMR spectrum of the Ir2Cl2C 16 H 24 dimer prepared by the present invention.

[0028] Figure 3 : 13C NMR spectrum of the Ir2Cl2C 16 H 24 dimer prepared by the present invention.

[0029] Figure 4 : Mass spectrum of the Ir2Cl2C 16 H 24 dimer prepared by the present invention.

[0030] Figure 5 : Infrared spectrum of the Ir2Cl2C 16 H 24 dimer prepared by the present invention. Specific implementation modes

[0031] The following provides a detailed description of specific implementation cases of the present invention. It should be understood that the specific implementation cases described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0032] The points and any values within the ranges disclosed in this document are not limited to the exact ranges or values. These ranges or values should be understood to include numerical values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this document.

[0033] Example 1:

[0034] Under argon protection, 500 g of iridium(III) chloride trihydrate and 1500 mL of distilled water were added to a raw material tube, heated to 80 °C, and stirred cyclically for 0.5 h to obtain Solution A; 460 mL of cyclooctadiene and 131 mL of formic acid were added to another raw material tube, and cyclically mixed evenly at room temperature to obtain Solution B; Solutions A and B were simultaneously and slowly injected into a continuous reactor for cyclic reaction. Each time the raw materials entered the continuous reactor, they stayed for 2 min, and the reaction temperature was 90 °C. The reaction was stopped, cooled to room temperature, most of the solvent was removed, filtered, and vacuum dried for 5 h to obtain 465.25 g of a brick-red solid, and the yield was 97.69%.

[0035] The above filtrate was transferred into a reaction kettle, and an appropriate amount of potassium permanganate and mercury catalyst were added and reacted for 3 h. Cooled to room temperature, filtered, and the filtrate was transferred to a waste barrel for recycling into metallic iridium.

[0036] Example 2:

[0037] Under argon protection, 2000 g of iridium(III) chloride trihydrate and 8000 mL of distilled water were added to a raw material tube, heated to 90 °C, and stirred cyclically for 1 h to obtain Solution A; 2453 mL of cyclooctadiene and 1025 mL of acetic acid were added to another raw material tube, and cyclically mixed evenly at room temperature to obtain Solution B; Solutions A and B were simultaneously and slowly injected into a continuous reactor for cyclic reaction. Each time the raw materials entered the continuous reactor, they stayed for 5 min, and the reaction temperature was 80 °C. The reaction was stopped, cooled to room temperature, most of the solvent was removed, filtered, and vacuum dried for 5 h to obtain 1863.5 g of a brick-red solid, and the yield was 97.82%.

[0038] The above filtrate was transferred into a reaction kettle, and an appropriate amount of potassium permanganate and mercury catalyst were added and reacted for 4 h. Cooled to room temperature, filtered, and the filtrate was transferred to a waste barrel for recycling into metallic iridium.

[0039] Example 3:

[0040] Under argon protection, 1894.8 g of iridium(IV) chloride hydrate and 8000 mL of distilled water were added to a raw material tube, heated to 90 °C, and stirred continuously for 1.5 h to obtain solution A; 2453 mL of cyclooctadiene and 1263 mL of propionic acid were added to another raw material tube, and cyclically mixed evenly at room temperature to obtain solution B; solutions A and B were simultaneously and slowly injected into a continuous reactor for cyclic reaction. Each time the raw materials entered the continuous reactor, they stayed for 7 min, and the reaction temperature was 85 °C. The reaction was stopped, cooled to room temperature, most of the solvent was removed, filtered, and vacuum dried for 5 h to obtain 1858.5 g of a brick-red solid, with a yield of 97.56%.

[0041] The above filtrate was transferred to a reaction kettle, and an appropriate amount of potassium permanganate and mercury catalyst were continuously added for reaction for 5 h. It was cooled to room temperature, filtered, and the filtrate was transferred to a waste barrel for recycling into metallic iridium.

[0042] Example 4:

[0043] Under argon protection, 2000 g of iridium(III) chloride hydrate and 10000 mL of distilled water were added to a raw material tube, heated to 70 °C, and stirred continuously for 2 h to obtain solution A; 2453 mL of cyclooctadiene and 1025 mL of acetic acid were added to another raw material tube, and cyclically mixed evenly at room temperature to obtain solution B; solutions A and B were simultaneously and slowly injected into a continuous reactor for cyclic reaction. Each time the raw materials entered the continuous reactor, they stayed for 6 min, and the reaction temperature was 80 °C. The reaction was stopped, cooled to room temperature, most of the solvent was removed, filtered, and vacuum dried for 5 h to obtain 1863.5 g of a brick-red solid, with a yield of 97.82%.

[0044] The above filtrate was transferred to a reaction kettle, and an appropriate amount of potassium permanganate and mercury catalyst were continuously added for reaction for 5 h. It was cooled to room temperature, filtered, and the filtrate was transferred to a waste barrel for recycling into metallic iridium.

[0045] The Ir2Cl2C 16 H 24 dimer structure analysis:

[0046] (1) Elemental analysis, theoretical values (%) : C 28.61, H 3.60; Measured values (%) : C 28.60, H 3.58. The measured values are in agreement with the theoretical values.

[0047] (2) 1H NMR ( 1 1H NMR, 500 MHz, CDCl3, as Figure 2 shown), chemical shift (ppm): 1.50 - 1.54 (m, 8H, -CH2), 2.24 - 2.26 (m, 8H, CH2), 4.22 (br, s, 8H, =CH).

[0048] (3) 13C NMR (13 C NMR, 500 MHz, CDCl3, as Figure 3 As shown), chemical shift (ppm): 31.80 (-CH2), 62.21 (=CH).

[0049] (4) Mass spectrometry (ESI-MS, such as Figure 4 As shown): 671 molecular ion peaks appeared, which is Ir2Cl2C 16 H 24 The molecular weight of the dimer indicates that the test results are consistent with the target product.

[0050] (5) Infrared spectrum IR (cm -1 , KBr, such as Figure 5 As shown) (Note: ν represents stretching vibration, δ represents deformation vibration): 2906, 2827 belong to ν(CH2), 1617 belongs to ν(C=C), 1471, 1446, 1424 belong to δ(CH2), 1321, 1206, 1154 belong to δ(CH), 999, 977, 968, 903, 869, 830, 805 belong to ν(CC), 530 belongs to ν(CH2), and 414 belongs to ν(Ir-C).

[0051] The results of elemental analysis, hydrogen spectrum, carbon spectrum, mass spectrum, infrared spectrum and crystal structure show that the sample is Ir2Cl2C 16 H 24 The dimer target is consistent.

[0052] In summary, the embodiment of the present invention provides a method for reducing the amount of cyclooctadiene, reducing waste liquid treatment, and reducing production costs. In the process of waste liquid treatment, mercury is added to potassium permanganate for catalytic oxidation, and cyclooctadiene in the waste liquid is precipitated into a mercury complex, which greatly reduces the pollution of the waste liquid to the environment. In a preferred case, a pure product with a yield of up to 97% is obtained, and the preparation method has few reaction steps, is easy to operate, and has a high yield, and is suitable for industrial production.

[0053] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A preparation method of an iridium dimer catalyst, the iridium dimer catalyst being Ir2Cl2C 16 H 24 dimer, characterized in that, The method includes: Step (1), under an argon atmosphere, dissolving an iridium-containing and chlorine-containing compound in an appropriate amount of distilled water, injecting it into a raw material tube, heating and circulating to mix evenly to obtain solution A; the iridium-containing and chlorine-containing compound is iridium tetrachloride hydrate; the conditions for the mixing reaction include: reacting at a reaction temperature of 60-100 °C for 0.5-3 h; Step (2), under an argon atmosphere, mixing cyclooctadiene and a reducing agent acid evenly and injecting them into another raw material tube, circulating at room temperature to mix evenly to obtain solution B; the reducing agent acid is propionic acid; Step (3): Slowly inject the A and B solutions into a continuous reactor simultaneously, heat them, and perform a cyclic reaction to obtain a solution of iridium(I) chloride. Treat the solution of iridium(I) chloride to obtain an Ir2Cl2C 16 H 24 dimer; the conditions of the continuous reaction flow include: the reaction temperature is 60-100 °C; Step (4), transferring the filtrate to a sealed reaction bottle, adding an appropriate amount of potassium permanganate and a mercury catalyst, and generating a mercury complex precipitate from the cyclooctadiene in the waste liquid to reduce the environmental pollution of cyclooctadiene; Step (5), the filtrate after filtration is to be recycled into metallic iridium; The molar ratio of the iridium-containing and chlorine-containing compound, the reducing agent acid, and cyclooctadiene is 1:2-6:3-6.

2. The preparation method according to claim 1, wherein In step (1), the weight ratio of the iridium-containing and chlorine-containing compound to distilled water is 1:3-13.

3. The preparation method according to any one of claims 1-2, characterized in that, Step (3) further includes: successively cooling to room temperature, removing most of the solvent, filtering, washing the filter cake with ice methanol, and vacuum drying after the continuous reaction stream.

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