Coordination metal catalysts, processes for their preparation and use, and hindered amines, processes for their preparation

Abstract

The application provides a coordination metal catalyst, a preparation method and application thereof, a hindered amine and a preparation method thereof. The preparation method of the coordination metal catalyst comprises uniformly mixing a first metal salt and a second metal salt, then adding an amide-substituted benzene, standing, drying to obtain the coordination metal catalyst; the metal element in the first metal salt comprises one of Co, Pd and Ni or a combination of two or more thereof; the second metal salt is triflate and / or chloride. The application further provides the coordination metal catalyst obtained by the above preparation method and a hindered amine catalyst comprising the coordination metal catalyst. The application further provides the hindered amine and a preparation method thereof, which is prepared by using the above hindered amine catalyst. The coordination metal catalyst provided by the application has the advantages of low cost, high catalytic activity, mild reaction conditions and the like, and can be used for the hindered amine and other reactions related to alcohol amine synthesis.

Description

Technical Field

[0001] This invention relates to the field of organic catalysis technology, and in particular to a coordination metal catalyst, its preparation method and application, and a sterically hindered amine and its preparation method. Background Technology

[0002] Currently, the main methods used in natural gas purification are the alkanolamine method and the sulfoneamine method, which use methyl diethanolamine (MDEA) as the core solvent. However, these purification processes have certain limitations, with relatively limited ability to remove organic sulfur, and face significant pressure to meet the new natural gas standards. Faced with the pressure to meet total sulfur standards in purified gas, hindered amines have been introduced into the desulfurization field. Commonly used sterically hindered amines for natural gas or refinery gas desulfurization include tert-butylaminoethoxyethanol (TBEE), 2-amino-2-methyl-1-propanol (AMP), and 2-piperidineethanol (PE). While TBEE can selectively remove hydrogen sulfide, its effect on organic sulfur removal is poor. AMP and PE can remove CO2 but lack selectivity and are also ineffective at removing organic sulfur. Against this backdrop, a sterically hindered amine, 2-(tert-butylamino)ethane-1-ol (also known as 2-(tert-butylamino)ethanol), with highly efficient organic sulfur removal capabilities, was synthesized.

[0003] Currently, Cu-Ni catalysts are widely used in the synthesis of 2-(tert-butylamino)ethane-1-ol, but these catalysts all suffer from low catalytic efficiency. To improve catalytic activity, noble metals such as Au, Pt, Ru, and Rh are typically added, but this method usually results in increased production costs and extremely low economic benefits. Exxon has published a patent demonstrating that a Ni-Al₂O₃-SiO₂ ternary catalyst can achieve a yield of up to 54% in the synthesis of secondary amines; adding 1% of the noble metal Ru catalyst can increase the yield by 20%; and adding Pt increases the yield by 3%. While the addition of noble metals improves the catalytic activity to some extent, it also leads to higher costs, and noble metal catalysis often requires harsh reaction conditions such as high temperature and high pressure. This makes large-scale production and promotion difficult in terms of both economics and operability. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a coordination metal catalyst, its preparation method and application, and a hindered amine and its preparation method. The coordination metal catalyst provided by the present invention possesses numerous advantages, including low cost, high catalytic activity, and mild reaction conditions, and can be used in reactions involving the synthesis of hindered amines and other alcohol amines.

[0005] To achieve the above objectives, the present invention provides a coordination metal catalyst, the structural formula of which is as follows:

[0006]

[0007] Among them, M 1 Selected from Co, Pd, Ni; M 2 Includes one or more of the following: Group IA metallic elements, Group IIA elements, and rare earth elements; R 1 R 2 R 3 Selected from one or more combinations of H, F, Cl, Br, Me, and OMe respectively; R 4 It is one of chloride ion, acetate ion, or trifluoroacetate ion; R 5 It consists of trifluoromethanesulfonate and / or chloride ions.

[0008] In the above-mentioned coordination metal catalysts, M 1 As the central metal, on the one hand, M 1 Through R 4 With M 2 Connected, on the other hand M 1 The N atom of the amide group is chemically bonded to the M atom, while M... 1 It also forms a π-coordinated complex with the benzene ring at a certain angle, M 1 Composed of benzene ring and R 5 The metal is sandwiched to form a sandwich-type coordination metal catalyst.

[0009] In the above-mentioned coordination metal catalysts, M 1 With M 2 The molar ratio can be controlled between 0.5:1 and 20:1.

[0010] In the above-mentioned coordination metal catalysts, R 5 It has the function of Lewis acid and can attract M 2 The electrons then attract M 1 electrons, increase M 1 The oxidizing power of M, which is in an electron-deficient state, makes it possible for M to oxidize. 1 M readily forms p-π conjugation with the benzene ring, thus stabilizing it. 1 In some specific implementation schemes, R 5 Trifluoromethanesulfonate (-OTf) is preferred.

[0011] In the above-mentioned coordination metal catalysts, M 2 With R 5 This forms an ionizable ionic compound. The M... 2 Generally, choose Easy and R. 5 Ionized metallic elements, such as those selected from Na, Zn, Ca, Mg, Al, Sc, Y, and Yb.

[0012] In the above-mentioned coordination metal catalysts, R 1 R 2 R 3 It can be a substituent on the benzene ring or H (when it is an H atom, it is not considered a substituent). Specifically, the R... 1 R 2 R 3 It can be selected from one of H, F, Cl, Br, Me (methyl, -CH3), and OMe (methoxy, -OCH3). Further research found that, compared to electron-donating groups, R... 1 R 2 R 3 Selecting electron-withdrawing groups can enhance the catalytic activity of coordination metal catalysts, i.e., R 1 R 2 R 3 The components are preferably selected from H, F, Cl, and Br. More preferably, R... 1 It is one of F, Cl, Br, R 2 R 3 They are H respectively.

[0013] In the above-mentioned coordination metal catalysts, R 4 It can bridge M 1 and M 2 (e.g., via coordinate bonds with M) 1 and M 2 (Connection), so that the resulting coordination compound is a bimetallic central complex. Specifically, R 4 It can be acetate (-OAc, i.e., -COOH).

[0014] According to a specific embodiment of the present invention, the structural formula of the coordination metal catalyst may be:

[0015]

[0016] Among them, M 1 Selected from Co, Pd, and Ni;

[0017] M 2 Selected from one of the metal elements in Group IA, the elements in Group IIA, or the rare earth elements;

[0018] R 1 R 2 R 3 Each of the following is selected: H, F, Cl, Br, Me, and OMe.

[0019] The present invention also provides a method for preparing the above-mentioned coordination metal catalyst, the method comprising:

[0020] The first metal salt and the second metal salt were mixed evenly, and then amide-substituted benzene was added and mixed. The mixture was allowed to stand and dried to obtain a coordinated metal catalyst.

[0021] The first metal salt contains one of Co, Pd, and Ni; the second metal salt contains one or more of Group IA, Group IIA, and rare earth elements; the second metal salt contains trifluoromethanesulfonate and / or chloride ions; the molar ratio of the first metal salt to the second metal salt is 1:0.5-20 based on the metal elements; and the molar ratio of the first metal salt to the amide-substituted benzene is 1:1-1:10 based on the metal elements of the first metal salt.

[0022] According to a specific embodiment of the present invention, the amide-substituted benzene refers to a compound formed in which at least one hydrogen atom on the benzene ring is replaced by an amide in benzene or a benzene derivative. In amide-substituted benzene, the amide group can react with the metal element in the first metal salt to form a coordinate bond, thereby fixing the metal element in the first metal salt; the benzene ring can form a coordination relationship with the metal element in the first metal salt through p-π conjugation, further stabilizing the metal element. Compared with alkyl amide groups with large steric hindrance, the amide group has a shorter carbon chain, which can promote the coordination of the benzene ring with the metal element in the first metal salt and improve the coordination effect.

[0023] In some specific embodiments, the substituents on the benzene ring in the amide-substituted benzene include, but are not limited to, amide groups, and may further include one or more combinations of -F, -Cl, -Br, -Me, -OMe, etc. Except for the amide group, the other substituents in the amide-substituted benzene are generally located at the para and / or meta positions of the amide group to avoid steric hindrance affecting the coordination effect between the metal element in the first metal salt and the benzene ring. This invention has found that, among the substituents other than the amide group, coordination metal catalysts made from amide-substituted benzene with electrophilic (electron-withdrawing) substituents (-F, -Cl, -Br) exhibit better catalytic performance than nucleophilic groups (electron-donating groups, -Me, -OMe).

[0024] In some specific embodiments, the chemical formula of the amide-substituted benzene may be: Among them, R 1 R 2 R 3 It is selected from one or more of H, F, Cl, Br, Me, and OMe. Preferably, R 1 R 2 R 3 It is selected from one or more combinations of H, F, Cl, and Br. More preferably, R 1It is one of F, Cl, Br, R 2 R 3 They are H respectively.

[0025] According to specific embodiments of the present invention, in the above reaction, the metal ions in the first metal salt and the metal ions in the second metal salt can generally be bridged by the anion of the first metal salt (specifically, through coordination). In some specific embodiments, the first metal salt can be a metal salt soluble in organic solvents (furthermore, the first metal salt has excellent solubility in organic solvents), and the anion of the first metal salt can include one or more combinations of chloride ions, acetate ions, trifluoroacetate ions, etc., for example, acetate ions.

[0026] According to a specific embodiment of the present invention, the molar ratio of the first metal salt to the amide-substituted benzene, based on the metal element of the first metal salt, can be further controlled to be 1:(1-2).

[0027] According to a specific embodiment of the present invention, the second metal salt is a metal salt without redox activity, that is, the cation in the second metal salt does not have redox activity. The anion of the second metal salt is generally trifluoromethanesulfonate, chloride, etc. Because the metal element in the second metal salt has a bridging effect with the metal element in the first metal salt, the anion in the second metal salt can attract electrons from the metal atoms in the second metal salt, and further attract electrons from the metal atoms in the first metal salt, making it easier for the electron-deficient metal atoms in the first metal salt to form p-π conjugated coordinate bonds with the benzene ring in the amide-substituted benzene. Preferably, the anion of the second metal salt is trifluoromethanesulfonate, then the general formula of the second metal salt can be represented as M... 2 (OTf) x Where x can be 1-3.

[0028] According to a specific embodiment of the present invention, the metal element in the second metal salt is generally a metal element that is easily ionized. Specifically, the metal element in the second metal salt may include one or more combinations of Na, Zn, Ca, Mg, Al, Sc, Y, and Yb. Further research of the present invention has found that the higher the chemical valence of the metal element in the second metal salt, the better the catalytic effect of the resulting coordinated metal catalyst. Preferably, the metal element in the second metal salt is ytterbium, aluminum, scandium, yttrium, etc.

[0029] According to a specific embodiment of the present invention, in the above preparation method, the standing time is generally controlled to be 8h-12h.

[0030] According to specific embodiments of the present invention, in the above preparation method, the first metal salt, the second metal salt, and the amide-substituted benzene can be mixed in a solvent. The solvent used can be an organic solvent, such as acetonitrile, glacial acetic acid, tetrahydrofuran, or a combination of two or more of these. Specifically, the first metal salt can participate in the reaction in the form of a solution formed by mixing it with the above-mentioned solvent. The concentration of the first metal salt in the first metal salt solution can be 0.5 mmol / L to 20 mmol / L. In some specific embodiments, the first metal salt solution can be obtained by mixing the first metal salt with a solvent and stirring at 15-30°C at a speed of 300-800 r / min for 5-10 min until completely dissolved.

[0031] According to a specific embodiment of the present invention, in the above preparation method, the first metal salt may be mixed with the second metal salt first, and then amide-substituted benzene may be added for further mixing. The mixing of the first metal salt and the second metal salt may be carried out under conditions of stirring and heating, wherein the stirring speed may be 300-600 r / min, for example 500 r / min, and the mixing temperature may be 80-100℃.

[0032] According to a specific embodiment of the present invention, in the above preparation method, after adding amide-substituted benzene, the preparation method may include an ultrasonic operation to promote the uniform mixing of amide-substituted benzene with the first metal salt and the second metal salt by ultrasonic means.

[0033] According to a specific embodiment of the present invention, after mixing the first metal salt, the second metal salt, and the amide-substituted benzene, and before allowing it to stand, the above preparation method may further include a filtration operation, wherein the filtrate obtained after filtration is allowed to stand. In some specific embodiments, the filtration device may be organic filter paper with a pore size of 1-3 μm.

[0034] According to a specific embodiment of the present invention, the preparation method may further include removing the solvent, drying, and grinding the product after it has been left to stand. The drying temperature can be controlled at 100°C, and the drying time can be 6 hours.

[0035] According to a specific embodiment of the present invention, the above preparation method may include:

[0036] 1. Mix the first metal salt solution with the second metal salt, stir and heat to 80-100℃ until the second metal salt is completely dissolved to obtain the first solution; wherein, based on the metal element, the molar ratio of the first metal salt to the second metal salt is 1:0.5-1:20;

[0037] 2. Add amide-substituted benzene to the first solution and sonicate until completely dissolved to obtain the second solution, wherein the molar ratio of the first metal salt to the amide-substituted benzene is 1:1 to 1:10;

[0038] 3. Filter the second solution using organic filter paper with a pore size of 1-3 μm, and let the filtrate stand at room temperature for 8-12 hours to obtain the third solution;

[0039] 4. Remove the solvent from the third solution and dry it at 100°C for 6 hours to obtain a solid powder; grind the solid powder to obtain the coordination metal catalyst.

[0040] The present invention also provides a sterically hindered amine catalyst comprising the above-described coordinated metal catalyst.

[0041] The present invention also provides a method for preparing a hindered amine, the method comprising: mixing a substrate with the above-mentioned hindered amine catalyst at a molar ratio of 300-500:1, reacting at 20-30°C to obtain the hindered amine; wherein the substrate comprises one of the following: a combination of tert-butylamine and 1-chloroethanol (the molar ratio of tert-butylamine to 1-chloroethanol is preferably 1:1), a combination of tert-butylamine and 1-chlorobutanol (the molar ratio of tert-butylamine to 1-chlorobutanol is preferably 1:1), or a combination of 2,4,4-trimethylpentane-2-amine and 1-chloroethanol (the molar ratio of 2,4,4-trimethylpentane-2-amine to 1-chloroethanol is preferably 1:1).

[0042] According to a specific embodiment of the present invention, the above-mentioned preparation process of the hindered amine is achieved by using a catalyst to catalyze the coupling reaction of C-C bonds, and the yield of the hindered amine can reach more than 60%, and in some specific embodiments it can reach more than 90%.

[0043] According to a specific embodiment of the present invention, the activity of the coordination metal catalyst can be controlled by changing the type of metal in the second metal salt and the type of benzene substituted with amide, making it applicable to more types of substrates and synthesizing a variety of sterically hindered amines.

[0044] This invention provides a hindered amine obtained by the above-described method for preparing hindered amines, which has a highly efficient ability to remove organic sulfur in the field of natural gas purification.

[0045] In some specific embodiments, the sterically hindered amine may include one or a combination of two or more of 2-(tert-butylamino)ethanol, 4-(tert-butylamino)-1-butanol, and 2-((2,4,4-trimethylpentan-2-yl)amino)-1-ethanol.

[0046] The structural formula of 2-(tert-butylamino)ethanol is:

[0047] The structural formula of 4-(tert-butylamino)ethanol is:

[0048] The structural formula of 2-((2,4,4-trimethylpent-2-yl)amino)-1-ethanol is:

[0049] The beneficial effects of this invention are as follows:

[0050] 1. The coordination metal catalyst provided by the present invention has high catalytic activity, especially in the reaction to generate alcohol amines through coupling reaction, and the product yield can reach more than 90%.

[0051] 2. In the coordination metal catalyst provided by this invention, the metal element M in the first metal salt 1 As the active component in catalysis, it plays a central role; the amide group and benzene ring in amide-substituted benzene fix and stabilize the metal M. 1 This allows the substituents in amide-substituted benzene to stabilize the catalyst, and the substituents can adjust the metal M through electronic effects. 1 The catalytic ability; the electrophilic group R contained in the second metal salt 4 Acting as a Lewis acid, it can increase the metal M by withdrawing electrons. 1 The oxidation capacity of metal M, thereby promoting the oxidation of metal M 1 p-π conjugation between amide-substituted benzene and benzene.

[0052] 3. The preparation method of the coordination metal catalyst provided by the present invention has the characteristics of mild reaction conditions, low catalyst loading, and high catalytic efficiency. Attached Figure Description

[0053] Figure 1 The NMR spectrum of the coordination metal catalyst prepared in Example 9 is shown.

[0054] Figure 2 The UV-Vis absorption spectra of the catalyst in Example 9 and the catalyst in Example 1 are shown.

[0055] Figure 3 The NMR spectrum of the sterically hindered amine prepared by the catalyst of Example 9 is shown. Detailed Implementation

[0056] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0057] In the chemical formulas involved in this invention, the "-" indicates only the connection between groups and does not specifically refer to a single bond. For example, the connection between groups can be a single bond connection, a coordination connection, or a combination of single bond connection and coordination connection.

[0058] The test methods used in the following embodiments and test examples are as follows:

[0059] NMR testing method: Weigh 30 mg of the sample to be tested and dissolve it in 0.6 ml of DMSO-d6 solvent to form a homogeneous solution. Then, use a pipette to transfer the homogeneous solution into a standard NMR tube and test it on a 400 MHz NMR instrument.

[0060] UV testing method: Weigh 10 mg of the sample to be tested and dissolve it in 2 ml of acetonitrile solution. Then, using pure acetonitrile solvent as a reference solution, perform UV scanning test on the catalyst solution.

[0061] Example 1

[0062] Example 1 provides a coordination metal catalyst, the preparation method of which includes:

[0063] 1. Mix cobalt acetate tetrahydrate with acetonitrile and stir for 5-10 minutes at 15-30℃ and 300-800r / min until the cobalt acetate tetrahydrate is completely dissolved to obtain solution A, the concentration of which is 10mmol / L.

[0064] 2. According to the molar ratio of cobalt acetate tetrahydrate to trifluoromethanesulfonic acid of 0.5:1, mix solution A with trifluoromethanesulfonic acid to obtain solution B;

[0065] 3. Add benzamide to solution B according to a molar ratio of cobalt acetate tetrahydrate to benzamide of 1:1, and sonicate until the benzamide is completely dissolved to obtain solution C;

[0066] 4. Filter solution C using organic filter paper with a pore size of 1-3 μm, and let the filtrate stand at room temperature for 8-12 hours to obtain suspension D;

[0067] 5. Remove the solvent from the suspension D using a Buchner funnel, and then dry the solvent-removed suspension D (which is brownish-green) in a 100°C oven for 6 hours to obtain a solid powder. Grind the solid powder into powder in an agate mortar to obtain a coordinated metal catalyst.

[0068] Examples 2-9

[0069] Examples 2 to 9 provide methods for preparing coordination metal catalysts. Except for the type of the second metal salt (see Table 1), all other preparation parameters are the same in Examples 2 to 9. The specific preparation methods are as follows:

[0070] 1. Mix cobalt acetate tetrahydrate with acetonitrile and stir for 5-10 minutes at 15-30℃ and 300-800r / min until the cobalt acetate tetrahydrate is completely dissolved to obtain solution A, the concentration of which is 10mmol / L.

[0071] 2. According to the molar ratio of cobalt acetate tetrahydrate to the second metal salt of 0.5:1, solution A is mixed with the second metal salt, stirred at 500 r / min and heated to 80-100℃ until the second metal salt is completely dissolved to obtain solution B; wherein, the second metal salt is a trifluoromethanesulfonate of metal.

[0072] 3. Add benzamide to solution B according to a molar ratio of cobalt acetate tetrahydrate to benzamide of 1:1, and sonicate until the benzamide is completely dissolved to obtain solution C;

[0073] 4. Filter solution C using organic filter paper with a pore size of 1-3 μm, and let the filtrate stand at room temperature for 8-12 hours to obtain suspension D;

[0074] 5. Remove the solvent from the suspension D using a Buchner funnel, and then dry the solvent-removed suspension D (which is brownish-green) in a 100°C oven for 6 hours to obtain a solid powder. Grind the solid powder into powder in an agate mortar to obtain a coordinated metal catalyst.

[0075] Table 1 shows the addition of the second metal salt in Examples 1 to 9.

[0076] Table 1

[0077]

[0078]

[0079] Test Example 1

[0080] This test example tests the catalytic performance of the coordination metal catalysts in Examples 1 to 9.

[0081] 2-(tert-butylamino)ethanol was synthesized using the coordination metal catalysts of Examples 1 to 9. The synthesis method is as follows:

[0082] Using tert-butylamine and 1-chloroethanol in a molar ratio of 1:1 as substrates, a coordination metal catalyst was mixed with the substrates in a molar ratio of 1:300 to 1:500, and the mixture was reacted at 20-30°C for 4 hours to obtain 2-(tert-butylamino)ethanol.

[0083] The yield of each coordination metal catalyst for hindered amines was calculated as follows: hindered amine yield = actual yield of hindered amine / theoretical yield of hindered amine × 100%;

[0084] The theoretical yield of the hindered amine is calculated as: amount of tert-butylamine × molar mass of the hindered amine. The calculation results are summarized in Table 2. In Example 1, no second metal was added; instead, trifluoromethanesulfonic acid was used to replace the second metal in other examples.

[0085] Table 2

[0086] Example The added second metal hindered amine yield / % 1 none 50 2 Sodium trifluoromethanesulfonate 63 3 Zinc trifluoromethanesulfonate 66 4 Calcium trifluoromethanesulfonate 65 5 Magnesium trifluoromethanesulfonate 72 6 Aluminum trifluoromethanesulfonate 78 7 Scandium trifluoromethanesulfonate 76 8 Yttrium trifluoromethanesulfonate 77 9 Ytterbium trifluoromethanesulfonate 82

[0087] As shown in Table 2, Examples 2-9 demonstrate that the catalysts obtained using different trifluoromethanesulfonates possess different catalytic abilities for the synthesis of 2-(tert-butylamino)ethanol. Furthermore, the catalytic ability of the trifluoromethanesulfonate gradually increases with the increasing valence state of the metal ion in the trifluoromethanesulfonate. Compared to other trifluoromethanesulfonates, ytterbium trifluoromethanesulfonate exhibits superior performance.

[0088] Examples 10 to 16

[0089] Examples 10 to 16 provide methods for preparing coordination metal catalysts, using ytterbium trifluoromethanesulfonate as the second metal salt. Except for the type of amide-substituted benzene used (see Table 3 for the types of amide-substituted benzene), the preparation parameters for Examples 10 to 16 are the same as those for Example 9.

[0090] Test Example 2

[0091] This test example tests the catalytic performance of the coordination metal catalysts in Examples 10 to 16.

[0092] The method for synthesizing 2-(tert-butylamino)ethanol using a coordination metal catalyst and the method for calculating the yield of sterically hindered amines are the same as in Test Example 1. The results are summarized in Table 3.

[0093] The general molecular formula of the amide-substituted benzene used in Examples 10 to 16 in Table 3 is as follows:

[0094] R 1 R 2 R 3 The types are summarized in Table 3.

[0095] Table 3

[0096] Example <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> hindered amine yield / % 10 -F -H -H 84 11 -Cl -H -H 89 12 -Br -H -H 92 13 -Me -H -H 70 14 -OMe -H -H 76 15 -H -Cl -Cl 79 16 -H -OMe -OMe 72

[0097] As shown in Table 3, the activity of the coordination metal catalyst can be adjusted by changing the type of substituents on the benzene ring in amide-substituted benzene. Compared to benzene with two substituents on the benzene ring, amide-substituted benzene with only one substituent on the benzene ring has a greater effect on improving the catalyst activity.

[0098] When R 2 R 3 When both are H, R 1Choosing electron-withdrawing catalytic elements -F, -Cl, and -Br significantly enhances catalytic activity compared to electron-donating catalytic elements -Me and -OMe; furthermore, -Br exhibits a more significant enhancement of catalytic activity than -F and -Cl, with the highest yield reaching 92%.

[0099] Examples 17 to 21

[0100] Examples 17 to 21 provide methods for preparing coordination metal catalysts, using amide-substituted benzene as described in Example 12. Except for the ratio of cobalt acetate tetrahydrate to ytterbium trifluoromethanesulfonate, the preparation parameters for Examples 17 to 21 are identical to those for Example 12.

[0101] Test Example 3

[0102] This test example tests the catalytic performance of the coordination metal catalysts of Examples 17 to 21.

[0103] The method for synthesizing 2-(tert-butylamino)ethanol using a coordination metal catalyst and the method for calculating the yield of sterically hindered amines are the same as in Test Example 1. The results are summarized in Table 4. In Table 4, Co / Yb represents the molar ratio of cobalt in cobalt acetate tetrahydrate to ytterbium in ytterbium trifluoromethanesulfonate.

[0104] Table 4

[0105] Example Co / Yb hindered amine yield / % 17 1：0.5 87 18 1：1 88 19 1：4 94 20 1：10 95 21 1：20 96

[0106] As can be seen from Table 4, by adjusting the molar ratio of the first metal salt (cobalt acetate tetrahydrate) to the second metal salt (ytterbium trifluoromethanesulfonate), the catalytic effect of the catalyst on the synthesis of 2-(tert-butylamino)ethanol can be adjusted, and the sterically hindered amine yield can reach up to 96%.

[0107] The above results demonstrate that the coordination metal catalyst provided by this invention has high catalytic activity and can achieve high-yield synthesis of 2-(tert-butylamino)ethanol.

[0108] Table 5 summarizes the experimental parameters and sterically hindered amine yields for Examples 1 to 21. In Table 5, M... 1 :M 2 R represents the molar ratio of cobalt in the first metal salt cobalt acetate tetrahydrate to the metal element in the second metal salt. 1 R 2 R 3 General formula for amide-substituted benzene Substituents in.

[0109] Table 5

[0110]

[0111]

[0112] Figure 1 The NMR spectrum of the coordination metal catalyst prepared in Example 9 was obtained by... Figure 1 The configuration of the coordination metal catalyst can be determined by combining NMR standards as follows:

[0113]

[0114] Figure 2 The UV-Vis absorption spectra of the catalysts in Example 9 and Example 1 are shown. Figure 2 It can be seen that the catalyst without the second metal (Example 1) has almost no absorption at 350 nm, while the catalyst prepared with the second metal (Example 9) has absorption at 350 nm. This shows that the addition of the second metal salt changed the absorption band of the catalyst.

[0115] Figure 3 The NMR spectrum of the sterically hindered amine prepared by the catalyst in Example 9. 2-(tert-Butylamino)ethanol: 1 ¹H NMR (400 MHz, CDCl₃) δ 5.52 (s, 1H), 4.81 (s, 1H), 3.09 (t, 2H), 2.8 (t, 2H), 1.18 (s, 9H). This confirms that the sterically hindered amine is 2-(tert-butylamino)ethanol.

[0116] The coordination metal catalysts of Examples 2-21 were subjected to NMR analysis using the same method, and the results are as follows:

[0117] NMR data of the catalyst in Example 2: 1 H NMR (400MHz, DMSO-d6) δ10.73(s,1H),7.76(m,2H),7.48(t,1H),7.32(m,2H),1.29(s,6H).

[0118] NMR data of the catalyst in Example 3: 1 H NMR (400MHz, DMSO-d6) δ10.76(s,1H),7.8(m,2H),7.44(t,1H),7.37(m,2H),1.31(s,6H).

[0119] Example 4: Catalyst NMR data: 1 H NMR (400MHz, DMSO-d6) δ10.77(s,1H),7.61(m,2H),7.45(t,1H),7.31(m,2H),1.28(s,6H).

[0120] Example 5 Catalyst NMR Data: 1H NMR (400MHz, DMSO-d6) δ10.73(s,1H),7.82(m,2H),7.47(t,1H),7.35(m,2H),1.27(s,6H).

[0121] Example 6 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.24(s,1H),7.66(m,2H),7.58(t,1H),7.27(m,2H),1.22(s,6H).

[0122] Example 7 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.33(s,1H),7.68(m,2H),7.52(t,1H),7.32(m,2H),1.33(s,6H).

[0123] Example 8 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.46(s,1H),7.73(m,2H),7.39(t,1H),7.31(m,2H),1.27(s,6H).

[0124] Example 9 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.75(s,1H),7.78(m,2H),7.44(t,1H),7.33(m,2H),1.28(s,6H).

[0125] Example 10 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.03(s,1H),7.37(d,2H),7.32(d,2H),1.21(s,6H).

[0126] Example 11 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.10(s,1H),7.38(d,2H),7.28(d,2H),1.22(s,6H).

[0127] Example 12 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.08(s,1H),7.40(d,2H),7.31(d,2H),1.21(s,6H).

[0128] Example 13 Catalyst NMR Data: 1H NMR (400MHz, DMSO-d6) δ10.77(s,1H),7.32(d,2H),7.13(d,2H),1.30(s,6H),1.15(s,3H).

[0129] Example 14 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.62(s,1H),7.27(d,2H),7.08(d,2H),1.32(s,3H)1.30(s,6H).

[0130] Example 15 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.25(s,1H),7.33(s,1H),7.27(d,1H),7.18(d,1H),1.27(s,6H).

[0131] Example 16 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.21(s,1H),7.27(s,1H),7.21(s,1H),7.11(s,1H),1.34(s,6H)1.28(s,6H).

[0132] Example 17 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.74(s,1H),7.79(d,2H),7.3(d,2H),1.23(s,6H).

[0133] Example 18 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.74(s,1H),7.77(d,2H),7.37(d,2H),1.26(s,6H).

[0134] Example 19 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.67(s,1H),7.57(d,2H),7.23(d,2H),1.28(s,6H).

[0135] Example 20 Catalyst NMR Data: 1 H NMR (400MHz, DMSO-d6) δ10.68(s,1H),7.71(d,2H),7.63(d,2H),1.28(s,6H).

[0136] Example 21 Catalyst NMR Data:1 H NMR (400MHz, DMSO-d6) δ10.73(s,1H),7.70(d,2H),7.35(d,2H),1.27(s,6H).

[0137] The above NMR test data proves that the molecular structures of the coordination metal catalysts prepared in Examples 2 to 21 conform to the following molecular formula:

[0138]

[0139] M 1 Selected from Co;

[0140] M 2 Selected from one of Na, Zn, Ca, Mg, Al, Sc, Y, and Yb;

[0141] R 1 R 2 R 3 Each of the following is selected: H, F, Cl, Br, Me, and OMe.

[0142] Test Example 4

[0143] A coordination metal catalyst was synthesized according to the method of Example 9, using cobalt acetate tetrahydrate as the first metal salt, benzamide as an amide-substituted benzene, and ytterbium trifluoromethanesulfonate as the second metal salt. This catalyst was then applied to the synthesis of 2-(2,4,4-trimethylpentane-2-amino)-1-ethanol. The substrate used was 2,4,4-trimethylpentane-2-amine / 1-chloroethanol (molar ratio 1:1), the catalyst-to-substrate molar ratio was 1:400, the reaction temperature was 25°C, and the corresponding sterically hindered amine yield was 90%.

[0144] NMR data for the sterically hindered amine product: 1 ¹H NMR (400MHz, CDCl₃) δ 5.52 (s, 1H), 4.81 (s, 1H), 3.48 (t, 2H), 2.74 (t, 2H), 1.22 (s, 6H), 1.15 (s, 3H), 0.91 (s, 9H), which confirms that the sterically hindered amine product is 2-((2,4,4-trimethylpentan-2-yl)amino)-1-ethanol.

[0145] Test Example 5

[0146] A coordination metal catalyst was synthesized according to the method of Example 9, using cobalt acetate tetrahydrate as the first metal salt, benzamide as an amide-substituted benzene, and ytterbium trifluoromethanesulfonate as the second metal salt. This catalyst was then applied to the synthesis of 4-(tert-butylamino)-1-butanol. The substrate used was tert-butylamine / 1-chlorobutanol (molar ratio 1:1), the catalyst-to-substrate molar ratio was 1:500, the reaction temperature was 20°C, and the corresponding sterically hindered amine yield was 94%.

[0147] NMR data of sterically hindered amine products: 1 ¹H NMR (400MHz, CDCl₃) δ 6.32 (s, 1H), 4.15 (s, 1H), 3.50 (m, 2H), 3.03 (m, 2H), 2.84 (m, 2H), 2.59 (m, 2H), 1.24 (s, 9H). This confirms that the sterically hindered amine product is 4-(tert-butylamino)-1-butanol.

[0148] The above results demonstrate that the coordination metal catalyst provided by this invention has high catalytic activity and can prepare sterically hindered amines and other alcoholic amines through coupling reactions with high yields.

[0149] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a sterically hindered amine, the method comprising: The substrate was mixed with a sterically hindered amine catalyst at a molar ratio of 300-500:1 and reacted at 20℃-30℃ to obtain the sterically hindered amine. The substrate includes one of the following: a combination of tert-butylamine and 1-chloroethanol, a combination of tert-butylamine and 1-chlorobutanol, or a combination of 2,4,4-trimethylpentane-2-amine and 1-chloroethanol; The sterically hindered amine catalyst includes a coordinated metal catalyst; The structural formula of the coordination metal catalyst is as follows: ， Among them, M 1 Selected from Co, Pd, and Ni; M 2 Selected from one of Al, Sc, Y, and Yb; R 1 R 2 R 3 Each of the following is selected from H, F, Cl, Br, Me, and OMe; R 4 It is one of chloride ions, acetate ions, and trifluoroacetate ions; R 5 It consists of trifluoromethanesulfonate and / or chloride ions.

2. The method for preparing a sterically hindered amine according to claim 1, wherein, R 1 R 2 R 3 Each of H, F, Cl, and Br is selected.

3. The method for preparing a sterically hindered amine according to claim 2, wherein, R 1 It is one of F, Cl, Br, R 2 R 3 They are H respectively.

4. The method for preparing a sterically hindered amine according to claim 1, wherein, R 5 It is trifluoromethanesulfonate.

5. The method for preparing a sterically hindered amine according to claim 1, wherein, The structural formula of the coordination metal catalyst is as follows: ， Among them, M 1 Selected from Co, Pd, and Ni; M 2 Selected from one of Al, Sc, Y, and Yb; R 1 R 2 R 3 Each of the following is selected: H, F, Cl, Br, Me, and OMe.

6. The method for preparing a sterically hindered amine according to any one of claims 1-5, wherein, The preparation method of the coordination metal catalyst includes: The first metal salt and the second metal salt were mixed evenly, and then amide-substituted benzene was added and mixed. The mixture was allowed to stand and dried to obtain a coordinated metal catalyst. The first metal salt contains one of Co, Pd, and Ni; the second metal salt contains one of Al, Sc, Y, and Yb; and the second metal salt contains trifluoromethanesulfonate and / or chloride ions. The molar ratio of the first metal salt to the second metal salt is 1:0.5-1:20 based on the metal element content of the first metal salt; the molar ratio of the first metal salt to the amide-substituted benzene is 1:1-1:10 based on the metal element content of the first metal salt.

7. The method for preparing a sterically hindered amine according to claim 6, wherein, In the amide-substituted benzene, the substituents on the benzene ring also include one or more combinations of -F, -Cl, -Br, -Me, and -OMe.

8. The method for preparing a sterically hindered amine according to claim 7, wherein, The substituents on the benzene ring include one of -F, -Cl, and -Br.

9. The method for preparing a sterically hindered amine according to claim 6, wherein, The chemical formula of the amide-substituted benzene is: ， Among them, R 1 R 2 R 3 Each of the following is selected: H, F, Cl, Br, Me, and OMe.

10. The method for preparing a sterically hindered amine according to claim 9, wherein, R 1 R 2 R 3 Each of H, F, Cl, and Br is selected.

11. The method for preparing a sterically hindered amine according to claim 9, wherein, R 1 It is one of F, Cl, Br, R 2 R 3 They are H respectively.

12. The method for preparing a sterically hindered amine according to claim 6, wherein, The anion of the first metal salt includes one of chloride ion, acetate ion, and trifluoroacetate ion.

13. The method for preparing a sterically hindered amine according to claim 12, wherein, The anion of the first metal salt is acetate.

14. The method for preparing a sterically hindered amine according to claim 6, wherein, Based on the metal element of the first metal salt, the molar ratio of the first metal salt to the amide-substituted benzene is 1:(1-2).

15. The method for preparing a sterically hindered amine according to claim 6, wherein, The settling time is 8-12 hours.

16. The method for preparing a sterically hindered amine according to claim 6, wherein, The first metal salt is added in solution form, and the solvent of the first metal salt solution includes one or more of acetonitrile, glacial acetic acid, and tetrahydrofuran.

17. The method for preparing a sterically hindered amine according to claim 16, wherein, The concentration of the first metal salt is 0.5 mmol / L-20 mmol / L.

18. The method for preparing a sterically hindered amine according to claim 1, wherein, The yield of the hindered amine is over 60%.

19. The method for preparing a sterically hindered amine according to claim 1, wherein, The yield of the hindered amine is over 90%.

20. The preparation method according to claim 1, wherein, The hindered amine includes one of 2-(tert-butylamino)ethanol, 4-(tert-butylamino)-1-butanol, and 2-(2,4,4-trimethylpentane-2-amino)-1-ethanol.

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