A double beta-diketiminate lutetium compound, its preparation method and application
By preparing bisβ-diketone imine lutetium compounds as catalysts, the problem of insufficient catalytic activity of rare earth compounds was solved, and efficient catalytic synthesis of biodegradable materials was achieved, meeting the application needs of the biomedical and packaging fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PRICE BIOTECHNOLOGY CO LTD
- Filing Date
- 2026-03-30
- Publication Date
- 2026-06-09
AI Technical Summary
Existing rare earth compound catalysts have insufficient catalytic activity in the synthesis of biodegradable polymer materials, making it difficult to meet market demand, and the application of synthesized biodegradable materials in the fields of biomedicine and packaging is insufficient.
A bisβ-diketone imine lutetium compound was developed. Through the reaction of a specific ligand with the lutetium compound, a catalyst with strong Lewis acidity was prepared for catalyzing the ring-opening polymerization of lactide and caprolactone. The structure-activity relationship of the catalyst was controlled to achieve high-efficiency catalysis.
It achieves efficient activation of lactone monomers, catalyzing the synthesis of biodegradable thermoplastic materials such as polylactide and polycaprolactone for use in biomedical and packaging fields. The molecular weight distribution of the catalyst can be controlled to meet market demands.
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Figure CN122167456A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of rare earth metal organometallic compounds, specifically relating to a bisβ-diketone imine lutetium compound, its preparation method, and its application. Background Technology
[0002] Based on global considerations for sustainable ecological development, the development of green, economical, and renewable biodegradable polymer materials has become a research hotspot in the field of polymer chemistry. Biodegradable polymer materials are mainly divided into naturally biodegradable materials and synthetic biodegradable materials. Naturally biodegradable polymer materials include silk, chitin, and gelatin, which, while possessing excellent biocompatibility, have limited sources and poor mechanical strength, making it difficult to meet current market demands. In contrast, synthetic biodegradable polymer materials are not only widely available but also possess advantages such as tunable structure and properties, and the ability to be mass-produced to meet market needs.
[0003] With the development of organometallic chemistry, rare earth compounds have become a research hotspot for scholars both domestically and internationally due to their superior physicochemical properties. Rare earth organometallic compounds can efficiently catalyze organic reactions, such as hydrogenation-amylation, hydrogenation-silanization, and polymerization reactions. Among them, biodegradable and renewable thermoplastic polylactide (PLA) and polycaprolactone (PCL) have been extensively studied and applied in fields such as biopharmaceutical materials and pharmaceuticals, and food packaging. Therefore, developing highly efficient rare earth compound-catalyzed polymerization reactions has significant application value. Summary of the Invention
[0004] To address the shortcomings of existing technologies, the purpose of this application is to provide a bisβ-diketone imine lutetium compound, its preparation method, and its applications. This objective can be achieved through the following technical solutions: A first aspect of the present invention relates to a bisβ-diketone imine lutetium compound having a structure as shown in formula (I): Formula (I) In formula (I), Lu is the rare earth metal lutetium; X is fluorine or chlorine; the compound contains a -N(SiMe3)2 group as an amido ligand, and Me is a methyl group.
[0005] Optionally, the compound is selected from one of the following: (1) X is fluorine, with the molecular formula C 30 H 44 F2N5Si2Lu; (2) X is chlorine, with the molecular formula C. 30 H 44 Cl2N5Si2Lu.
[0006] Optionally, the compound is prepared by reacting a bis-β-diketone imine ligand as shown in formula (II) with Lu[N(SiMe3)2]3; In formula (II), the two β-diketone imine units are bridged by ethylenediamine, and each β-diketone imine unit has a fluorine or chlorine substituent attached to the para-position of the benzene ring.
[0007] A second aspect of the present invention relates to a method for preparing the above-mentioned bisβ-diketone imine lutetium compound, characterized in that, under an inert atmosphere, the bisβ-diketone imine ligand shown in formula (II) is mixed with Lu[N(SiMe3)2]3 in an organic solvent and reacted at 25°C to 80°C for 12 to 72 hours; after the reaction is completed, the solvent is removed, the mixture is washed and purified with n-hexane, and dried to obtain the bisβ-diketone imine lutetium compound (I).
[0008] Optionally, the preparation method of the ligand of formula (II) includes the following steps: Step 1: Acetylacetone, p-halogenated aniline, and a catalytic amount of p-toluenesulfonic acid are refluxed in toluene for 8–24 hours. After cooling, the solvent is removed, and the mixture is recrystallized from ethanol to obtain β-enamine ketone intermediate TM. The amount of p-toluenesulfonic acid used is 0.5–2 mol% of the molar amount of acetylacetone. Step 2: Dissolve the intermediate TM obtained in Step 1 in dichloromethane, add triethyloxonium tetrafluoroborate [Et3O][BF4], and stir the reaction at room temperature for 18-30 hours; then add ethylenediamine and triethylamine, and continue stirring the reaction at room temperature for 36-60 hours; after the reaction, alkalize with saturated sodium hydroxide aqueous solution, extract with dichloromethane, dry with anhydrous sodium sulfate, rotary evaporate, and recrystallize with anhydrous ethanol to obtain ligand (II).
[0009] Optionally, the organic solvent is selected from one or a mixture of two of tetrahydrofuran, toluene, benzene, diethyl ether, n-hexane and petroleum ether; the molar ratio of the ligand of formula (II) to Lu[N(SiMe3)2]3 is 1:1 to 1.1:1; the reaction temperature is 60℃ to 80℃, and the reaction time is 12 to 24 hours.
[0010] Optionally, the inert atmosphere is high-purity nitrogen or argon; the mixing and reaction steps of the ligand with Lu[N(SiMe3)2]3 are carried out in a glove box or Schlenk operating system.
[0011] A third aspect of the invention relates to the above-described bisβ-diketone imine lutetium compounds in lactide and / or Application of caprolactone as a catalyst in the ring-opening polymerization.
[0012] Optionally, the ring-opening polymerization is carried out in solution at 25°C to 80°C; the molar ratio of catalyst to monomer is 1:100 to 1:1000. Polymerization is carried out in the presence of an alcohol initiator, wherein the alcohol initiator is a straight-chain, branched, or cyclic alkyl alcohol containing 1 to 10 carbon atoms, or a benzyl alkyl alcohol containing 7 to 12 carbon atoms; when an alcohol initiator is used, the molar ratio of catalyst, alcohol initiator and monomer is 1:1 to 10:100 to 1000.
[0013] Optionally, the ring-opening polymerization is solution polymerization; the resulting polymer is polylactide or polycaprolactone; the number-average molecular weight Mn is 1.5 × 10⁻⁶. 4 ~4.0×10 4 g / mol, with a molecular weight distribution index (PDI) of 1.4–1.7.
[0014] The beneficial effects of this application are: (1) The strong Lewis acidity of Lu helps to activate lactone monomers and promotes the breaking of acyl-oxygen bonds, thereby achieving efficient catalysis of lactone ring-opening polymerization and filling the gap in the existing rare earth BDI system for catalytic activity of polar monomers.
[0015] (2) The introduction of halogen substituents endows the ligands with π electron enrichment characteristics. At the same time, through the series of changes from F to Cl to Br to I, the adsorption and insertion ability of the metal center on the lactone monomer can be continuously adjusted, providing a clear means of regulation for the study of the structure-activity relationship of the catalyst.
[0016] (3) The obtained polylactide (PLA), polycaprolactone (PCL) and other products are biodegradable thermoplastic materials with important application value in the fields of biomedicine and packaging. The efficient catalysis of polar lactone monomers by these complexes makes up for the shortcomings of existing rare earth BDI catalysts in the synthesis of biodegradable polymer materials.
[0017] (4) The retained single amido group (N(SiMe3)2) can serve as the initiation site for lactone ROP in the presence of alcohol, realizing "initiator-controlled" living / controllable polymerization, giving the polymer molecular weight distribution adjustable (PDI = 1.4~1.62). Detailed Implementation
[0018] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0019] The present invention provides a dual β-Diketone imine lutetium compound (I), having the following general formula: (I) In formula (Ⅰ), X is a halogen (fluorine, chlorine, bromine, iodine); Lu represents the rare earth metal lutetium.
[0020] Preferred double β The structure of the -diketone imine lutetium compound is: The dual invention β The preparation method of the diketimine lutetium compound (I) is as follows: First, acetylacetone, p-halogen aniline, and p-toluenesulfonic acid were refluxed in toluene overnight and recrystallized from ethanol to obtain intermediate TM. Next, intermediate TM was dissolved in dichloromethane, and triethyloxonium tetrafluoroboric acid [Et3O][BF4] was added. The mixture was stirred at room temperature for 1 day, and then ethylenediamine and triethylamine were added and reacted for 2 days to obtain ligand (II). Optionally, the obtained ligand (II) reacts with Lu[N(SiMe3)2]3 in an organic medium at a temperature of 25°C to 80°C for 12 to 72 hours. The bis(II) is then collected from the reaction product. β -Diketone imine lutetium compound (Ⅰ); In the above preparation method, substituent X is the same as the bifurcation described in any one of claims 1 to 3. β - The requirements for each corresponding group of the diketimine ligand (II) and its lutetium metal compound (I) are consistent; X and the dual as described in any one of claims 1 to 2 β The requirements for the corresponding groups in lutetium compounds (Ⅰ) with -diketone imine ligands are consistent; The alcohol compound is R`OH, where R` represents alkyl or benzyl, and the alkyl group is preferably a C1 to C5 alkyl group; pair β The molar ratio of diketoimine ligand (II) to Lu[N(SiMe3)2]3 is 2:1 to 1:1; The organic medium is selected from one or two of toluene, tetrahydrofuran, benzene, diethyl ether, n-hexane, and petroleum ether; The dual β -Diketone imine lutetium compounds are lactone polymerization catalysts and can be used for... L -lactide, D -lactide, rac -lactide, meso -Lactose, caprolactoneβ -Butyrolactone, α The polymerization reaction of methyltrimethylene cyclic carbonate can be carried out by solution polymerization and melt polymerization.
[0021] The dual β - A diketimine lutetium compound is used as a catalyst to polymerize lactide. The molar ratio of the catalyst to the lactide monomer during polymerization is 1:1 to 10000.
[0022] The dual β Using a diketimine-based lutetium compound as a catalyst, lactide is polymerized at 25°C to 80°C in the presence of an alcohol. The molar ratio of catalyst to alcohol and monomer during polymerization is 1:1 to 50:1 to 10000; the alcohol is C1 to C2. 10 Alkyl alcohols with straight-chain, branched, or cyclic structures, C7~C 20 Mono- or polyaryl-substituted alkyl alcohols.
[0023] The dual β Using a diketimine-lutetium compound as a catalyst, in the presence of an alcohol, ... caprolactone or β α-Butyrolactone or α-methyltrimethylene cyclic carbonate polymerization; wherein the alcohol is C1~C1. 10 Alkyl alcohols with straight-chain, branched, or cyclic structures, C7~C 20 Mono- or polyaryl-substituted alkyl alcohols.
[0024] Example 1 Synthesis of TM1 Weigh p-fluoroaniline (4.44 g, 40 mmol), acetylacetone (4 g, 40 mmol), and p-toluenesulfonic acid (0.076 g, 1 mol%) into a 250 mL round-bottom flask. Reflux in toluene for 12 hours, cool to room temperature, remove toluene, recrystallize with ethanol, filter, remove solvent, and dry to obtain a yellow powder. Name the obtained substance TM1 for later use. Yield: 5.03 g, yield: 65.1%. The structural formula of TM1 is as follows: Elemental Analysis: calcd. For C 11 H 12 FNO: C 68.38; H 6.26; N 7.25.Found: C 68.55; H 6.53; N 6.98.
[0025] Ligand H2L 1 Synthesis TM1 (3.86 g, 20 mmol) was weighed and dissolved in 10 mL of dichloromethane. Then, triethyloxonium tetrafluoroboric acid ([Et3O][BF4]) (3.8 g, 20 mmol) was added. The mixture was stirred at room temperature for one day, followed by the addition of ethylenediamine (0.64 g, 10 mmol) and two drops of triethylamine. Stirring continued for two more days. After the reaction was complete, the solvent was evaporated to dryness, and the solid was dissolved in saturated sodium hydroxide solution. The mixture was extracted three times with dichloromethane, and the organic layers were combined. The solids were dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated to dryness again. Anhydrous ethanol was used as the recrystallization reagent, and the mixture was allowed to stand at low temperature to obtain the ligand H2L. 1 Yield: 2.28 g, Yield: 55.5%. Ligand H2L 1 The structure is as follows: Elemental Analysis: calcd. For C 24 H 28 F2N4: C 70.22; H 6.88; N 13.65. Found: C 70.61; H 6.56; N 13.82.
[0026] Synthesis of Lu1 Weigh out H2L in a glove box filled with high-purity nitrogen. 1 Dissolve 0.4102 g (1 mmol) of Lu[N(SiMe3)2]3 (0.6552 g, 1 mmol) in 2 mL of tetrahydrofuran in a Schlenk flask. Then, add the reaction mixture to the Schlenk flask and react in an oil bath at 75°C for 12 hours. Dry the mixture under vacuum, add n-hexane, stir, allow to stand, and discard the supernatant. Repeat this process twice. Finally, dry the solvent to obtain compound Lu1. Yield: 0.4474 g, 60.2%.
[0027] Elemental Analysis: calcd. For C 30 H 44 F2N5Si2Lu: C 48.44; H 5.96; N9.42. Found: C 48.65; H 5.76; N 9.68.
[0028] Example 2 Synthesis of TM2 Weigh p-chloroaniline (5.08 g, 40 mmol), acetylacetone (4 g, 40 mmol), and p-toluenesulfonic acid (0.076 g, 1 mol%) into a 250 mL round-bottom flask. Reflux in toluene for 12 hours, cool to room temperature, remove toluene, recrystallize with ethanol, filter, remove solvent, and dry to obtain a yellow powder. Name the obtained substance TM2 for later use. Yield: 5.18 g, yield: 61.9%. The structural formula of TM2 is as follows: Elemental Analysis: calcd. For C 11 H 12 ClNO: C 63.01; H 5.77; N 6.68. Found: C 63.24; H 5.96; N 6.38.
[0029] Ligand H2L 2 Synthesis TM2 (4.18 g, 20 mmol) was weighed and dissolved in 10 mL of dichloromethane. Then, triethyloxonium tetrafluoroboric acid ([Et3O][BF4]) (3.8 g, 20 mmol) was added. The mixture was stirred at room temperature for one day, followed by the addition of ethylenediamine (0.64 g, 10 mmol) and two drops of triethylamine. Stirring continued for two more days. After the reaction was complete, the solvent was evaporated to dryness, and the solid was dissolved in saturated sodium hydroxide solution. The mixture was extracted three times with dichloromethane, and the organic layers were combined. The solids were dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated to dryness again. Anhydrous ethanol was used as the recrystallization reagent, and the mixture was allowed to stand at low temperature to obtain the ligand H2L. 2 Yield: 2.29 g, Yield: 51.9%. Ligand H2L 2 The structure is as follows: Elemental Analysis: calcd. For C 24 H 28 Cl2N4: C 65.01; H 6.37; N 12.64. Found: C 65.24; H 6.68; N 12.24.
[0030] Synthesis of Lu2 Weigh out H2L in a glove box filled with high-purity nitrogen. 2(0.4422 g, 1 mmol) was dissolved in a Schlenk flask with 2 mL of tetrahydrofuran. Then, 0.6322 g, 1 mmol) of Lu[N(SiMe3)2]3 was weighed and added to the same Schlenk flask. The mixture was reacted in an oil bath at 75°C for 12 hours. The mixture was then dried under vacuum, and n-hexane was added. The mixture was stirred, allowed to stand, and the supernatant was discarded. This process was repeated twice. Finally, the solvent was dried to obtain compound Lu2. Yield: 0.5155 g, 66.5%.
[0031] Elemental Analysis: calcd. For C 30 H 44 Cl2N5Si2Lu: C 46.39; H 5.71; N9.02. Found: C 46.25; H 5.67; N 9.18.
[0032] Example 3 Initiator-free polymerization: In a glove box filled with high-purity nitrogen, add to a 10 mL dry Schlenk flask... rac -LA monomer (0.144 g, 1 mmol), then add 0.5 mL of tetrahydrofuran. Weigh compound Lu1 (0.0677 g, 0.1 mmol) into the above solution, then take the Schlenk flask out of the glove box and place it in a 60°C oil bath with stirring for 80 min. After stirring, use 4 mL of concentrated V... HCl :V EtOH The reaction was quenched with a 1:5 mixed solution. After the solvent was removed under reduced pressure, the polymer was dissolved in tetrahydrofuran, and a small amount of the solution was dried under reduced pressure to determine the conversion rate. The remaining solution was precipitated in methanol until complete precipitation, and then dried under vacuum to constant weight. 1 ¹H NMR isonuclear decoupling assay and GPC analysis. Conversion rate 89%, Mn = 3.42 × 10⁻⁶. 4 g / mol, molecular weight distribution: PDI = 1.62, isotacticity: P m = 0.42.
[0033] Example 4 Polymerization with benzyl alcohol (BnOH) as an initiator: In a glove box filled with high-purity nitrogen, add [the following to a 10 mL dry Schlenk flask] rac -LA monomer (0.144 g, 1 mmol) and a prepared tetrahydrofuran solution of benzyl alcohol (2.16 mg / mL, 0.02 mmol / mL) were added to the above solution. Compound Lu1 (0.0677 g, 0.1 mmol) was then added to the above solution. The Schlenk flask was removed from the glove box and reacted in a 60°C oil bath for 45 min. The remaining post-processing was the same as in Example 3. The conversion rate was 92%, and Mn = 1.78 × 10⁻⁶. 4 g / mol, molecular weight distribution: PDI = 1.4, isotacticity: P m = 0.39.
[0034] Example 5 Polymerization of benzyl alcohol (BnOH) without initiator: In a glove box filled with high-purity nitrogen, add [the following to a 10 mL dry Schlenk flask] rac -LA monomer (0.144 g, 1 mmol) and a prepared tetrahydrofuran solution of benzyl alcohol (2.16 mg / mL, 0.02 mmol / mL) were added to the above solution. Compound Lu2 (0.0775 g, 0.1 mmol) was then added to the above solution. The Schlenk flask was removed from the glove box and reacted in a 60°C oil bath for 90 min. The remaining post-processing was the same as in Example 3. The conversion rate was 88%, and Mn = 3.28 × 10⁻⁶. 4 g / mol, molecular weight distribution: PDI = 1.68, isotacticity: P m = 0.4.
[0035] Example 6 At 25ºC, in a glove box filled with high-purity nitrogen, add to a 10 mL dry Schlenk flask Add caprolactone (0.114 g, 1.0 mmol) to 0.5 mL of [a solution containing...]. i Dissolve compound Lu1 in tetrahydrofuran solution (PrOH), weigh 0.0677 g (0.1 mmol), and add to a Schlenk flask. React for 50 min, then proceed as in Example 3. The conversion rate was 84%, Mn = 2.8 × 10⁻⁶. 4 g / mol, molecular weight distribution PDI = 1.42.
[0036] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0037] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of the claims of this application.
Claims
1. A bisβ-diketone imine lutetium compound, characterized in that, It has the structure shown in equation (I): Formula (I) In formula (I), Lu is the rare earth metal lutetium; X is fluorine or chlorine; the compound contains a -N(SiMe3)2 group as an amido ligand, and Me is a methyl group.
2. The bisβ-diketone imine lutetium compound according to claim 1, characterized in that, The compound is selected from one of the following: (1) X is fluorine, with the molecular formula C 30 H 44 F2N5Si2Lu; (2) X is chlorine, with the molecular formula C. 30 H 44 Cl2N5Si2Lu.
3. The bisβ-diketone imine lutetium compound according to claim 1 or 2, characterized in that, The compound was prepared by reacting a bis-β-diketone imine ligand as shown in formula (II) with Lu[N(SiMe3)2]3; In formula (II), the two β-diketone imine units are bridged by ethylenediamine, and each β-diketone imine unit has a fluorine or chlorine substituent attached to the para-position of the benzene ring.
4. The method for preparing the bisβ-diketone imine lutetium compound according to any one of claims 1 to 3, characterized in that, Under an inert atmosphere, the bisβ-diketone imine ligand shown in formula (II) was mixed with Lu[N(SiMe3)2]3 in an organic solvent and reacted at 25℃ to 80℃ for 12 to 72 hours. After the reaction was completed, the solvent was removed, the mixture was washed with n-hexane for purification, and dried to obtain the bisβ-diketone imine lutetium compound (I).
5. The method for preparing the bisβ-diketone imine lutetium compound according to claim 4, characterized in that, The preparation method of the ligand of formula (II) includes the following steps: Step 1: Acetylacetone, p-halogenated aniline, and a catalytic amount of p-toluenesulfonic acid are refluxed in toluene for 8–24 hours. After cooling, the solvent is removed, and the mixture is recrystallized from ethanol to obtain β-enamine ketone intermediate TM. The amount of p-toluenesulfonic acid used is 0.5–2 mol% of the molar amount of acetylacetone. Step 2: Dissolve the intermediate TM obtained in Step 1 in dichloromethane, add triethyloxonium tetrafluoroborate [Et3O][BF4], and stir the reaction at room temperature for 18-30 hours; then add ethylenediamine and triethylamine, and continue stirring the reaction at room temperature for 36-60 hours; after the reaction, alkalize with saturated sodium hydroxide aqueous solution, extract with dichloromethane, dry with anhydrous sodium sulfate, rotary evaporate, and recrystallize with anhydrous ethanol to obtain ligand (II).
6. The method for preparing the bisβ-diketone imine lutetium compound according to claim 4, characterized in that, The organic solvent is selected from one or a mixture of two of tetrahydrofuran, toluene, benzene, diethyl ether, n-hexane and petroleum ether; the molar ratio of the ligand of formula (II) to Lu[N(SiMe3)2]3 is 1:1 to 1.1:1; the reaction temperature is 60℃ to 80℃ and the reaction time is 12 to 24 hours.
7. The method for preparing the bisβ-diketone imine lutetium compound according to claim 4 or 6, characterized in that, The inert atmosphere is high-purity nitrogen or argon; the mixing and reaction steps of the ligand with Lu[N(SiMe3)2]3 are carried out in a glove box or Schlenk operating system.
8. The bisβ-diketone imine lutetium compound of claim 1 or 2 in lactide and / or Application of caprolactone as a catalyst in the ring-opening polymerization.
9. The application according to claim 8, characterized in that: The ring-opening polymerization is carried out in solution at 25°C to 80°C; the molar ratio of catalyst to monomer is 1:100 to 1:1000. Polymerization is carried out in the presence of an alcohol initiator, wherein the alcohol initiator is a straight-chain, branched, or cyclic alkyl alcohol containing 1 to 10 carbon atoms, or a benzyl alkyl alcohol containing 7 to 12 carbon atoms; when an alcohol initiator is used, the molar ratio of catalyst, alcohol initiator and monomer is 1:1 to 10:100 to 1000.
10. The application according to claim 8 or 9, characterized in that, The ring-opening polymerization is a solution polymerization; the resulting polymer is polylactide or polycaprolactone; the number-average molecular weight Mn is 1.5 × 10⁻⁶. 4 ~4.0×10 4 g / mol, with a molecular weight distribution index (PDI) of 1.4–1.7.