Bilateral alkyne palladium catalyst as well as preparation method and application thereof
By preparing bilateral alkynyl palladium catalysts, the problem of difficulty in controlling the activity of existing isonitrile polymerization catalysts is solved, efficient isonitrile polymerization and polymer stability are achieved, and the possibilities of modification and post-modification of the catalyst are expanded.
Patent Information
- Application Number
- CN202510635338.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-16
- Publication Date
- 2025-08-15
AI Technical Summary
The existing isonitrile polymerization catalysts have difficulty in controlling activity, are sensitive to monomer substituents and steric hindrance to affect catalyst activity. In addition, organic small molecule catalysts have strict requirements on reaction conditions, making it difficult to achieve efficient isonitrile active polymerization.
A bilateral alkyne palladium catalyst is developed with symmetric bilateral alkyne structural units. It is prepared by a simple synthetic method. The aromatic groups at the end can be replaced and used to catalyze the polymerization of isonitrile monomers. A high-purity catalyst is obtained by mixing reagents in a specific molar ratio and cleaning, recrystallization and other steps.
Highly active polymerization is achieved, with high monomer conversion rate and narrow molecular weight distribution. The polymerization activity can be controlled by regulating the catalyst substituents and the polymerization rate is regulated by terminal functional groups. It is suitable for post-modification and functionalization of isonitrile polymers.
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Figure CN120484029A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of chemistry and polymer synthesis, and in particular to a double acetylene palladium catalyst and a preparation method and application thereof. Background Art
[0002] The polymerization of isonitriles is an important route to construct nitrogen-containing polymer materials. Its product, polyisocyanates, exhibits unique application prospects in optoelectronic materials, self-healing elastomers, and biomedical polymers due to their potential as typical C1 polymers and their conjugated properties. Currently, the catalysts commonly used for isonitrile polymerization include transition metal complexes, such as Ni(II), Pd(II), Pd(II)-Pt(II), or Rh(III) metal complexes; while organic small molecule catalysts include N-heterocyclic carbenes (NHCs) and phosphazene bases (t-Bu-P4). However, existing metal catalysts often have many problems, such as difficulty in controlling active polymerization, sensitivity to monomer substituents, and steric hindrance that reduces catalyst activity. Organic small molecule catalysts also have shortcomings such as sensitivity to the electronic properties of the monomers and the need for precise control of reaction conditions. Therefore, the creation of active polymerization catalysts for isonitriles remains challenging.
[0003] In recent years, Wu et al. have developed a class of unilateral alkyne palladium catalysts, with Pd(II)-OMe as its representative structure, which can achieve the active polymerization of a variety of isonitrile monomers and induce optically active chiral helical polymers through chiral ligands. Positive progress has been made in self-assembly, circularly polarized luminescence and bioantibacterial properties; however, its regulation of catalyst activity and efficient post-modification and functionalization of isonitrile polymers still deserve further exploration.
[0004] Therefore, those skilled in the art are committed to developing a new catalyst with high catalytic activity, simple preparation and convenient synthesis for the active polymerization of phenyl isonitriles. Summary of the Invention
[0005] The purpose of the present invention is to provide a double sided acetylene palladium catalyst and its preparation method and application. The double sided acetylene palladium catalyst prepared by the present invention has high catalytic activity for the polymerization of compounds containing benzene isonitrile, the obtained polymer has stable properties, and the synthesis is simple.
[0006] In one aspect of the present invention, a double-sided alkyne palladium catalyst is provided. According to an embodiment of the present invention, the catalyst has a symmetrical double-sided alkyne structural unit, and the terminal aromatic group and the aromatic-like group can be replaced. Its structural formula is as follows:
[0007]
[0008] Wherein, R2 is a straight chain saturated alkyl group; R1 is One of them.
[0009] In another aspect of the present invention, the present invention provides a method for preparing a double acetylene palladium catalyst. According to an embodiment of the present invention, the method comprises the following steps: under a nitrogen atmosphere, mixing reagent A, trans-bis(triethylphosphine)palladium dichloride, cuprous chloride, and a mixed solvent of dichloromethane and triethylamine, reacting at room temperature for 2-5 hours, and washing and spin-drying after the reaction to obtain a crude product of the double acetylene palladium catalyst, wherein the structural formula of reagent A is: One of them.
[0010] In addition, the preparation method of a double sided alkyne palladium catalyst according to the above embodiment of the present invention may also have the following additional technical features:
[0011] In some embodiments of the present invention, the molar ratio of the reagent A, trans-bis(triethylphosphine)palladium dichloride, and cuprous chloride is (1:2:0.05)-(1:4:0.1).
[0012] In some embodiments of the present invention, the volume ratio of dichloromethane to triethylamine is 1:(1-3).
[0013] In some embodiments of the present invention, the cleaning is carried out by water washing, alkali washing and salt washing in sequence.
[0014] In some embodiments of the present invention, the alkaline washing uses a saturated sodium bicarbonate solution, and the salt washing uses a saturated sodium chloride solution.
[0015] In some embodiments of the present invention, the crude product is mixed with silica gel at a mass ratio of 1-3 times, loaded on a 200-300 mesh silica gel column, and purified by elution with an eluent, the eluent being composed of petroleum ether and ethyl acetate, and the obtained product is further purified by recrystallization with dichloromethane and methanol to obtain a refined double acetylene palladium catalyst.
[0016] In another aspect of the present invention, the present invention provides an application of a double sided acetylene palladium catalyst. According to an embodiment of the present invention, the catalyst is used to catalyze the polymerization reaction of isonitrile monomers.
[0017] In addition, the application of the double sided alkyne palladium catalyst according to the above embodiment of the present invention may also have the following additional technical features:
[0018] In some embodiments of the present invention, the structural formula of the isonitrile monomer is:
[0019] C 16 H 33 、C 10 H21 or C6H 13 One of them.
[0020] Compared with the prior art, the present invention has the following beneficial effects:
[0021] 1) The double-sided alkyne palladium catalyst prepared by the present invention has a simple process and can usually be obtained by only one-step reaction. It has good scalability, is easy to modify and tailor, and is post-functionalized. The monomer conversion rate is high during active polymerization, and the obtained polyphenyl isocyanide has a narrow molecular weight distribution. It is an active controllable polymerization. At the same time, the polymerization activity of the catalyst can be regulated by the catalyst substituents on both sides.
[0022] 2) The present invention can precisely control the polymerization degree of isocyanide by controlling the feed ratio of isocyanide polymerization monomer to catalyst, and on this basis, the chemical reaction and conversion of the terminal functional groups of the isocyanide polymer are carried out to facilitate post-modification and functionalization of the isocyanide polymer, and the polymerization rate of the isocyanide can be regulated by the electron-withdrawing passivation effect and electron-donating activation effect of the terminal functional group substituents of the isocyanide polymer. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 is the double acetylene palladium catalyst in Example 1 of the present invention 1 HNMR (400M H Z ) spectrum;
[0024] Figure 2 is the double acetylene palladium catalyst in Example 1 of the present invention 13 C NMR (101M H Z ) spectrum;
[0025] Figure 3 is an infrared absorption spectrum of the double sided yne palladium catalyst in Example 1 of the present invention;
[0026] Figure 4 is the double acetylene palladium catalyst in Example 2 of the present invention 1 HNMR (400 MHz) spectrum;
[0027] Figure 5 is the double acetylene palladium catalyst in Example 2 of the present invention 13 C NMR (101M H Z ) spectrum;
[0028] Figure 6 The polymer NMR obtained by polymerization with double sided acetylene palladium catalyst in Example 2 of the present invention is 1 H NMR (400 MHz) spectrum;
[0029] Figure 7 The double acetylene palladium catalyst R in Examples 3 and 4 of the present invention 1Aand R 1B Gel permeation chromatograms of samples taken at different times during the polymerization of the same achiral polyphenyl isocyanide, wherein the sample was taken during the polymerization of step 8 in Example 3 (left), and the sampling times from bottom to top are 0h, 2h (M n =6.1kDa, PDI=1.13), 4h(M n =14.8kDa, PDI=1.05), 6h(M n =20.3kDa, PDI=1.08), Example 4 (right) was sampled during step 8 polymerization, and the sampling time from bottom to top was 0h, 2h (M n =4.7kDa, PDI=1.08), 4h(M n =8.7kDa, PDI=1.06), 8h(M n =13.9kDa, PDI=1.15), 12h(M n =19.1 kDa, PDI =1.15). DETAILED DESCRIPTION
[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.
[0031] Example 1
[0032] A method for preparing a double-sided alkyne palladium catalyst comprises the following steps:
[0033] (1) 4-Ethynylanisole (0.10 g, 0.76 mmol), cuprous chloride (10.8 mg, 0.11 mmol), and trans-bistriethylphosphine palladium dichloride (0.67 g, 1.60 mmol) were weighed into a 50 mL two-necked flask. The atmosphere was replaced with nitrogen using a nitrogen balloon. The solvent was 20 mL of triethylamine and dichloromethane in a molar ratio of 1:1. The reaction was monitored by thin-layer chromatography (ethyl acetate:n-hexane = 1:1). The reaction was complete within three hours.
[0034] (2) After the reaction, the organic phase was washed sequentially with water (20 mL × 2), saturated sodium bicarbonate (20 mL × 2), and saturated brine (20 mL × 2), and then dried over anhydrous sodium sulfate. After removing the solvent, the product was loaded onto a 200-mesh column for separation (eluent: ethyl acetate: n-hexane = 1:3) to obtain a crude product as a gray solid.
[0035] (3) The obtained off-white solid was recrystallized from a solution of dichloromethane and n-hexane (v / v = 1:10, 50 mL in total) to obtain white crystals (0.28 g, 61%), which is the double acetylene palladium catalyst, denoted as R 1A The obtained H-C NMR chemical shift is 1 H NMR (400MHz, CDCl3) δ9.95 (s, 2H), 7.86-7.66 (m, 4H), 7.40 (d, J = 8.0Hz, 4H), 2.07 (qt, J = 7.5, 3.3Hz, 12H), 1.39-1.17 (m, 19H). 13 C NMR (101 MHz, CDCl3) δ191.54, 134.80, 133.13, 131.12, 129.66, 119.90, 111.56, 17.20, 8.60. The H-NMR and C-NMR spectra confirmed the correct structure of the catalyst.
[0036] The synthetic chemical reaction equation and synthetic route of the double-sided anisole alkyne palladium catalyst are as follows:
[0037]
[0038] Example 2
[0039] A method for preparing a double-sided alkyne palladium catalyst comprises the following steps:
[0040] (1) 4-Ethynylbenzaldehyde (0.10 g, 0.77 mmol), cuprous chloride (10.8 mg, 0.11 mmol) and trans-bistriethylphosphine palladium dichloride (0.67 g, 1.60 mmol) were weighed into a 50 mL two-necked flask and replaced with a nitrogen atmosphere using a nitrogen balloon. The solvent was triethylamine and dichloromethane in a molar ratio of 1:1, totaling 20 mL. During the reaction, thin layer chromatography (ethyl acetate:n-hexane = 1:1) was used for monitoring. The reaction was completed within three hours.
[0041] (2) After the reaction, the organic phase was washed with water (20 mL × 2), saturated sodium bicarbonate (20 mL × 2), and saturated brine (20 mL × 2), and then dried over anhydrous sodium sulfate. After removing the solvent, the mixture was loaded on a 200-mesh column for separation (eluent: ethyl acetate: n-hexane = 1:2) to obtain a crude product as a gray solid.
[0042] (3) The obtained off-white solid was recrystallized from a solution of dichloromethane and n-hexane (v / v = 1:10, 50 mL in total) to obtain white crystals (0.33 g, 71%), which is the double acetylene palladium catalyst, denoted as R 1B The obtained H-C NMR chemical shift is 1H NMR (400MHz, CDCl3) δ9.95 (s, 2H), 7.86-7.66 (m, 4H), 7.40 (d, J = 8.0Hz, 4H), 2.07 (qt, J = 7.5, 3.3Hz, 12H), 1.39-1.17 (m, 19H). 13 C NMR (101 MHz, CDCl3) δ191.54, 134.80, 133.13, 131.12, 129.66, 119.90, 111.56, 17.20, 8.60. The H-NMR and C-NMR spectra confirmed the correct structure of the catalyst.
[0043] The synthetic chemical reaction equation and synthetic route of the bilateral benzaldehyde alkyne palladium catalyst are shown below:
[0044]
[0045] Example 3
[0046] Bilateral alkyne palladium catalyst R 1A Initiating a polymerization reaction of an achiral benzene isonitrile-containing monomer comprises the following steps:
[0047] (1) First, a 10 mL polymerization bottle was dehydrated and deoxygenated to ensure an anhydrous and oxygen-free environment. Non-chiral phenyl isonitrile-containing monomer (100 mg, 0.33 mmol) and the double-sided alkyne palladium catalyst R prepared in Example 1 were added to the polymerization bottle. 1A (2.0 mg, 0.0033 mmol); wherein, the structural formula of the achiral benzene isonitrile-containing monomer is as follows:
[0048]
[0049] (2) The nitrogen atmosphere was replaced by vacuum three times, 1.2 mL of dry tetrahydrofuran was added, and the mixture was reacted at 55°C for 9 h. The mixture was then cooled to room temperature and added to 10 mL of methanol. The yellow-brown precipitate was washed three times with methanol and dried under vacuum until the mass remained unchanged, yielding 67.4 mg of polyisocyanide with a number average molecular weight of 2.28 × 10 4 , the molecular weight distribution index is 1.08, and its structural formula is as follows:
[0050]
[0051] Where, n=25-150.
[0052] like Figure 7 As shown, it is proved that R 1A Catalyst for the controlled living polymerization of achiral isonitriles.
[0053] Example 4
[0054] Bilateral alkyne palladium catalyst R 1B Initiating a polymerization reaction of an achiral benzene isonitrile-containing monomer comprises the following steps:
[0055] (1) First, a 10 mL polymerization bottle was dehydrated and deoxygenated to ensure an anhydrous and oxygen-free environment. Non-chiral phenyl isonitrile-containing monomer (100 mg, 0.33 mmol) and the double-sided alkyne palladium catalyst R prepared in Example 2 were added to the polymerization bottle. 1B (2.0 mg, 0.0033 mmol); wherein, the structural formula of the achiral benzene isonitrile-containing monomer is as follows:
[0056]
[0057] (2) The nitrogen atmosphere was replaced by vacuum three times, 1.2 mL of dry tetrahydrofuran was added, and the mixture was reacted at 55°C for 9 h. The mixture was then cooled to room temperature and added to 10 mL of methanol. The yellow-brown precipitate was washed three times with methanol and dried under vacuum until the mass remained unchanged, yielding 72.1 mg of polyisocyanide with a number average molecular weight of 2.32 × 10 4 , the molecular weight distribution index is 1.05, and its structural formula is as follows:
[0058]
[0059] Where, n=25-150.
[0060] like Figure 7 As shown, it is proved that R 1B Catalyst for the controlled living polymerization of achiral isonitriles.
[0061] Example 5
[0062] Double sided alkyne palladium catalyst catalyst R 1B Initiating a chiral polymerization reaction containing benzene isonitrile comprises the following steps:
[0063] (1) First, a 10 mL polymerization bottle was dehydrated and deoxygenated to ensure an anhydrous and oxygen-free environment. A chiral benzene isocyanide-containing monomer (100 mg, 0.28 mmol) and the palladium catalyst prepared in Example 2 (1.7 mg, 0.0028 mmol) were added. The chiral benzene isocyanide-containing monomer has the following structural formula:
[0064]
[0065] (2) The nitrogen atmosphere was replaced by vacuum three times, 1.2 mL of dry tetrahydrofuran was added, and the mixture was reacted at 55°C for 9 h. The mixture was then cooled to room temperature and added to 10 mL of methanol. The yellow-brown precipitate was washed three times with methanol and dried under vacuum until the mass remained unchanged, yielding 60.1 mg of polyisocyanate with a number average molecular weight of 2.82 × 10 4 , the molecular weight distribution index is 1.11, and its structure is as follows:
[0066]
[0067] Where, n=25-150.
[0068] Example 6
[0069] Bilateral alkyne palladium catalyst R 1B Initiating a polymerization reaction of a chiral benzene isocyanide-containing monomer comprises the following steps:
[0070] (1) First, a 10 mL polymerization bottle was dehydrated and deoxygenated to ensure an anhydrous and oxygen-free environment. Chiral phenyl isonitrile-containing monomer (100 mg, 0.28 mmol) and the double-sided alkyne palladium catalyst R prepared in Example 2 were added. 1B (1.7 mg, 0.0028 mmol) was added to the polymerization bottle, wherein the chiral benzene isonitrile-containing monomer has the following structural formula:
[0071]
[0072] (2) The nitrogen atmosphere was replaced by vacuum three times, 1.2 mL of dry tetrahydrofuran was added, and the mixture was reacted at 55°C for 9 h. The mixture was then cooled to room temperature and added to 10 mL of methanol. The yellow-brown precipitate was washed three times with methanol and dried under vacuum until the mass remained unchanged, yielding 53.8 mg of polyisocyanide with a number average molecular weight of 3.01×10 4 , the molecular weight distribution index is 1.15, and its structural formula is as follows:
[0073]
[0074] Where, n=25-150.
[0075] This example demonstrates that R 1B Catalyst for the controlled living polymerization of chiral isonitriles.
[0076] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they shall fall within the scope of protection of the present invention.
Claims
1. A double sided alkyne palladium catalyst, characterized in that It has a symmetrical double-sided alkyne structural unit, and the terminal aromatic group and quasi-aromatic group can be replaced. Its structural formula is shown below: Wherein, R2 is a straight chain saturated alkyl group; R1 is, One of them.
2. A method for preparing the double sided alkyne palladium catalyst according to claim 1, characterized in that: The following steps are involved: Under a nitrogen atmosphere, reagent A, trans-bis(triethylphosphine)palladium dichloride, cuprous chloride, and a mixed solvent of dichloromethane and triethylamine were mixed and reacted at room temperature for 2-5 hours. After the reaction, the crude product of the double acetylene palladium catalyst was obtained by washing and spin drying. The structural formula of reagent A is: One of them.
3. The preparation method of a double sided alkyne palladium catalyst according to claim 2, wherein: The molar ratio of the reagent A, trans-bis(triethylphosphine)palladium dichloride and cuprous chloride is (1:2:0.05)-(1:4:0.1).
4. The preparation method of a double sided alkyne palladium catalyst according to claim 2, wherein: The molar ratio of the dichloromethane to triethylamine is 1:(1-3).
5. The preparation method of a double sided alkyne palladium catalyst according to claim 2, wherein: The cleaning is carried out by water washing, alkali washing and salt washing in sequence.
6. The method for preparing a double sided alkyne palladium catalyst according to claim 5, wherein: The alkali washing adopts saturated sodium bicarbonate, and the salt washing adopts saturated sodium chloride.
7. The preparation method of a double sided alkyne palladium catalyst according to claim 2, wherein: The crude product is mixed with silica gel at a mass ratio of 1-3 times, loaded on a 200-300 mesh silica gel column, and purified by elution with an eluent consisting of petroleum ether and ethyl acetate. The obtained product is further purified by recrystallization with dichloromethane and methanol to obtain a refined double acetylene palladium catalyst.
8. An application of the double sided alkyne palladium catalyst according to claim 1, characterized in that: Used to catalyze the polymerization of isocyanide monomers.
9. The use of the double sided alkyne palladium catalyst according to claim 8, wherein The structural formula of the isonitrile monomer is: One of them.