Preparation of oxidized polymeric nickel catalysts and their photocatalytic applications

Abstract

This invention relates to the polymerization of carbazole terpyridine oxidized by ferric chloride. Following methanol quenching, ammonia washing, and Soxhlet extraction with methanol, the corresponding oxidized carbazole terpyridine ligand is obtained. This ligand is then refluxed with anhydrous nickel bromide in methanol for 12 hours. After methanol washing, filtration, Soxhlet extraction, and drying, the corresponding oxidized carbazole terpyridine nickel catalyst is obtained. This oxidized carbazole terpyridine nickel catalyst exhibits excellent catalytic activity in visible light-promoted C-N, C-O, and C-S coupling reactions.

Description

Technical Field

[0001] This invention belongs to the field of heterogeneous transition metal-organic photocatalyst preparation technology, specifically relating to the preparation and catalytic application of a class of oxidative polymerization carbazole terpyridine nickel catalysts. Background Technology

[0002] With the deepening of green chemistry and sustainable manufacturing concepts, photocatalytic organic synthesis technology driven by visible light has attracted widespread attention. This type of photocatalytic process can achieve electron transfer and chemical bond reconstruction under relatively mild conditions, providing an effective pathway for the formation of carbon-heterobonds such as CN, CO, and CS. It features low energy consumption, mild conditions, and good functional group compatibility. Due to the abundant reserves of nickel, its relatively low cost, and its ability to reversibly convert multiple valence states, nickel catalysis has shown good application value in fields such as photo-promoted coupling reactions. In this type of system, nitrogen ligands have a significant regulatory effect on the electron density and spatial environment of the nickel metal center, thereby affecting the formation of active species, substrate activation mechanisms, and reaction selectivity. Among them, 2,2′:6′,2″-terpyridine (abbreviated as terpyridine), as a typical tripentate nitrogen ligand, has the characteristics of strong coordination ability, good structural rigidity, and easy modification. It can form stable coordination complexes with transition metals such as nickel and is widely used in transition metal-promoted homogeneous photocatalytic reactions. However, this type of catalytic system still faces problems such as the need to use additional noble metals iridium and ruthenium photosensitizers to achieve reaction driving and the difficulty in catalyst recovery, which greatly restricts its large-scale application in industry.

[0003] Carbazole groups possess strong electron-donating capabilities and excellent photoelectric properties. Introducing the carbazole structure into the terpyridine ligand framework is expected to enhance its photoresponsiveness and charge transfer efficiency, thereby preparing a novel class of photoresponsive terpyridine ligands (referred to as carbazole terpyridine ligands). The terpyridine nickel complexes formed by these ligands and nickel precursors can serve as potential photocatalysts for photocatalytic coupling reactions. Based on this design concept, the inventors of this patent synthesized a class of carbazole-modified terpyridine nickel complexes (referred to as carbazole terpyridine nickel complexes) and successfully demonstrated their good catalytic activity in coupling reactions using CN, CO, and CS (patent application: 202511099317.X). It is worth mentioning that in this type of catalytic system, the carbazole terpyridine nickel complex simultaneously possesses the dual functions of a photosensitive active unit and a catalytic active center, effectively simplifying the reaction system. However, this system still faces the bottleneck problem of difficult catalyst recovery.

[0004] Considering its electrochemical properties, carbazole readily undergoes oxidative polymerization to form a class of organic polymers. The inventors of this patent believe that, based on oxidation, the carbazole moiety in carbazole-terpyridine can be oxidized to obtain oxidized oxidized carbazole-terpyridine ligands. These ligands can then coordinate with a nickel precursor to ultimately yield a class of oxidized oxidized carbazole-modified terpyridine nickel complexes, referred to simply as oxidized oxidized carbazole-terpyridine nickel complexes. Since the nickel catalytic center and ligand framework structure remain unchanged during the oxidative polymerization process, and the carbazole moiety is directly linked through carbon-carbon bonds, further increasing the range of ligand conjugation systems, this type of organometallic polymer combines the intrinsic catalytic activity of homogeneous catalysts with the ease of separation and recyclability of heterogeneous catalysts. Therefore, it can be widely used as a class of heterogeneous catalysts in visible light-promoted photocatalytic reactions. Summary of the Invention

[0005] The purpose of this invention is to design and prepare a class of highly active oxidative polymerized carbazole terpyridine nickel catalysts. A stable polymer backbone, namely oxidative polymerized carbazole terpyridine, is constructed by oxidative polymerization of carbazole terpyridine ligand units, and further complexed with anhydrous nickel bromide to construct nickel active sites, thereby obtaining a reusable oxidative polymerized carbazole terpyridine nickel complex. Visible light-promoted CN, CO, and CS coupling reactions demonstrate that this heterogeneous catalyst exhibits good photo / nickel synergistic catalytic activity under mild conditions.

[0006]

[0007] Wherein: Cat.1-Cat.3 are abbreviations for three oxidative polymerization carbazole terpyridine nickel catalysts; the “)” in the structural formula represents the carbazole molecules being linked together by carbon-carbon bonds.

[0008] This invention involves the polymerization of three carbazole terpyridine ligands (L1, L2, and L3, the synthesis methods of which are described in patent application: 202511099317.X) by ferric chloride oxidation. After methanol quenching, ammonia washing, and methanol Soxhlet extraction, the corresponding oxidatively polymerized carbazole terpyridine ligands are obtained. These ligands are then refluxed with anhydrous nickel bromide in anhydrous methanol for 12 hours. After methanol washing, filtration, Soxhlet extraction, and drying, the corresponding oxidatively polymerized carbazole terpyridine nickel catalyst is obtained.

[0009] The specific synthesis reaction process of the oxidative polymerization carbazole terpyridine nickel catalyst designed in this invention is as follows:

[0010] Under a nitrogen atmosphere, ferric chloride (5.4 mmol) and anhydrous chloroform (30 mL) were added sequentially to a 100 mL Schlenk reaction flask, and the mixture was stirred to obtain a homogeneous suspension. A 30 mL solution of anhydrous chloroform containing 0.3 mmol of carbazole terpyridine ligand L was slowly added dropwise to this turbid solution. After the addition was complete, the reaction mixture was stirred continuously at room temperature for 24 hours. After the reaction was complete, methanol (50 mL) was added to the system, and stirring was continued for 2 hours. The reaction solvent was removed by filtration, and the filter cake was transferred to a 6 M, 30 mL solution of hydrochloric acid in methanol and refluxed at 80°C with stirring for 24 hours. After cooling to room temperature, the reaction solvent was removed by filtration, and the filter cake was thoroughly washed successively with 10 wt% ammonia and methanol. The filter cake was then transferred to a Soxhlet extraction apparatus, and purification was performed using methanol as the solvent for 24 hours. After cooling to room temperature, the solid product was placed in a vacuum drying oven and dried at 80 degrees Celsius for 12 hours to obtain the oxidized polymerized carbazole terpyridine ligand Poly-L.

[0011] Under a nitrogen atmosphere, 0.2 mmol of the oxidatively polymerized carbazole terpyridine ligand Poly-L, 0.26 mmol of anhydrous nickel bromide, and 20 mL of methanol were added sequentially to a 50 mL Schlenk flask. The reaction was refluxed at 80 °C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, the reaction solvent was removed by filtration, and the filter cake was purified by Soxhlet extraction with methanol for 24 hours. After cooling to room temperature, the solid product was placed in a vacuum drying oven and dried at 80 °C for 12 hours to obtain the oxidatively polymerized carbazole terpyridine nickel catalyst.

[0012] The reaction formula is as follows:

[0013]

[0014] The oxidative polymerization carbazole terpyridine nickel catalyst designed and synthesized in this invention was used for visible light-promoted CN, CO and CS coupling reactions, further demonstrating the excellent photo / nickel synergistic catalytic activity of the catalyst itself.

[0015] The visible light-promoted CN coupling reaction catalyzed by the nickel terpyridine catalyst in the oxidative polymerization of carbazole is described in the following steps:

[0016] Under a nitrogen atmosphere, 3-bromopyridine (0.4 mmol), catalyst (Cat.) (2 mol%), tetrahydropyrrole (1.2 mmol), and N,N-dimethylformamide (4 mL) were added sequentially to a Schlenk reaction tube. The reaction mixture was stirred for 24 hours under blue LED illumination (427 nm). After the reaction, the product was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography and dried under vacuum to obtain a colorless oily target product. The reaction formula is as follows:

[0017]

[0018] The visible light-promoted CO coupling reaction catalyzed by the nickel terpyridine catalyst for the oxidative polymerization of carbazole is described in the following steps:

[0019] Under a nitrogen atmosphere, 3-iodopyridine (0.4 mmol), catalyst (Cat.) (1 mol%), 2-phenylethanol (1.2 mmol), and N,N-dimethylformamide (4 mL) were added sequentially to a Schlenk reaction tube. The reaction was stirred for 24 hours under blue LED light (427 nm). After the reaction, the mixture was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography and dried under vacuum to obtain a colorless oily target product. The reaction formula is as follows:

[0020]

[0021] The visible light-promoted CS coupling reaction catalyzed by the nickel terpyridine catalyst in the oxidative polymerization of carbazole is described in the following steps:

[0022] Under a nitrogen atmosphere, 3-iodopyridine (0.4 mmol), catalyst Cat. (1 mol%), p-methoxythiophenol (1.2 mmol), and N,N-dimethylacetamide (4 mL) were added sequentially to a Schlenk reaction tube. The reaction was stirred for 12 hours under blue LED light (427 nm). After the reaction, the product was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography and dried under vacuum to obtain a colorless oily target product. The reaction formula is as follows:

[0023] Attached Figure Description

[0024] Figure 1 This is a scanning electron microscope image of the nickel terpyridine catalyst Cat.1 used in the oxidative polymerization of carbazole in Example 1.

[0025] Figure 2 This is a scanning electron microscope image of the nickel terpyridine catalyst Cat.2 used in the oxidative polymerization of carbazole in Example 2.

[0026] Figure 3 This is a scanning electron microscope image of the nickel terpyridine catalyst Cat.3 used in the oxidative polymerization of carbazole implemented in Example 3.

[0027] Figure 4The image shows the 1H NMR spectrum of the product from the oxidative polymerization of carbazole terpyridine nickel catalyst Cat.1 catalyzed CN coupling reaction in Example 4.

[0028] Figure 5 The image shows the 1H NMR spectrum of the product from the oxidative polymerization of carbazole terpyridine nickel catalyst Cat.1 catalyzed CN coupling reaction in Example 5.

[0029] Figure 6 The image shows the 1H NMR spectrum of the product from the CO coupling reaction catalyzed by the nickel terpyridine catalyst Cat.1 in Example 6, which was carried out during the oxidative polymerization of carbazole.

[0030] Figure 7 The image shows the 1H NMR spectrum of the product from the CO coupling reaction catalyzed by the nickel terpyridine catalyst Cat.1 in Example 7, which was carried out during the oxidative polymerization of carbazole.

[0031] Figure 8 The image shows the 1H NMR spectrum of the product from the oxidative polymerization of carbazole terpyridine nickel catalyst Cat.1 catalyzed CS coupling reaction in Example 8. Detailed Implementation

[0032] The present invention will be further described in detail below through embodiments, but the present invention is not limited to the following embodiments.

[0033] Example 1: Preparation of nickel terpyridine catalyst Cat.1 for oxidative polymerization of carbazole:

[0034]

[0035] Synthesis of the oxidatively polymerized carbazole terpyridine ligand Poly-L1: Under a nitrogen atmosphere, ferric chloride (5.4 mmol, 876 mg) and anhydrous chloroform (30 mL) were added sequentially to a 100 mL Schlenk reaction flask, and the mixture was stirred to obtain a homogeneous suspension. An anhydrous chloroform solution (30 mL) of carbazole terpyridine ligand L1 (0.3 mmol, 291 mg) was slowly added dropwise to this turbid mixture. After the addition was complete, the reaction mixture was stirred continuously at room temperature for 24 hours. After the reaction was complete, methanol (50 mL) was added to the system, and stirring was continued for 2 hours. The reaction solvent was removed by filtration, and the filter cake was transferred to a methanol solution of hydrochloric acid (6 M, 30 mL), and refluxed at 80 °C with stirring for 24 hours. After cooling to room temperature, the reaction solvent was removed by filtration, and the filter cake was thoroughly washed successively with 10 wt% ammonia and methanol. The filter cake was then transferred to a Soxhlet extraction apparatus, and purification was performed using methanol as the solvent for 24 hours. After cooling to room temperature, the solid product was placed in a vacuum drying oven and dried at 80°C for 12 hours to obtain the oxidatively polymerized carbazole terpyridine ligand Poly-L1. Yield: 0.276 g, 95%.

[0036] Synthesis of the oxidative polymerization of carbazole terpyridine nickel catalyst Cat.1: Under a nitrogen atmosphere, the oxidative polymerization of carbazole terpyridine ligand Poly-L1 (0.2 mmol, 191 mg), anhydrous nickel bromide (0.26 mmol, 57 mg), and methanol (20 mL) were added sequentially to a 50 mL Schlenk flask. The reaction was refluxed at 80 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature, the reaction solvent was removed by filtration, and the filter cake was purified by Soxhlet extraction with methanol for 24 h. After cooling to room temperature, the solid product was placed in a vacuum drying oven and dried at 80 °C for 12 h to obtain the reddish-brown solid oxidative polymerization of carbazole terpyridine nickel catalyst Cat.1. Yield: 0.230 g, 97%.

[0037] Example 2: Preparation of nickel terpyridine catalyst Cat.2 for oxidative polymerization of carbazole:

[0038]

[0039] Synthesis of the oxidatively polymerized carbazole terpyridine ligand Poly-L2: Under a nitrogen atmosphere, ferric chloride (14.4 mmol, 2.3 g) and anhydrous chloroform (50 mL) were added sequentially to a 100 mL Schlenk reaction flask, and the mixture was stirred to obtain a homogeneous suspension. An anhydrous chloroform solution (30 mL) of carbazole terpyridine ligand L2 (0.8 mmol, 512 mg) was slowly added dropwise to this turbid mixture. After the addition was complete, the reaction mixture was stirred continuously at room temperature for 24 hours. After the reaction was complete, methanol (50 mL) was added to the system, and stirring was continued for 2 hours. The reaction solvent was removed by filtration, and the filter cake was transferred to a methanol solution of hydrochloric acid (6 M, 30 mL), and refluxed at 80 °C with stirring for 24 hours. After cooling to room temperature, the reaction solvent was removed by filtration, and the filter cake was thoroughly washed successively with 10 wt% ammonia and methanol. The filter cake was then transferred to a Soxhlet extraction apparatus, and purification was performed using methanol as the solvent for 24 hours. After cooling to room temperature, the solid product was placed in a vacuum drying oven and dried at 80°C for 12 hours to obtain the oxidized polymerized carbazole terpyridine ligand Poly-L2. Yield: 0.486 g, 95%

[0040] Synthesis of the oxidative polymerization of carbazole terpyridine nickel catalyst Cat.2: Under a nitrogen atmosphere, oxidative polymerization of carbazole terpyridine ligand Poly-L2 (0.2 mmol, 238 mg), anhydrous nickel bromide (0.26 mmol, 57 mg), and methanol (20 mL) were added sequentially to a 50 mL Schlenk flask. The reaction was refluxed at 80 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature, the reaction solvent was removed by filtration, and the filter cake was purified by Soxhlet extraction with methanol for 24 h. After cooling to room temperature, the solid product was placed in a vacuum drying oven and dried at 80 °C for 12 h to obtain a brown solid oxidative polymerization of carbazole terpyridine nickel catalyst Cat.2. Yield: 0.177 g, 97%.

[0041] Example 3: Preparation of nickel terpyridine catalyst Cat.3 for oxidative polymerization of carbazole:

[0042]

[0043] Synthesis of the oxidatively polymerized carbazole terpyridine ligand Poly-L3: Under a nitrogen atmosphere, ferric chloride (9 mmol, 1.46 g) and anhydrous chloroform (30 mL) were added sequentially to a 100 mL Schlenk reaction flask, and the mixture was stirred to obtain a homogeneous suspension. An anhydrous chloroform solution (30 mL) of carbazole terpyridine ligand L3 (0.5 mmol, 320 mg) was slowly added dropwise to this turbid mixture. After the addition was complete, the reaction mixture was stirred continuously at room temperature for 24 hours. After the reaction was complete, methanol (50 mL) was added to the system, and stirring was continued for 2 hours. The reaction solvent was removed by filtration, and the filter cake was transferred to a methanol solution of hydrochloric acid (6 M, 30 mL), and refluxed at 80 °C with stirring for 24 hours. After cooling to room temperature, the reaction solvent was removed by filtration, and the filter cake was washed thoroughly with 10 wt% ammonia and methanol sequentially. The filter cake was then transferred to a Soxhlet extraction apparatus, and purification was performed using methanol as the solvent for 24 hours. After cooling to room temperature, the solid product was placed in a vacuum drying oven and dried at 80°C for 12 hours to obtain the oxidized polymerized carbazole terpyridine ligand Poly-L3. Yield: 0.30 g, 94%.

[0044] Synthesis of the oxidative polymerization carbazole terpyridine nickel catalyst Cat.3: Under a nitrogen atmosphere, oxidative polymerization carbazole terpyridine ligand Poly-L3 (0.2 mmol, 238 mg), anhydrous nickel bromide (0.26 mmol, 57 mg), and methanol (20 mL) were added sequentially to a 50 mL Schlenk flask. The reaction was refluxed at 80 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature, the reaction solvent was removed by filtration, and the filter cake was purified by Soxhlet extraction with methanol for 24 h. After cooling to room temperature, the solid product was placed in a vacuum drying oven and dried at 80 °C for 12 h to obtain the brown solid oxidative polymerization carbazole terpyridine nickel catalyst Cat.3. Yield: 0.173 g, 98%.

[0045] Example 4: Nickel terpyridine catalyst Cat.1 for catalyzing CN coupling reaction in oxidative polymerization of carbazole:

[0046]

[0047] Under a nitrogen atmosphere, 3-bromopyridine (0.4 mmol), catalyst Cat.1 (2 mol%), tetrahydropyrrole (1.2 mmol), and N,N-dimethylformamide (4 mL) were added sequentially to a Schlenk reaction tube. The reaction was stirred for 24 hours under blue LED light (wavelength 427 nm). After the reaction was complete, the product was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography (PE:EA = 20:1), followed by vacuum drying to obtain a colorless oily target product. Yield: 0.050 g, 85%.

[0048] NMR analysis: 1 H NMR (600MHz, CDCl3): δ=7.42-7.43(m, 2H), 6.53-6.55(m, 2H), 3.30-3.32(m, 4H), 2.01-2.04(m, 4H).

[0049] Example 5: Nickel terpyridine catalyst Cat.1 for catalyzing CN coupling reaction in oxidative polymerization of carbazole:

[0050]

[0051] Under a nitrogen atmosphere, 4-bromobenzonitrile (0.4 mmol), catalyst Cat.1 (2 mol%), tetrahydropyrrole (1.2 mmol), and N,N-dimethylformamide (4 mL) were added sequentially to a Schlenk reaction tube. The reaction was stirred for 24 hours under blue LED light (wavelength 427 nm). After the reaction was complete, the product was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography (PE:EA = 10:1), followed by vacuum drying to obtain a colorless oily target product. Yield: 0.062 g, 90%.

[0052] NMR analysis: 1 H NMR (600MHz, CDCl3): δ=7.45 (d, J=8.9Hz, 2H), 6.50 (d, J=8.8Hz, 2H), 3.33 (t, J=6.7Hz, 4H), 2.05-2.03 (m, 4H).

[0053] Example 6: Nickel terpyridine catalyst Cat.1 for catalyzing CO coupling reaction during oxidative polymerization of carbazole:

[0054]

[0055] Under a nitrogen atmosphere, 3-iodopyridine (0.4 mmol), catalyst Cat.1 (1 mol%), benzyl alcohol (1.2 mmol), 2-tert-butyl-1,1,3,3-tetramethylguanidine (tBuMG, 1.2 mmol), and tetrahydrofuran (4 mL) were added sequentially to a Schlenk reaction tube. The reaction was stirred for 24 hours under blue LED light (wavelength 427 nm). After the reaction was completed, the product was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography (PE:EA = 10:1), followed by vacuum drying to obtain a colorless oily target product. Yield: 0.063 g, 85%.

[0056] NMR analysis: 1 H NMR (600MHz, CDCl3): δ=8.45 (s, 1H), 8.29 (s, 1H), 7.50-7.41 (m, 5H), 7.32 (t, J=6.4Hz, 2H), 5.17 (s, 2H).

[0057] Example 7: Nickel terpyridine catalyst Cat.1 for catalyzing CO coupling reaction during oxidative polymerization of carbazole:

[0058]

[0059] Under a nitrogen atmosphere, 3-iodopyridine (0.4 mmol), catalyst Cat.1 (1 mol%), n-butanol (1.2 mmol), 2-tert-butyl-1,1,3,3-tetramethylguanidine (tBuMG, 1.2 mmol), and N,N-dimethylformamide (4 mL) were added sequentially to a Schlenk reaction tube. The reaction was stirred for 24 hours under blue LED light (wavelength 427 nm). After the reaction was completed, the product was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography (PE:EA = 10:1). After vacuum drying, a colorless oily target product was obtained. Yield: 0.053 g, 87%.

[0060] NMR analysis: 1 H NMR (600MHz, CDCl3): δ=8.30 (d, J=2.3Hz, 1H), 8.20 (d, J=4.1Hz, 1H), 7.21-7.17 (m, 2H ), 4.01 (t, J=6.5Hz, 2H), 1.81-1.76 (m, 2H), 1.53-1.47 (m, 2H), 0.99 (t, J=7.4Hz, 3H).

[0061] Example 8: Nickel terpyridine catalyst Cat.1 for catalyzing CS coupling reaction in oxidative polymerization of carbazole:

[0062]

[0063] Under a nitrogen atmosphere, 3-iodopyridine (0.4 mmol), catalyst Cat.1 (1 mol%), 4-methoxythiophenol (1.2 mmol), and N,N-dimethylacetamide (4 mL) were added sequentially to a Schlenk reaction tube. The reaction was stirred for 12 hours under blue LED light (wavelength 427 nm). After the reaction was complete, the mixture was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography (PE:EA = 10:1), followed by vacuum drying to obtain a colorless oily target product. Yield: 0.085 g, 98%.

[0064] NMR analysis: 1 H NMR (600MHz, CDCl3): δ=8.43 (d, J=1.7Hz, 1H), 8.36 (d, J=3.8Hz, 1H), 7.44-7.41 (m, 3H), 7.14 (q, J=4.2Hz, 1H), 6.92-6.90 (m, 2H), 3.83 (s, 3H).

[0065] Example 9: Nickel terpyridine catalyst Cat.2 for catalyzing CS coupling reaction in the oxidative polymerization of carbazole:

[0066]

[0067] Under a nitrogen atmosphere, 3-iodopyridine (0.4 mmol), catalyst Cat.2 (1 mol%), 4-methoxybenzylthiol (1.2 mmol), and N,N-dimethylacetamide (4 mL) were added sequentially to a Schlenk reaction tube. The reaction was stirred for 12 hours under blue LED light (wavelength 427 nm). After the reaction was complete, the mixture was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography (PE:EA = 10:1), followed by vacuum drying to obtain a colorless oily target product. Yield: 0.053 g, 61%.

[0068] NMR analysis: 1 H NMR (600MHz, CDCl3): δ=8.43 (d, J=1.7Hz, 1H), 8.36 (d, J=3.8Hz, 1H), 7.44-7.41 (m, 3H), 7.14 (q, J=4.2Hz, 1H), 6.92-6.90 (m, 2H), 3.83 (s, 3H).

[0069] Example 10: Nickel terpyridine catalyst Cat.3 for catalyzing CS coupling reaction in the oxidative polymerization of carbazole:

[0070]

[0071] Under a nitrogen atmosphere, 3-iodopyridine (0.4 mmol), catalyst Cat.3 (1 mol%), 4-methoxythiophenol (1.2 mmol), and N,N-dimethylacetamide (4 mL) were added sequentially to a Schlenk reaction tube. The reaction was stirred for 12 hours under blue LED light (wavelength 427 nm). After the reaction was complete, the mixture was extracted with ethyl acetate (3 × 25 mL), the organic phases were combined, the solvent was removed under reduced pressure, and the product was purified by column chromatography (PE:EA = 10:1), followed by vacuum drying to obtain a colorless oily target product. Yield: 0.068 g, 78%.

[0072] NMR analysis: 1 H NMR (600MHz, CDCl3): δ=8.43 (d, J=1.7Hz, 1H), 8.36 (d, J=3.8Hz, 1H), 7.44-7.41 (m, 3H), 7.14 (q, J=4.2Hz, 1H), 6.92-6.90 (m, 2H), 3.83 (s, 3H).

Claims

1. A class of nickel terpyridine catalysts for the oxidative polymerization of carbazole, the specific structure of which is shown below: Cat.1-Cat.3 are abbreviations for three nickel terpyridine catalysts for the oxidative polymerization of carbazole.

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