Chiral oxazoline cyclic palladium catalysts of acenaphthene-imidazolium nitrogen heterocyclic carbene and their preparation methods and applications

Abstract

This invention belongs to the field of transition metal organometallic catalyst preparation technology, specifically relating to the design and preparation method of a class of chiral oxazoline cyclic palladium catalysts containing acenaphthezide nitrogen-heterocyclic carbene. The objective of this invention is to design and synthesize a class of chiral oxazoline cyclic palladium catalysts containing acenaphthezide nitrogen-heterocyclic carbene with high catalytic activity. The specific synthesis steps involve reacting the corresponding chiral oxazoline cyclic palladium dimer with acenaphthezide nitrogen-heterocyclic carbene in the dry solvent dichloromethane. After column chromatography and other operations, the catalyst is vacuum dried to obtain the corresponding chiral oxazoline cyclic palladium catalyst containing acenaphthezide nitrogen-heterocyclic carbene. This chiral oxazoline cyclic palladium catalyst containing acenaphthezide nitrogen-heterocyclic carbene exhibits high catalytic activity for the Suzuki coupling reaction.

Description

Technical Field

[0001] This invention belongs to the field of transition metal organocatalyst preparation technology, specifically relating to the preparation of a class of acenaphthene-imidazolium nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalysts. Background Technology

[0002] Chiral compounds, such as chiral drugs and natural products, have a crucial impact on human health and well-being. With the development of different types of chiral catalytic systems, transition metal-involved asymmetric catalytic reactions have become one of the most direct and important pathways for synthesizing chiral compounds. As early as 2001, the Nobel Prize in Chemistry was awarded for research on "asymmetric catalytic reactions," in which chiral phosphine ligands played a key role. In the past few decades, in addition to chiral phosphine ligands, sterically hindered chiral nitrogen heterocyclic carbenes (NHCs) and their coordination organometallic compounds have been increasingly widely used in transition metal-catalyzed asymmetric reactions, achieving promising catalytic results. The main reasons are: 1) Using sterically hindered chiral amines as starting materials, chiral nitrogen heterocyclic carbenes with a large steric environment can be synthesized simply and rapidly, and the carbon-metal bond in the carbene in their coordination organometallic compounds exhibits excellent stability to air, water, and high temperatures. 2) The large steric environment of chiral nitrogen heterocyclic carbenes allows the catalyst to exhibit excellent enantiomer selectivity to the substrate. 3) As a ligand, nitrogen-containing heterocyclic carbene has strong σ-electron donor properties and weak π-electron acceptor properties, which further increases the electron density of the metal center. This not only effectively stabilizes the carbene carbon-metal bond, but also improves the catalytic activity of organometallic compounds.

[0003] Nitrogen-heterocyclic carbene ring palladium compounds are a very important class of nitrogen-heterocyclic carbene organometallic compounds. They possess the special properties of cyclic palladium organometallic compounds, exhibiting excellent stability and demonstrating very high catalytic activity in a series of organocatalytic reactions, such as the α-arylation and amination of ketones, and the Suzuki coupling reaction of arylboronic acids and aryl halides. In the structure of nitrogen-heterocyclic carbene ring palladium compounds, in addition to containing carbene carbon-palladium (C... NHC In addition to the -Pd) bond, there is an auxiliary nitrogen ligand containing a nitrogen (N) atom that forms a second carbon-palladium (C) bond with the palladium metal center. NThe carbon-palladium (-Pd) bond is bonded to form a metal heterocyclic ring framework structure containing carbon-palladium bonds. Furthermore, chiral oxazolines, as a class of general nitrogen ligands, have exhibited extremely high catalytic activity and excellent chiral selectivity in transition metal-catalyzed asymmetric reactions. However, regrettably, there are no reported examples of using chiral oxazolines as auxiliary nitrogen ligands to construct chiral nitrogen heterocyclic carbene palladium catalysts. Most importantly, by modifying or replacing different types of chiral oxazolines to construct chiral metal heterocyclic ring framework structures, it is possible to effectively regulate the electronic and chiral spatial environment of the palladium catalytic center, rapidly construct a database of highly catalytically active nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalysts, develop excellent catalytic systems, and provide more alternative catalytic methods for transition metal-catalyzed organic reactions. Summary of the Invention

[0004] The purpose of this invention is to design and prepare a class of highly catalytically active chiral oxazoline cyclic palladium catalysts containing acenaphthene-imidazolium nitrogen-heterocyclic carbenes, and to further demonstrate the high catalytic activity of the catalysts themselves using the Suzuki coupling reaction. The specific structure of the highly catalytically active chiral oxazoline cyclic palladium catalysts designed and synthesized in this invention is shown below:

[0005]

[0006] R 1 =H,Me,iPr;R 2 =H,Me,iPr;

[0007] R 5 =iPr,tBu,Ph; X=Cl,Br.

[0008] Where: Me is methyl, iPr is isopropyl, iBu is tert-butyl, and Ph is phenyl.

[0009] This invention involves reacting different types of chiral oxazoline cyclic palladium dimers with corresponding acenaphthene-imidazolium nitrogen heterocyclic carbenes in dry dichloromethane. After separation by column chromatography and other operations, the corresponding acenaphthene-imidazolium nitrogen heterocyclic carbenes are obtained by vacuum drying.

[0010] The method for synthesizing the chiral oxazoline cyclic palladium catalyst of acenaphthene-imidazolium nitrogen heterocyclic carbene designed in this invention is as follows:

[0011] Method 1:

[0012] Under a nitrogen atmosphere, palladium dichloride (PdCl2, 1 mmol), (S)-2-phenyl-4-isopropyloxazoline (1 mmol), and acetonitrile (ACN, 20 mL) as dry solvent were added sequentially to a Schlenk flask. The mixture was heated and stirred at 70 °C until the reaction system became clear. Under a nitrogen atmosphere, potassium carbonate (K2CO3, 2.5 mmol) was added and stirred. After the system had completely changed color, acenaphthene-imidazole hydrochloride (AnNHC·HCl, 1.00 mmol) was added. The reaction was stirred at 80 °C for 24 hours. After the reaction was completed, the solvent was removed directly under reduced pressure. After separation by column chromatography and other operations, the mixture was dried under vacuum to obtain the corresponding acenaphthene-imidazole nitrogen-containing heterocyclic carbene chiral oxazoline cyclic palladium catalyst. The reaction formula is as follows:

[0013]

[0014] Method 2:

[0015] Under a nitrogen atmosphere, bromine-bridged chiral oxazoline palladium dimer (0.5 mmol), acenaphthene-imidazolium nitrogen heterocyclic carbene (AnNHC, 1.05 mmol), and dry solvent dichloromethane (DCM, 10 mL) were added sequentially to a Schlenk reaction flask. The reaction was stirred at 30 °C for 24 hours. After the reaction was completed, the solvent was removed directly under reduced pressure, and after separation by column chromatography and other operations, the corresponding acenaphthene-imidazolium nitrogen heterocyclic carbene chiral oxazoline palladium catalyst was obtained by vacuum drying. The reaction formula is as follows:

[0016]

[0017] The chiral oxazoline palladium catalyst, designed and synthesized in this invention, for the catalytic Suzuki coupling reaction was used to further demonstrate the high catalytic activity of the catalyst itself. The specific operation procedure of the Suzuki coupling reaction is as follows:

[0018] Under a nitrogen atmosphere, potassium hydroxide (KOH, 1.5 mmol), acenaphthene-imidazolium-based heterocyclic carbene chiral oxazoline palladium catalyst (Cat., 0.5 mol%), 1-bromo-2-methoxynaphthalene (1.0 mmol), 1-naphthoic acid (1.0 mmol), water (H₂O, 0.2 mL), and ethanol (EtOH, 1.8 mL) were added sequentially to a 25 mL Schlenk reaction tube. The reaction was stirred at a specific temperature for a specified time. After the reaction was complete, the solvent was removed under reduced pressure, and the product was separated by column chromatography and dried under vacuum to obtain a white solid coupling reaction target product. The reaction formula is as follows:

[0019] Attached Figure Description

[0020] Figure 1This is a high-resolution mass spectrometry analysis of the acenaphthene imidazole nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 2 (Cat.2) prepared in Example 2.

[0021] Figure 2 This is a high-resolution mass spectrometry analysis of the acenaphthene imidazole nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 3 (Cat.3) prepared in Example 3.

[0022] Figure 3 This is a high-resolution mass spectrometry analysis of the acenaphthene-imidazolium nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 5 (Cat.5) prepared in Example 5. Detailed Implementation

[0023] The present invention will be further described in detail below through embodiments, but the present invention is not limited to the following embodiments.

[0024] Example 1: Preparation of chiral oxazoline cyclic palladium catalyst 1 (Cat. 1) of acenaphthene-imidazolium nitrogen heterocyclic carbene:

[0025]

[0026] Under a nitrogen atmosphere, palladium dichloride (PdCl2, 1 mmol, 0.177 g), (S)-2-phenyl-4-isopropyloxazoline (1 mmol, 0.189 g), and acetonitrile (ACN, 20 mL) as a dry solvent were added sequentially to a Schlenk flask. The mixture was heated and stirred at 70 °C until the reaction system became clear. Under a nitrogen atmosphere, potassium carbonate (K2CO3, 2.5 mmol, 0.346 g) was added and stirred. After the system had completely changed color, acenaphthene-imidazole hydrochloride (AnIPr·HCl, 1.00 mmol, 0.549 g) was added. The reaction was stirred at 80 °C for 24 hours. After the reaction was completed, the solvent was removed directly under reduced pressure. After column chromatography and other operations, the mixture was dried under vacuum to obtain the corresponding acenaphthene-imidazole nitrogen-containing heterocyclic carbene chiral oxazoline cyclic palladium catalyst 1 (Cat. 1). Yield: 0.314 g, 37%.

[0027] NMR analysis: 1H NMR (CDCl3, 600MHz, 298K): δ=7.72 (q, J=3.9Hz, 2H), 7.52 (q, J=7.5Hz, 2H), 7.33-7.40 (m, 4H), 7.30 (t, J=4.3Hz, 2H ), 7.12 (q, J=3.0Hz, 1H), 6.88-6.99 (m, 4H), 6.81 (d, J=7Hz, 1H), 4.37 (q, J=4.5Hz, 1H), 4.29 (t, J=9.2Hz, H), 4.18- 4.22 (m, 1H), 3.49-3.55 (m, 2H), 3.14-3.22 (m, 2H), 2.47-2.54 (m, 1H), 1.48 (q, J=5.9Hz, 6H), 1.14 (q, J=6.5Hz, 6H) , 0.73 (d, J=7.1Hz, 3H), 0.69 (d, J=6.8Hz, 3H), 0.63 (d, J=6.8Hz, 3H), 0.52 (d, J=6.7Hz, 3H), 0.45 (q, J=6.7Hz, 6H); 13 C NMR (CDCl3, 600MHz, 298K) δ = 185.2, 173.8, 153.1, 148.0, 148.0, 146.0, 145.8, 141.2, 140.9 , 137.8, 134.9, 134.8, 133.2, 130.3, 130.2, 130.1, 129.7, 129.6, 127.9, 127.9, 127.4, 127.3 ,126.3,126.2,125.4,125.0,124.7,124.6,124.5,122.9,121.83,121.7,70.2,66.2,53.4,29.1,29.0(5),29.0(2),28.7,28.6(8),25.7,25.5,25.2,24.3,24.1,23.8,23.7,18.7,13.9.

[0028] Mass spectrometry analysis: HR-MS (ESI): m / z 806.3358 (calcd, [M-Cl]) + ); 806.3358 (found, [M-Cl] + ).

[0029] Example 2: Preparation of acenaphthene-imidazolium nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 2 (Cat. 2):

[0030]

[0031] Under a nitrogen atmosphere, bromine-bridged chiral oxazoline palladium dimer Oxa was added sequentially to a Schlenk reaction flask.iPr Pd-dimer 1 (0.5 mmol, 0.375 g), acenaphthene-imidazolium-based heterocyclic carbene (1.05 mmol, 0.538 g), and dry solvent dichloromethane (DCM, 10 mL) were used. The reaction mixture was stirred at 30 °C for 24 hours. After the reaction was complete, the solvent was removed under reduced pressure, and the mixture was separated by column chromatography and then dried under vacuum to obtain the corresponding chiral oxazoline-based palladium catalyst 2 (Cat. 2). Yield: 0.514 g, 58%.

[0032] NMR analysis: 1 H NMR (CDCl3, 600MHz, 298K): δ=7.72 (q, J=4.0Hz, 2H), 7.52 (q, J=8.2Hz, 2H), 7.34-7.40 (m, 4H), 7.30 (d, J=7.7Hz, 2H), 7.12 (q, J=2.9Hz, d, J=1 .4Hz, 1H), 6.88-6.98 (m, 4H), 6.82 (d, J=7Hz, 1H), 4.40 (qq, J=3.8Hz, J=4.5Hz, 1H), 4.18-4.31 (m, 2H), 3.63-3.70 (m, 1H), 3.44-3.54 (m, 1H), 3 .13-3.28(m, 1H), 2.93-3.00(m, 1H), 2.46-2.58(m, 1H), 1.48(td, J=6.4Hz, J=6.7Hz, 6H), 1.11(qd, J=6.5Hz, J=6.8Hz, 6H), 0.73(d, J=7.1Hz, 3 13C NMR (CDCl3, 600MHz, 298K) δ = 185.3, 174.1, 154.8, 147.8, 146.1, 145.9, 141.3(3), 141.3 (0), 137.8, 137.6, 134.9, 133.1, 130.3, 130.2, 130.1, 129.7, 129.5, 127.9, 127.4, 127.3 (8), 126.3, 126.3, 125.3, 125.0, 124.9, 124.8, 124.5, 123.1, 121.8, 121.7, 70.1, 66.6, 29.2, 29.1, 29.0, 28.7, 28.6, 25.7, 25.6, 25.3, 25.0, 24.3, 24.3, 23.9, 23.3, 18.6, 13.6.

[0033] Mass spectrometry analysis: HR-MS (ESI): m / z 806.3359 (calcd, [M-Br]) + ); 806.3359 (found, [M-Br] + ).

[0034] Example 3: Preparation of chiral oxazoline cyclic palladium catalyst 3 (Cat. 3) of acenaphthene-imidazolium nitrogen heterocyclic carbene:

[0035]

[0036] Under a nitrogen atmosphere, bromine-bridged chiral oxazoline palladium dimer Oxa was added sequentially to a Schlenk reaction flask. Ph Pd-dimer 2 (0.5 mmol, 0.409 g), acenaphthene-imidazolium-based heterocyclic carbene (1.05 mmol, 0.538 g), and dry solvent dichloromethane (DCM, 10 mL) were used. The reaction mixture was stirred at 30 °C for 24 hours. After the reaction was complete, the solvent was removed under reduced pressure, and the mixture was separated by column chromatography and then dried under vacuum to obtain the corresponding chiral oxazoline-based palladium catalyst 3 (Cat. 3). Yield: 0.657 g, 71%.

[0037] NMR analysis: 1 H NMR (CDCl3, 600MHz, 298K): δ=7.72 (q, J=3.9Hz, 2H), 7.59 (t, J=7.8Hz, 1H), 7.50 (t, J=7.8Hz, 1H), 7.30-7.40 (m, 6H), 7.19-7.22 (m, 1 H), 7.11-7.14(m, 1H), 7.02-7.08(m, 5H), 6.98-7.01(m, 2H), 6.96(d, J=7Hz, 1H), 6.96(dd, J=7Hz, J=6.9Hz, 1H), 5.5(qq, J=4.6Hz, J=4 .6Hz, 1H), 4.75 (t, J=9.1Hz, 1H), 4.47 (q, J=4.3Hz, 1H), 3.58-3.66 (m, 1H), 3.39-3.55 (m, 2H), 3.14-3.31 (m, 1H), 2.95-3.02 (m, 1H), 1 .43 (dd, J=6.5Hz, J=6.8Hz, 3H), 1.16 (q, J=5.7Hz, 9H), 0.64 (d, J=6.8Hz, 3H), 0.58 (dd, J=7.1Hz, J=7.0Hz, 3H), 0.46 (d, J=6.6Hz, 3H).

[0038] Mass spectrometry analysis: HR-MS (ESI): m / z 840.3145 (calcd, [M-Br]) + ); 840.3146 (found, [M-Br] + ).

[0039] Example 4: Preparation of chiral oxazoline cyclic palladium catalyst 4 (Cat. 4) of acenaphthene-imidazolium nitrogen heterocyclic carbene:

[0040]

[0041] Under a nitrogen atmosphere, bromine-bridged chiral oxazoline palladium dimer OxaMe was added sequentially to a Schlenk reaction flask. Ph Pd-dimer 3 (0.25 mmol, 0.211 g), acenaphthene-imidazolium-based heterocyclic carbene (0.55 mmol, 0.269 g), and dry solvent dichloromethane (DCM, 10 mL) were used. The reaction was carried out at 30 °C with stirring for 24 hours. After the reaction was completed, the solvent was removed directly under reduced pressure, and the mixture was separated by column chromatography and then dried under vacuum to obtain the corresponding chiral oxazoline-based palladium catalyst 4 (Cat. 4). Yield: 0.289 g, 62%.

[0042] NMR analysis: 1 H NMR (CDCl3, 600MHz, 298K): δ=7.70 (q, J=3.9Hz, 2H), 7.55 (t, J=7.8Hz, 1H), 7.48 (t, J=7.7Hz, 1H), 7.28-7.39 (m, 6H), 7.17 (q, J =2.9Hz, 1H), 7.09-7.12 (m, 4H), 7.04 (t, J = 7.3Hz, 2H), 6.97 (t, J = 7.5Hz, 1H), 6.90 (d, J = 7.0Hz, 1H), 6.79 (d, J = 7.0Hz, 1H), 5.5 7 (q, J=4.6Hz, 1H), 4.73 (q, J=6.1Hz, 1H), 4.47 (q, J=4.7Hz, 1H), 3.93-3.98 (m, 1H), 3.70-3.75 (m, 1H), 2.70-2.76 (m, 2H), 1.36 (d, J=6.6Hz, 3H), 1.17 (d, J=6.6Hz, 3H), 1.09 (d, J=6.8Hz, 3H), 1.05 (d, J=6.8Hz, 3H), 0.77 (d, J=6.7Hz, 3H), 0.66-0.71 (m, 9H).

[0043] Mass spectrometry analysis: HR-MS (ESI): m / z 854.3302 (calcd, [M-Br]) +); 854.3302 (found, [M-Br] + ).

[0044] Example 5: Preparation of acenaphthene-imidazolium nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 5 (Cat.5):

[0045]

[0046] Under a nitrogen atmosphere, bromine-bridged chiral oxazoline-cyclic palladium dimer OxatBuNaphthPd-dimer 4 (0.5 mmol, 0.439 g), acenaphthene-imidazolium-based heterocyclic carbene (1.05 mmol, 0.538 g), and dry solvent dichloromethane (DCM, 10 mL) were added sequentially to a Schlenk flask. The reaction was stirred at 30 °C for 24 hours. After the reaction was complete, the solvent was removed directly under reduced pressure, and after column chromatography and other operations, the product was dried under vacuum to obtain the corresponding acenaphthene-imidazolium-based heterocyclic carbene chiral oxazoline-cyclic palladium catalyst 5 (Cat. 5). Yield: 0.303 g, 64%.

[0047] NMR analysis: 1 H NMR (CDCl3, 600MHz, 298K): δ=7.76 (q, J=6.9Hz, 2H), 7.62 (d, J=7.9Hz, 1H), 7.50 (q, J=7.2Hz, 2H), 7.41 (t, J=7.7Hz, 2H), 7.28-7.37 (m, 5H), 7.17 (t, J=7.4Hz, 1H), 7.11 (q, J=2.9Hz, 1H), 7.04 (d, J=7.0Hz, 1H), 7.04 (t, J=7.5 Hz, 2H), 6.84 (d, J=8.8Hz, 1H), 6.76 (d, J=6.9Hz, 1H), 6.69~6.72 (m, 1H), 4. 50-4.55(m, 1H), 4.29-4.35(m, 1H), 4.15-4.24(m, 1H), 3.15-3.22(m, 1H), 2.95-3.05 (m, 2H), 1.45 (q, J=7.2Hz, 6H), 0.81 (dd, J=6.9Hz, J=6.8Hz, 3H) , 0.76 (dd, J=6.8Hz, J=6.9Hz, 3H), 0.69 (m, 12H), 0.41 (dd, J=6.8Hz, J=6.8Hz, 3H), 0.35 (dd, J=6.7Hz, J=6.7Hz, 3H), -0.1 (dd, J=6.7Hz, J=6.7Hz, 3H).

[0048] Mass spectrometry analysis: HR-MS (ESI): m / z 870.3615 (calcd, [M-Br]) +); 870.3613 (found, [M-Br] + ).

[0049] Example 6: Acenamethanilamide nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 1 (Cat. 1) for catalyzing the Suzuki coupling reaction:

[0050]

[0051] Under a nitrogen atmosphere, potassium hydroxide (KOH, 1.5 mmol, 0.084 g), acenaphthene-imidazolium-based heterocyclic carbene chiral oxazoline palladium catalyst 1 (Cat. 1, 0.5 mol%, 4.2 mg), 1-bromo-2-methoxynaphthalene (1.0 mmol, 0.237 g), 1-naphthoic acid (1.0 mmol, 0.172 g), water (H₂O, 0.2 mL), and ethanol (EtOH, 1.8 mL) were added sequentially to a 25 mL Schlenk reaction tube. The reaction was stirred at 40 °C for 12 hours. After the reaction was completed, the solvent was removed under reduced pressure, and the product was separated by column chromatography and dried under vacuum to obtain a white solid coupling reaction target product. Yield: 0.245 g, 86%.

[0052] NMR analysis: 1 H NMR (CDCl3, 600MHz, 298K): δ=7.99 (d, J=9.1Hz, 1H), 7.95 (t, J=7.2Hz, 2H), 7.88 (d, J=8.2Hz, 1H), 7.62 (q, J=6.1Hz, 1H), 7.43-7.48 (m, 3H), 7.31-7.35 (m, 2H), 7.26-7.30 (m, 1H), 7.21-7.25 (m, 1H), 7.16 (d, J=8.5Hz, 1H), 3.77 (s, 3H).

[0053] Example 7: Acenamethanilimidazole nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 2 (Cat. 2) for catalyzing the Suzuki coupling reaction:

[0054]

[0055] Under a nitrogen atmosphere, potassium hydroxide (KOH, 1.5 mmol, 0.084 g), acenaphthene-imidazolium-based heterocyclic carbene chiral oxazoline palladium catalyst 2 (Cat. 2, 0.5 mol%, 4.4 mg), 1-bromo-2-methoxynaphthalene (1.0 mmol, 0.237 g), 1-naphthoic acid (1.0 mmol, 0.172 g), water (H₂O, 0.2 mL), and ethanol (EtOH, 1.8 mL) were added sequentially to a 25 mL Schlenk reaction tube. The reaction was stirred at 40 °C for 12 hours. After the reaction was completed, the solvent was removed under reduced pressure, and the product was separated by column chromatography and dried under vacuum to obtain a white solid coupling reaction target product. Yield: 0.245 g, 86%.

[0056] NMR analysis: 1 H NMR (CDCl3, 600MHz, 298K): δ=7.99 (d, J=9.1Hz, 1H), 7.95 (t, J=7.2Hz, 2H), 7.88 (d, J=8.2Hz, 1H), 7.62 (q, J=6.1Hz, 1H), 7.43-7.48 (m, 3H), 7.31-7.35 (m, 2H), 7.26-7.30 (m, 1H), 7.21-7.25 (m, 1H), 7.16 (d, J=8.5Hz, 1H), 3.77 (s, 3H).

[0057] Example 8: Acenamethanilimidazole nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 4 (Cat. 4) for catalyzing the Suzuki coupling reaction:

[0058]

[0059] Under a nitrogen atmosphere, potassium hydroxide (KOH, 1.5 mmol, 0.084 g), acenaphthene-imidazolium-based heterocyclic carbene chiral oxazoline palladium catalyst 4 (Cat. 4, 0.5 mol%, 4.8 mg), 1-bromo-2-methoxynaphthalene (1.0 mmol, 0.237 g), 1-naphthoic acid (1.0 mmol, 0.172 g), water (H₂O, 0.2 mL), and ethanol (EtOH, 1.8 mL) were added sequentially to a 25 mL Schlenk reaction tube. The reaction was stirred at 40 °C for 12 hours. After the reaction was completed, the solvent was removed under reduced pressure, and the product was separated by column chromatography and dried under vacuum to obtain a white solid coupling reaction target product. Yield: 0.249 g, 87%.

[0060] NMR analysis: 1H NMR (CDCl3, 600MHz, 298K): δ=7.99 (d, J=9.1Hz, 1H), 7.95 (t, J=7.2Hz, 2H), 7.88 (d, J=8.2Hz, 1H), 7.62 (q, J=6.1Hz, 1H), 7.43-7.48 (m, 3H), 7.31-7.35 (m, 2H), 7.26-7.30 (m, 1H), 7.21-7.25 (m, 1H), 7.16 (d, J=8.5Hz, 1H), 3.77 (s, 3H).

[0061] Example 9: Acenamethanilimidazole nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 5 (Cat. 5) for catalyzing the Suzuki coupling reaction:

[0062]

[0063] Under a nitrogen atmosphere, potassium hydroxide (KOH, 1.5 mmol, 0.084 g), acenaphthene-imidazolium-based heterocyclic carbene chiral oxazoline palladium catalyst 5 (Cat. 5, 0.5 mol%, 4.7 mg), 1-bromo-2-methoxynaphthalene (1.0 mmol, 0.237 g), 1-naphthoic acid (1.0 mmol, 0.172 g), water (H₂O, 0.2 mL), and ethanol (EtOH, 1.8 mL) were added sequentially to a 25 mL Schlenk reaction tube. The reaction was stirred at 40 °C for 12 hours. After the reaction was completed, the solvent was removed under reduced pressure, and the product was separated by column chromatography and dried under vacuum to obtain a white solid coupling reaction target product. Yield: 0.254 g, 89%.

[0064] NMR analysis: 1 H NMR (CDCl3, 600MHz, 298K): δ=7.99 (d, J=9.1Hz, 1H), 7.95 (t, J=7.2Hz, 2H), 7.88 (d, J=8.2Hz, 1H), 7.62 (q, J=6.1Hz, 1H), 7.43-7.48 (m, 3H), 7.31-7.35 (m, 2H), 7.26-7.30 (m, 1H), 7.21-7.25 (m, 1H), 7.16 (d, J=8.5Hz, 1H), 3.77 (s, 3H).

[0065] Example 10: Acenamethanilimidazole nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 5 (Cat. 5) for catalyzing the Suzuki coupling reaction:

[0066]

[0067] Under a nitrogen atmosphere, potassium hydroxide (KOH, 1.5 mmol, 0.084 g), acenaphthene-imidazolium-based heterocyclic carbene chiral oxazoline palladium catalyst 5 (Cat. 5, 0.5 mol%, 4.7 mg), 1-bromo-2-methoxynaphthalene (1.0 mmol, 0.237 g), 1-naphthoic acid (1.0 mmol, 0.172 g), water (H₂O, 0.2 mL), and ethanol (EtOH, 1.8 mL) were added sequentially to a 25 mL Schlenk reaction tube. The reaction was stirred at 40 °C for 5 minutes. After the reaction was complete, the solvent was removed under reduced pressure, and the product was separated by column chromatography and dried under vacuum to obtain a white solid coupling reaction target product. Yield: 0.245 g, 86%.

[0068] NMR analysis: 1 H NMR (CDCl3, 600MHz, 298K): δ=7.99 (d, J=9.1Hz, 1H), 7.95 (t, J=7.2Hz, 2H), 7.88 (d, J=8.2Hz, 1H), 7.62 (q, J=6.1Hz, 1H), 7.43-7.48 (m, 3H), 7.31-7.35 (m, 2H), 7.26-7.30 (m, 1H), 7.21-7.25 (m, 1H), 7.16 (d, J=8.5Hz, 1H), 3.77 (s, 3H).

[0069] Example 11: Acenamethanilamide nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst 5 (Cat. 5) for catalyzing the Suzuki coupling reaction:

[0070]

[0071] Under a nitrogen atmosphere, potassium hydroxide (KOH, 1.5 mmol, 0.084 g), acenaphthene-imidazolium-based heterocyclic carbene chiral oxazoline palladium catalyst 5 (Cat. 5, 0.5 mol%, 4.8 mg), 5-bromo-6-methoxyquinoline (1.0 mmol, 0.238 g), 1-naphthoboric acid (1.0 mmol, 0.172 g), water (H₂O, 0.2 mL), and ethanol (EtOH, 1.8 mL) were added sequentially to a 25 mL Schlenk reaction tube. The reaction mixture was stirred at 50 °C for 12 hours. After the reaction was complete, the solvent was removed under reduced pressure, and the product was separated by column chromatography and dried under vacuum to obtain a white solid coupling reaction target product. Yield: 0.263 g, 92%.

[0072] NMR analysis: 1H NMR(CDCl3,600MHz,298K):δ=8.77(q,J=1.9Hz,1H),8.26(d,J=9.3Hz,1H),7.96(q,J=6.3Hz,2H),7.67(d,J=9.4Hz,1H),7.62(q,J=5.1Hz,1H),7.46-7.52(m,2H),7.41(q,J=2.6Hz,1H),7.26-7.32(m,2H),7.14(q,J=4.2Hz,1H),3.80(s,3H)。

Claims

1. A chiral oxazoline cyclic palladium catalyst containing acenaphthene-imidazolium nitrogen-heterocyclic carbene, characterized in that, The specific structure of the catalyst is shown below: R 1 =H,Me,iPr;R 2 =H,Me,iPr;R 5 =iPr,tBu,Ph;X=Cl,Br; Where: Me is methyl, iPr is isopropyl, tBu is tert-butyl, and Ph is phenyl.

2. The method for synthesizing the chiral oxazoline cyclic palladium catalyst of acenaphthene-imidazolium nitrogen heterocyclic carbene according to claim 1, characterized in that, The specific steps are as follows: under a nitrogen atmosphere, the chiral oxazoline cyclic palladium dimer and the acenaphthene-imidazolium nitrogen heterocyclic carbene are reacted in the dry solvent dichloromethane.

3. The application of the acenaphthene-imidazolium nitrogen heterocyclic carbene chiral oxazoline cyclic palladium catalyst according to claim 1 in the Suzuki coupling reaction.

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