Oxazoline-type chiral N, P ligand and its preparation method and application

Abstract

This invention belongs to the field of metal-organic complex synthetic chemistry, specifically relating to an oxazoline-type chiral N,P ligand represented by formula (I), its preparation method, and application. The oxazoline-type chiral N,P ligand represented by formula (I) can be used to prepare an oxazoline-type chiral N,P ligand manganese complex. The resulting manganese complex has a simple structure and is easy to synthesize. It can also be used to catalyze the asymmetric hydrogenation of aromatic ketone compounds under mild reaction conditions, broadening the application range of the manganese complex. #imgabs0#

Description

Technical Field

[0001] The present invention belongs to the field of metal organic complex synthetic chemistry, and in particular relates to an oxazoline-type chiral N, P ligand, a preparation method and an application thereof. Background Art

[0002] Asymmetric catalysis holds significant application value in the synthesis of chiral compounds due to its high activity, low toxicity, and high atom economy. By manipulating the structure of chiral ligands, diverse reaction types can be catalyzed with high efficiency and selectivity. The design and synthesis of novel chiral ligands plays a crucial role in asymmetric synthesis. Thousands of chiral ligands and catalytic systems have been reported and applied to hydrogenation reactions of unsaturated organic compounds. Among the numerous chiral ligands, nitrogen-containing ligands offer advantages such as easy metal complex formation, high efficiency, and stability. However, these catalytic systems primarily utilize precious metals such as Ru, Rh, Pd, and Ir. Driven by the principles of sustainable development and green catalysis, catalytic transformations involving early transition metals such as Fe, Co, and Ni have rapidly developed in recent years, significantly enriching the field of catalytic research and providing an effective alternative to precious metal reagents. In contrast, the application of manganese-based catalysts in catalytic transformations is still in its early stages. Therefore, the development of manganese-catalyzed asymmetric hydrogenation reactions for the efficient synthesis of chiral alcohols and fine organic chemicals is of great significance. Summary of the Invention

[0003] The present invention aims to provide an oxazoline-type chiral N, P ligand and to prepare an oxazoline-type chiral N, P ligand manganese complex. The oxazoline-type chiral N, P ligand manganese complex has good reactivity and selectivity in asymmetric hydrogenation reactions.

[0004] Another object of the present invention is to provide a method for preparing the oxazoline-type chiral N, P ligand.

[0005] Another object of the present invention is to provide the use of the oxazoline-type chiral N, P ligand in the preparation of oxazoline-type chiral N, P ligand manganese complexes.

[0006] Another object of the present invention is to provide a method for preparing the oxazoline-type chiral N, P ligand manganese complex.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] The oxazoline-type chiral N, P ligand has the structure of formula (I):

[0009]

[0010] The R 1 Selected from phenyl, isopropyl, tert-butyl;

[0011] R2 is selected from isopropyl, phenyl, benzyl; R 3 For hydrogen.

[0012] Furthermore, the R 1 is isopropyl, R 2 It is isopropyl.

[0013] The preparation method of the oxazoline-type chiral N, P ligand comprises the following steps:

[0014] S1. Preparation of 2-hydroxymethyloxazoline compounds: dissolving a chiral amino alcohol compound represented by formula (Ⅳ) and glycolic acid in a solvent, reacting, and post-treating to obtain a 2-hydroxymethyloxazoline compound represented by formula (V);

[0015]

[0016] S2. Preparation of oxazoline-type chiral N, P ligands: 2-hydroxymethyloxazoline compounds of formula (V) prepared in step S1 and disubstituted phosphorus chloride (R 1 )2PCl reacts in a solvent under the action of a base and is post-treated to obtain an oxazoline-type chiral N,P ligand represented by formula (I).

[0017] Specifically, in step S1., the synthetic route for preparing 2-hydroxymethyloxazoline compounds is as follows:

[0018]

[0019] In step S2., the synthetic route for preparing the oxazoline-type chiral N, P ligand is as follows:

[0020]

[0021] Furthermore, in step S1., the post-processing is:

[0022] When R 2 When it is isopropyl, it is purified by vacuum distillation at a temperature of 180°C;

[0023] When R 2 When it is phenyl or benzyl, the system is cooled to room temperature, filtered under reduced pressure, and purified by recrystallization. The solvent system for the recrystallization is petroleum ether-ethyl acetate or n-hexane-ethyl acetate.

[0024] Furthermore, in step S1., the solvent is one or more of tetrahydrofuran, dichloromethane, chlorobenzene, petroleum ether, n-hexane or ethyl acetate.

[0025] Furthermore, in step S1., the reaction time is 18 to 24 hours.

[0026] Furthermore, in step S1., the reaction temperature is 160°C.

[0027] Furthermore, in step S1, the molar ratio of the chiral amino alcohol compound to glycolic acid is 1:1.1-1.5.

[0028] Furthermore, in step S2, when R 1 When it is tert-butyl, the base is 1,8-diazabicyclo[5.4.0]undec-7-ene;

[0029] When R 1 When it is phenyl or isopropyl, the base is triethylamine.

[0030] Furthermore, in step S2., the solvent is tetrahydrofuran.

[0031] Furthermore, in step S2., the reaction time is 4 to 12 hours.

[0032] Furthermore, in step S2, the reaction temperature is -40°C to room temperature, usually 25°C.

[0033] Furthermore, in step S2, the molar ratio of the disubstituted phosphorus chloride: 2-hydroxymethyloxazoline compound: base is 1: 1.05-1.2: 1.05-12.

[0034] The oxazoline-type chiral N, P ligand manganese complex has a structure of formula (II):

[0035]

[0036] The preparation method of the oxazoline-type chiral N, P ligand manganese complex comprises the following steps:

[0037] The above-mentioned oxazoline-type chiral N, P ligand and Mn(CO)5Br are dissolved in a solvent under an inert atmosphere, stirred at room temperature for reaction, and then post-treated to obtain an oxazoline-type chiral N, P ligand manganese complex.

[0038] Specifically, the synthesis route of the oxazoline-type chiral N, P ligand manganese complex is as follows:

[0039]

[0040] Furthermore, the solvent is tetrahydrofuran.

[0041] Furthermore, the reaction time is 12 to 24 hours.

[0042] Furthermore, the molar ratio of the oxazoline-type chiral N, P ligand to Mn(CO)5Br is 1:1.1-1.5.

[0043] Furthermore, the post-treatment is to filter with a syringe filter, remove the solvent in vacuo, wash with n-hexane, and remove the residual solvent in vacuo to obtain the oxazoline-type chiral N, P ligand manganese complex.

[0044] Another object of the present invention is to provide the use of the oxazoline-type chiral N, P ligand manganese complex as a catalyst for the asymmetric hydrogenation of aromatic ketone compounds.

[0045] Furthermore, the aromatic ketone compound has the structure of formula (III):

[0046]

[0047] The R 4 is selected from one of methyl, nitro, methoxy, phenyl, cyano or halogen; said R 5 Selected from methyl or phenyl.

[0048] Specifically, the steps of using the oxazoline-type chiral N, P ligand manganese complex for the asymmetric hydrogenation of aromatic ketone compounds are as follows:

[0049] An oxazoline-type chiral N, P ligand manganese complex, an aromatic ketone compound represented by formula (III), and silane are placed in toluene under an inert atmosphere, stirred at room temperature for reaction, and post-treated to obtain a chiral alcohol represented by formula (VI);

[0050]

[0051] Specifically, the synthesis route of the chiral alcohol represented by formula (VI) is as follows:

[0052]

[0053] Furthermore, the silane is phenylsilane.

[0054] Furthermore, the reaction time is 12 to 24 hours.

[0055] Furthermore, the molar ratio of the oxazoline-type chiral N, P ligand manganese complex, the aromatic ketone compound and the silane is 1:50-100:50-100.

[0056] Furthermore, the post-treatment is to extract with ethyl acetate and purify with column chromatography and then rotary evaporation to obtain chiral alcohol.

[0057] Furthermore, the eluent used in the column chromatography is petroleum ether and ethyl acetate in a volume ratio of 10:1.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] The present invention provides an oxazoline-type chiral N,P ligand and a preparation method thereof, which are simple, efficient and easy to synthesize, and at the same time enrich the types of N,P ligands and provide options for the construction of metal complexes and the development of catalysts. The oxazoline-type chiral N,P ligand can be used to prepare an oxazoline-type chiral N,P ligand manganese complex. The prepared manganese complex has a simple structure and is easy to synthesize. It can be used to catalyze the asymmetric hydrogenation reaction of aromatic ketone compounds under mild reaction conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a roadmap for the synthesis of oxazoline-type chiral N, P ligand manganese complexes;

[0061] Figure 2 is the H NMR spectrum of the isopropyl-substituted 2-hydroxymethyloxazoline in Example 1;

[0062] Figure 3 is the C NMR spectrum of the isopropyl-substituted 2-hydroxymethyloxazoline in Example 1;

[0063] Figure 4 is the H NMR spectrum of the oxazoline-type chiral N,P ligand in Example 1;

[0064] Figure 5 is the C NMR spectrum of the oxazoline-type chiral N,P ligand in Example 1;

[0065] Figure 6 is the nuclear magnetic phosphorus spectrum of the oxazoline-type chiral N, P ligand in Example 1;

[0066] Figure 7 is the H NMR spectrum of the phenyl-substituted 2-hydroxymethyloxazoline in Example 2;

[0067] Figure 8 is the C NMR spectrum of the phenyl-substituted 2-hydroxymethyloxazoline in Example 2;

[0068] Figure 9 This is the H NMR spectrum of the oxazoline-type chiral N,P ligand in Example 2;

[0069] Figure 10 is the nuclear magnetic phosphorus spectrum of the oxazoline-type chiral N, P ligand in Example 2;

[0070] Figure 11 is the H NMR spectrum of the benzyl-substituted 2-hydroxymethyloxazoline in Example 3;

[0071] Figure 12 is the C NMR spectrum of the benzyl-substituted 2-hydroxymethyloxazoline in Example 3;

[0072] Figure 13 This is the H NMR spectrum of the oxazoline-type chiral N,P ligand in Example 3;

[0073] Figure 14 This is the nuclear magnetic phosphorus spectrum of the oxazoline-type chiral N,P ligand in Example 3;

[0074] Figure 15 This is the H-NMR spectrum of the oxazoline-type chiral N,P ligand manganese complex prepared in Example 4;

[0075] Figure 16 This is the C NMR spectrum of the oxazoline-type chiral N,P ligand manganese complex prepared in Example 4;

[0076] Figure 17 This is the NMR phosphorus spectrum of the oxazoline-type chiral N, P ligand manganese complex prepared in Example 4;

[0077] Figure 18 The single crystal structure of the oxazoline-type chiral N, P ligand manganese complex prepared in Example 4;

[0078] Figure 19 The H NMR spectrum of the naphthaleneethanol prepared in Example 5 is shown in FIG.

[0079] Figure 20 The NMR carbon spectrum of naphthaleneethanol prepared in Example 5;

[0080] Figure 21 This is the H NMR spectrum of phenylethanol prepared in Example 5;

[0081] Figure 22 This is the C NMR spectrum of the phenylethanol prepared in Example 5. DETAILED DESCRIPTION

[0082] The present invention is further described in detail below with reference to specific examples. The examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are commercially available reagents and materials unless otherwise specified.

[0083] Example 1

[0084] Oxazoline-type chiral N, P ligand, the structure is as follows:

[0085]

[0086] The preparation method of the oxazoline-type chiral N, P ligand of the above structure is as follows:

[0087] S1. Weigh the isopropyl-substituted chiral amino alcohol (5.15 g, 0.05 mol) and glycolic acid (4.56 g, 0.06 mol, 1.2 eq) and dissolve them in chlorobenzene (60 mL). Install a reflux condenser and a water separator. Stir and react at 160°C for 18 hours. Distill under reduced pressure at 180°C to obtain a white solid, the isopropyl-substituted 2-hydroxymethyloxazoline, in a yield of 62%. Its H NMR and C NMR spectra are as follows: Figure 2 and Figure 3 shown.

[0088] from Figure 2 The H NMR spectrum data are as follows: 1 H NMR(400MHz,C6D6)δ5.42(br,1H),4.25(m,2H),3.81–3.66(m,1H),3.62–3.49(m ,2H),1.46(pd,J=6.8,5.5Hz,1H),0.82(d,J=6.7Hz,3H),0.67(d,J=6.8Hz,3H).

[0089] from Figure 3 The NMR carbon spectrum data are as follows: 13 C{ 1 H}NMR(101MHz,C6D6)δ168.86,71.54,70.69,57.05,32.59,18.45,18.10.

[0090] S2. Weigh the isopropyl-substituted 2-hydroxymethyloxazoline (150 mg, 1.05 mmol) prepared in step S1, dissolve it in tetrahydrofuran, add triethylamine (1.22 g, 12 mmol) dropwise, stir evenly, and then continue to add chlorodiisopropylphosphine (152 mg, 1 mol) dropwise. A white precipitate is quickly produced. Stir and react overnight. Monitor the reaction by NMR. After the reaction is complete, filter with diatomaceous earth and drain the filtrate to obtain a colorless liquid. Yield 92%. H NMR spectrum, C NMR spectrum and P NMR spectrum are as follows: Figures 4 to 6 shown.

[0091] from Figure 4 The H NMR spectrum data are as follows: 1H NMR (400MHz, C6D6) δ4.43(dd,J=9.4,1.0Hz,2H),3.80(td,J=7.2,1.3Hz,1H),3.68–3.54(m,2H),1.68(dtt,J=14.2,7.1,1.7Hz,2H),1.49(d q,J=13.4,6.7Hz,1H),1.16(ddd,J=10.4,7.0,1.5Hz,6H),1.00(ddd,J=15.5,7.2,1.9Hz,6H),0.91(d,J=6.7Hz,3H),0.72(d,J=6.7Hz,3H).

[0092] from Figure 5 The NMR carbon spectrum data are as follows: 13 C{ 1 H}NMR(101MHz,C6D6)δ163.62,72.33,70.03,66.87,66.64,32.76,28.31,28 .30,28.14,28.12,18.48,18.31,17.71,17.51,16.79,16.77,16.70,16.68.

[0093] from Figure 6 The NMR phosphorus spectrum data are as follows: 31 P{ 1 H}NMR (162MHz, C6D6) δ161.45.

[0094] Example 2

[0095]

[0096] The preparation method of the oxazoline-type chiral N, P ligand of the above structure is as follows:

[0097] S1. Weigh phenyl-substituted chiral amino alcohol (6.85 g, 0.05 mol) and glycolic acid (4.56 g, 0.06 mol, 1.2 eq) and dissolve them in chlorobenzene (60 mL). Install a reflux condenser and a water separator. Stir and react at 160°C for 18 hours. After the reaction is completed, cool to room temperature and the product will precipitate as a solid. Filter and recrystallize using a mixed solvent of ethyl acetate / petroleum ether to obtain a white powdery solid, which is phenyl-substituted 2-hydroxymethyloxazoline. The yield is 86%. Its H NMR spectrum and C NMR spectrum are as follows: Figure 7 and 8 shown.

[0098] from Figure 7 The H NMR spectrum data are as follows: 1H NMR (400MHz, MeOD) δ7.39–7.33(m,4H),7.27(m,1H),5.05(dd,J=6.7,5.2Hz,1H),4.05(d,J=3.3Hz,2H),3.81(dd,J=6.0,3.4Hz,2H),3.33(br,1H).

[0099] from Figure 8 The NMR carbon spectrum data are as follows: 13 C{ 1 H}NMR(101MHz,MeOD)δ173.46,139.63,128.10,127.05,126.52,64.63,61.30,54.94.

[0100] S2. Weigh the phenyl-substituted 2-hydroxymethyloxazoline prepared in step S1 (114.5 mg, 1.05 mmol), dissolve it in tetrahydrofuran, add triethylamine (1.22 g, 12 mmol) dropwise, stir evenly, and then continue to add chlorodiisopropylphosphine (152 mg, 1 mol) dropwise. A white precipitate will quickly form. Stir and react overnight. Monitor the reaction by NMR. After the reaction is complete, filter with celite and drain the filtrate to obtain a white solid. Yield 92%. H NMR and P NMR spectra are as follows: Figure 9 and 10 shown.

[0101] The H-NMR spectrum data are as follows: 1 H NMR (400MHz, Chloroform-d) δ7.36–7.25(m,5H),5.58(t,J=0.9Hz,1H),4.66(d,J=4.6Hz,2H),3.96–3.89(m,2H),2.01(s,2H),1.22(t,J=12.5Hz,12H).

[0102] The NMR carbon spectrum data are as follows: 13 C{ 1 H}NMR(101MHz,Chloroform-d)δ153.21,138.61,128.92,128.60,128.58,69.03,68.97,65.84,34.71,19.20.

[0103] The NMR phosphorus spectrum data are as follows: 31 P{ 1 H}NMR(162MHz,Chloroform-d)δ165.35.

[0104] Example 3

[0105] Oxazoline-type chiral N, P ligand, the structure is as follows:

[0106]

[0107] The preparation method of the oxazoline-type chiral N, P ligand of the above structure is as follows:

[0108] The steps and parameters are the same as those in Example 2, except that in step S1, an equal amount of benzyl-substituted chiral amino alcohol is used to replace the phenyl-substituted chiral amino alcohol to obtain a white solid, namely, benzyl-substituted 2-hydroxymethyloxazoline. The yield is 82%. Its H NMR and C NMR spectra are as follows: Figure 11 and Figure 12 shown.

[0109] from Figure 11 The H NMR spectrum data are as follows: 1 H NMR(400MHz,MeOD)δ7.35–7.17(m,5H),4.18(td,J=7.5,3.9Hz,1H),3.99–3.86(m,2H),3.57 (d,J=5.0Hz,2H),3.33(br,1H),2.94(dd,J=13.7,6.6Hz,1H),2.81(dd,J=13.7,7.9Hz,1H).

[0110] from Figure 12 The NMR carbon spectrum data are as follows: 13 C{ 1 H}NMR(101MHz,MeOD)δ173.43,138.19,128.94,127.99,125.99,62.34,61.11,52.18,36.59.

[0111] The yield of the prepared oxazoline-type chiral N, P ligand was 94%. Figure 13 and 14 shown.

[0112] The H-NMR spectrum data are as follows: 1 H NMR(500MHz,Chloroform-d)δ7.30–6.97(m,5H),4.27(d,J=2.4Hz,2H),4.26–4.21(m,2H),4.12(d,J=12.5 Hz,1H),3.23(dt,J=12.4,1.0Hz,1H),2.73(dt,J=12.5,1.0Hz,1H),2.01(s,2H),1.22(d,J=25.1Hz,12H).

[0113] The NMR carbon spectrum data are as follows: 13 C{1 H}NMR(101MHz,Chloroform-d)δ160.00,136.18,129.27,129.20,128.63,70.20,66.96,65.11,35.77,34.40,19.20.

[0114] The NMR phosphorus spectrum data are as follows: 31 P{ 1 H}NMR(162MHz,Chloroform-d)δ167.61.

[0115] Example 4

[0116] Oxazoline type chiral N, P ligand (0.5mmol) and metal manganese precursor Mn(CO)5Br (151.2mg, 0.55mmol) were prepared in Example 1 and dissolved in THF (10mL). The reaction was stirred at room temperature overnight. Nuclear magnetic detection was used to track the reaction process. After the raw material reaction was complete, the reaction mixture was allowed to stand. The reaction solution was filtered through a syringe filter, and the filtrate was drained to obtain a yellow viscous liquid. The mixture was washed several times with n-hexane, and the washings were transferred out. The oxazoline type chiral N, P ligand manganese complex was drained to obtain Mn-1, which has the following structure:

[0117]

[0118] The H NMR spectrum, C NMR spectrum and P NMR spectrum of the oxazoline-type chiral N, P ligand manganese complex prepared in Example 4 are as follows: Figures 15-17 As shown, the single crystal structure is shown in Figure 18 The crystal data are shown in Table 1:

[0119] from Figure 15 The H NMR spectrum data are as follows: 1 H NMR(400MHz,C6D6)δ4.48(ddd,J=15.7,8.5,1.3Hz,1H),4.09–4.01(m,1H),3.87(dd,J=23.8,15.7 Hz,1H),3.63(dp,J=10.1,7.2Hz,1H),3.47(dd,J=9.0,6.4Hz,1H),3.39–3.32(m,1H),2.57(dtt,J =10.2,6.8,3.3Hz,1H),2.36(dp,J=14.3,7.2Hz,1H),1.35(dd,J=16.2,7.4Hz,3H),1.13(ddd,J=1 8.3,15.6,7.1Hz,6H),0.95(dd,J=11.2,7.1Hz,3H),0.48(d,J=6.8Hz,3H),0.40(d,J=7.0Hz,3H).

[0120] from Figure 16 The NMR carbon spectrum data are as follows: 13 C{ 1 H}NMR(101MHz,C6D6)δ169.32,169.28,76.40,76.37,67.52,59.54,59.50,28.52,2 8.44,28.40,28.19,27.93,18.04,17.23,17.18,16.78,16.69,15.77,15.73,13.03.

[0121] from Figure 17 The NMR phosphorus spectrum data are as follows: 31 P{ 1 H}NMR (162 MHz, C6D6) δ 185.15.

[0122] Table 1 Crystal structure data of the oxazoline-type chiral N, P ligand manganese complex prepared in Example 4

[0123]

[0124] Example 5 Catalytic reaction

[0125] (1) The oxazoline-type chiral N, P ligand manganese complex prepared in Example 4 was used to catalyze the asymmetric hydrogenation reaction of aromatic ketone compounds, as follows: 170 mg, 1 mmol) and phenylsilane (108 mg, 1 mmol) were weighed in a glove box and placed in a round-bottom flask. 2 mol% of the oxazoline-type chiral N, P ligand manganese complex prepared in Example 10 (10.7 mg, 0.02 mmol) was added and stirred at room temperature with toluene as solvent for 36 hours. The reaction was monitored by TLC. After the reaction was completed, ethyl acetate was used for extraction. Column chromatography silica gel was added, the solvent was removed by rotary evaporation, and the target product was isolated by column chromatography. Petroleum ether and ethyl acetate were used as eluents (petroleum ether:ethyl acetate = 10:1), the eluate containing the product was collected, and the solvent was removed under reduced pressure to obtain the product, i.e., naphthaleneethanol. The yield was 80%. The enantiomeric excess was analyzed by high performance liquid chromatography using an OD-3 chiral column, and the ee value was 92%. The mobile phase was n-hexane and isopropanol (volume ratio 95:5), the flow rate was 1 mL / min, the wavelength of the light source was 220 nm, and the retention times were tR = 18.2 min (minor) and tR = 19.2 min (major). Figure 19 and 20 shown.

[0126] Depend on Figure 19 The H NMR spectrum data are as follows: 1H NMR (400MHz, CDCl3) δ7.79–7.72(m,4H),7.47–7.39(m,3H),4.96(q,J=6.5Hz,1H),2.34(s,1H),1.51(d,J=6.5Hz,3H).

[0127] Depend on Figure 20 The NMR carbon spectrum data are as follows: 13 C{ 1 H}NMR (101MHz, CDCl3) δ143.3,133.4,132.9,128.3,128.0,127.7,126.2,125.8,123.9,123.8,70.5,25.2.

[0128] (2) The oxazoline-type chiral N, P ligand manganese complex prepared in Example 4 was used to catalyze the asymmetric hydrogenation reaction of aromatic ketone compounds, as follows: Acetophenone (120 mg, 1 mmol) and phenylsilane (108 mg, 1 mmol) were weighed in a glove box and placed in a round-bottom flask. 2 mol% of the oxazoline-type chiral N, P ligand manganese complex prepared in Example 10 (10.7 mg, 0.02 mmol) was added, and toluene was used as solvent. The reaction was stirred at room temperature for 36 hours. The reaction was monitored by TLC. After the reaction was completed, ethyl acetate was used for extraction. Column chromatography silica gel was added, the solvent was removed by rotary evaporation, and the target product was isolated by column chromatography. Petroleum ether and ethyl acetate were used as eluents (petroleum ether:ethyl acetate = 10:1), the eluate containing the product was collected, and the solvent was removed under reduced pressure to obtain the product, i.e., phenylethanol. The yield was 85%. The enantiomeric excess was analyzed by high performance liquid chromatography using an OD-3 chiral column, and the ee value was 83%. The mobile phase was n-hexane and isopropanol (volume ratio 95:5), the flow rate was 1 mL / min, the wavelength of the light source was 220 nm, and the retention times were tR = 10.2 min (minor) and tR = 11.2 min (major). Figure 21 and 22 shown.

[0129] Depend on Figure 21 The H NMR spectrum data are as follows: 1 H NMR (400MHz, Chloroform-d) δ7.35–7.23 (m, 5H), 4.83 (qt, J=6.5, 1.5Hz, 1H), 1.45 (d, J=6.5Hz, 3H).

[0130] Depend on Figure 22 The NMR carbon spectrum data are as follows: 13 C{ 1H}NMR(101MHz,Chloroform-d)δ145.9,128.5,127.4,125.4,70.3,25.2.

[0131] The oxazoline-type chiral N, P ligand manganese complex prepared by the invention is used for catalyzing the asymmetric hydrogenation reaction of aromatic ketone compounds, has good activity and high yield.

[0132] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Oxazoline-type chiral N, P ligand, characterized in that: The oxazoline-type chiral N, P ligand has a structure of formula (I): （Ⅰ） The R 1 isopropyl; R 2 isopropyl; R 3 For hydrogen.

2. The method for preparing the oxazoline-type chiral N,P ligand according to claim 1, characterized in that: The steps include: S1. Preparation of 2-hydroxymethyloxazoline compounds: dissolving a chiral amino alcohol compound represented by formula (Ⅳ) and glycolic acid in a solvent, reacting, and post-treating to obtain a 2-hydroxymethyloxazoline compound represented by formula (V); （Ⅳ）（Ⅴ） S2. Preparation of oxazoline-type chiral N, P ligands: 2-hydroxymethyloxazoline compounds of formula (V) prepared in step S1. and disubstituted phosphorus chloride (R 1 )2PCl reacts in a solvent under the action of a base and is post-treated to obtain an oxazoline-type chiral N,P ligand represented by formula (I).

3. The preparation method according to claim 2, characterized in that: In step S1., the post-processing is: The product was purified by vacuum distillation at a temperature of 180°C.

4. The preparation method according to claim 2, characterized in that In step S2, The base is triethylamine.

5. Use of the oxazoline-type chiral N, P ligand according to claim 1 in the preparation of an oxazoline-type chiral N, P ligand manganese complex.

6. Oxazoline-type chiral N, P ligand manganese complex, characterized in that: The oxazoline-type chiral N, P ligand manganese complex has a structure of formula (II): （Ⅱ）。 7. The method for preparing the oxazoline-type chiral N,P ligand manganese complex according to claim 5, characterized in that: The steps include: The oxazoline-type chiral N, P ligand and Mn(CO)5Br described in claim 1 are dissolved in a solvent under an inert atmosphere, stirred for reaction at room temperature, and post-treated to obtain an oxazoline-type chiral N, P ligand manganese complex.

8. Use of the oxazoline-type chiral N,P ligand manganese complex according to claim 6 as a catalyst for the asymmetric hydrogenation of aromatic ketone compounds.

9. A method for the asymmetric hydrogenation of aromatic ketone compounds, characterized in that: Here are the steps: The oxazoline-type chiral N, P ligand manganese complex according to claim 6, the aromatic ketone compound represented by formula (III) and silane are placed in toluene under an inert atmosphere, stirred at room temperature for reaction, and post-treated to obtain the chiral alcohol represented by formula (VI); （Ⅲ）； （Ⅵ） The R 4 is selected from one of methyl, nitro, methoxy, phenyl, cyano or halogen; said R 5 Selected from methyl or phenyl.

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