Chiral ferrocene skeleton PNNO tetradentate ligand and application thereof in asymmetric hydrogenation reaction

Abstract

The invention relates to a chiral ferrocene skeleton PNNO tetradentate ligand and application thereof in asymmetric hydrogenation reaction. The ligand has the advantages of simple synthesis, good stability, high selectivity and the like. A metal complex of the ligand shows very excellent catalytic activity and extremely high enantioselectivity in an asymmetric hydrogenation reaction of ketone, can efficiently catalyze reduction of prochiral ketones such as aryl alkyl ketone, heteroaryl alkyl ketone, aryl (hetero) aryl ketone, aliphatic ketone and the like into corresponding chiral alcohol, and has huge industrial application potential.

Description

Technical Field

[0001] This invention belongs to the field of fine chemicals and relates to chiral ligands and their applications, specifically to a chiral ferrocene framework PNNO tetradentate ligand and its application in asymmetric hydrogenation reactions. Background Technology

[0002] Chiral alcohols are a crucial class of fine chemical products. The preparation of chiral alcohols via catalytic asymmetric hydrogenation offers advantages such as good atom economy, high efficiency, and simple post-processing. The key to asymmetric hydrogenation technology lies in highly active and stereoselective metal complex catalysts, with ligands being the crucial and core component. Therefore, developing chiral ligands with novel structures, excellent performance, simple preparation, and low cost has always been a core focus of asymmetric hydrogenation research.

[0003] In the study of asymmetric hydrogenation of ketones, researchers both domestically and internationally have developed many excellent ligands and catalysts, such as [RuCl2(diphosphine)(diamine)], SpiroPAP, f-amphox, f-amphol, f-ampha, and f-phamidol. These ligands and their metal complex catalysts have achieved great success in the asymmetric hydrogenation of simple ketones and have been successfully applied to the industrial production of many fine chemical products. However, although significant progress has been made in the asymmetric hydrogenation of ketones, drawbacks such as low catalyst selectivity, difficult preparation, high cost, and low activity of substrates with special structures still exist. Therefore, the development of novel ligands and their catalytic systems remains of significant research value. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the purpose of this invention is to provide a class of chiral ferrocene framework PNNO tetradentate ligands and their application in asymmetric hydrogenation reactions. This provides an important method for the synthesis of key fragments of some drug molecules and has significant application value.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A class of chiral ferrocene framework tetradentate ligands, with general structural formulas represented as I-III, are as follows:

[0007] ;

[0008] in:

[0009] In formulas I-III, R 1 It is aryl or substituted aryl;

[0010] In formula I, R 2 The substituents or groups are independently selected from H, R, Ar, OCR, and OCAr;

[0011] In formula II, R 3 R 4 and R 5 Independently selected from H, R, Ar, OR substituents or groups;

[0012] Linker 1 in Equations I-III has any of the following structures:

[0013] R 6 It can be hydrogen, alkyl, aryl, or substituted aryl.

[0014] Furthermore, this ligand is used to prepare catalysts for asymmetric catalytic reactions.

[0015] Furthermore, the catalyst is a complex formed by the complexation of a tetradentate ligand and a transition metal salt.

[0016] Furthermore, the transition metal salts mentioned are RuX3, RuHX(L)2 (diphosphine), RuX2(L)2 (diphosphine), Ru(arene)X2 (diphosphine), Ru(arylgroup)X2, Ru(RCOO)2 (diphsphine), Ru(methallyl)2 (diphine), Ru(arylgroup)X2 (PPh3)3, Ru(COD)(COT), Ru(COD)(COT)X, RuX2 (cymene), Ru(COD)n, Ru(arylgroup)X2 (diphosphine), RuCl2 (COD), [Ru(COD)2]X, RuX2 (diphosphine), and RuCl2 (=CHR). (PR'3)2, Ru(ArH)C12, Ru(COD)(methallyl)2, Rh(CO)2C12, [Rh(NBD)2]BF4, [Rh(NBD)C1]2, [Rh(COD)C1]2, [Rh(COD)2]X, Rh(acac)(CO)2, Rh(ethylene)2(acac), [Rh(ethylene)2C1]2, RhC1(PPh3)3, PdX2, Pd(PPh3)4, Pd(allyl)Cl, IrX3, [Ir(NB D)2)C1]2, [Ir(COD)C1]2, Ir(COD)X, FeX2, FeX3, Ni(acac)2, NiX2, [Ni(allyl)X]2, Ni(COD)2, CuX, CuX2, MoO2(acac)2, ScX2, Ti(OiPr)4, VO(acac)2, CrX2, CrX3, MnX2, Mn(acac)2, or MeReO3, wherein in the transition metal precursor salt, R and R' can be alkyl, alkoxy, or substituted alkyl; aryl is aryl; X is an anion Cl ‐ ,Br ‐ I ‐ ClO4 ‐ BF4 ‐ Sb6 ‐ PF6 ‐ CF3SO3 ‐ RCOO ‐ BAr4 ‐ L represents an acetonitrile solvent molecule.

[0017] Furthermore, when the catalyst is a complex formed by the above-mentioned tetradentate ligand and Ir metal salt, it exhibits high catalytic activity and enantioselectivity for the asymmetric hydrogenation of a series of prochiral ketones, including arylalkyl ketones, heteroarylalkyl ketones, and aryl(hetero)aryl ketones.

[0018] Furthermore, the transition metal in the transition metal salt is one of Ru, Rh, Pd, Ir, Fe, Co, Ni, Cu, Sc, Ti, V, Cr, Mn, or Re.

[0019] Furthermore, the asymmetric catalytic reactions include asymmetric hydrogenation, asymmetric transfer hydrogenation, asymmetric hydroamylation, asymmetric hydrocyanation, asymmetric hydrosilylation, asymmetric hydroboration, asymmetric allyl alkylation, asymmetric coupling, asymmetric cyclization, asymmetric Michael addition, asymmetric asymmetric epoxidation, asymmetric Aldol, asymmetric Mannich, asymmetric Diels-Alder, and asymmetric cycloisomerization.

[0020] Furthermore, the catalyst can be applied to the asymmetric hydrogenation of prochiral ketones to synthesize chiral alcohols.

[0021] The beneficial effects of this invention are:

[0022] Unlike previous ligands such as SpiroPAP, which require the reduction of imine to secondary amine, this invention can directly use imine as a ligand, reducing the number of synthetic steps and offering advantages such as low cost, simple synthesis, and good stability. The metal complexes of this type of ligand exhibit excellent catalytic activity and extremely high enantioselectivity in the asymmetric hydrogenation of ketones, efficiently catalyzing the reduction of prochiral ketones such as arylalkyl ketones, heteroarylalkyl ketones, aryl(hetero)aryl ketones, and aliphatic ketones to the corresponding chiral alcohols, demonstrating significant potential for industrial applications. Detailed Implementation

[0023] The present invention will be further described below with reference to embodiments, but this is not intended to limit the invention.

[0024] Unless otherwise stated, the terms used in the specification and claims have the following meanings.

[0025] The term "aryl" refers to a 6- to 14-membered all-carbon monocyclic or fused polycyclic (i.e., a ring sharing adjacent carbon atom pairs) group having a conjugated π-electron system, preferably 6- to 10-membered, such as phenyl and naphthyl. A substituted aryl group refers to an aryl group with at least one substituent, preferably one or more of the following groups independently selected from alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, mercapto, hydroxyl, nitro, cyano, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cycloalkoxy, heterocycloalkoxy, cycloalkylthio, heterocycloalkylthio, carboxyl, or carboxylic acid ester group.

[0026] A. Ligand synthesis;

[0027] Implementation Example 1: Synthesis of Ligand I-1;

[0028]

[0029] Compound 1 (0.61 g, 1 mmol) was dissolved in methanol (8 mL), phenolic resin (1 mmol) was added, and the reaction was carried out overnight at 60 °C. After the reaction was completed, the mixture was washed with 20 mL of water and extracted with dichloromethane (10 mL * 2). The organic layers were combined, dried over anhydrous sodium sulfate, and the concentrated reaction solution was subjected to column chromatography to obtain 0.78 g of orange-yellow solid I-1, with a yield of 95%. 1 H NMR (400 MHz, Chloroform-d) δ 13.63 (s, 1H), 8.03 (s, 1H), 7.44 – 7.25 (m, 11H), 7.15 (dd,J = 5.2, 1.9 Hz, 3H), 7.11 – 7.00 (m, 6H), 6.90 (dt, J = 6.7, 3.6 Hz, 2H), 4.34 (q, J = 2.0 Hz, 1H), 4.24 (d, J = 8.4 Hz, 1H), 4.19 (t, J = 2.5 Hz, 1H), 3.89 (s, 5H), 3.78 (d, J = 8.4 Hz, 1H), 3.72 – 3.62 (m, 2H), 3.48 (s, 1H), 1.45 (s, 9H), 1.32 (s, 9H), 1.27 (d, J = 6.5 Hz, 3H). 31 P NMR (162 MHz, Chloroform-d) δ -23.82.

[0030] Implementation Example 2: Synthesis of Ligand I-2;

[0031]

[0032] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.70 g of orange-yellow solid I-2, with a yield of 96%. 1 H NMR (400 MHz, Chloroform-d) δ 7.83 (s, 1H), 7.51 (dt, J= 9.5, 3.7 Hz, 2H), 7.38 – 7.31 (m, 4H), 7.29 – 7.17 (m, 6H), 7.03 (d, J =2.4 Hz, 1H), 4.38 (s, 1H), 4.19 (d, J = 9.1 Hz, 2H), 3.94 (s, 5H), 3.71 (s,1H), 2.66 (s, 1H), 2.25 (s, 1H), 2.01 (d, J = 12.2 Hz, 1H), 1.66 – 1.55 (m,2H), 1.44 (s, 11H), 1.32 (s, 13H), 1.24 – 1.01 (m, 1H), 0.93 – 0.69 (m, 3H). 31 P NMR (162 MHz, CDCl3) δ -24.57.

[0033] Implementation Example 3: Synthesis of Ligand I-3;

[0034]

[0035] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.76 g of orange-yellow solid I-3, with a yield of 95%. 1H NMR (400 MHz, Chloroform-d) δ 8.51 (s, 1H), 7.41 – 7.37(m, 1H), 7.34 (d, J = 1.9 Hz, 1H), 7.31 (d, J = 1.9 Hz, 2H), 7.13 (d, J = 1.8Hz, 1H), 7.12 – 7.10 (m, 1H), 7.09 – 7.06 (m, 1H), 6.92 (dd, J = 7.8, 1.1 Hz,1H), 6.83 (dd, J = 8.5, 1.1 Hz, 1H), 4.38 (dt, J = 2.8, 1.6 Hz, 1H), 4.21 (t,J = 2.5 Hz, 1H), 4.04 (dt, J = 6.3, 3.4 Hz, 1H), 4.01 (s, 5H), 3.56 (dt, J =2.3, 1.1 Hz, 1H), 2.29 (td, J = 12.7, 11.1, 6.6 Hz, 2H), 1.93 – 1.83 (m, 1H),1.75 (d, J = 13.0 Hz, 1H), 1.60 (dd, J = 10.1, 3.6 Hz, 1H), 1.52 – 1.36 (m,1H), 1.28 (s, 18H), 1.24 (s, 18H), 1.22 – 1.18 (m, 3H), 1.16 – 1.05 (m, 1H),1.03 – 0.69 (m, 4H), -0.05 (d, J = 12.2 Hz, 1H). 31 P NMR (162 MHz, CDCl3) δ -24.44.

[0036] Implementation Example 4: Synthesis of Ligand II-1;

[0037]

[0038] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.80 g of orange-yellow solid II-1, in 88% yield. 1H NMR (400 MHz, Chloroform-d) δ 7.39 (d, J = 1.9 Hz, 1H), 7.34 (dt, J = 6.4, 1.9 Hz, 3H), 7.23 (d, J = 7.4 Hz, 1H), 7.13 (dd, J = 7.9,1.9 Hz, 2H), 6.90 (d, J = 7.3 Hz, 1H), 6.73 (t, J = 7.3 Hz, 1H), 4.45 (d, J =2.5 Hz, 1H), 4.23 (s, 1H), 4.16 (d, J = 5.9 Hz, 1H), 4.06 (s, 5H), 3.74 (d, J= 13.8 Hz, 1H), 3.59 – 3.48 (m, 2H), 2.22 – 1.98 (m, 3H), 1.87 (d, J = 12.6Hz, 1H), 1.54 (d, J = 12.6 Hz, 2H), 1.26 (d, J = 18.0 Hz, 38H), 1.15 – 0.73(m, 6H), 0.29 (s, 9H). 31 P NMR (162 MHz, Chloroform-d) δ -24.72.

[0039] Implementation Example 5: Synthesis of Ligand II-2;

[0040]

[0041] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.75 g of orange-yellow solid II-2, in 79% yield. 1H NMR (400 MHz, Chloroform-d) δ 13.84 (s, 1H), 8.00 (s,1H), 7.41 – 7.28 (m, 5H), 7.20 – 7.08 (m, 3H), 6.83 (t, J = 7.3 Hz, 1H), 4.27(s, 1H), 4.17 (s, 1H), 4.03 (s, 1H), 3.97 (s, 5H), 3.60 (s, 1H), 2.40 (s,1H), 2.29 (s, 1H), 1.79 (d, J = 13.1 Hz, 1H), 1.56 (s, 4H), 1.25 (d, J = 18.0Hz, 39H), 0.97 (dd, J = 8.1, 6.8 Hz, 10H), 0.93 – 0.83 (m, 7H), 0.19 (d, J =12.2 Hz, 2H). 31 P NMR (162 MHz, Chloroform-d) δ -24.38.

[0042] Implementation Example 6: Synthesis of Ligand II-3;

[0043]

[0044] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.75 g of orange-yellow solid II-2, in 75% yield. 1H NMR (400 MHz, Chloroform-d) δ 13.87 (s, 1H), 8.01 (s,1H), 7.43 – 7.37 (m, 2H), 7.34 (dd, J = 8.3, 1.8 Hz, 2H), 7.30 (t, J = 1.8Hz, 1H), 7.14 (ddd, J = 13.2, 7.7, 1.7 Hz, 3H), 6.83 (t, J = 7.4 Hz, 1H), 4.26 (s, 1H), 4.16 (s, 1H), 4.05 – 4.00 (m, 1H), 3.97 (s, 5H), 3.59 (s, 1H),2.45 – 2.34 (m, 1H), 2.28 (s, 1H), 1.79 (dd, J = 13.5, 4.0 Hz, 1H), 1.55 (p,J = 7.3 Hz, 5H), 1.28 (s, 20H), 1.23 (s, 20H), 1.12 (dd, J = 7.5, 3.8 Hz,21H). 31 P NMR (162 MHz, Chloroform-d) δ -24.24.

[0045] Implementation Example 7: Synthesis of Ligand II-4;

[0046]

[0047] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.85 g of orange-yellow solid II-4, in 82% yield. 1H NMR (400 MHz, Chloroform-d) δ 7.99 (s, 1H), 7.38 (d, J= 1.8 Hz, 1H), 7.36 – 7.32 (m, 3H), 7.30 (d, J = 1.9 Hz, 1H), 7.13 (ddd, J =11.6, 7.7, 1.7 Hz, 3H), 6.82 (t, J = 7.3 Hz, 1H), 4.27 (s, 1H), 4.17 (d, J =2.5 Hz, 1H), 4.04 (dd, J = 6.9, 2.8 Hz, 1H), 3.97 (s, 5H), 3.59 (s, 1H), 2.39(d, J = 10.4 Hz, 1H), 2.25 (d, J = 13.9 Hz, 1H), 1.84 (d, J = 13.1 Hz, 1H), 1.58 (d, J = 10.0 Hz, 2H), 1.25 (d, J = 17.9 Hz, 59H), 0.91 – 0.86 (m, 14H),0.13 (d, J = 12.8 Hz, 1H). 31 P NMR (162 MHz, Chloroform-d) δ -24.25.

[0048] Implementation Example 8: Synthesis of Ligand II-5;

[0049]

[0050] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.92 g of orange-yellow solid II-5, in 84% yield. 1H NMR (400 MHz, Chloroform-d) δ 14.24 (s, 1H), 8.00 (s,1H), 7.64 (d, J = 7.2 Hz, 6H), 7.47 – 7.20 (m, 15H), 7.14 (dd, J = 24.6, 7.7Hz, 3H), 6.77 (t, J = 7.4 Hz, 1H), 4.27 (s, 1H), 4.18 (s, 1H), 4.01 (s, 6H), 3.59 (s, 1H), 2.31 – 2.11 (m, 2H), 1.81 (d, J = 13.2 Hz, 1H), 1.63 (d, J =12.8 Hz, 2H), 1.59 – 1.36 (m, 2H), 1.28 (s, 18H), 1.23 (s, 18H), 1.20 – 1.06(m, 3H), 0.90 (dd, J = 29.5, 9.7 Hz, 2H), 0.00 (d, J = 24.4 Hz, 1H). 31 P NMR (162 MHz, CDCl3) δ -24.27.

[0051] Implementation Example 9: Synthesis of Ligand II-6;

[0052]

[0053] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.78 g of orange-yellow solid II-6, in 83% yield. 1H NMR (400 MHz, Chloroform-d) δ 13.85 (s, 1H), 8.01 (s,1H), 7.41 – 7.28 (m, 5H), 7.14 (ddd, J = 10.0, 7.7, 1.8 Hz, 3H), 6.82 (t, J =7.3 Hz, 1H), 4.29 (s, 1H), 4.18 (d, J = 2.5 Hz, 1H), 4.05 (dt, J = 6.1, 3.0Hz, 1H), 3.97 (s, 5H), 3.61 (s, 1H), 2.47 – 2.25 (m, 2H), 1.86 – 1.73 (m,1H), 1.61 – 1.52 (m, 2H), 1.25 (d, J = 17.7 Hz, 44H), 1.02 – 0.91 (m, 8H), 0.28 (s, 6H). 31 P NMR (162 MHz, Chloroform-d) δ -24.46.

[0054] Implementation Example 10: Synthesis of Ligand II-7;

[0055]

[0056] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.81 g of orange-yellow solid II-7, in 85% yield. 1H NMR (400 MHz, Chloroform-d) δ 13.82 (s, 1H), 8.01 (s,1H), 7.40 – 7.32 (m, 4H), 7.30 (s, 1H), 7.14 (ddd, J = 11.0, 7.8, 1.8 Hz,3H), 6.82 (t, J = 7.3 Hz, 1H), 4.28 (s, 1H), 4.17 (s, 1H), 4.08 – 4.01 (m,1H), 3.97 (s, 5H), 3.60 (s, 1H), 2.40 (d, J = 10.1 Hz, 1H), 2.30 (d, J = 10.6Hz, 1H), 1.80 (d, J = 13.2 Hz, 1H), 1.56 (d, J = 10.8 Hz, 3H), 1.25 (d, J =19.0 Hz, 42H), 0.93 (s, 9H), 0.34 (d, J = 9.8 Hz, 6H), 0.19 (q, J = 13.2, 9.1Hz, 2H). 31 P NMR (162 MHz, Chloroform-d) δ -24.38.

[0057] Implementation Example 11: Synthesis of Ligand II-8;

[0058]

[0059] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.88 g of orange-yellow solid II-8, in 82% yield. 1H NMR (400 MHz, Chloroform-d) δ 14.28 (s, 1H), 8.03 (s,1H), 7.57 (td, J = 7.6, 1.6 Hz, 4H), 7.44 – 7.28 (m, 10H), 7.25 – 7.19 (m,1H), 7.11 (ddd, J = 7.1, 5.4, 1.7 Hz, 3H), 6.73 (t, J = 7.4 Hz, 1H), 4.25 (s,1H), 4.18 (t, J = 2.4 Hz, 1H), 3.99 (s, 6H), 3.58 (s, 1H), 2.27 (dd, J =19.2, 8.3 Hz, 2H), 1.78 (d, J = 13.2 Hz, 1H), 1.60 (dd, J = 28.5, 12.5 Hz, 3H), 1.51 – 1.42 (m, 2H), 1.35 – 1.04 (m, 50H), 0.96 (d, J = 11.9 Hz, 1H). 31 PNMR (162 MHz, Chloroform-d) δ -24.37.

[0060] Implementation Example 12: Synthesis of Ligand III-1;

[0061]

[0062] Compound 1b (0.51 g, 1 mmol) and an aldehyde (1 mmol) were reacted in the same manner as in Example 1 to give 0.98 g of orange-yellow solid III-1, in 95% yield. 1H NMR (400 MHz, Chloroform-d) δ 13.89 (s, 1H), 8.25 (s,1H), 7.97 (s, 1H), 7.95 – 7.89 (m, 2H), 7.85 (d, J = 8.0 Hz, 1H), 7.46 (td, J= 7.9, 1.6 Hz, 2H), 7.40 – 7.26 (m, 7H), 7.25 – 7.18 (m, 4H), 7.15 (d, J =8.2 Hz, 1H), 7.11 (d, J = 8.4 Hz, 1H), 5.19 (s, 1H), 4.35 (d, J = 2.4 Hz,1H), 4.21 (t, J = 2.5 Hz, 1H), 4.09 (dd, J = 6.5, 2.4 Hz, 1H), 3.95 (s, 5H), 3.77 – 3.71 (m, 2H), 2.57 – 2.49 (m, 1H), 2.42 (d, J = 10.1 Hz, 1H), 1.98 (d,J = 13.5 Hz, 1H), 1.88 – 1.81 (m, 1H), 1.64 – 1.49 (m, 2H), 1.40 (q, J =11.5, 11.0 Hz, 1H), 1.32 – 1.19 (m, 4H), 1.11 (td, J = 10.9, 6.0 Hz, 2H),0.87 (d, J = 6.9 Hz, 1H), 0.64 (t, J = 12.0 Hz, 1H). 31 P NMR (162 MHz, CDCl3)δ -25.10.

[0063] B. Catalytic asymmetric hydrogenation reaction;

[0064] Implementation Example 13: Asymmetric hydrogenation of acetophenone;

[0065] Weigh out the metal precursor [Ir(COD)Cl]₂ (1.6 mg, 2.4 μmol) and ligand L (5.4 μmol) and add them to an ampoule. Add MeOH (1 mL) and stir at room temperature for 20 min. Then add KO tBu (4.6 mg, 0.05 mmol, 10 mol%) was added, followed by the substrate (0.5 mmol) and THF (1 mL). The ampoule was transferred to a hydrogenation reactor, purged three times with 10 bar H2, and then pressurized to 50 bar. The reaction was carried out at 50 °C for 20 h. The heating was turned off, and the ampoule was removed after depressurization in a fume hood. Water and dichloromethane were added, and the organic layer was washed with saturated NaCl solution, dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain the hydrogenated product. 1 Conversion was determined by 1H NMR, and enantioselectivity of the product was determined by HPLC. The screening results for some ligands are as follows:

[0066] ;

[0067]

Claims

1. A class of chiral ferrocene framework PNNO tetradentate ligands, characterized in that, The ligands represented by the general structural formulas I-III are as follows: ； in: In formulas I-III, R 1 It is aryl or substituted aryl; In formula I, R 2 The substituents or groups are independently selected from H, R, Ar, OCR, and OCAr; In formula II, R 3 R 4 and R 5 Independently selected from H, R, Ar, OR substituents or groups; Linker 1 in Equations I-III has any of the following structures: R 6 It can be hydrogen, alkyl, aryl, or substituted aryl.

2. The chiral ferrocene framework PNNO tetradentate ligand according to claim 1, characterized in that, The general structural formulas include the following: ； ； ； 。 3. The chiral ferrocene framework PNNO tetradentate ligand according to claim 1, characterized in that, This ligand is used to prepare chiral catalysts for asymmetric catalytic reactions.

4. The chiral catalyst according to claim 4, characterized in that, The chiral catalyst is a complex formed by the complexation of a tetradentate ligand and a transition metal salt.

5. The chiral catalyst according to claim 4, characterized in that, The transition metal salts mentioned are RuX3, RuHX(L)2 (diphosphine), RuX2(L)2 (diphosphine), Ru(arene)X2 (diphosphine), Ru(arylgroup)X2, Ru(RCOO)2 (diphosphhine), Ru(methallyl)2 (diphine), Ru(arylgroup)X2 (PPh3)3, Ru(COD)(COT), Ru(COD)(COT)X, RuX2 (cymene), Ru(COD)n, Ru(arylgroup)X2 (diphosphine), RuCl2 (COD), [Ru(COD)2]X, RuX2 (diphosphine), and RuCl2 (=CHR). (PR'3)2, Ru(ArH)C12, Ru(COD)(methallyl)2, Rh(CO)2C12, [Rh(NBD)2]BF4, [Rh(NBD)C1]2, [Rh(COD)C1]2, [Rh(COD)2]X, Rh(acac)(CO)2, Rh(ethylene)2(acac), [Rh(ethylene)2C1]2, RhC1(PPh3)3, PdX2, Pd(PPh3)4, Pd(allyl)Cl, IrX3, [Ir(NB D)2)C1]2, [Ir(COD)C1]2, Ir(COD)X, FeX2, FeX3, Ni(acac)2, NiX2, [Ni(allyl)X]2, Ni(COD)2, CuX, CuX2, MoO2(acac)2, ScX2, Ti(OiPr)4, VO(acac)2, CrX2, CrX3, MnX2, Mn(acac)2, or MeReO3, wherein in the transition metal precursor salt, R and R' can be alkyl, alkoxy, or substituted alkyl; aryl is aryl; X is an anion Cl ‐ ,Br ‐ I ‐ ClO4 ‐ BF4 ‐ Sb6 ‐ PF6 ‐ CF3SO3 ‐ RCOO ‐ ,BArF ‐ L represents an acetonitrile solvent molecule.

6. The chiral catalyst according to claim 3, characterized in that, When the chiral catalyst is a complex formed by the combination of the above-mentioned tetradentate ligand and Ir metal salt, it exhibits high catalytic activity and enantioselectivity for the asymmetric hydrogenation of a series of prochiral ketones, including arylalkyl ketones, heteroarylalkyl ketones, aryl(hetero)aryl ketones, and aliphatic ketones.

7. The chiral catalyst according to claim 3, characterized in that, The transition metal in the transition metal salt is one of Ru, Rh, Pd, Ir, Fe, Co, Ni, Cu, Sc, Ti, V, Cr, Mn or Re.

8. The catalyst for preparing asymmetric catalytic reactions according to claim 3, characterized in that, The asymmetric catalytic reactions include asymmetric hydrogenation, asymmetric transfer hydrogenation, asymmetric hydroamylation, asymmetric hydrocyanation, asymmetric hydrosilylation, asymmetric hydroboration, asymmetric allyl alkylation, asymmetric coupling, asymmetric cyclization, asymmetric Michael addition, asymmetric asymmetric epoxidation, asymmetric Aldol, asymmetric Mannich, asymmetric Diels-Alder, and asymmetric cycloisomerization.

9. The chiral catalyst according to claim 3, characterized in that, The catalyst described above can be used for the asymmetric hydrogenation of prochiral ketones to synthesize chiral alcohols.

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