Biphenyl type tridentate ligand iridium complex and application thereof in asymmetric hydrogenation of alpha, beta-unsaturated aldehyde compound

Abstract

The invention discloses a biphenyl type tridentate ligand iridium complex and application of the biphenyl type tridentate ligand iridium complex in asymmetric hydrogenation of alpha, beta-unsaturated aldehyde compounds. The preparation method of the biphenyl type tridentate ligand iridium complex comprises the following steps: S1, reacting a metal iridium precursor and a biphenyl type tridentate ligand for 0.3-0.7 h in absolute ethyl alcohol in a glove box environment of an argon atmosphere, and replacing the argon atmosphere with hydrogen for 3-5 times; s2, the reaction mixture is subjected to a reaction for 0.3-0.7 h under the normal-pressure hydrogen condition; s3, concentrating the reaction mixture under high vacuum to obtain a product. The preparation method is simple and good in stability, and when the biphenyl type tridentate ligand iridium complex is used as a catalyst for non-hydrogenation reaction of alpha, beta-unsaturated aldehyde compounds, the biphenyl type tridentate ligand iridium complex shows very high catalytic activity and chemical selectivity.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, specifically to biphenyl-type tripentate ligand iridium complexes and their application in the asymmetric hydrogenation of α,β-unsaturated aldehydes. Background Technology

[0002] Catalytic conversion is a core pillar of modern industry, playing an irreplaceable role in pharmaceutical synthesis and numerous other fields such as chemical and energy conversion. It is a key technology for achieving green and sustainable development. Ligands and catalysts, as crucial components of catalytic conversion, directly determine the activity, selectivity, and efficiency of catalytic reactions through their structure and performance. As the fine chemical industry develops towards green and high-efficiency directions, traditional ligands and catalysts, due to their low efficiency and insufficient selectivity, are unable to meet the ever-increasing demands of industrial production. Therefore, developing novel and efficient ligands and catalysts to improve the efficiency and selectivity of catalytic conversion, reduce energy consumption and environmental pollution, and expand the application boundaries of catalytic conversion has significant scientific and practical value.

[0003] Selective catalytic hydrogenation of unsaturated aldehydes is a crucial reaction in the fine chemical industry. The carbonyl hydrogenation product, unsaturated alcohols, are key chemical intermediates widely used in the fragrance, pharmaceutical, pesticide, and cosmetic industries. For example, cinnamyl alcohol and limonene alcohol are core raw materials for the preparation of high-grade fragrances and flavors. However, α,β-unsaturated aldehydes possess both carbon-carbon double bonds (C=C) and aldehyde groups (C=O), both of which are reducible, making the selective hydrogenation of their carbonyl groups to synthesize allyl alcohols a challenge. In recent years, although some ligands and catalysts have been developed to achieve the selective catalytic hydrogenation of α,β-unsaturated aldehydes to synthesize allyl alcohols, the efficiency and selectivity of catalytic hydrogenation remain low (In Comprehensive Organic Synthesis II; Elsevier Ltd., 2014; pp 198–273). Developing novel and efficient ligands and catalysts remains key to improving the efficiency and selectivity of selective hydrogenation of α,β-unsaturated aldehydes.

[0004] Developing ligands and catalysts suitable for the selective catalytic hydrogenation of carbonyl compounds, with rigid skeletons and multidentate coordination being current trends and key to achieving high efficiency and selectivity, is crucial. For example, the iridium catalyst Ir-SpiroPAP, with its rigid spirocyclic skeleton and tridentate pyridine aminophosphine ligand, exhibits high stability and catalytic efficiency, effectively catalyzing the asymmetric hydrogenation of a series of simple ketones and unsaturated ketones to synthesize chiral alcohols (Angew. Chem. Int. Ed. 2011, 50, 7329-7332, Acc. Chem. Res. 2023, 56, 332-349). Inspired by this, ruthenium complexes with biphenyl skeletons and tridentate pyridine aminophosphine ligands have also achieved high activity and catalytic efficiency in the catalytic hydrogenation of esters (CN109956970A). However, there are currently no literature or patent reports on the selective hydrogenation of α,β-unsaturated aldehydes using corresponding iridium and ruthenium catalysts. Therefore, designing and developing novel catalytic systems to address the efficiency and selectivity issues currently faced in the selective hydrogenation of α,β-unsaturated aldehydes remains of significant research value and application potential. Summary of the Invention

[0005] One object of the present invention is to provide a method for preparing a biphenyl-type tridentate iridium complex; another object of the present invention is to provide an application of the biphenyl-type tridentate iridium complex in the asymmetric hydrogenation of α,β-unsaturated aldehyde compounds.

[0006] Therefore, the present invention adopts the following technical solution:

[0007] A biphenyl-type tridentate ligand having the structure shown in Formula I:

[0008]

[0009] R1 is selected from H, 3-methyl and 4-methyl.

[0010] A method for preparing the above-mentioned biphenyl-type tridentate ligand includes the following steps:

[0011] Reactant 1 and NaBH(OAc)3 were added to a Schlenk flask. After replacing the atmosphere with argon, 1,2-dichloroethane (DCE) was added and stirred thoroughly until completely dissolved. Then, pyridine carboxaldehyde was added, and the reaction was stirred for 15-25 hours. The reaction was then quenched. After extraction, combining the organic phases, drying the organic phases, and purification, the target product was obtained. The structural formula of reactant 1 is as follows:

[0012] .

[0013] In the above preparation method, the molar ratio of reactant 1, NaBH(OAc)3, and pyridine formaldehyde is 1:(4.5-5.5):(2.5-3.5); the amount of 1,2-dichloroethane (DCE) used is (80-120) ml / mmol of reactant 1; and the reaction temperature is 20-30℃.

[0014] A biphenyl-type tripenteric ligand iridium complex, prepared from the above-mentioned biphenyl-type tripenteric ligand, has the following structural formula:

[0015]

[0016] In the formula, R1 is selected from H, 3-methyl and 4-methyl.

[0017] A method for preparing the above-mentioned biphenyl-type tridentate iridium complex includes the following steps:

[0018] S1, In a glove box environment under an argon atmosphere, the metallic iridium precursor and the biphenyl-type tridentate ligand react in anhydrous ethanol for 0.3 to 0.7 hours, and then the argon atmosphere is replaced with hydrogen 3 to 5 times.

[0019] S2, allowing the reaction mixture to react under atmospheric pressure and hydrogen conditions for 0.3–0.7 h;

[0020] S3, the reaction mixture was concentrated under high vacuum to obtain a biphenyl-type tripentate iridium complex;

[0021] The metallic iridium precursor is [Ir(COD)Cl]2, where COD = cyclooctadiene.

[0022] In the above preparation method, the amount of anhydrous ethanol used in S1 is (2-3) ml / 0.1 mmol reactant 1; the amount of the biphenyl-type tridentate ligand used is 1.0-1.5 times the amount of iridium atoms in the metallic iridium precursor; the reaction temperature is 20-30℃; in S2, the reaction is carried out at 20-30℃; in S3, the high vacuum is 0.2-0.3 torr.

[0023] An application of the above-mentioned biphenyl-type tridentate iridium complex in the asymmetric catalytic hydrogenation reaction of α,β-unsaturated aldehydes is described below:

[0024] In an organic solvent and under an argon atmosphere, using the biphenyl-type tridentate iridium complex as a chiral catalyst, α,β-unsaturated aldehydes and a base are added, followed by stirring at 25-30°C for 8-48 hours under a hydrogen atmosphere to obtain chiral alcohols, wherein:

[0025] The amount of the chiral catalyst is 0.005~1 mol% of the α,β-unsaturated aldehyde compound.

[0026] In the reaction system, the concentration of the α,β-unsaturated aldehyde compound is 0.001~10.0M, and the concentration of the base is 0.005~0.1M;

[0027] The pressure of the hydrogen gas is 0.1 to 100 atm.

[0028] In the above applications, the solvent is one or a mixture of several of the following: methanol, ethanol, propanol, isopropanol, butanol, tetrahydrofuran, toluene, methyl tert-butyl ether, dioxane, N,N-dimethylformamide, and dimethyl sulfoxide.

[0029] In the above applications, the alkali is sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium ethoxide, potassium ethoxide, sodium tert-butoxide, potassium tert-butoxide, lithium tert-butoxide, triethylamine, tributylamine, or N-methylmorpholine.

[0030] In the above applications, the α,β-unsaturated aldehyde compounds have the following structures:

[0031] , , , , , , , , , , , , ,

[0032] , , , or

[0033] .

[0034] In this invention, the iridium catalysis based on biphenyl-type tridentate ligands is designed according to the relationship between structure, catalytic activity and enantioselectivity in the asymmetric catalytic hydrogenation of α,β-unsaturated aldehydes. A tert-butyl group is introduced at the 5,5'-position of the biphenyl ligand to make it a novel biphenyl tridentate ligand.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] 1. The biphenyl-type tripenteric ligand of the present invention is easy to synthesize; the preparation method of the biphenyl-type tripenteric ligand iridium complex is simple and has good stability;

[0037] 2. The biphenyl-type tripentate ligand iridium complex prepared by this invention exhibits excellent catalytic activity in the hydrogenation reaction of α,β-unsaturated aldehydes. It requires a small amount of catalyst, has mild reaction conditions, good selectivity (up to 99:1), and achieves a conversion number (TON) as high as 78,000, thus possessing high industrial application value. Detailed Implementation

[0038] The present invention will be further described in detail and completely below with reference to the embodiments. The listed embodiments will help to understand the present invention, but should not limit the scope of the present invention.

[0039] In the following examples, S / B represents substrate / base, and S / C represents substrate / solvent.

[0040] Example 1

[0041] The synthesis of biphenyl-type tridentate ligand 1, including the reaction formula and steps, is as follows:

[0042]

[0043] Compound 7 (70.7 mg, 0.2 mmol) and NaBH(OAc)3 (0.21 g, 1.0 mmol) were added to a dry, clean 50 mL Schlenk flask equipped with a magnetic stirrer. After replacing the atmosphere with argon, 10 mL of 1,2-dichloroethane (DCE) was added, and the mixture was stirred thoroughly until completely dissolved. Then, pyridinecarboxaldehyde 8 (0.6 mmol) was added, and the mixture was stirred at 25 °C for 20 h. The reaction was monitored by TLC. The reaction was slowly quenched with 10 mL of saturated sodium carbonate aqueous solution, and the aqueous phase was replaced with 20 mL of dichloromethane. 3) Extraction, combining the organic phases, and drying the organic phases with anhydrous magnesium sulfate. Filter to remove the drying agent, remove the solvent from the filtrate using a rotary evaporator, and purify the residue by silica gel column chromatography using petroleum ether / ethyl acetate (20:1~10:1) as the eluent to obtain 87 mg of a white solid, yield 78%, melting point: 113~115℃.

[0044] 11H NMR (400 MHz, CDCl3) δ: = 8.48 (d, J = 4.8 Hz, 1H), 7.56 (t, J = 7.4 Hz, 1H), 7.45–7.36 (m, 2H), 7.31–7.05 (m, 13H), 6.99 (dd, J = 8.2, 1.4 Hz, 1H), 6.73 (s, 1H), 6.46 (d, J = 8.4 Hz, 1H), 4.40 (d, J = 16.4 Hz, 1H), 4.33 (d, J = 16.4 Hz, 1H), 4.26 (s, 1H), 1.32 (s, 9H), 0.99 (s, 9H). 13 C{ 1 1H}NMR (101 MHz, CDCl3) δ: = 159.8, 152.4, 149.1, 144.8, 144.5, 142.3, 142.3, 138.7, 138.4 (d, J C-P = 3.9 Hz), 137.7 (d, J C-P = 13.1 Hz), 136.6, 134.4 (d, J C-P = 11.1 Hz), 134.1, 133.9 (d, J C-P = 3.0 Hz), 133.7 (d, J C-P = 2.0 Hz), 128.3 (d, J C-P = 5.1 Hz), 128.2, 128.1, 127.8 (d, J C-P = 5.1 Hz), 126.9 (d, J C-P = 7.1 Hz), 125.4, 124.9, 110.0, 49.7, 34.8, 33.6, 31.3, 31.3. 31 P{ 1 1H} NMR (162 MHz, CDCl3) δ: = −14.9. HRMS (ESI) Calcd for C 38 1H 42 N2P + (M+H) + : 557.3080; Found: 557.3093.

[0045] Example 2

[0046] The synthesis of biphenyl-type tridentate ligand 2, including the reaction formula and steps, is as follows:

[0047]

[0048] Compound 7 (70.7 mg, 0.2 mmol) and NaBH(OAc)3 (0.21 g, 1.0 mmol) were added to a dry, clean 50 mL Schlenk flask equipped with a magnetic stirrer. After replacing the atmosphere with argon, 10 mL of 1,2-dichloroethane (DCE) was added, and the mixture was stirred thoroughly until completely dissolved. Then, pyridinecarboxaldehyde 9 (0.8 mmol) was added. The reaction was stirred at 30 °C for 24 h, and the reaction was monitored by TLC. The reaction was slowly quenched with 10 mL of saturated sodium carbonate aqueous solution, and the aqueous phase was replaced with dichloromethane (20 mL). 3) Extraction, combined organic phases, and dried with anhydrous magnesium sulfate. Filter to remove the drying agent, remove the solvent from the filtrate using a rotary evaporator, and purify the residue by silica gel column chromatography using petroleum ether / ethyl acetate (20:1~10:1) as eluent to obtain 82 mg of white solid, yield 72%, melting point: 127~129℃.

[0049] 1 H NMR (400 MHz, CDCl3) δ:= 8.29 (dd, J = 4.4 Hz, 1H), 7.56–7.53 (m,1H), 7.45 (d, J = 7.6 Hz, 1H), 7.39–7.27 (m, 7H), 7.24–7.19 (m, 1H), 7.16–7.06 (m, 6H), 6.97-6.92 (m, 1H), 6.75 (d, J = 8.4 Hz, 1H), 5.32 (s, 1H), 4.39 (d, J = 15.6 Hz, 1H), 4.19 (d, J = 15.6 Hz, 1H), 2.36 (s, 3H), 1.40 (s, 9H), 1.15 (s, 9H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 155.5, 152.1, 145.9, 144.7 (d,J C-P = 29.3 Hz), 142.9, 138.6 (d, J C-P = 13.1 Hz), 138.2, 138.1 (d, J C-P = 17.2Hz), 137.2, 134.3 (d, J C-P= 10.1 Hz), 134.11, 134.07, 133.9 (d, J C-P = 1.0Hz), 133.7, 130.6, 128.4, 128.3, 128.2, 127.9, 128.0, 127.8 (d, J C-P = 3.0Hz), 126.9 (d, J C-P = 6.1 Hz), 125.4, 124.7, 121.7, 47.1, 34.8, 33.6, 31.4,31.3, 17.8. 31 P{ 1 H} NMR (162 MHz, CDCl3) δ: = −14.4 (major), −15.6 (minor).HRMS (ESI) Calcd for C 39 H 44 N2P + (M+H) + : 571.3237; Found: 571.3231.

[0050] Example 3

[0051] The synthetic reaction formula and steps for biphenyl-type tripentate ligand 3 are as follows:

[0052]

[0053] Compound 7 (70.7 mg, 0.2 mmol) and NaBH(OAc)3 (0.21 g, 1.0 mmol) were added to a dry, clean 50 mL Schlenk flask equipped with a magnetic stirrer. After purging with an argon atmosphere, 12 mL of 1,2-dichloroethane (DCE) was added, and the mixture was stirred thoroughly until completely dissolved. Then, pyridinecarboxaldehyde 10 (0.7 mmol) was added. The reaction was stirred at 25 °C for 18 h, and the reaction was monitored by TLC. The reaction was slowly quenched with 10 mL of saturated sodium carbonate aqueous solution, and the aqueous phase was replaced with dichloromethane (20 mL). 3) Extraction, combined organic phases, and dried with anhydrous magnesium sulfate. Filter to remove the drying agent, remove the solvent from the filtrate using a rotary evaporator, and purify the residue by silica gel column chromatography using petroleum ether / ethyl acetate (20:1~10:1) as eluent to obtain 84 mg of white solid, yield 74%, melting point: 128~139℃.

[0054] 1H NMR (400 MHz, Chloroform-d) δ: = 8.28 (d, J = 4.8 Hz, 1H), 7.38–7.33 (m, 1H), 7.27–7.19 (m, 5H), 7.11-7.03 (m, 3H), 6.93 (dd, J = 8.0, 3.6Hz, 1H), 6.86 (d, J = 5.6 Hz, 1H), 6.60 (d, J = 3.6 Hz, 1H), 6.43 (d, J = 8.4Hz, 1H), 4.30 (d, J = 16.0 Hz, 1H), 4.25 (d, J = 16.0 Hz, 1H), 4.16 (s, 1H),2.19 (s, 3H), 1.26 (s, 9H), 0.93 (s, 9H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: =159.5, 152.4, 148.7, 147.8, 138.1 (d, J C-P = 32.3 Hz), 142.3, 138.6, 138.5 (d,J C-P = 13.1 Hz), 137.6 (d, J C-P = 13.1 Hz), 134.3 (d, J C-P = 10.1 Hz), 134.1,134.0 (d, J C-P = 11.1 Hz), 133.7 (d, J C-P = 11.1 Hz), 128.3 (d, J C-P = 8.1 Hz),128.2 (d, J C-P = 2.0 Hz), 128.1, 127.9 (d, J C-P = 5.1 Hz), 126.8 (d, J C-P = 7.1Hz), 125.4, 124.9, 122.9, 122.0 (d, J C-P = 4.0 Hz), 110.0, 49.5, 34.8, 33.6,31.3, 31.2, 29.7. 21.1. 31 P{ 1H} NMR (162 MHz, CDCl3) δ: = −14.5 (major), −15.7(minor). HRMS (ESI) Calcd for C 39 H 44 N2P + (M+H) + Found: 571.3237; Found: 571.3233.

[0055] Example 4

[0056] The preparation of biphenyl-type tridentate iridium complex 4, the reaction formula and steps are as follows:

[0057]

[0058] In an argon-atmospheric glove box, 0.1 mmol of biphenyl-type tridentate ligand 1 and 33.5 mg (0.05 mmol) of [Ir(COD)Cl]₂ were added to a dry, clean Schlenk tube (15 mL) equipped with a magnetic stirrer, followed by 2 mL of anhydrous ethanol. The reaction mixture was stirred at room temperature for 0.5 h under argon protection, and the argon atmosphere was replaced five times with hydrogen. The reaction mixture was then stirred for 0.5 h at 25 °C and atmospheric pressure under hydrogen. The solvent was removed from the reaction mixture under high vacuum (0.2 torr) to obtain 75 mg of a grayish-white powder, with a yield of 95%. This iridium complex can be used directly without further purification and should be stored at room temperature under an inert atmosphere.

[0059] Example 5

[0060] The preparation of biphenyl-type tridentate iridium complex 5, the reaction formula and steps are as follows:

[0061]

[0062] In an argon-atmospheric glove box, 0.1 mmol of biphenyl-type tridentate ligand 1 and 33.5 mg (0.05 mmol) of [Ir(COD)Cl]2 prepared in Example 1 were added to a dry, clean Schlenk tube (15 mL) equipped with a magnetic stirrer, followed by 3 mL of anhydrous ethanol. The reaction mixture was stirred at room temperature for 0.6 h under argon protection, and the argon atmosphere was replaced five times with hydrogen. The reaction mixture was then stirred at 30 °C under atmospheric pressure with hydrogen for 0.6 h. The solvent was removed from the reaction mixture under high vacuum (0.3 torr) to obtain 75 mg of a pale yellow powder, with a yield of 94%. This iridium complex can be used directly without further purification and should be stored at room temperature under an inert atmosphere.

[0063] Example 6

[0064] The preparation of biphenyl-type tridentate iridium complex 6, the reaction formula and steps are as follows:

[0065]

[0066] In an argon-atmospheric glove box, 0.1 mmol of biphenyl-type tridentate ligand 1 and 33.5 mg (0.05 mmol) of [Ir(COD)Cl]2 prepared in Example 1 were added to a dry, clean Schlenk tube (15 mL) equipped with a magnetic stirrer, followed by 3 mL of anhydrous ethanol. The reaction mixture was stirred at room temperature for 0.8 h under argon protection, and the argon atmosphere was replaced five times with hydrogen. The reaction mixture was then stirred for 0.8 h at 25 °C and atmospheric pressure under hydrogen. The solvent was removed from the reaction mixture under high vacuum to obtain 76 mg of a pale yellow powder, with a yield of 95%. This iridium complex can be used directly without further purification and should be stored at room temperature under an inert atmosphere.

[0067] The catalysts used in the reaction formulas of Examples 7-25 below are all biphenyl-type tridentate ligand iridium complexes 4 prepared in Example 4.

[0068] Example 7

[0069] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0070]

[0071] In a glove box, weigh substrate 11 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 8 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 303 mg of the corresponding colorless allyl alcohol oil, with a yield of 98%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0072] 1H NMR (400 MHz, CDCl3) δ: = 5.45–5.37 (m, 1H), 5.13–5.07 (m, 1H), 4.15 (d, J = 7.2 Hz, 2H), 2.14–2.08 (m, 2H), 2.06-2.00 (m, 2H), 1.73 (s, 1H), 1.69 (s, 3H), 1.68 (s, 3H), 1.61 (s, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: =138.7, 131.50, 131.47, 123.9, 123.6, 123.5, 59.0, 58.96, 58.92, 39.5, 26.4,25.6, 17.6, 16.1.

[0073] Example 8

[0074] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0075]

[0076] In a glove box, weigh substrate 12 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge it with an argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 263 mg of the corresponding colorless allyl alcohol oil, with a yield of 98%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0077] 1H NMR (400 MHz, CDCl3) δ: = 7.38 (d, J = 7.2 Hz, 2H), 7.31 (t, J =7.2 Hz, 2H), 7.26–7.21 (m, 1H), 6.59 (d, J = 16.0 Hz, 1H), 6.28 (dt, J =16.0, 6.0 Hz, 1H), 4.23 (dd, J = 5.6, 1.6 Hz, 2H), 1.88 (s, 1H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 136.0, 130.5, 128.0, 127.9, 127.1, 125.8, 63.0.

[0078] Example 9

[0079] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0080]

[0081] In a glove box, weigh substrate 13 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge it with an argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 291 mg of the corresponding colorless allyl alcohol oil, with a yield of 98%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0082] 1 H NMR (400 MHz, CDCl3) δ: = 7.24 (m, 2H), 7.09 (m, 2H), 6.53 (d, J =16.0 Hz, 1H), 6.34-6.15 (m, 1H), 4.27 (s, 2H), 3.31 (s, 1H), 2.33 (s, 3H). 13 C{ 1H} NMR (101 MHz, CDCl3) δ: = 137.4, 134.1, 130.9, 129.4, 127.7, 126.5, 63.5,21.3.

[0083] Example 10

[0084] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0085]

[0086] In a glove box, weigh substrate 14 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 322 mg of the corresponding colorless allyl alcohol oil, with a yield of 98%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0087] 1 H NMR (400 MHz, CDCl3) 1 H NMR (400 MHz, CDCl3) δ: = 7.25 (d, J = 8.6Hz, 2H), 6.79 (d, J = 8.6 Hz, 2H), 6.48 (d, J = 16.0 Hz, 1H), 6.16 (dt, J =16.0, 6.0 Hz, 1H), 4.22 (d, J = 6.4 Hz, 2H), 3.74 (s, 3H), 1.88 (s, 1H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 159.3, 130.9, 129.5, 127.7, 126.3, 114.0, 63.8,55.3.

[0088] Example 11

[0089] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0090]

[0091] In a glove box, weigh substrate 15 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 401 mg of the corresponding allyl alcohol yellow solid, yield 94%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0092] 1 H NMR (400 MHz, CDCl3) δ: = 7.39 (d, J = 8.2 Hz, 2H), 7.16 (d, J =8.2 Hz, 2H), 6.49 (d, J = 15.6 Hz, 1H), 6.28 (dt, J = 15.6, 5.6 Hz, 1H), 4.26(d, J = 5.6 Hz, 2H), 2.73 (s, 1H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 135.6,131.7, 129.6, 129.4, 128.0 0, 121.4, 63.3.

[0093] Example 12

[0094] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0095]

[0096] In a glove box, weigh substrate 16 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 289 mg of the corresponding colorless allyl alcohol oil, with a yield of 95%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0097] 1 H NMR (400 MHz, CDCl3) δ: = 7.36 (dd, J = 8.4, 5.4 Hz, 2H), 7.00 (t,J = 8.4 Hz, 2H), 6.58 (d, J = 16.0 Hz, 1H), 6.28 (dt, J = 16.0, 6.0 Hz, 1H), 4.31 (d, J = 5.6 Hz, 2H), 1.59 (s, 1H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 162.4(d, J C-F = 248.5 Hz), 132.8 (d, J C-F = 3.0 Hz), 130.0, 128.2 (d, J C-F = 2.0 Hz), 128.0 (d, J C-F = 8.1 Hz), 115.5 (d, J C-F = 21.2 Hz), 63.6.

[0098] Example 13

[0099] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0100]

[0101] In a glove box, weigh substrate 17 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge it with an argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 316 mg of the corresponding colorless allyl alcohol oil, with a yield of 96%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0102] 1 H NMR (400 MHz, CDCl3) δ: = 7.48 (d, J = 8.4 Hz, 1H), 7.26 (t, J =6.4 Hz, 1H), 7.04 (d, J = 16.0 Hz, 1H), 6.96 (t, J = 7.6 Hz, 1H), 6.86 (d, J= 8.4 Hz, 1H), 6.44 (dt, J = 16.0, 5.6 Hz, 1H), 4.37 (d, J = 5.2 Hz, 2H), 4.13 (s, 1H), 3.78 (s, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 156.8, 129.6,128.7, 127.0, 126.0, 125.7, 120.8, 111.0, 63.7, 55.4.

[0103] Example 14

[0104] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0105]

[0106] In a glove box, weigh substrate 18 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 15 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 291 mg of the corresponding colorless allyl alcohol oil, with a yield of 98%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0107] 1 H NMR (400 MHz, CDCl3) δ: = 7.43-7.06 (m, 5H), 6.48 (s, 1H), 4.13 (s,2H), 2.20 (bs, 1H), 1.85 (s, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 137.7,137.6, 128.9, 128.2, 126.4, 125.0, 68.9, 15.31.

[0108] Example 15

[0109] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0110]

[0111] In a glove box, weigh substrate 19 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 16 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 390 mg of the corresponding colorless allyl alcohol oil, yielding 92%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0112] 1 H NMR (400 MHz, CDCl3) δ: = 7.58–7.48 (m, 2H), 7.32–7.14 (m, 3H), 7.02–6.92 (m, 1H), 4.33–4.26 (m, 2H), 3.66-3.58 (m, 1H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 135.1, 129.2, 128.33, 128.30, 127.8, 125.3, 69.3.

[0113] Example 16

[0114] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0115]

[0116] In a glove box, weigh substrate 20 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 268 mg of the corresponding colorless allyl alcohol oil, with a yield of 97%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0117] 1 H NMR (400 MHz, CDCl3) δ: = 6.22 (d, J = 16.0 Hz, 1H), 6.13-6.02 (m,1H), 5.97 (s, 1H), 5.82 (s, 1H), 4.10 (d, J = 5.6 Hz, 2H), 3.25 (s, 1H), 2.16(s, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 151.9, 151.0, 125.7, 119.3, 109.1,107.4, 62.9, 13.6.

[0118] Example 17

[0119] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0120]

[0121] In a glove box, weigh substrate 21 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 272 mg of the corresponding colorless allyl alcohol oil, with a yield of 97%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0122] 1 H NMR (400 MHz, CDCl3) δ: = 7.27-7.18 (m, 1H), 6.33 (d, J = 15.6 Hz,1H), 6.28-6.24 (m, 1H), 6.22-6.08 (m, 2H), 4.17 (s, 2H), 1.97 (s, 1H). 13 C{ 1 H}NMR (101 MHz, CDCl3) δ: = 152.4, 142.0, 127.3, 119.2, 111.3, 107.9, 63.1.

[0123] Example 18

[0124] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0125]

[0126] In a glove box, weigh substrate 22 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 251 mg of the corresponding colorless allyl alcohol oil, with a yield of 98%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0127] 1 H NMR (400 MHz, CDCl3) δ: = 5.72-5.51 (m, 2H), 4.07–3.98 (m, 2H), 2.69 (s, 1H), 2.03-1.97 (m, 2H), 1.39-1.32 (m, 2H), 1.30-1.23 (m, 4H), 0.86(t, J = 6.9 Hz, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 133.07, 128.86, 63.39, 32.15, 31.36, 28.81, 22.48, 13.95.

[0128] Example 19

[0129] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0130]

[0131] In a glove box, weigh substrate 23 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 300 mg of the corresponding colorless allyl alcohol oil, yielding 96%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0132] 1 H NMR (400 MHz, CDCl3) δ: = 5.62–5.43 (m, 2H), 3.92 (d, J = 5.5 Hz,2H), 3.49–3.42 (m, 1H), 2.00-1.88 (m, 2H), 1.28-1.13 (m, 10H), 0.78 (t, J =6.0 Hz, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: =132.7, 128.9, 63.1, 32.2, 31.8,29.2, 22.6, 13.9.

[0133] Example 20

[0134] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0135]

[0136] In a glove box, weigh substrate 24 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge it with an argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 30 °C for 8 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 167 mg of the corresponding colorless allyl alcohol oil, with a yield of 97%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0137] 1 H NMR (400 MHz, CDCl3) δ: = 5.39 (tt, J = 7.2, 1.2 Hz, 1H), 4.10 (d,J = 6.8 Hz, 2H), 2.53 (s, 1H), 1.74 (s, 3H), 1.67 (s, 3H). 13 C{ 1 H} NMR (101MHz, CDCl3) δ: = 135.7, 123.7, 59.0, 25.7, 17.7.

[0138] Example 21

[0139] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0140]

[0141] In a glove box, weigh substrate 25 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge it with an argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25°C for 8 hours until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 283 mg of the corresponding colorless allyl alcohol oil, with a yield of 95%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0142] 1 H NMR (400 MHz, CDCl3) δ: = 5.70–5.64 (m, 1H), 4.75-4.67 (m, 2H), 4.02-3.90 (m, 2H), 2.89 (bs, 1H), 2.19-2.02 (m, 4H), 2.00-1.79 (m, 2H), 1.73(s, 3H), 1.54-1.40 (m, 1H). 13 C NMR (101 MHz, CDCl3) δ: = 149.8, 137.2, 122.1,108.6, 66.8, 41.2, 30.4, 27.5, 26.1, 20.8.

[0143] Example 22

[0144] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0145]

[0146] In a glove box, weigh substrate 26 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 30 atm. Stir the reaction at 30 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 185 mg of the corresponding colorless allyl alcohol oil, yielding 94%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0147] 1 H NMR (400 MHz, CDCl3) δ: = 6.19 (dd, J = 15.2, 10.4 Hz, 1H), 6.00(dd, J = 15.2, 10.4 Hz, 1H), 5.67-5.56 (m, 2H), 4.07-3.98 (m, 2H), 3.09-3.00(m, 1H), 1.68 (d, J = 6.8 Hz, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 131.6,130.9, 129.7, 129.3, 63.0, 18.0.

[0148] Example 23

[0149] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0150]

[0151] In a glove box, weigh substrate 27 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge it with an argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 25 °C for 8 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 296 mg of the corresponding colorless allyl alcohol oil, with a yield of 96%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0152] 1 H NMR (400 MHz, CDCl3) δ: = 6.19 (dd, J = 15.2, 10.4 Hz, 1H), 6.03(dd, J = 15.2, 10.4 Hz, 2H), 5.75-5.64 (m, 2H), 4.11 (d, J = 6.0 Hz, 2H),2.63 (s, 1H), 2.07 (q, J = 7.2 Hz, 2H), 1.45-1.34 (m, 2H), 1.34-1.23 (m, 4H),0.87 (t, J = 6.8 Hz, 3H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 135.5, 131.9,129.5, 129.4, 63.2, 32.6, 31.4, 28.9, 22.5, 14.0.

[0153] Example 24

[0154] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes, with the following reaction formula and steps:

[0155]

[0156] In a glove box, weigh substrate 28 (2.0 mmol) and potassium carbonate (2.8 mg, 0.02 mmol) into a glass reaction tube equipped with a magnetic stirrer. Add a pre-prepared anhydrous ethanol solution (0.4 mL, 0.4 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge with argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 30 atm. Stir the reaction at 30 °C for 12 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. Purify the residue by rapid column chromatography to obtain 248 mg of the corresponding colorless allyl alcohol oil, yielding 94%. The molar ratio of the target product to the byproduct is determined by the crude reaction mixture. 1 HNMR spectrum confirmed >99 / 1.

[0157] 1 H NMR (400 MHz, CDCl3) δ: = 7.46-7.40 (m, 2H), 7.31-7.23 (m, 3H), 4.49 (s, 2H), 2.80 (s, 1H). 13 C{ 1 H} NMR (101 MHz, CDCl3) δ: = 131.7, 128.5,128.4, 122.6, 87.4, 85.6, 51.5.

[0158] Example 25

[0159] An asymmetric catalytic hydrogenation method for α,β-unsaturated aldehydes (substrate / catalyst = 100,000), with the following reaction formula and steps:

[0160]

[0161] Weigh substrate 11 (10.0 mmol) and potassium carbonate (13.8 mg, 0.1 mmol) into a glass reaction tube equipped with a magnetic stirrer in a glove box. Add a pre-prepared anhydrous ethanol solution (0.1 mL, 0.1 μmol, 1 μmol / mL) of biphenyl-type tridentate iridium complex 4 to the solution using a syringe. Place the reaction tube in a 50 mL stainless steel autoclave, purge it with an argon atmosphere, and add anhydrous ethanol (3.6 mL). Replace the inert gas in the autoclave three times with hydrogen, then adjust the hydrogen pressure to 50 atm. Stir the reaction at 30 °C for 48 h until the pressure gauge no longer changes. After slowly releasing the hydrogen pressure, remove the solvent using a rotary evaporator. The molar ratio of the target product / byproduct is determined by the crude reaction mixture. 1The HNMR spectrum was confirmed to be 78 / 22.

[0162] The above examples demonstrate that biphenyl-type tridentate ligands are easy to synthesize, their corresponding iridium complexes are simple to prepare and have good stability, and exhibit excellent catalytic activity in the hydrogenation of α,β-unsaturated aldehydes. They require small amounts of catalyst, have mild reaction conditions, and exhibit good selectivity, showing great industrial application value.

Claims

1. A biphenyl-type tridentate ligand, characterized in that, It has the structure shown in Equation I: ， R1 is selected from H, 3-methyl and 4-methyl.

2. A method for preparing the biphenyl-type tridentate ligand according to claim 1, characterized in that, Includes the following steps: Reactant 1 and NaBH(OAc)3 were added to a Schlenk flask. After replacing the atmosphere with argon, 1,2-dichloroethane (DCE) was added and stirred thoroughly until completely dissolved. Then, pyridine carboxaldehyde was added, and the reaction was stirred for 15-25 hours. The reaction was then quenched. After extraction, combining the organic phases, drying the organic phases, and purification, the target product was obtained. The structural formula of reactant 1 is as follows: 。 3. The preparation method according to claim 2, characterized in that: The molar ratio of reactant 1, NaBH(OAc)3, and pyridine formaldehyde is 1:(4.5-5.5):(2.5-3.5); the amount of 1,2-dichloroethane (DCE) used is (80-120) ml / mmol of reactant 1; the reaction temperature is 20-30℃.

4. A biphenyl-type tripentate iridium complex, characterized in that, Prepared from the biphenyl-type tridentate ligand of claim 1, with the following structural formula: ， In the formula, R1 is selected from H, 3-methyl and 4-methyl.

5. A method for preparing the biphenyl-type tripenteric ligand iridium complex according to claim 4, characterized in that, Includes the following steps: S1, In a glove box environment under an argon atmosphere, the metallic iridium precursor and the biphenyl-type tridentate ligand react in anhydrous ethanol for 0.3 to 0.7 hours, and then the argon atmosphere is replaced with hydrogen 3 to 5 times. S2, allowing the reaction mixture to react under atmospheric pressure and hydrogen conditions for 0.3–0.7 h; S3, the reaction mixture was concentrated under high vacuum to obtain a biphenyl-type tripentate iridium complex; The metallic iridium precursor is [Ir(COD)Cl]2, where COD = cyclooctadiene.

6. The preparation method according to claim 5, characterized in that: In S1, the amount of anhydrous ethanol used is (2-3) ml / 0.1 mmol reactant 1; the amount of biphenyl-type tridentate ligand used is 1.0-1.5 times the amount of iridium atoms in the metallic iridium precursor; the reaction temperature is 20-30℃; In S2, the reaction occurs at 20–30°C; In S3, the high vacuum is 0.2 to 0.3 torr.

7. The application of the biphenyl-type tripentate ligand iridium complex of claim 4 in the asymmetric catalytic hydrogenation reaction of α,β-unsaturated aldehydes, characterized in that, The steps are as follows: In an organic solvent and under an argon atmosphere, using the biphenyl-type tridentate iridium complex as a chiral catalyst, α,β-unsaturated aldehydes and a base were added, and then the reaction was carried out under a hydrogen atmosphere at 25–30°C for 8–48 hours with stirring to obtain chiral alcohols, wherein: The amount of the chiral catalyst is 0.005~1 mol% of the α,β-unsaturated aldehyde compound. In the reaction system, the concentration of the α,β-unsaturated aldehyde compound is 0.001~10.0M, and the concentration of the base is 0.005~1.0 M; The pressure of the hydrogen gas is 0.1 to 100 atm.

8. The application according to claim 7, characterized in that: The solvent is one or a mixture of several of the following: methanol, ethanol, propanol, isopropanol, butanol, tetrahydrofuran, toluene, methyl tert-butyl ether, dioxane, N,N-dimethylformamide, and dimethyl sulfoxide.

9. The application according to claim 7, characterized in that: The alkali is sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium ethoxide, potassium ethoxide, sodium tert-butoxide, potassium tert-butoxide, lithium tert-butoxide, triethylamine, tributylamine, or N-methylmorpholine.

10. The application according to claim 7, characterized in that, The α,β-unsaturated aldehyde compounds have the following structures: ， ， ， ， ， ， ， ， ， ， ， ， ， , , , or .

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