Method for catalytic hydrogenation of trisubstituted acetate or tertiary alkyl ester, and catalyst

Abstract

The present disclosure provides a method for catalytic hydrogenation of trisubstituted acetate or tertiary alkyl ester, comprising the following steps: performing a hydrogenation reaction by using a trisubstituted acetate or tertiary alkyl ester as a substrate in the presence of hydrogen and a manganese catalyst or a manganese catalytic system; the manganese catalyst is selected from compounds represented by formula (1): According to the present disclosure, a metallic manganese catalyst is used to achieve hydrogenation reduction of trisubstituted acetate or tertiary alkyl ester, which, compared to precious metal ruthenium catalysts, has advantages of low costs, easy availability, and low toxicity; and compared to existing inexpensive metal copper or cobalt catalysts, has advantages such as broad substrate applicability, mild reaction conditions, and high yield of target products.

Description

Methods and catalysts for the catalytic hydrogenation of trisubstituted acetates or tertiary alkyl esters Technical Field

[0001] This disclosure relates to a method and catalyst for the catalytic hydrogenation of trisubstituted acetates or tertiary alkyl esters, belonging to the field of catalytic hydrogenation technology. Background Technology

[0002] The hydrogenation of esters is a crucial class of reactions in organic synthesis, enabling the convenient synthesis of various alcohols from widely distributed carboxylic acids. Due to the strong electron-donating effect of the alkoxy group in esters, the carbonyl group has a higher electron cloud density, making esters more difficult to reduce than common unsaturated substrates such as aldehydes, ketones, and imines. In particular, when the steric hindrance on both sides of the ester group increases (e.g., in trisubstituted acetates or tertiary alkyl esters), the steric repulsion between the ester and the catalyst is significantly enhanced, making it difficult for the substrate to approach the active site of the catalyst, thus further hindering hydrogenation. Although some examples exist of the catalytic hydrogenation of trisubstituted acetates such as tert-valerate and adamantane carboxylate, as well as tertiary alkyl esters such as tert-butyl ester, catalytic systems with mild conditions and broad substrate applicability remain scarce. Therefore, developing a catalytic system for the hydrogenation of trisubstituted acetates and tertiary alkyl esters under mild conditions with broad substrate applicability is a vital and pressing scientific problem in modern organic chemistry.

[0003] References:

[0004] Chem.Eur.J. 2017, 23, 14848;

[0005] J.Am.Chem.Soc.1931,53,1091;

[0006] J.Am.Chem.Soc.1931,53,1095;

[0007] ACS Catal. 2013, 3, 32;

[0008] Chin. J. Chem. 2019, 37, 1125;

[0009] ACS Catal. 2016, 6, 3113;

[0010] Angew.Chem.Int.Ed.2006,45,1113;

[0011] Chem.Eur.J. 2014, 20, 15727;

[0012] J.Am.Chem.Soc.2015,137,7620;

[0013] Chem.Commun. 2011, 47, 8349;

[0014] Angew.Chem.Int.Ed.2017,56,7531;

[0015] Catal.Sci.Technol.2017,7,1297;

[0016] J.Am.Chem.Soc.2021,143,16865;

[0017] ChemCatChem 2022,14,e202101443;

[0018] WO2016035080A1;

[0019] WO2014203963A1;

[0020] CN102146019A. Summary of the Invention

[0021] The problem the invention aims to solve

[0022] In view of the technical problems existing in the prior art, this disclosure provides a method for catalytic hydrogenation of trisubstituted acetates or tertiary alkyl esters. This disclosure uses an NNP-type pincer-shaped manganese catalyst to catalyze the hydrogenation of trisubstituted acetates and tertiary alkyl esters, which has the advantages of wide substrate applicability and good catalytic effect.

[0023] Solution for solving the problem

[0024] [1] A method for catalytic hydrogenation of trisubstituted acetates or tertiary alkyl esters, comprising the following steps:

[0025] Hydrogenation reactions are carried out using trisubstituted acetates or tert-alkyl esters as substrates in the presence of hydrogen and a manganese catalyst or manganese catalytic system; wherein...

[0026] The manganese catalyst is selected from compounds represented by formula (1):

[0027] Among them, R 1 It represents C1-C7 alkylene, -(C1-C7 alkylene)-phenylene, or -(C1-C7 alkylene)-ferrocene;

[0028] R 2 It represents phenyl, C1-C6 alkyl or cyclohexyl;

[0029] X represents -CR 3 Or -NH, Y represents -CR 4 Or -NH, Z represents -CR 5Or -NH, and at least one of X, Y, and Z represents -NH;

[0030] R 3 R 4 and R 5 Each can independently represent H, C1-C7 alkyl or C2-C7 alkenyl, or R 3 With R 4 The atoms to which it is attached may optionally form C6 to C6. 10 aryl, or R 4 With R 5 The atoms to which it is attached may optionally form C6 to C6. 10 Aryl;

[0031] Indicates a single or double bond, and two adjacent bonds. Not both are double bonds;

[0032] A represents halogen;

[0033] Preferably, the molar ratio of the manganese catalyst to the trisubstituted acetate or tertiary alkyl ester is (0.0167–2):100.

[0034] [2] According to the method described in [1] above, the manganese catalyst comprises one or more of the following formulas (I) to (XV):

[0035] [3] According to the method described in [1] or [2] above, wherein the manganese catalytic system comprises manganese pentacarbonyl bromide and a ligand, wherein the ligand is selected from compounds represented by the following formula (2):

[0036] Among them, R 1 R 2 The definitions of X, Y, and Z are the same as in claim 1;

[0037] V represents N or NH; Indicates a single bond or a double bond;

[0038] When V is N This indicates a double bond; when V is NH, Indicates a single key.

[0039] Preferably, the molar ratio of the ligand to manganese pentacarbonyl bromide is (1.0–1.2):1, and the molar ratio of manganese pentacarbonyl bromide to trisubstituted acetate or tert-alkyl ester is (0.0167–2):100.

[0040] [4] According to the method described in [3] above, wherein the ligand comprises one or more of the compounds shown in Formulas XVI to XIX:

[0041] [5] The method according to any one of [1] to [4] above, wherein the trisubstituted acetate comprises compounds represented by formulas XX to XXX:

[0042] In formula XX, R 6 R 7 R 8 R 9 Each of these can be independently represented as C1–C7 alkyl, phenyl, benzyl, p-methoxybenzyl, 2,6-dimethylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 4-phenylbenzyl, 4-tert-butylbenzyl, 2-trifluoromethylbenzyl, 3-ferroceneylbenzyl, 3,5-dimethoxybenzyl, 4-benzyloxybenzyl, 3-fluorobenzyl, 4-diphenylphosphinebenzyl, 4-chlorobenzyl, 4-phenylselenobenzyl, 3-bromobenzyl, 4- Bromobenzyl, 3-phenyltellurylbenzyl, 4-iodobenzyl, (4'-dimethylamino-[1,1'-biphenyl]-3-yl)methyl, (4'-methylthio-[1,1'-biphenyl]-3-yl)methyl, 3-(phenanthrene-9-yl)benzyl, 3-(benzo[d][1,3]dioxolane-5-yl)benzyl, 3-(pyridin-4-yl)benzyl, 4-(furan-3-yl)benzyl, 3-(thiophene-3-yl) Benzyl, 4-(piperidin-1-yl)benzyl, 3-(pyrrolidine-1-yl)benzyl, 3-(azacycloheptyl-1-yl)benzyl, 3-morpholinylbenzyl, 3-thiomorpholinylbenzyl, 4-(indol-1-yl)benzyl, 4-(pyrazol-1-yl)benzyl, 4-(anthracite-9-yl)benzyl, (E)-(4'-phenyldiazetenyl-[1,1'-biphenyl]-4-yl)methyl, 4-trifluoromethoxy Benzyl, 4-trifluoromethylthiobenzyl, 3-ethylthiopropyl-1-yl, (E)-hex-3-en-1-yl, (Z)-hex-3-en-1-yl, 3-methyl-but-2-en-1-yl, hepta-4-ynyl, 2-(naphthyl-1-yl)ethyl, (dioxolane-2-yl)methyl, 2-((tetrahydro-2H-pyran-2-yl)oxy)ethyl or 3-(2,5-dimethylphenoxy)propyl-1-yl;

[0043] In formula XXI, R 10 R 11 Independently represents C1–C7 alkyl, phenyl, benzyl; X 1 The symbols represent C1-C7 alkylene, C2-C7 alkenylene, difluoromethylene, and oxygen; m and n independently represent 0, 1, 2, and 3.

[0044] In formula XXX, n 1 It represents 0, 1, and 2.

[0045] [6] The method according to any one of [1] to [4] above, wherein the tertiary alkyl ester comprises compounds represented by formulas XXXI to XXXIII:

[0046] [7] The method according to any one of [1] to [6] above, wherein the hydrogenation reaction is carried out in the presence of an alkaline reagent and an organic solvent;

[0047] Preferably, the molar ratio of the alkaline reagent to the trisubstituted acetate or tertiary alkyl ester is (1-20):100; and the molar ratio of the organic solvent to the trisubstituted acetate or tertiary alkyl ester is (0.05-2.0 mL):(0.25 mmol).

[0048] More preferably, the alkaline reagent includes one or more of potassium tert-butoxide, sodium tert-butoxide, lithium tert-butoxide, sodium tert-pentoxide, potassium methoxide, sodium methoxide, lithium methoxide, potassium ethoxide, sodium ethoxide, or lithium ethoxide; the organic solvent includes one or more of diethyl ether, tetrahydrofuran, dioxane, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, methyl tert-butyl ether, or anisole.

[0049] [8] The method according to any one of [1] to [7] above, wherein the method comprises mixing an alkaline reagent, a manganese catalyst or a manganese catalytic system, an organic solvent and a trisubstituted acetate or tertiary alkyl ester in a protective atmosphere, replacing the protective atmosphere with hydrogen, and carrying out a hydrogenation reaction in a hydrogen atmosphere.

[0050] Preferably, the pressure of the hydrogen gas is 20-60 bar, more preferably 30-40 bar;

[0051] The hydrogenation reaction is carried out at a temperature of 25–100°C for 12–48 hours.

[0052] [9] A manganese catalyst, said manganese catalyst being selected from compounds represented by formula (1):

[0053] Among them, R 1 It represents C1-C7 alkylene, -(C1-C7 alkylene)-phenylene, or -(C1-C7 alkylene)-ferrocene;

[0054] R 2 It represents phenyl, C1-C6 alkyl or cyclohexyl;

[0055] X represents -CR 3 Or -NH, Y represents -CR 4 Or -NH, Z represents -CR 5Or -NH, and at least one of X, Y, and Z represents -NH;

[0056] R 3 R 4 and R 5 Each can independently represent H, C1-C7 alkyl or C2-C7 alkenyl, or R 3 With R 4 The atoms to which it is attached may optionally form C6 to C6. 10 aryl, or R 4 With R 5 The atoms to which it is attached may optionally form C6 to C6. 10 Aryl;

[0057] Indicates a single or double bond, and two adjacent bonds. Not both are double bonds;

[0058] A represents halogen.

[0059]

[0010] Use of the manganese catalyst according to [9] above for the catalytic hydrogenation of trisubstituted acetates or tertiary alkyl esters.

[0060] The effects of the invention

[0061] This disclosure utilizes a manganese metal catalyst to achieve the hydrogenation reduction of trisubstituted acetates or tertiary alkyl esters. Compared with the precious metal ruthenium catalyst, it has the advantages of low price, easy availability, and low toxicity. Compared with existing inexpensive metal copper or cobalt catalysts, it has the advantages of broad substrate applicability, mild reaction conditions, and high yield of target product.

[0062] The manganese catalyst used in this disclosure is an NH heterocyclic NNP type pincer manganese catalyst. Compared with N-substituted imidazole or pyridine NNP type pincer manganese catalysts, the N-cation generated after NH deprotonation can better activate the carbonyl group. Therefore, it exhibits higher reactivity in a series of hydrogenation reactions, and the yield of the target product can reach up to 99%. Attached Figure Description

[0063] Figure 1 shows the crystal structure diagram of the manganese catalyst with the formula IV structure. Detailed Implementation

[0064] Various exemplary embodiments, features, and aspects of this disclosure will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment illustrated herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0065] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0066] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this disclosure should be understood to include systematic errors that are unavoidable in industrial production.

[0067] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0068] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0069] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0070] In this specification, "room temperature" means that no additional heating or cooling is required; in the embodiments disclosed herein, room temperature may specifically refer to 22–28°C.

[0071] In this manual, "halogen" generally refers to F, Cl, Br, and I.

[0072] In this specification, "Ph" represents phenyl, "Me" represents methyl, "Et" represents ethyl, "Pr" represents propyl, "iPr" represents isopropyl, "Bu" represents butyl, "nBu" represents n-butyl, "tBu" represents tert-butyl, "Bn" represents benzyl, "OBn" represents benzyloxy, "Cy" represents cyclohexyl, "TMS" represents trimethylsilyl, "TBS" represents tert-butyldimethylsilyl, "TBDPS" represents tert-butyldiphenylsilyl, "TIPS" represents triisopropylsilyl, "Boc" represents tert-butyloxycarbonyl, "SePh" represents phenylselenoyl, "TePh" represents phenyltelluryl, and "PMP" represents p-methoxyphenyl.

[0073] In this specification, the protective atmosphere may be an inert atmosphere, which means a gas that does not react with the substances used in the preparation process, such as nitrogen atmosphere, argon atmosphere, etc.

[0074] <First Aspect>

[0075] The first aspect of this disclosure provides a method for the catalytic hydrogenation of trisubstituted acetates or tertiary alkyl esters, comprising the following steps:

[0076] Hydrogenation reactions are carried out using trisubstituted acetates or tert-alkyl esters as substrates in the presence of hydrogen and a manganese catalyst or manganese catalytic system; wherein...

[0077] The manganese catalyst is selected from compounds represented by formula (1):

[0078] Among them, R 1 It represents C1-C7 alkylene, -(C1-C7 alkylene)-phenylene, or -(C1-C7 alkylene)-ferrocene;

[0079] R 2 It represents phenyl, C1-C6 alkyl or cyclohexyl;

[0080] X represents -CR 3 Or -NH, Y represents -CR 4 Or -NH, Z represents -CR 5 Or -NH, and at least one of X, Y, and Z represents -NH;

[0081] R 3 R 4 and R 5 Each can independently represent H, C1-C7 alkyl or C2-C7 alkenyl, or R 3 With R 4 The atoms to which it is attached may optionally form C6 to C6. 10 aryl, or R 4 With R 5 The atoms to which it is attached may optionally form C6 to C6. 10 Aryl;

[0082] Indicates a single or double bond, and two adjacent bonds. Not both are double bonds;

[0083] A represents halogen.

[0084] This disclosure utilizes an inexpensive manganese catalyst to achieve the hydrogenation reduction of trisubstituted acetates or tertiary alkyl esters. Compared to precious ruthenium catalysts, it offers advantages such as low cost, availability, and low toxicity. Compared to existing inexpensive copper or cobalt catalysts, it boasts advantages such as broad substrate applicability, mild reaction conditions, and high yield of the target product. The manganese catalyst used in this disclosure is an NH heterocyclic NNP-type pincer-shaped manganese catalyst. Compared to N-substituted imidazole or pyridine NNP-type pincer-shaped manganese catalysts, the N-cation generated after deprotonation of NH can better activate the carbonyl group, thus exhibiting higher reactivity in a series of hydrogenation reactions, with the target product yield reaching up to 99%.

[0085] In some specific implementation schemes, R 1 It represents C1-C4 alkylene, -(C1-C4 alkylene)-phenylene, or -(C1-C4 alkylene)-ferrocene;

[0086] R 2 It represents phenyl, C1-C4 alkyl or cyclohexyl;

[0087] R 3 R 4 and R 5 Each can independently represent H, C1-C4 alkyl or C2-C4 alkenyl, or R 3 With R 4 The atoms to which it is attached may optionally form C6 to C6. 10 aryl, or R 4 With R 5 The atoms to which it is attached may optionally form C6-C8 aryl groups;

[0088] A represents Cl or Br.

[0089] In some specific embodiments, the manganese catalyst comprises one or more combinations of formulas (I) to (XV):

[0090] Preferably, the manganese catalyst comprises one or more of the compounds shown in Formulas III to V and XIII to XV; more preferably, the manganese catalyst comprises one or more of the compounds shown in Formulas IV, V, XIII, and XV.

[0091] In some specific embodiments, for better catalytic hydrogenation, the molar ratio of the manganese catalyst to the trisubstituted acetate or tertiary alkyl ester is (0.0167–2):100.

[0092] In some specific embodiments, the manganese catalytic system comprises manganese pentacarbonyl bromide and a ligand selected from compounds represented by formula (2):

[0093] Among them, R 1 R 2 The definitions of X, Y, and Z are the same as in claim 1;

[0094] V represents N or NH; Indicates a single bond or a double bond;

[0095] When V is N This indicates a double bond; when V is NH, Indicates a single key.

[0096] Specifically, the ligand comprises one or more of the compounds shown in Formulas XVI to XIX:

[0097] Preferably, the ligand comprises one or a combination of two of the compounds with structures shown in Formula XVII or Formula XIX.

[0098] In some specific embodiments, in order to facilitate better catalytic hydrogenation, the molar ratio of the ligand to manganese pentacarbonyl bromide is (1.0-1.2):1, and the molar ratio of manganese pentacarbonyl bromide to trisubstituted acetate or tertiary alkyl ester is (0.0167-2):100.

[0099] Unless otherwise specified in this disclosure, all reactants and reagents required are commercially available products well known to those skilled in the art.

[0100] The present disclosure does not particularly limit the substrate, i.e., trisubstituted acetate or tertiary alkyl ester, as long as it can be catalytically hydrogenated.

[0101] In some specific embodiments, the trisubstituted acetate comprises compounds represented by formulas XX to XXX:

[0102] In formula XX, R 6 R 7 R 8 R 9Each of these can be independently represented as C1–C7 alkyl, phenyl, benzyl, p-methoxybenzyl, 2,6-dimethylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 4-phenylbenzyl, 4-tert-butylbenzyl, 2-trifluoromethylbenzyl, 3-ferroceneylbenzyl, 3,5-dimethoxybenzyl, 4-benzyloxybenzyl, 3-fluorobenzyl, 4-diphenylphosphinebenzyl, 4-chlorobenzyl, 4-phenylselenobenzyl, 3-bromobenzyl, 4- Bromobenzyl, 3-phenyltellurylbenzyl, 4-iodobenzyl, (4'-dimethylamino-[1,1'-biphenyl]-3-yl)methyl, (4'-methylthio-[1,1'-biphenyl]-3-yl)methyl, 3-(phenanthrene-9-yl)benzyl, 3-(benzo[d][1,3]dioxolane-5-yl)benzyl, 3-(pyridin-4-yl)benzyl, 4-(furan-3-yl)benzyl, 3-(thiophene-3-yl) Benzyl, 4-(piperidin-1-yl)benzyl, 3-(pyrrolidine-1-yl)benzyl, 3-(azacycloheptyl-1-yl)benzyl, 3-morpholinylbenzyl, 3-thiomorpholinylbenzyl, 4-(indol-1-yl)benzyl, 4-(pyrazol-1-yl)benzyl, 4-(anthracite-9-yl)benzyl, (E)-(4'-phenyldiazetenyl-[1,1'-biphenyl]-4-yl)methyl, 4-trifluoromethoxy Benzyl, 4-trifluoromethylthiobenzyl, 3-ethylthiopropyl-1-yl, (E)-hex-3-en-1-yl, (Z)-hex-3-en-1-yl, 3-methyl-but-2-en-1-yl, hepta-4-ynyl, 2-(naphthyl-1-yl)ethyl, (dioxolane-2-yl)methyl, 2-((tetrahydro-2H-pyran-2-yl)oxy)ethyl or 3-(2,5-dimethylphenoxy)propyl-1-yl;

[0103] In formula XXI, R 10 R 11 Independently represents C1–C7 alkyl, phenyl, benzyl; X 1 The symbols represent C1-C7 alkylene, C2-C7 alkenylene, difluoromethylene, and oxygen; m and n independently represent 0, 1, 2, and 3.

[0104] In formula XXX, n 1 It represents 0, 1, and 2.

[0105] In some specific embodiments, the tertiary alkyl ester comprises compounds represented by formulas XXXI to XXXIII:

[0106] In this disclosure, the amount of the trisubstituted acetate or tertiary alkyl ester used each time catalytic hydrogenation is preferably at least 0.25 mmol.

[0107] In some specific embodiments, the hydrogenation reaction is carried out in the presence of an alkaline reagent and an organic solvent; preferably, the molar ratio of the alkaline reagent to the trisubstituted acetate or tertiary alkyl ester is (1-20):100; and the molar ratio of the organic solvent to the trisubstituted acetate or tertiary alkyl ester is (0.05-2.0 mL):(0.25 mmol).

[0108] Specifically, the alkaline reagent includes one or more of potassium tert-butoxide, sodium tert-butoxide, lithium tert-butoxide, sodium tert-pentoxide, potassium methoxide, sodium methoxide, lithium methoxide, potassium ethoxide, sodium ethoxide, or lithium ethoxide, preferably potassium tert-butoxide; the organic solvent includes one or more of diethyl ether, tetrahydrofuran, dioxane, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, methyl tert-butyl ether, or anisole, preferably tetrahydrofuran and / or diethylene glycol dimethyl ether.

[0109] In some specific embodiments, the method includes mixing an alkaline reagent, a manganese catalyst or manganese catalytic system, an organic solvent, and a trisubstituted acetate or tert-alkyl ester in a protective atmosphere, replacing the protective atmosphere with hydrogen, and carrying out a hydrogenation reaction in a hydrogen atmosphere. Preferably, the hydrogen pressure is 20–60 bar, more preferably 30–40 bar; the hydrogenation reaction temperature is 25–100°C; and the hydrogenation reaction time is 12–48 h.

[0110] Furthermore, in this disclosure, the hydrogenation reaction is preferably carried out under stirring conditions. This disclosure does not have a special limitation on the stirring speed, as long as the hydrogenation reaction proceeds smoothly.

[0111] Specifically, in an argon-filled glove box, an alkaline reagent, a manganese catalyst or manganese catalytic system, an organic solvent, and a trisubstituted acetate or tert-alkyl ester are added sequentially to a glass bottle equipped with a stir bar. The bottle is then capped, and a needle with a vent hole (preferably 3-4 cm in length and 1-2 mm in diameter) is inserted into the cap. The glass bottle is then placed into an autoclave. Afterward, the autoclave is removed from the glove box, and the argon gas in the autoclave is replaced with hydrogen (3×5 bar). Then, 20-60 bar of hydrogen is introduced, and the hydrogenation reaction is carried out under stirring and at 25-100°C for 12-48 hours.

[0112] After the hydrogenation reaction is completed, the autoclave is preferably cooled to room temperature (this step is omitted if the reaction temperature is room temperature). Then, the gas inside the autoclave is carefully released, and the resulting product system is sampled for GC quantification and column chromatography separation to obtain the target product. This disclosure does not impose any special limitations on the chromatographic conditions used for GC quantification or the reagents used for column chromatography separation; conditions well known to those skilled in the art can be used depending on the specific type of the target product.

[0113] <Second aspect>

[0114] A second aspect of this disclosure provides a manganese catalyst selected from compounds represented by formula (1):

[0115] Among them, R 1 It represents C1-C7 alkylene, -(C1-C7 alkylene)-phenylene, or -(C1-C7 alkylene)-ferrocene;

[0116] R 2 It represents phenyl, C1-C6 alkyl or cyclohexyl;

[0117] X represents -CR 3 Or -NH, Y represents -CR 4 Or -NH, Z represents -CR 5 Or -NH, and at least one of X, Y, and Z represents -NH;

[0118] R 3 R 4 and R 5 Each can independently represent H, C1-C7 alkyl or C2-C7 alkenyl, or R 3 With R 4 The atoms to which it is attached may optionally form C6 to C6. 10 aryl, or R 4 With R 5 The atoms to which it is attached may optionally form C6 to C6. 10 Aryl;

[0119] Indicates a single or double bond, and two adjacent bonds. Not both are double bonds;

[0120] A represents halogen.

[0121] The manganese catalyst used in this disclosure is an NH heterocyclic NNP type pincer-shaped manganese catalyst, which has the advantages of low price, easy availability and low toxicity compared with precious metal catalysts; compared with existing copper or cobalt catalysts, it has the advantages of broad substrate applicability, mild reaction conditions and high yield of target product; compared with N-substituted imidazole or pyridine NNP type pincer-shaped manganese catalysts, the N-cation generated after deprotonation of NH can better activate carbonyl groups, so it exhibits higher reactivity in a series of hydrogenation reactions, and the yield of target product can reach up to 99%.

[0122] In some specific implementation schemes, R 1 It represents C1-C4 alkylene, -(C1-C4 alkylene)-phenylene, or -(C1-C4 alkylene)-ferrocene;

[0123] R 2 It represents phenyl, C1-C4 alkyl or cyclohexyl;

[0124] R 3 R 4 and R 5 Each can independently represent H, C1-C4 alkyl or C2-C4 alkenyl, or R 3 With R 4 The atoms to which it is attached may optionally form C6 to C6. 10 aryl, or R 4 With R 5 The atoms to which it is attached may optionally form C6-C8 aryl groups;

[0125] A represents Cl or Br.

[0126] In some specific embodiments, the manganese catalyst comprises one or more combinations of formulas (I) to (XV):

[0127] Preferably, the manganese catalyst comprises one or more of the compounds shown in Formulas III to V and XIII to XV; more preferably, the manganese catalyst comprises one or more of the compounds shown in Formulas IV, V, XIII, and XV.

[0128] Manganese catalysts of formulas (I) to (IV)

[0129] In this disclosure, the method for preparing manganese catalysts [Mn]-1 to [Mn]-4 of formulas (I) to (IV) preferably includes the following steps:

[0130] In a protective atmosphere, 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride, diphenylphosphine, a binding agent and a first solvent are mixed and subjected to a substitution reaction to obtain 2-(diphenylphosphine)ethyl-1-amine or 3-(diphenylphosphine)propyl-1-amine.

[0131] The 2-(diphenylphosphine)ethyl-1-amine or 3-(diphenylphosphine)prop-1-amine is mixed with the corresponding imidazole-2-carboxaldehyde or benzimidazole-2-carboxaldehyde and a second solvent and then subjected to a condensation reaction. After that, a reducing agent is added to carry out a reduction reaction to obtain imidazole or benzimidazole NNP ligands.

[0132] In a protective atmosphere, the imidazole or benzimidazole NNP ligand is mixed with manganese pentacarbonyl bromide and a third solvent and then subjected to a coordination substitution reaction to obtain manganese catalysts with structures shown in Formulas I to VI, namely manganese catalysts [Mn]-1 to [Mn]-4.

[0133] In this disclosure, 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride, diphenylphosphine, a binding agent, and a first solvent are mixed in a protective atmosphere and subjected to a substitution reaction to obtain 2-(diphenylphosphine)ethyl-1-amine or 3-(diphenylphosphine)propyl-1-amine. In this disclosure, the molar ratio of 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride, diphenylphosphine, and the binding agent is preferably 10:(10-12):(20-24). This disclosure does not have a specific limitation on the amount of the first solvent, as long as it is sufficient to ensure the smooth progress of the substitution reaction. The binding agent can be tert-butylethanol to neutralize the hydrogen chloride generated during the substitution process, and the first solvent can be tetrahydrofuran.

[0134] In this disclosure, the mixing of the 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride, diphenylphosphine, binding agent and first solvent is preferably carried out by dissolving the 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride and the binding agent in the first solvent under a protective atmosphere, and then adding diphenylphosphine to the resulting system.

[0135] In this disclosure, the preferred temperature for the substitution reaction is 70–90°C; the preferred time is 10–14 h; and it is preferably carried out under stirring conditions. This disclosure does not impose any special limitation on the stirring speed, as long as it can ensure that the substitution reaction proceeds smoothly.

[0136] After the substitution reaction is completed, a post-treatment is performed. The post-treatment preferably includes diluting the reaction solution with dichloromethane, then extracting it 1 to 5 times with 1 mol / L hydrochloric acid, combining the aqueous phases, adding 1 to 10 mol / L sodium hydroxide solution to adjust the pH of the solution to be greater than 7, then extracting the aqueous phase three times with dichloromethane, combining the organic phases, preferably adding anhydrous sodium sulfate to the combined organic phases for drying, filtering to remove sodium sulfate, and using a rotary evaporator to remove the solvent. The remaining oily liquid after rotary evaporation is the target product, namely 2-(diphenylphosphine)ethyl-1-amine or 3-(diphenylphosphine)propyl-1-amine.

[0137] After obtaining 2-(diphenylphosphine)ethyl-1-amine or 3-(diphenylphosphine)prop-1-amine, this disclosure involves mixing the 2-(diphenylphosphine)ethyl-1-amine or 3-(diphenylphosphine)prop-1-amine, imidazole-2-carboxaldehyde or benzimidazole-2-carboxaldehyde, and a second solvent to perform a condensation reaction. A reducing agent is then added to perform a reduction reaction to obtain an imidazole or benzimidazole NNP ligand. In this disclosure, the molar ratio of the 2-(diphenylphosphine)ethyl-1-amine or 3-(diphenylphosphine)prop-1-amine to imidazole-2-carboxaldehyde or benzimidazole-2-carboxaldehyde is preferably 1:(0.9–1.1). This disclosure does not have a specific limitation on the amount of the second solvent, as long as it ensures the smooth progress of the condensation reaction; the second solvent can be methanol.

[0138] In this disclosure, the condensation reaction is preferably carried out at room temperature and for a time of 10 to 14 hours.

[0139] After the condensation reaction is completed, a reducing agent is directly added to the reaction solution to carry out a reduction reaction, thereby obtaining imidazole or benzimidazole NNP ligands. In this disclosure, the reducing agent can be sodium borohydride; the preferred molar ratio of the reducing agent to 2-(diphenylphosphine)ethyl-1-amine or 3-(diphenylphosphine)propyl-1-amine is (2-4):1.

[0140] In this disclosure, the reduction reaction temperature is preferably room temperature, and the time is preferably 10 to 14 hours.

[0141] After the reduction reaction is completed, post-processing is performed. The post-processing preferably includes quenching the reaction with water in the obtained product system, followed by extraction with dichloromethane 1-5 times, combining the organic phases, preferably adding anhydrous sodium sulfate to the combined organic phases for drying, filtering to remove sodium sulfate, removing the second solvent by rotary evaporation of the filtrate, and then separating by column chromatography to obtain the target product, i.e., imidazole or benzimidazole NNP ligands. Examples include: (N-((1H-imidazol-2-yl)methyl)-2-(diphenylphosphine)ethyl-1-amine, N-((1H-benzi[d]imidazol-2-yl)methyl)-2-(diphenylphosphine)ethyl-1-amine, N-((1H-imidazol-2-yl)methyl)-3-(diphenylphosphine)propyl-1-amine, N-((1H-benzi[d]imidazol-2-yl)methyl)-3-(diphenylphosphine)propyl-1-amine). In this disclosure, the eluent used in the column chromatography separation is preferably a mixture of dichloromethane and methanol, and the volume ratio of dichloromethane to methanol is preferably (10-30):1.

[0142] After obtaining the imidazole or benzimidazole NNP ligand, this disclosure describes a coordination substitution reaction in which the imidazole or benzimidazole NNP ligand is mixed with manganese pentacarbonyl bromide and a third solvent under a protective atmosphere to obtain a manganese catalyst having structures of formulas I to IV, namely manganese catalysts [Mn]-1 to [Mn]-4. In this disclosure, the molar ratio of the imidazole or benzimidazole NNP ligand to manganese pentacarbonyl bromide is preferably (0.60–0.70):0.60. In this disclosure, the mixing process of the imidazole or benzimidazole NNP ligand with manganese pentacarbonyl bromide and the subsequent coordination substitution reaction are preferably carried out in a glove box under argon protection.

[0143] In this disclosure, the coordination substitution reaction is carried out at a temperature of 25–120°C for 1–4 hours. The third solvent is preferably one or a combination of two or more of methanol, ethanol, isopropanol, diethyl ether, tetrahydrofuran, benzene, and toluene, more preferably ethanol. This disclosure does not impose any specific limitation on the amount of the third solvent, as long as it is sufficient to ensure the smooth progress of the coordination substitution reaction.

[0144] After the coordination substitution reaction is completed, a post-processing is performed. This post-processing preferably includes cooling the resulting system to room temperature and removing the solvent to obtain a crude product of the target product. In this disclosure, the solvent removal is preferably performed by using an oil pump to dry the product through a Shrek pipeline connected to a cold trap. After solvent removal, the crude product is dispersed in diethyl ether, filtered, and the filter cake is washed 1-5 times with diethyl ether, then washed 1-5 times with n-pentane, followed by vacuum drying to obtain the target product, namely the manganese catalysts [Mn]-1-[Mn]-4 having structures of formulas I-IV. This disclosure does not specify the specific conditions for the vacuum drying; any conditions sufficient for thorough drying of the material are acceptable.

[0145] <Manganese catalysts of formulas (V) to (IX)>

[0146] In this disclosure, the preparation method of the manganese catalysts [Mn]-5 to [Mn]-9 preferably includes the following steps:

[0147] In a protective atmosphere, o-fluorobenzonitrile, diphenylphosphine, a binding agent and a first solvent are mixed and subjected to a substitution reaction to obtain 2-(diphenylphosphine)benzonitrile;

[0148] The 2-(diphenylphosphine)benzonitrile, reducing agent, and second solvent are mixed and subjected to a first reduction reaction to obtain 2-(diphenylphosphine)benzylamine.

[0149] The 2-(diphenylphosphine)benzylamine was mixed with the corresponding nitrogen-containing heterocyclic formaldehyde and a third solvent and subjected to a condensation reaction. Then, a second reducing agent was added to carry out a second reduction reaction to obtain the NNP ligand.

[0150] In a protective atmosphere, the NNP ligand is mixed with manganese pentacarbonyl bromide and a fourth solvent and then subjected to a coordination substitution reaction to obtain manganese catalysts with structures shown in Formulas V to IX, namely manganese catalysts [Mn]-5 to [Mn]-9.

[0151] This disclosure describes a substitution reaction in which o-fluorobenzonitrile, diphenylphosphine, a binding agent, and a first solvent are mixed under a protective atmosphere to obtain 2-(diphenylphosphine)benzonitrile. In this disclosure, the molar ratio of o-fluorobenzonitrile, diphenylphosphine, and the binding agent is preferably 20:(20-22):(20-24). This disclosure does not have a specific limitation on the amount of dimethyl sulfoxide used, as long as it ensures the substitution reaction proceeds smoothly. The binding agent can be potassium tert-butoxide, used to neutralize the hydrofluoric acid generated during the substitution process, and the first solvent can be dimethyl sulfoxide. In this disclosure, the mixing of o-fluorobenzonitrile, diphenylphosphine, the binding agent, and the first solvent is preferably carried out under a protective atmosphere by dissolving the binding agent in the first solvent, and then sequentially adding diphenylphosphine and o-fluorobenzonitrile to the system.

[0152] In this disclosure, the substitution reaction is preferably carried out at room temperature for 1 to 14 hours. The substitution reaction is preferably conducted under stirring conditions. This disclosure does not specify a particular stirring speed, as long as it ensures the substitution reaction proceeds smoothly.

[0153] After the substitution reaction is completed, water is preferably added to the reaction system, filtered, the filter cake is washed with water 1 to 5 times, and then vacuum dried to obtain the target product, namely 2-(diphenylphosphine)benzonitrile.

[0154] After obtaining 2-(diphenylphosphine)benzonitrile, this disclosure involves mixing the 2-(diphenylphosphine)benzonitrile, a first reducing agent, and a third solvent to conduct a first reduction reaction, yielding 2-(diphenylphosphine)benzylamine. In this disclosure, the molar ratio of 2-(diphenylphosphine)benzonitrile to the first reducing agent is preferably 15:(30-150). This disclosure does not have a specific limitation on the amount of the second solvent, as long as it ensures the smooth progress of the first reduction reaction. The first reducing agent can be lithium aluminum hydride, and the second solvent can be tetrahydrofuran. In this disclosure, the mixing of the 2-(diphenylphosphine)benzonitrile, the first reducing agent, and the second solvent is preferably carried out by dissolving the 2-(diphenylphosphine)benzonitrile in the second solvent, and then adding the first reducing agent to the system in batches.

[0155] In this disclosure, the temperature of the first reduction reaction is preferably -5 to 5°C, and the time is preferably 0.5 to 3.5 h.

[0156] After the first reduction reaction is completed, post-processing is performed. The post-processing preferably includes adding water to the obtained product system to quench the reaction, filtering, and preferably extracting the filtrate with dichloromethane 1 to 5 times, combining the organic phases, preferably adding anhydrous sodium sulfate to the combined organic phases for drying, filtering to remove sodium sulfate, and using a rotary evaporator to remove the solvent from the filtrate to obtain the target product, namely 2-(diphenylphosphine)benzylamine.

[0157] After obtaining 2-(diphenylphosphine)benzylamine, this disclosure involves mixing the 2-(diphenylphosphine)benzylamine, NH heterocyclic formaldehyde, and a second solvent to undergo a condensation reaction. A second reducing agent is then added to carry out a second reduction reaction to obtain the NH heterocyclic NNP ligand. In this disclosure, the molar ratio of 2-(diphenylphosphine)benzylamine to NH heterocyclic formaldehyde is preferably 1:(0.9–1.1). This disclosure does not have a specific limitation on the amount of the second solvent used, as long as it ensures the smooth progress of the condensation reaction; the second solvent can be methanol.

[0158] In this disclosure, the condensation reaction is preferably carried out at room temperature for 10 to 14 hours.

[0159] After the condensation reaction is completed, a second reducing agent is directly added to the reaction solution to carry out a second reduction reaction, yielding an NH heterocyclic NNP ligand. In this disclosure, the second reducing agent can be sodium borohydride; the preferred molar ratio of the second reducing agent to 2-(diphenylphosphine)benzylamine is (2-4):1.

[0160] In this disclosure, the second reduction reaction temperature is preferably room temperature, and the time is preferably 10 to 14 hours.

[0161] After the second reduction reaction is completed, post-processing is performed. The post-processing preferably includes quenching the reaction with water in the obtained product system, extraction with dichloromethane 1-5 times, combining the organic phases, adding anhydrous sodium sulfate to the combined organic phases for drying, filtering to remove the sodium sulfate, removing the solvent by rotary evaporation of the filtrate, and then separating by column chromatography to obtain the target product, namely the NH heterocyclic NNP ligand (N-((1H-imidazol-2-yl)methyl)-1-(2-( The following compounds are used in this disclosure: N-((1H-benzis[d]imidazol-2-yl)methyl)-1-(2-(diphenylphosphine)phenyl)methylamine, N-((1H-imidazol-4-yl)methyl)-1-(2-(diphenylphosphine)phenyl)methylamine, N-((1H-pyrazole-3-yl)methyl)-1-(2-(diphenylphosphine)phenyl)methylamine, and N-((1H-indazole-3-yl)methyl)-1-(2-(diphenylphosphine)phenyl)methylamine). In this disclosure, the eluent used for column chromatography is preferably a mixture of dichloromethane and methanol, with a preferred volume ratio of dichloromethane to methanol of (10–30):1.

[0162] After obtaining the NH heterocyclic NNP ligand, this disclosure describes a coordination substitution reaction in which the NH heterocyclic NNP ligand is mixed with manganese pentacarbonyl bromide and a fourth solvent under a protective atmosphere to obtain a manganese catalyst having structures of formulas V to IX, namely manganese catalysts [Mn]-5 to [Mn]-9. In this disclosure, the molar ratio of the imidazole or benzimidazole NNP ligand to manganese pentacarbonyl bromide is preferably (0.80–0.90):0.80. In this disclosure, the mixing process of the NH heterocyclic NNP ligand with manganese pentacarbonyl bromide and the subsequent coordination substitution reaction are preferably carried out in a glove box under argon protection.

[0163] In this disclosure, the coordination substitution reaction temperature is 25–120°C; the preferred time is 1–4 h; the fourth solvent is preferably one or a combination of two or more of methanol, ethanol, isopropanol, diethyl ether, tetrahydrofuran, benzene, and toluene, more preferably ethanol. This disclosure does not impose any special limitation on the amount of the fourth solvent, as long as it is sufficient to ensure the smooth progress of the coordination substitution reaction.

[0164] After the coordination substitution reaction is completed, a post-processing is performed. The post-processing preferably includes cooling the resulting system to room temperature and removing the solvent to obtain a crude product of the target product. In this disclosure, the solvent removal is preferably performed by using an oil pump to dry the product through a Shrek pipeline connected to a cold trap. After solvent removal, the crude product is dispersed in diethyl ether, filtered, and the filter cake is washed 1-5 times with diethyl ether, then washed 1-5 times with n-pentane, followed by vacuum drying to obtain the target product, i.e., the manganese catalyst having structures of formulas V to IX, specifically [Mn]-5 to [Mn]-9. This disclosure does not specify the specific conditions for the vacuum drying; any conditions sufficient for thorough drying of the material are acceptable.

[0165] <Manganese catalysts of formulas (X) to (XIII)>

[0166] In a protective atmosphere, diisopropylphosphine chloride or diethylphosphine chloride, borane-tetrahydrofuran complex and a first solvent are mixed and subjected to a coordination reaction. A first reducing agent is added to the resulting product system to carry out a first reduction reaction to obtain diisopropylphosphine-borane complex or diethylphosphine-borane complex.

[0167] A first substitution reaction is carried out by mixing 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride, trimethylchlorosilane, a binding agent, and a second solvent to obtain N,N-di(trimethylsilyl)-2-chloroethyl-1-amine or N,N-di(trimethylsilyl)-3-chloropropyl-1-amine;

[0168] In a protective atmosphere, the diisopropylphosphine-borane complex or diethylphosphine-borane complex, n-butyllithium, and a third solvent are mixed and subjected to an acid-base reaction. N,N-di(trimethylsilyl)-2-chloroethylamine or N,N-di(trimethylsilyl)-3-chloropropylamine is added to the resulting product system, and a second substitution reaction is performed to remove the trimethylsilyl group, yielding 2-(diisopropylphosphine)ethyl-1-amine-borane complex, 2-(diethylphosphine)ethyl-1-amine-borane complex, or 3-(diisopropylphosphine)propyl-1-amine-borane complex.

[0169] The 2-(diisopropylphosphine)ethyl-1-amine-borane complex, 2-(diethylphosphine)ethyl-1-amine-borane complex, or 3-(diisopropylphosphine)propyl-1-amine-borane complex is mixed with the corresponding nitrogen-containing heterocyclic formaldehyde and a fourth solvent and subjected to a condensation reaction. A second reducing agent is added to the resulting product system to carry out a second reduction reaction to obtain the NNP ligand-borane complex.

[0170] In a protective atmosphere, the NNP ligand-borane complex was mixed with piperidine and subjected to a first coordination substitution reaction. Then, piperidine and the piperidine-borane complex were removed from the product system, and an alcoholysis reagent was added to carry out an alcoholysis reaction. After removing the alcoholysis reagent from the product system, manganese pentacarbonyl bromide and a fifth solvent were added to carry out a second coordination substitution reaction to obtain a manganese catalyst with the structure shown in Formulas X to XIII, namely manganese catalysts [Mn]-10 to [Mn]-13.

[0171] This disclosure involves mixing diisopropylphosphine chloride or diethylphosphine chloride, a borane-tetrahydrofuran complex, and a first solvent under a protective atmosphere to perform a coordination reaction, followed by the addition of a first reducing agent to perform a first reduction reaction, yielding a diisopropylphosphine-borane complex or a diethylphosphine-borane complex. In this disclosure, the molar ratio of diisopropylphosphine chloride or diethylphosphine chloride to the borane-tetrahydrofuran complex is preferably 100:(100-120); the borane-tetrahydrofuran complex is preferably used in the form of a tetrahydrofuran solution of the borane-tetrahydrofuran complex, and the concentration of the tetrahydrofuran solution of the borane-tetrahydrofuran complex (commercially available) is preferably 0.5-2 mol / L; this disclosure does not have a specific limitation on the amount of the first solvent, as long as it ensures the smooth progress of the complexation reaction, and the first solvent can be tetrahydrofuran. In this disclosure, the mixing of the diisopropylphosphine chloride or diethylphosphine chloride, the borane-tetrahydrofuran complex, and the first solvent is preferably carried out by dissolving the diisopropylphosphine chloride or diethylphosphine chloride in the first solvent under argon protection, and then adding the tetrahydrofuran solution of the borane-tetrahydrofuran complex at 0°C.

[0172] In this disclosure, the preferred temperature for the coordination reaction is -5 to 5°C, and the preferred time is 0.5 to 2.5 hours. In this disclosure, the coordination reaction is preferably carried out under stirring conditions. This disclosure does not impose specific limitations on the stirring speed, as long as it ensures the smooth progress of the coordination reaction.

[0173] After the coordination reaction is completed, this disclosure involves directly adding a first reducing agent to the reaction solution under a protective atmosphere to carry out a first reduction reaction, yielding a diisopropylphosphine-borane complex or a diethylphosphine-borane complex. In this disclosure, the first reducing agent can be lithium aluminum hydride; the preferred molar ratio of the first reducing agent to diisopropylphosphine chloride or diethylphosphine chloride is (100-120):100. Preferably, this disclosure allows for the first reduction reaction to be slowly added to the reaction system in batches under argon protection.

[0174] In this disclosure, the preferred temperature for the first reduction reaction is -5 to 5°C, and the preferred time is 0.5 to 2.5 hours. In this disclosure, the first reduction reaction is preferably carried out under stirring conditions. This disclosure does not impose specific limitations on the stirring speed, as long as it ensures the smooth progress of the first reduction reaction.

[0175] After the first reduction reaction is completed, post-processing is performed. The post-processing preferably includes adding water to the obtained product system to quench the reaction, filtering, and preferably extracting the filtrate with dichloromethane 1 to 5 times, combining the organic phases, preferably adding anhydrous sodium sulfate to the combined organic phases for drying, filtering to remove sodium sulfate, and using a rotary evaporator to remove the solvent from the filtrate to obtain diisopropylphosphine-borane complex or diethylphosphine-borane complex.

[0176] This disclosure involves mixing 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride, trimethylchlorosilane, a binding agent, and a second solvent to conduct a first substitution reaction, yielding N,N-di(trimethylsilyl)-2-chloroethyl-1-amine or N,N-di(trimethylsilyl)-3-chloropropyl-1-amine. In this disclosure, the preferred ratio of 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride, trimethylchlorosilane, and the binding agent is 40:(80-96):(120-144). This disclosure does not have a specific limitation on the amount of the second solvent, as long as it is sufficient to ensure the smooth progress of the first substitution reaction. The binding agent can be triethylamine to neutralize the hydrochloric acid produced during the substitution process, and the second solvent can be dichloromethane. In this disclosure, the mixing of the 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride, trimethylchlorosilane, binding agent, and second solvent is preferably carried out by dispersing the 2-chloroethylamine hydrochloride or 3-chloropropylamine hydrochloride in the second solvent, and then adding the binding agent and trimethylchlorosilane sequentially to the resulting system.

[0177] In this disclosure, the temperature of the first substitution reaction is preferably room temperature, and the time is preferably 10-14 hours. In this disclosure, the first substitution reaction is preferably carried out under stirring conditions. This disclosure does not impose special limitations on the stirring speed, as long as it ensures the smooth progress of the first substitution reaction.

[0178] After the first substitution reaction is completed, a post-processing is performed. The post-processing preferably includes removing excess binding agent, trimethylchlorosilane and second solvent from the obtained product system under reduced pressure. Hexane is added to the obtained residue, and the mixture is stirred at room temperature for 30 min. Triethylamine hydrochloride is removed by filtration. Hexane is removed by rotary evaporation of the filtrate using a rotary evaporator. Then, the mixture is distilled under reduced pressure using an oil pump. The obtained fraction is the target product, namely N,N-di(trimethylsilyl)-2-chloroethyl-1-amine or N,N-di(trimethylsilyl)-3-chloroprop-1-amine.

[0179] After obtaining N,N-di(trimethylsilyl)-2-chloroethyl-1-amine or N,N-di(trimethylsilyl)-3-chloroprop-1-amine, this disclosure discloses, under a protective atmosphere, mixing the diisopropylphosphine-borane complex or diethylphosphine-borane complex, n-butyllithium, and a third solvent, and then subjecting the mixture to an acid-base reaction. The N,N-di(trimethylsilyl)-2-chloroethyl-1-amine or N,N-di(trimethylsilyl)-3-chloroprop-1-amine is added to the resulting product system, and a second substitution reaction is performed to remove the trimethylsilyl group, yielding 2-(diisopropylphosphine)ethyl-1-amine-borane complex, 2-(diethylphosphine)ethyl-1-amine-borane complex, or 3-(diisopropylphosphine)prop-1-amine-borane complex. In this disclosure, the molar ratio of the diisopropylphosphine-borane complex or diethylphosphine-borane complex, n-butyllithium, N,N-di(trimethylsilyl)-2-chloroethyl-1-amine or N,N-di(trimethylsilyl)-3-chloroprop-1-amine is preferably 10:(10.5-11.5):(10.5-11.5); the n-butyllithium is preferably used in the form of a n-hexane solution of n-butyllithium, and the concentration of the n-hexane solution of n-butyllithium (commercially available) is preferably 1-2 mol / L; this disclosure does not have a special limitation on the amount of the third solvent, as long as it can ensure the smooth progress of the second substitution reaction; wherein, the third solvent can be tetrahydrofuran.

[0180] In this disclosure, the mixing of diisopropylphosphine-borane complex or diethylphosphine-borane complex, n-butyllithium, and a third solvent is preferably carried out under argon protection and at 0°C by adding a tetrahydrofuran solution of the diisopropylphosphine-borane complex or diethylphosphine-borane complex to a Shrek flask, followed by the slow dropwise addition of a n-butyllithium solution in n-hexane. After the addition is complete, the temperature of the reaction system is adjusted to the temperature required for the acid-base reaction, and the acid-base reaction is carried out. This disclosure does not have a specific limitation on the dropping rate of the n-butyllithium solution in n-hexane; any dropping rate well known to those skilled in the art can be used.

[0181] In this disclosure, the acid-base reaction is preferably carried out at room temperature for 1.5–2.5 hours; the acid-base reaction is preferably carried out under stirring conditions, and this disclosure does not have a specific limitation on the stirring rate, a conventional stirring rate is sufficient. During the acid-base reaction, n-butyllithium can remove protons from the diisopropylphosphine-borane complex or the diethylphosphine-borane complex to form an anion of the diisopropylphosphine-borane complex or the diethylphosphine-borane complex, which is beneficial for the subsequent substitution reaction.

[0182] After the acid-base reaction is completed, this disclosure requires no post-processing of the resulting product system. N,N-di(trimethylsilyl)-2-chloroethyl-1-amine or N,N-di(trimethylsilyl)-3-chloroprop-1-amine is directly added to the product system to carry out the second substitution reaction, followed by the removal of the trimethylsilyl group to obtain a 2-(diisopropylphosphine)ethyl-1-amine-borane complex, a 2-(diethylphosphine)ethyl-1-amine-borane complex, or a 3-(diisopropylphosphine)prop-1-amine-borane complex. Preferably, this disclosure involves adding N,N-di(trimethylsilyl)-2-chloroethyl-1-amine or N,N-di(trimethylsilyl)-3-chloroprop-1-amine to the product system obtained after the acid-base reaction under argon protection. After the addition is complete, the temperature of the reaction system is adjusted to the temperature required for the second substitution reaction to carry out the second substitution reaction.

[0183] In this disclosure, the temperature of the second substitution reaction is preferably 70-90°C, specifically, the reaction system is kept under reflux; the time of the second substitution reaction is preferably 10-14 hours.

[0184] This disclosure does not specifically limit the method for removing the trimethylsilyl group after the second substitution reaction is completed. A method well known to those skilled in the art can be used. In the embodiments of this disclosure, the system obtained after the second substitution reaction is cooled to room temperature, water is added to quench any possible residual n-butyllithium, and then sulfuric acid (preferably 1-3 mol / L) is added and stirred for 0.5-2 h to remove the trimethylsilyl group. Subsequently, sodium hydroxide solution (preferably 3-5 mol / L) is added and stirred for 10-50 min to neutralize the sulfuric acid. The organic phase is separated, and the aqueous phase is preferably extracted with dichloromethane 1-5 times. The obtained organic phases are combined, and anhydrous sodium sulfate is preferably added to the combined organic phase for drying. The sodium sulfate is removed by filtration, and the solvent is removed by rotary evaporation of the filtrate to obtain the target product, namely 2-(diisopropylphosphine)ethyl-1-amine-borane complex, 2-(diethylphosphine)ethyl-1-amine-borane complex, or 3-(diisopropylphosphine)propyl-1-amine-borane complex.

[0185] After obtaining the 2-(diisopropylphosphine)ethyl-1-amine-borane complex, the 2-(diethylphosphine)ethyl-1-amine-borane complex, or the 3-(diisopropylphosphine)propyl-1-amine-borane complex, this disclosure further discloses the following: the 2-(diisopropylphosphine)ethyl-1-amine-borane complex, the 2-(diethylphosphine)ethyl-1-amine-borane complex, or the 3-(diisopropylphosphine)propyl-1-amine-borane complex, NH heterocyclic formaldehyde, and a fourth solvent are mixed and subjected to a condensation reaction. Then, sodium borohydride is added to carry out a second reduction reaction to obtain the NH heterocyclic NNP ligand-borane complex. In this disclosure, the molar ratio of the 2-(diisopropylphosphine)ethyl-1-amine-borane complex, the 2-(diethylphosphine)ethyl-1-amine-borane complex, or the 3-(diisopropylphosphine)propyl-1-amine-borane complex to NH heterocyclic formaldehyde is preferably 1:(0.9-1.1). This disclosure does not impose any special limitation on the amount of the fourth solvent, as long as it is sufficient to ensure the smooth progress of the condensation reaction. The fourth solvent can be methanol.

[0186] In this disclosure, the condensation reaction is preferably carried out at room temperature for 10 to 14 hours.

[0187] After the condensation reaction is completed, a second reducing agent is directly added to the reaction solution to carry out a second reduction reaction, yielding an NH heterocyclic NNP ligand-borane complex. In this disclosure, the second reducing agent can be sodium borohydride; the preferred molar ratio of the second reducing agent to the 2-(diisopropylphosphine)ethyl-1-amine-borane complex, the 2-(diethylphosphine)ethyl-1-amine-borane complex, or the 3-(diisopropylphosphine)propyl-1-amine-borane complex is (2-4):1.

[0188] In this disclosure, the second reduction reaction temperature is preferably room temperature, and the time is preferably 10 to 14 hours.

[0189] After the second reduction reaction is completed, post-processing is performed. The post-processing preferably includes quenching the reaction with water in the obtained product system, extraction with dichloromethane 1-5 times, combining the organic phases, adding anhydrous sodium sulfate to the combined organic phases for drying, filtering to remove the sodium sulfate, removing the solvent by rotary evaporation of the filtrate, and then separating by column chromatography to obtain the target product, namely the NH heterocyclic NNP ligand-borane complex (N-((1H-imidazol-2-yl)methyl). The following complexes are described: N-((1H-benzo[d]imidazol-2-yl)methyl)-2-(diisopropylphosphine)ethyl-1-amine-borane complex, N-((1H-benzo[d]imidazol-2-yl)methyl)-2-(diethylphosphine)ethyl-1-amine-borane complex, and N-((1H-benzo[d]imidazol-2-yl)methyl)-2-(diisopropylphosphine)propyl-1-amine-borane complex. In this disclosure, the eluent used for column chromatography is preferably a mixture of dichloromethane and methanol, with a preferred volume ratio of dichloromethane to methanol of (10–30):1.

[0190] After obtaining the NH heterocyclic NNP ligand-borane complex, this disclosure involves mixing the NH heterocyclic NNP ligand-borane complex with piperidine under a protective atmosphere to carry out a first ligand substitution reaction, yielding a mixture containing both NH heterocyclic NNP ligands and N-BH2 heterocyclic NNP ligands. This disclosure does not impose any particular limitation on the amount of piperidine used, as long as it ensures the smooth progress of the first ligand substitution reaction. Piperidine serves as both the substituted ligand and the solvent in the ligand substitution reaction. In this disclosure, the mixing process of the NH heterocyclic NNP ligand-borane complex with piperidine is preferably carried out in a glove box under argon protection.

[0191] In this disclosure, the preferred temperature for the first coordination substitution reaction is 110–130°C, and the preferred time is 0.5–3.5 h. In this disclosure, the first coordination substitution reaction is preferably carried out under stirring conditions. This disclosure does not impose specific limitations on the stirring speed, as long as it ensures the smooth progress of the first coordination substitution reaction.

[0192] After the first coordination substitution reaction is completed, a post-processing step is performed. This post-processing preferably includes cooling the resulting system to room temperature and then drying it under argon protection using an oil pump through a Shrek line connected to a cold trap. After solvent removal, the crude product is dispersed in diethyl ether, filtered, and the filter cake is washed with diethyl ether 1–5 times. The filtrates are combined. The combined filtrate is then dried again under argon protection using an oil pump through a Shrek line connected to a cold trap to obtain a mixture containing NH heterocyclic NNP ligands and N-BH2 heterocyclic NNP ligands.

[0193] After obtaining a mixture containing NH heterocyclic NNP ligands and N-BH2 heterocyclic NNP ligands, this disclosure preferably involves mixing the mixture with an alcoholysis reagent and then performing an alcoholysis reaction to obtain NH heterocyclic NNP ligands. This disclosure does not have a specific limitation on the amount of the alcoholysis reagent, as long as it ensures the smooth progress of the alcoholysis reaction. The alcoholysis reagent can be methanol, or it can be used as a solvent. In this disclosure, the mixing process of the mixture containing NH heterocyclic NNP ligands and N-BH2 heterocyclic NNP ligands with the alcoholysis reagent is preferably carried out in a glove box under argon protection.

[0194] In this disclosure, the preferred temperature for the alcoholysis reaction is 70–90°C, and the preferred time is 0.5–3.5 h. In this disclosure, the alcoholysis reaction is preferably carried out under stirring conditions. This disclosure does not impose specific limitations on the stirring speed, as long as it ensures the smooth progress of the coordination reaction.

[0195] After the alcoholysis reaction is completed, post-processing is performed. The post-processing preferably includes cooling the obtained system to room temperature and then evacuating it through a Shrek pipeline connected to a cold trap using an oil pump under argon protection to obtain a crude product containing NH heterocyclic NNP ligands. The crude product does not require further purification and can be directly used for the next step of feeding.

[0196] After obtaining the NH heterocyclic NNP ligand, this disclosure involves mixing the NH heterocyclic NNP ligand with manganese pentacarbonyl bromide and a fifth solvent under a protective atmosphere to carry out a second coordination substitution reaction, yielding a manganese catalyst having structures of formulas X to XIII, namely manganese catalysts [Mn]-10 to [Mn]-13. In this disclosure, the molar ratio of the imidazole or benzimidazole NNP ligand to manganese pentacarbonyl bromide is preferably (0.7–0.9):0.6. Specifically, the amount of NH heterocyclic NNP ligand is based on the amount of the aforementioned NH heterocyclic NNP ligand-borane complex. In this disclosure, the mixing process of the NH heterocyclic NNP ligand with manganese pentacarbonyl bromide and the subsequent second coordination substitution reaction are preferably carried out in a glove box under argon protection.

[0197] In this disclosure, the temperature of the second coordination substitution reaction is 25–120°C; the time is preferably 1–4 h, more preferably 0.5–3.5 h; the fifth solvent is preferably one or a combination of two or more of methanol, ethanol, isopropanol, diethyl ether, tetrahydrofuran, benzene, and toluene, more preferably ethanol. This disclosure does not impose any special limitation on the amount of the fifth solvent, as long as it is sufficient to ensure the smooth progress of the coordination substitution reaction.

[0198] After the second coordination substitution reaction is completed, post-processing is performed. This post-processing preferably includes cooling the resulting system to room temperature and removing the solvent to obtain a crude product of the target product. In this disclosure, the solvent removal is preferably performed by using an oil pump to dry the product through a Shrek pipeline connected to a cold trap. After solvent removal, the crude product is dispersed in diethyl ether, filtered, and the filter cake is washed 1-5 times with diethyl ether, then washed 1-5 times with n-pentane, followed by vacuum drying to obtain the target product, namely the manganese catalyst [Mn]-10 to [Mn]-13. This disclosure does not specify the specific conditions for the vacuum drying, as long as sufficient drying of the material is achieved.

[0199] In this disclosure, the manganese catalysts [Mn]-14, [Mn]-15 and the ligands L16 to L19 are preferably synthesized using the methods described in the references (Angew. Chem. Int. Ed. 2020, 60, 5108-5113; Angew. Chem. Int. Ed. 2022, 61, e202202814; Chem 2023, 9, 2585-2600.).

[0200] This disclosure also provides the use of the manganese catalyst according to this disclosure for the catalytic hydrogenation of trisubstituted acetates or tertiary alkyl esters.

[0201] Example

[0202] The embodiments of this disclosure will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this disclosure. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0203] Example 1

[0204] A manganese catalyst with formula IV, namely manganese catalyst [Mn]-4, was prepared, and its crystal structure is shown in Figure 1. The specific preparation method includes the following steps:

[0205] (1) Synthesis of 3-(diphenylphosphine)prop-1-amine

[0206] Under argon protection, (3-chloropropane-1-ammonium chloride) (1.3 g, 10 mmol), potassium tert-butoxide (tBuOK, 2.2 g, 20 mmol), and tetrahydrofuran (THF, 30 mL) were added to a Shrek flask. Diphenylphosphine (HPPh2, 1.9 g, 10 mmol) was added to the resulting system, and the mixture was stirred at 80 °C for 12 h. After the reaction was completed, the reaction system was cooled to room temperature, diluted with dichloromethane, and extracted three times with 1 mol / L hydrochloric acid. The aqueous phases were combined, and the pH of the aqueous phase was adjusted to 10 with 4 mol / L sodium hydroxide solution. The aqueous phase after pH adjustment was extracted three times with dichloromethane, and the organic phases were combined, dried over anhydrous sodium sulfate, and filtered. The filtrate was evaporated using a rotary evaporator to remove the solvent, yielding 3-(diphenylphosphine)propane-1-amine, a pale yellow oily liquid, with a yield of 2.15 g and a yield of 88%.

[0207] 1 H NMR (400MHz, CDCl3) δ=7.46-7.39(m,4H),7.37-7.27(m,6H),2.85-2.72(m,2H),2.11-2.03(m,2H),1.97-1.86(m,2H),1.63-1.53(m,2H)ppm.

[0208] 13 C NMR (101MHz, CDCl3) δ = 138.43 (d, J = 13.1Hz), 132.41 (d, J = 18.4Hz), 128.26, 128.1 3(d,J=6.6Hz), 42.87(d,J=13.8Hz), 29.51(d,J=15.6Hz), 25.02(d,J=11.8Hz)ppm.

[0209] 31 P NMR (162MHz, CDCl3) δ = -16.26ppm.

[0210] (2) Synthesis of benzimidazole NNP ligands

[0211] At room temperature, 3-(diphenylphosphine)prop-1-amine (243 mg, 1.0 mmol) and methanol (MeOH, 30 mL) were added to a round-bottom flask, followed by benzimidazole-2-carboxaldehyde (146 mg, 1.0 mmol). The reaction was carried out at room temperature for 12 h. Then, sodium borohydride (NaBH4, 76 mg, 2.0 mmol) was slowly added in portions, and the reaction was carried out at room temperature for 12 h. The reaction was then quenched with 100 mL of water. The mixture was extracted three times with dichloromethane, and the organic phases were combined. The organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was used to remove the solvent using a rotary evaporator. The residue was separated by column chromatography (using a mixture of dichloromethane and methanol as the eluent, with a volume ratio of dichloromethane to methanol of 20:1) to obtain a pale yellow oily liquid, which was the target product (yield of 242 mg, 65%).

[0212] 1 H NMR(400MHz, CDCl3)δ=7.59-7.52(m,2H),7.44-7.37(m,4H),7.36-7.27(m,6H),7.25-7.19(m ,2H),5.64(b,2H),4.07(s,2H),2.85-2.70(m,2H),2.17-2.00(m,2H),1.73-1.61(m,2H)ppm.

[0213] 13 C NMR (101MHz, CDCl3) δ = 153.26, 138.71, 138.50 (d, J = 12.5Hz), 132.81 (d, J = 18.5Hz), 128.81, 128.61 (d ,J=6.7Hz),122.49,115.16,50.48(d,J=12.8Hz),47.39,26.10(d,J=15.5Hz),25.74(d,J=11.9Hz)ppm.

[0214] 31 P NMR (162MHz, CDCl3) δ = -16.74ppm.

[0215] (3) Synthesis of manganese catalyst [Mn]-4

[0216] In an argon-filled glove box, benzimidazole NNP ligand (242 mg, 0.65 mmol), manganese pentacarbonyl bromide (Mn(CO)5Br, 165 mg, 0.60 mmol), and ethanol (EtOH, 30 mL) were added to a Shrek flask and refluxed at 80 °C for 2 h. After the reaction, the resulting system was cooled to room temperature, and the solvent was removed by pumping through a Shrek line connected to a cold trap. The crude product after solvent removal was dispersed in diethyl ether, filtered, and the filter cake was washed three times with diethyl ether and then three times with n-pentane. Subsequently, it was dried under vacuum to obtain the target manganese catalyst [Mn]-4 (yield 298 mg, 84%).

[0217] 1 H NMR (400MHz, DMSO-d6) δ = 13.21 (b, 1H), 7.71-7.65 (m, 1H), 7.58-7.54 (m, 1H), 7.53-7.46 (m, 3H), 7.45-7.31 (m, 5H), 7 .27-7.20(m,1H),7.05-6.88(m,4H),4.01-3.85(m,1H),3.48-3.06(m,5H),2.45-2.36(m,1H),2.33-2.25(m,1H)ppm.

[0218] 13 C NMR (101MHz, DMSO-d6) δ = 155.01, 141.02, 135.04, 134.24 (d, J = 43.5Hz), 131.73 (d, J = 9.4Hz), 130.69 (2C), 130.55 (d, J = 8.9Hz), 129.08 (d, J = 9 .3Hz), 128.36 (d, J = 8.7Hz), 127.03 (d, J = 28.9Hz), 123.80, 123.59, 115.69, 112.93, 50.01 (d, J = 4.7Hz), 45.26, 23.21 (d, J = 21.1Hz), 19.29ppm.

[0219] 31 P NMR (162MHz, DMSO-d6) δ = 34.39ppm.

[0220] Example 2

[0221] The preparation of a manganese catalyst with a VI-shaped structure, namely manganese catalyst [Mn]-6, includes the following steps:

[0222] (1) Synthesis of 2-(diphenylphosphine)benzonitrile

[0223] Under argon protection, potassium tert-butoxide (tBuOK, 2.2 g, 20 mmol) and dimethyl sulfoxide (DMSO, 30 mL) were added dropwise to the Shrek flask. Diphenylphosphine (HPPh2, 3.7 g, 20 mmol) and o-fluorobenzonitrile (2.4 g, 20 mmol) were then added dropwise to the resulting system. The mixture was stirred at room temperature for 12 h. After the reaction was complete, water was added to the system, resulting in the precipitation of a white solid. The mixture was filtered, and the filter cake was washed three times with water to obtain 2-(diphenylphosphine)benzonitrile, a white solid, with a yield of 4.42 g (77%).

[0224] 1 H NMR (400MHz, CDCl3) δ=7.75-7.65(m,1H),7.55-7.19(m,12H),7.12-6.96(m,1H)ppm.

[0225] 13 C NMR (101MHz, CDCl3) δ = 143.14 (d, J = 19.8Hz), 134.75 (d, J = 10.2Hz), 134.14 (d, J = 20.3Hz), 133.84 (d ,J=4.7Hz),133.52,132.51,129.54,128.98,128.91,118.02(d,J=32.9Hz),117.73(d,J=3.8Hz)ppm.

[0226] 31 P NMR (162MHz, CDCl3) δ = -8.51ppm.

[0227] (2) Synthesis of 2-(diphenylphosphine)benzylamine

[0228] At 0°C, 2-(diphenylphosphine)benzonitrile (4.3 g, 15 mmol) and tetrahydrofuran (THF, 30 mL) were added to a round-bottom flask, followed by the slow addition of lithium aluminum hydride (3.4 g, 90 mmol) in portions. The reaction was carried out at 0°C for 2 h, and then 100 mL of ice water was added to quench the reaction. The mixture was filtered, and the filtrate was extracted three times with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, and filtered. The solvent was removed from the filtrate using a rotary evaporator to obtain a yellow solid, which was the target product 2-(diphenylphosphine)benzylamine (yield 5.17 g, 71%).

[0229] 1H NMR (400MHz, CDCl3) δ=7.49-7.42(m,1H),7.41-7.24(m,12H),7.21-7.13(m,1H),6.93-6.96(8m,1H),4.03(s,2H),1.82-1.41(m,2H)ppm.

[0230] 13 C NMR (101MHz, CDCl3) δ = 147.41 (d, J = 23.5Hz), 136.52 (d, J = 9.8Hz), 135.21 (d, J = 13.6Hz), 134.03 (d, J = 19. 7Hz), 133.64, 129.45, 128.94, 128.72 (d, J = 7.0Hz), 128.12 (d, J = 5.3Hz), 127.26, 45.28 (d, J = 22.6Hz) ppm.

[0231] 31 P NMR (162MHz, CDCl3) δ = -15.87ppm.

[0232] (3) Synthesis of benzimidazole NNP ligands

[0233] At room temperature, 2-(diphenylphosphine)benzylamine (291 mg, 1.0 mmol) and methanol (MeOH, 30 mL) were added to a round-bottom flask, followed by benzimidazole-2-carboxaldehyde (146 mg, 1.0 mmol). The reaction was carried out at room temperature for 12 h. Then, sodium borohydride (NaBH4, 76 mg, 2.0 mmol) was slowly added in portions, and the reaction was carried out at room temperature for 12 h. The reaction was then quenched with 100 mL of water. The mixture was extracted three times with dichloromethane, and the organic phases were combined. The organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was used to remove the solvent using a rotary evaporator. The residue was separated by column chromatography (using a mixture of dichloromethane and methanol as the eluent, with a volume ratio of dichloromethane to methanol of 20:1) to obtain a pale yellow oily liquid, which was the target product (yield of 370 mg, yield of 88%).

[0234] 1 H NMR(400MHz, CDCl3)δ=7.50-7.45(m,2H),7.43-7.31(m,9H),7.30-7.27(m,3H),7.2 4-7.21(m,1H),7.21-7.18(m,2H),7.06-6.98(m,1H),4.12(s,2H),4.08(s,2H)ppm.

[0235] 13C NMR (101MHz, CDCl3) δ = 153.92, 144.15, 137.47 (d, J = 8.6Hz), 136.38 (d, J = 13.4Hz), 135.02, 134.06 (d, J = 19.9Hz), 133.83 (d, J = 19.3H z), 131.93 (d, J = 9.7Hz), 130.04 (d, J = 6.2Hz), 129.42, 128.95, 128.81 (d, J = 6.8Hz), 128.19, 122.18, 53.69 (d, J = 17.0Hz), 47.32ppm.

[0236] 31 P NMR (162MHz, CDCl3) δ = -15.88ppm.

[0237] (4) Synthesis of manganese catalyst [Mn]-6

[0238] In an argon-filled glove box, benzimidazole NNP ligand (370 mg, 0.88 mmol), manganese pentacarbonyl bromide (Mn(CO)5Br, 220 mg, 0.80 mmol), and ethanol (EtOH, 30 mL) were added to a Shrek flask and refluxed at 80 °C for 2 h. After the reaction, the resulting system was cooled to room temperature, and the solvent was removed by pumping through a Shrek line connected to a cold trap. The crude product after solvent removal was dispersed in diethyl ether, filtered, and the filter cake was washed three times with diethyl ether and then three times with n-pentane. Subsequently, it was dried under vacuum to obtain the target manganese catalyst [Mn]-6 (yield 364 mg, 71%).

[0239] 1 H NMR (400MHz, DMSO-d6) δ = 13.24 (b, 1H), 7.97-7.10 (m, 16H), 6.95-6.88 (m, 2H), 6.73-6.6 1(m,1H),4.39-4.28(m,1H),4.20-4.14(m,1H),3.85-3.72(m,1H),3.49-3.38(m,1H)ppm.

[0240] 13C NMR (101MHz, DMSO-d6) δ = 139.81, 133.35, 132.54 (d, J = 6.1Hz), 132.05, 131.95 (3C),131.81,130.90,130.72,130.29,130.13,129.06,129.02(d,J=9.1Hz),1 28.49(d,12.6Hz),127.95(d,J=8.4Hz),127.38(d,J=34.9Hz),125.13(d,J=30 .1Hz), 122.89 (d, J = 37.1Hz), 115.70, 112.91, 55.46 (d, J = 11.1Hz), 18.19ppm.

[0241] 31 P NMR (162MHz, DMSO-d6) δ = 40.95ppm.

[0242] Example 3

[0243] The preparation of a manganese catalyst having the structure of formula XIII, namely manganese catalyst [Mn]-13, includes the following steps:

[0244] (1) Synthesis of diisopropylphosphine-borane complex

[0245] Under argon protection and at 0°C, diisopropylphosphine chloride (15.3 g, 100 mmol) and tetrahydrofuran (THF, 100 mL) were added to a Shrek flask, followed by a tetrahydrofuran solution of the borane-tetrahydrofuran complex (BH3 THF, 1 mol / L, 110 mL, 110 mmol). The reaction was carried out at 0°C for 1 h. Then, lithium aluminum hydride (LAH, 4.2 g, 110 mmol) was added in portions under argon protection, and the reaction was carried out at 0°C for 1 h. The reaction was then quenched with 100 mL of ice water, filtered, and the filtrate was extracted three times with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate and filtered. The solvent was removed from the filtrate using a rotary evaporator to obtain a colorless oily liquid, which was the target product, diisopropylphosphine-borane complex (yield 12.98 g, 98% yield).

[0246] 1 H NMR (400MHz, CDCl3) δ=4.74-3.68(m,1H),2.22-2.00(m,2H),1.48-0.99(m,12H),0.89--0.10(m,3H)ppm.

[0247] 11B NMR (128MHz, CDCl3) δ = -45.21 (qd, J = 97.0, 51.4Hz) ppm.

[0248] 13 C NMR (101MHz, CDCl3) δ = 19.82 (d, J = 33.8Hz), 19.43 (d, J = 1.8Hz), 17.62ppm.

[0249] 31 P NMR (162MHz, CDCl3) δ = 27.27 (q, J = 48.8Hz) ppm.

[0250] (2) Synthesis of N,N-bis(trimethylsilyl)-3-chloroprop-1-amine

[0251] 3-Chloropropylamine hydrochloride (5.2 g, 40 mmol), triethylamine (TEA, 13.3 g, 132 mmol), and dichloromethane (DCM, 200 mL) were added to a Shrek flask. Trimethylchlorosilane (TMSCl, 9.6 g, 88 mmol) was added to the resulting system, and the mixture was stirred at room temperature for 12 h. After the reaction was completed, excess triethylamine, trimethylchlorosilane, and dichloromethane were removed under reduced pressure. 200 mL of n-hexane was added to the residue, and the mixture was stirred at room temperature for 30 min. Triethylamine hydrochloride was removed by filtration. The filtrate was then evaporated under reduced pressure using a rotary evaporator to remove n-hexane. Finally, the mixture was distilled under reduced pressure using an oil pump. The resulting fraction was the target product, N,N-di(trimethylsilyl)-3-chloropropyl-1-amine (colorless oily liquid, yield 8.09 g, 85% yield).

[0252] 1 H NMR (400MHz, CDCl3) δ = 3.57-3.36 (m, 2H), 3.05-2.80 (m, 2H), 1.92-1.75 (m, 2H), 0.10 (s, 18H) ppm.

[0253] 13 C NMR (101MHz, CDCl3) δ = 43.31, 43.02, 37.84, 2.23ppm.

[0254] (3) Synthesis of 3-(diisopropylphosphine)prop-1-amine-borane complex

[0255] Under argon protection, diisopropylphosphine-borane complex (1.3 g, 10 mmol) and tetrahydrofuran (20 mL) were added to a Shrek flask, followed by the slow dropwise addition of a hexane solution of n-butyllithium (1.6 mol / L, 7 mL, 11 mmol). After the addition was complete, the reaction system was heated to room temperature and stirred for 2 h. Then, N,N-di(trimethylsilyl)-3-chloroprop-1-amine (2.6 g, 11 mmol) was added under argon protection, and the mixture was refluxed at 80 °C for 12 h. After the reaction was completed, the resulting reaction system was cooled to room temperature, 5 mL of water and 6 mL of 2 mol / L sulfuric acid were added, and the mixture was stirred for 1 h. Then, 7 mL of 4 mol / L sodium hydroxide solution was added, and the mixture was stirred for 30 min. The organic phase was separated, and the aqueous phase was extracted three times with dichloromethane. The resulting organic phases were combined, dried with anhydrous sodium sulfate, and filtered. The filtrate was used to remove the solvent using a rotary evaporator to obtain a pale yellow oily liquid, which was the target product 3-(diisopropylphosphine)propyl-1-amine-borane complex (yield 1.50 g, yield 86%).

[0256] 1 H NMR (400MHz, CDCl3) δ=2.81-2.61(m,2H),2.05-1.90(m,4H),1.70-1.51(m,4H),1.21-1.04(m,12H),0.70--0.18(m,3H)ppm.

[0257] 11 B NMR (128MHz, CDCl3) δ = -43.97 (qd, J = 95.3, 66.7Hz) ppm.

[0258] 13 C NMR (101MHz, CDCl3) δ = 43.35 (d, J = 12.9Hz), 27.26, 21.84 (d, J = 33.1Hz), 17.20, 16.98 (d, J = 1.3Hz), 16.75 (d, J = 32.0Hz) ppm.

[0259] 31 P NMR (162MHz, CDCl3) δ = 27.27 (q, J = 56.0Hz) ppm.

[0260] (4) Synthesis of benzimidazole NNP ligand-borane complex

[0261] At room temperature, 3-(diisopropylphosphine)prop-1-amine-borane complex (175 mg, 1.0 mmol) and methanol (MeOH, 30 mL) were added to a round-bottom flask, followed by benzimidazole-2-carboxaldehyde (146 mg, 1.0 mmol). The reaction was carried out at room temperature for 12 h. Then, sodium borohydride (NaBH4, 76 mg, 2.0 mmol) was slowly added in portions, and the reaction was carried out at room temperature for 12 h. The reaction was then quenched with 100 mL of water. The mixture was extracted three times with dichloromethane, and the organic phases were combined. The organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was used to remove the solvent using a rotary evaporator. The residue was separated by column chromatography (using a mixture of dichloromethane and methanol as the eluent, with a volume ratio of dichloromethane to methanol of 20:1) to obtain a pale yellow oily liquid, which was the target product (yield of 255 mg, 80%).

[0262] 1 H NMR(400MHz, CDCl3)δ=7.65-7.52(m,2H),7.26-7.16(m,2H),6.58-5.52(m,2H),4.13(s,2H),2.8 7-2.66(m,2H),1.84-1.69(m,2H),1.64-1.53(m,2H),1.21-1.06(m,12H),0.77--0.12(m,3H)ppm.

[0263] 11 B NMR (128MHz, CDCl3) δ = -43.97 (qd, J = 89.3, 71.6Hz) ppm.

[0264] 13 C NMR (101MHz, CDCl3) δ = 153.36, 138.48, 122.60, 115.14, 50.85 (d, J = 11.1Hz), 47.4 0, 24.11, 22.00 (d, J = 33.2Hz), 17.30, 17.07 (d, J = 1.0Hz), 17.02 (d, J = 31.5Hz) ppm.

[0265] 31 P NMR (162MHz, CDCl3) δ = 32.42 (q, J = 53.0Hz) ppm.

[0266] (5) Synthesis of manganese catalyst [Mn]-13

[0267] In an argon-filled glove box, benzimidazole NNP ligand-borane complex (255 mg, 0.8 mmol) and piperidine (10 mL) were added to a Shrek flask and refluxed at 120 °C for 2 h. After the reaction, the resulting system was cooled to room temperature, and the solvent was then removed by pumping through a Shrek line connected to a cold trap. The residue after solvent removal was dissolved in 10 mL of diethyl ether, filtered, and the filter cake was washed three times with diethyl ether. The filtrates were combined, and the solvent was removed by pumping through a Shrek line connected to a cold trap to obtain a mixture containing NH heterocyclic NNP ligands and N-BH2 heterocyclic NNP ligands.

[0268] In an argon-filled glove box, a mixture containing NH heterocyclic NNP ligands and N-BH2 heterocyclic NNP ligands and methanol (20 mL) were added to a Shrek flask and refluxed at 80 °C for 2 h. After the reaction was completed, the resulting system was cooled to room temperature, and the solvent was then removed by pumping through the Shrek line connected to the cold trap to obtain a mixture containing NH heterocyclic NNP ligands.

[0269] In an argon-filled glove box, a mixture containing NH heterocyclic NNP ligands, manganese pentacarbonyl bromide (Mn(CO)5Br, 165 mg, 0.6 mmol), and ethanol (EtOH, 30 mL) were added to a Shrek flask and refluxed at 80 °C for 2 h. After the reaction, the resulting system was cooled to room temperature, and the solvent was then removed by pumping through a Shrek line connected to a cold trap. The crude product after solvent removal was dispersed in diethyl ether, filtered, and the filter cake was washed three times with diethyl ether and then three times with n-pentane. Subsequently, it was dried under vacuum to obtain the target manganese catalyst [Mn]-13 (yield 466 mg, 89%).

[0270] 1 H NMR (400MHz, DMSO-d6) δ = 13.18 (b, 1H), 7.95-7.52 (m, 2H), 7.52-7.07 (m, 3H), 4.32-3.89 (m, 2H), 3.19-2.78 (m,2H),2.46-1.70(m,5H),1.58-1.42(m,1H),1.42-1.13(m,6H),1.13-0.88(m,3H),0.63-0.24(m,3H)ppm.

[0271] 13C NMR (101MHz, DMSO-d6) δ = 156.14, 140.26, 135.24, 122.99, 122.48, 115.38, 112.47, 51.08 (d, J = 2.2Hz), 44.95, 25 .05(d,J=22.9Hz),21.34(d,J=12.3Hz),19.28,18.72,18.08,17.50,16.88(d,J=6.3Hz),16.31(d,J=15.2Hz)ppm.

[0272] 31 P NMR (162MHz, DMSO-d6) δ = 40.29ppm.

[0273] Example 4

[0274] In an argon-filled glove box, potassium tert-butoxide (5.6 mg, 0.05 mmol), manganese catalyst (0.005 mmol, wherein the manganese catalysts are those shown in Formulas I to IX and XIII to XV, namely [Mn]-1 to [Mn]-9 and [Mn]-13 to [Mn]-15, respectively), ethylene glycol dimethyl ether (0.5 mL), and ethyl dimethylphenylacetate (48 mg, 0.25 mmol) were added sequentially to a 4 mL glass bottle equipped with a stirrer. The bottle was capped, and a needle with a vent hole (3-4 cm long, 1-2 mm in diameter) was inserted into the cap. The glass bottle was then placed in an autoclave. The autoclave was then removed from the glove box, and the argon gas in the autoclave was replaced with hydrogen (3×5 bar). Then, 40 bar of hydrogen gas was introduced, and the hydrogenation reaction was carried out at 25°C for 16 hours with stirring. After the reaction was completed, the gas in the autoclave was carefully released, and the resulting product system was sampled for GC quantification and column chromatography separation to obtain the target product.

[0275] Taking the manganese catalyst [Mn]-4 as an example, the specific reaction process is as follows:

[0276] The structures of each manganese catalyst and the yields of the target products are listed in Table 1.

[0277] Table 1. Structures and yields of target products of manganese catalysts [Mn]⁻¹~[Mn]⁻⁹ and [Mn]⁻¹³~[Mn]⁻¹⁵.

[0278] As can be seen from the data in Table 1, the best reaction results can be obtained when the NP sidewall of the manganese catalyst has three carbons and the nitrogen-containing heterocycle is benzimidazole (i.e., [Mn]-4, [Mn]-6, [Mn]-13, [Mn]-15), and the yield of the target product 2-methyl-2-phenylprop-1-ol is the highest.

[0279] Example 5

[0280] In an argon-filled glove box, potassium tert-butoxide (2.8 mg, 0.025 mmol), manganese catalyst (0.005 mmol, wherein the manganese catalyst is one of the manganese catalysts shown in Formula I, Formula II, and Formula X to XII, namely [Mn]-1, [Mn]-2, [Mn]-10 to [Mn]-12, respectively), tetrahydrofuran (0.5 mL), and ethyl dimethylphenylacetate (48 mg, 0.25 mmol) were added sequentially to a 4 mL glass bottle equipped with a stirrer. Insert a needle with a vent hole (3-4 cm long, 1-2 mm in diameter) into the glass bottle and place it into an autoclave. Then, remove the autoclave from the glove box, replace the argon gas in the autoclave with hydrogen (3×5 bar), and then introduce 60 bar of hydrogen. Perform the hydrogenation reaction for 16 hours under stirring and at 100°C. After the reaction is complete, cool the autoclave to room temperature in air, carefully release the gas inside the autoclave, and sample the obtained product system for GC quantification and column chromatography separation to obtain the target product.

[0281] Taking manganese catalyst [Mn]-11 as an example, the specific reaction process is as follows:

[0282] The structures of each manganese catalyst and the yields of the target products are listed in Table 2.

[0283] Table 2. Structures and yields of target products of manganese catalysts [Mn]⁻¹, [Mn]⁻², [Mn]⁻¹⁰ to [Mn]⁻¹².

[0284] As can be seen from the data in Table 2, when the NP ligand of the manganese catalyst has only two carbons on its sidewall, better reaction results can be achieved by changing the solvent, increasing the reaction temperature, and increasing the hydrogen pressure. The best reaction results can be obtained when the nitrogen-containing heterocycle is benzimidazole and the phosphorus substituent is isopropyl (i.e., [Mn]-11), and the yield of the target product 2-methyl-2-phenylprop-1-ol is the highest.

[0285] Example 6

[0286] In an argon-filled glove box, potassium tert-butoxide (2.8 mg, 0.025 mmol), manganese pentacarbonyl bromide (0.005 mmol), ligands (0.0055 mmol, the ligands being those shown in formulas XVI to XIX, i.e., L16 to L19 respectively), tetrahydrofuran (0.5 mL), and ethyl dimethylphenylacetate (48 mg, 0.25 mmol) were added sequentially to a 4 mL glass vial equipped with a stir bar. The vial was capped, and a vial with a pore-forming device was inserted into the cap. A needle with a vent (3-4 cm long, 1-2 mm in diameter) was used to place the glass bottle into an autoclave. The autoclave was then removed from the glove box, and the argon gas in the autoclave was replaced with hydrogen (3×5 bar). Then, 30 bar of hydrogen gas was introduced, and the hydrogenation reaction was carried out at 80°C for 16 hours with stirring. After the reaction was completed, the autoclave was cooled to room temperature in air, and the gas inside the autoclave was carefully released. The resulting product system was sampled for GC quantification and separated by column chromatography to obtain the target product.

[0287] Taking ligand L19 as an example, the specific reaction process is as follows:

[0288] The structures of each ligand and the yields of the target products are listed in Table 3.

[0289] Table 3. Structures of ligands L16–L19 and yields of the target products.

[0290] As can be seen from the data in Table 3, when manganese pentacarbonyl bromide is used with ferrocene sidewall NH imidazole or NH benzimidazole ligands, good reaction results can also be obtained, and the target product 2-methyl-2-phenylprop-1-ol can be obtained almost quantitatively.

[0291] Example 7

[0292] Following the method of Example 4, trisubstituted acetates were catalytically hydrogenated using manganese catalyst [Mn]-4. The structural formulas and yields of each raw material, target product, and other specific products are listed in Table 4.

[0293] Table 4. Structural formulas and yields of each target product.

[0294] As can be seen from Example 7, the hydrogenation reaction of trisubstituted acetates catalyzed by manganese catalyst in this disclosure has good substrate applicability at room temperature, and is well compatible with esters of different structures and substituents with different electronic effects and steric effects on the esters.

[0295] Example 8

[0296] Following the method of Example 4, the amount of potassium tert-butoxide was reduced to 2.8 mg (0.025 mmol), the reaction temperature was increased to 60 °C, and the trisubstituted acetate was catalytically hydrogenated using manganese catalyst [Mn]-4. The structural formulas and yields of each raw material and target product are listed in Table 5.

[0297] Table 5. Structural formulas and yields of each target product.

[0298] As shown in Example 8, the hydrogenation reaction of trisubstituted acetates catalyzed by manganese catalyst in this disclosure still has good substrate applicability at 60°C, and the amount of potassium tert-butoxide can be appropriately reduced. It is also well compatible with esters of different structures and substituents with different electronic effects and steric effects on the esters.

[0299] Example 9

[0300] Following the method of Example 8, the trisubstituted acetate was replaced with an equimolar amount (0.25 mmol) of a tertiary alkyl ester and subjected to catalytic hydrogenation. The structural formulas and yields of each starting material and target product are listed in Table 6.

[0301] Table 6. Structural formulas and yields of each target product.

[0302] As can be seen from Example 9, the present disclosure uses a manganese catalyst to catalyze the hydrogenation reaction of esters, which not only has a good catalytic effect on trisubstituted acetates, but also has a good catalytic effect on tertiary alkyl esters such as camphor acetate and terpineol acetate, as well as tertiary lactones such as sage lactone.

[0303] Example 10

[0304] In an argon-filled glove box, potassium tert-butoxide (67.2 mg, 0.6 mmol), manganese catalyst [Mn]-6 (6.4 mg, 0.01 mmol), triethylene glycol dimethyl ether (12 mL), and ethyl dimethylphenylacetate (11.52 g, 60 mmol) were added sequentially to a 30 mL glass vial equipped with a stir bar. The vial was capped, and a needle with a vent hole (3–4 cm long, 1–2 mm in diameter) was inserted into the cap. The vial was then placed in an autoclave, and subsequently removed from the glove box. The argon gas in the autoclave was replaced with hydrogen (3×5 bar), and then 60 bar of hydrogen was introduced. The hydrogenation reaction was carried out at 100°C for 48 hours with stirring. After the reaction, the autoclave was cooled to room temperature in air, and the gas inside the autoclave was carefully released. A sample of the obtained product system was subjected to GC quantification and column chromatography to obtain the target product, 2-methyl-2-phenylprop-1-ol, with a GC yield of 85% and a catalyst conversion number (TON) of 5100. A colorless oily liquid was obtained, with a yield of 7.21 g, representing a yield of 80%. The specific reaction process is as follows:

[0305] Comparative Example

[0306] Following the method of Example 4, acetic acid dimethylphenylacetate was catalytically hydrogenated using pyridine or N-methylimidazolium NNP type pincer-shaped manganese catalysts (manganese catalysts [Mn]-16 to [Mn]-24). The structures of each manganese catalyst and the yields of the target products are listed in Table 7.

[0307] Table 7. Structures and yields of target products for each manganese catalyst.

[0308] Comparing the results in Tables 1, 2, 3, and 7, it can be seen that, using ethyl dimethylphenylacetate as a model substrate, the NH heterocyclic NNP type pincer-shaped manganese catalysts used in this disclosure, namely manganese catalysts [Mn]-1 to [Mn]-15, or pentacarbonyl manganese bromide and NH heterocyclic NNP type pincer-shaped ligands L1 to L4, all exhibit certain catalytic activity. However, when the NH heterocycle in the manganese catalyst is replaced with heterocycles without NH structures, such as pyridine or N-methyl heterocycles, almost no reactivity is observed. This indicates that the presence of NH structures on the catalyst heterocycles is crucial for the catalytic hydrogenation reaction.

[0309] In summary, NH heterocyclic NNP pincer-shaped manganese catalysts exhibit higher reactivity in the hydrogenation of sterically hindered esters (including trisubstituted acetates and tertiary alkyl esters) through metal-ligand synergistic effects.

[0310] It should be noted that although the technical solutions of this disclosure have been described with specific examples, those skilled in the art will understand that this disclosure should not be limited thereto.

[0311] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for the catalytic hydrogenation of trisubstituted acetates or tertiary alkyl esters, characterized in that, Includes the following steps: Hydrogenation reactions are carried out using trisubstituted acetates or tert-alkyl esters as substrates in the presence of hydrogen and a manganese catalyst or manganese catalytic system; wherein... The manganese catalyst is selected from compounds represented by formula (1): Among them, R 1 It represents C1-C7 alkylene, -(C1-C7 alkylene)-phenylene, or -(C1-C7 alkylene)-ferrocene; R 2 It represents phenyl, C1-C6 alkyl or cyclohexyl; X represents -CR 3 Or -NH, Y represents -CR 4 Or -NH, Z represents -CR 5 Or -NH, and at least one of X, Y, and Z represents -NH; R 3 R 4 and R 5 Each can independently represent H, C1-C7 alkyl or C2-C7 alkenyl, or R 3 With R 4 The atoms to which it is attached may optionally form C6 to C6. 10 aryl, or R 4 With R 5 The atoms to which it is attached may optionally form C6 to C6. 10 Aryl; Indicates a single or double bond, and two adjacent bonds. Not both are double bonds; A represents halogen; Preferably, the molar ratio of the manganese catalyst to the trisubstituted acetate or tertiary alkyl ester is (0.0167–2):

100.

2. The method according to claim 1, characterized in that, The manganese catalyst comprises one or more of the following formulas (I) to (XV):

3. The method according to claim 1 or 2, characterized in that, The manganese catalytic system comprises manganese pentacarbonyl bromide and a ligand, wherein the ligand is selected from compounds represented by formula (2) below: Among them, R 1 R 2 The definitions of X, Y, and Z are the same as in claim 1; V represents N or NH; Indicates a single bond or a double bond; When V is N This indicates a double bond; when V is NH, Indicates a single key; Preferably, the molar ratio of the ligand to manganese pentacarbonyl bromide is (1.0-1.2):1, and the molar ratio of manganese pentacarbonyl bromide to trisubstituted acetate or tertiary alkyl ester is (0.0167-2):

100.

4. The method according to claim 3, characterized in that, The ligand comprises one or more of the compounds shown in Formulas XVI to XIX:

5. The method according to any one of claims 1 to 4, characterized in that, The trisubstituted acetates include compounds represented by formulas XX to XXX: In formula XX, R 6 R 7 R 8 R 9 Each of these can be independently represented as C1–C7 alkyl, phenyl, benzyl, p-methoxybenzyl, 2,6-dimethylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 4-phenylbenzyl, 4-tert-butylbenzyl, 2-trifluoromethylbenzyl, 3-ferroceneylbenzyl, 3,5-dimethoxybenzyl, 4-benzyloxybenzyl, 3-fluorobenzyl, 4-diphenylphosphinebenzyl, 4-chlorobenzyl, 4-phenylselenobenzyl, 3-bromobenzyl, 4- Bromobenzyl, 3-phenyltellurylbenzyl, 4-iodobenzyl, (4'-dimethylamino-[1,1'-biphenyl]-3-yl)methyl, (4'-methylthio-[1,1'-biphenyl]-3-yl)methyl, 3-(phenanthrene-9-yl)benzyl, 3-(benzo[d][1,3]dioxolane-5-yl)benzyl, 3-(pyridin-4-yl)benzyl, 4-(furan-3-yl)benzyl, 3-(thiophene-3-yl) Benzyl, 4-(piperidin-1-yl)benzyl, 3-(pyrrolidine-1-yl)benzyl, 3-(azacycloheptyl-1-yl)benzyl, 3-morpholinylbenzyl, 3-thiomorpholinylbenzyl, 4-(indol-1-yl)benzyl, 4-(pyrazol-1-yl)benzyl, 4-(anthracite-9-yl)benzyl, (E)-(4'-phenyldiazetenyl-[1,1'-biphenyl]-4-yl)methyl, 4-trifluoromethoxy Benzyl, 4-trifluoromethylthiobenzyl, 3-ethylthiopropyl-1-yl, (E)-hex-3-en-1-yl, (Z)-hex-3-en-1-yl, 3-methyl-but-2-en-1-yl, hepta-4-ynyl, 2-(naphthyl-1-yl)ethyl, (dioxolane-2-yl)methyl, 2-((tetrahydro-2H-pyran-2-yl)oxy)ethyl or 3-(2,5-dimethylphenoxy)propyl-1-yl; In formula XXI, R 10 R 11 Independently represents C1–C7 alkyl, phenyl, and benzyl groups; X 1 The symbols represent C1-C7 alkylene, C2-C7 alkenylene, difluoromethylene, and oxygen; m and n independently represent 0, 1, 2, and 3. In formula XXX, n 1 It represents 0, 1, and 2.

6. The method according to any one of claims 1 to 4, characterized in that, The tertiary alkyl esters include compounds represented by formulas XXXI to XXXIII:

7. The method according to any one of claims 1 to 6, characterized in that, The hydrogenation reaction is carried out in the presence of an alkaline reagent and an organic solvent; Preferably, the molar ratio of the alkaline reagent to the trisubstituted acetate or tertiary alkyl ester is (1-20):100; and the molar ratio of the organic solvent to the trisubstituted acetate or tertiary alkyl ester is (0.05-2.0 mL):(0.25 mmol). More preferably, the alkaline reagent includes one or more of potassium tert-butoxide, sodium tert-butoxide, lithium tert-butoxide, sodium tert-pentoxide, potassium methoxide, sodium methoxide, lithium methoxide, potassium ethoxide, sodium ethoxide, or lithium ethoxide; the organic solvent includes one or more of diethyl ether, tetrahydrofuran, dioxane, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, methyl tert-butyl ether, or anisole.

8. The method according to any one of claims 1 to 7, characterized in that, The method includes mixing an alkaline reagent, a manganese catalyst or manganese catalytic system, an organic solvent, and a trisubstituted acetate or tert-alkyl ester in a protective atmosphere, replacing the protective atmosphere with hydrogen, and carrying out a hydrogenation reaction in a hydrogen atmosphere. Preferably, the pressure of the hydrogen gas is 20-60 bar, more preferably 30-40 bar; The hydrogenation reaction is carried out at a temperature of 25–100°C for 12–48 hours.

9. A manganese catalyst, characterized in that, The manganese catalyst is selected from compounds represented by formula (1): Among them, R 1 It represents C1-C7 alkylene, -(C1-C7 alkylene)-phenylene, or -(C1-C7 alkylene)-ferrocene; R 2 It represents phenyl, C1-C6 alkyl or cyclohexyl; X represents -CR 3 Or -NH, Y represents -CR 4 Or -NH, Z represents -CR 5 Or -NH, and at least one of X, Y, and Z represents -NH; R 3 R 4 and R 5 Each can independently represent H, C1-C7 alkyl or C2-C7 alkenyl, or R 3 With R 4 The atoms to which it is attached may optionally form C6 to C6. 10 aryl, or R 4 With R 5 The atoms to which it is attached may optionally form C6 to C6. 10 Aryl; Indicates a single or double bond, and two adjacent bonds. Not both are double bonds; A represents halogen.

10. Use of the manganese catalyst according to claim 9 for the catalytic hydrogenation of trisubstituted acetates or tertiary alkyl esters.

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