Method for preparing aldehyde or ketone through catalytic oxidation of alcohol

Abstract

The invention discloses a method for preparing aldehyde or ketone by catalytically oxidizing alcohol, which is characterized in that in the presence of an oxonium nitrate compound, an alcohol compound is subjected to oxidation reaction to generate corresponding aldehyde or ketone. The method provided by the invention has the advantages of mild reaction conditions, wide substrate universality, and realization of efficient catalysis of alcohol oxidation without metal and other co-catalysis in the reaction, and is a method suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic synthesis catalysis, and particularly relates to application of a high-efficiency non-metallic catalytic system in selective oxidation of alcohol compounds to prepare aldehydes or ketones. The core of the system is to use an oxonium nitrate compound as a catalyst. BACKGROUND

[0002] Oxidation of alcohol compounds to generate aldehydes or ketones is one of important reactions for constructing carbonyl functional groups, and is widely applied in synthesis of drug intermediates (such as precursors of ibuprofen), perfumes (such as vanillin) and functional materials. Traditional industrial oxidation methods mainly rely on stoichiometric metal oxidants (such as potassium permanganate, potassium dichromate, pyridine chromate, etc.) or organic peroxides. Such methods are prone to produce a large amount of metal waste or toxic by-products in the reaction process, and have disadvantages of serious environmental pollution, poor atom economy, low process safety, etc., which limit further popularization in industrial production.

[0003] With the continuous development of the concept of green chemistry, development of alcohol oxidation technology with high selectivity and environmental friendliness by using molecular oxygen or air as a terminal oxidant has become a research hotspot. Nitrogen oxide radical catalytic system has been widely concerned in alcohol oxidation reaction due to its excellent selectivity, but the existing technology still has the following limitations: (1) TEMPO catalytic system usually relies on halogen (such as bromine or iodine) as a co-catalyst. For example, the system disclosed in CN1651381A needs to activate molecular oxygen by bromine or iodine and nitrite, although the method has good selectivity, but the use of halogen may cause equipment corrosion, produce toxic by-products and complicate the post-processing process; (2) the composite catalytic system composed of TEMPO and transition metals (such as Cu, Fe) can use oxygen as an oxidant, but the metal catalyst itself is expensive and easy to deactivate (J. Am. Chem. Soc. 2011, 133, 16901-16910; Org. Process Res. Dev. 2019, 23, 825−835); (3) although it has been reported that oxammonium salt containing nitrate anion is used for alcohol oxidation (J. Am. Chem. Soc. 2011, 133, 6497–6500), but the structure of the catalyst is complex, the synthesis cost is high, and it is difficult to popularize; in addition, some oxammonium salts can only be used for equivalent oxidation, and it is difficult to realize catalytic oxidation (Tetrahedron Lett. 2020, 61, 151464–151468), which limits its practicability and economy.

[0004] Therefore, it is of great significance to develop a high-efficiency catalytic system without participation of metals or halogens, and only using oxygen or air as an oxidant, for realizing green synthesis, reducing production cost and improving process safety. Summary of the Invention

[0005] To address the shortcomings of existing alcohol oxidation technologies, such as catalyst dependence on metals / halogens, harsh conditions, environmental unfriendliness, complex catalyst structures, or high raw material costs, this invention provides a green and efficient solution: under mild conditions, using non-metallic catalysts such as oxonium nitrate compounds to achieve efficient oxidation of alcohol compounds.

[0006] The technical solution of the present invention is as follows:

[0007] A method for catalytic oxidation of alcohols to prepare aldehydes or ketones includes: in the presence of an oxonium nitrate compound, an alcohol compound undergoes an oxidation reaction to generate the corresponding aldehyde or ketone;

[0008] The reaction is as shown in formula (I) or (II):

[0009] (I)

[0010] (II)

[0011] R is a C1-C6 alkyl, C1-C6 alkamido group, or C6-C6 alkyl group. 12 Aryl, hydroxyl, carboxyl, or C1-C6 alkoxy groups;

[0012] In formula (I), R1 and R2 are independently selected from H, substituted or unsubstituted C1~C 20 Alkyl, C3~C 20 cycloalkyl, C2~C 20 alkenyl or phenyl substituted C2~C 20 alkenyl, C2~C 20 Alkyne, C1-C6 alkoxycarbonyl, substituted or unsubstituted C6-C 12 aryl, substituted or unsubstituted 5-12 heteroaryl groups, wherein C6-C 12 The substituents on the aryl group or the 5-12-membered heteroaryl group are selected from C1-C6 alkyl, C1-C6 alkoxy, nitro, hydroxyl, cyano, or halogen, wherein the C1-C6 group... 20 The substituents on the alkyl group are hydroxyl, C1-C6 alkoxy, or phenyl; or R1, R2, together with the carbons connecting R1 and R2, form substituted or unsubstituted C5-C groups. 12 cycloalkyl, C5~C 12 Cycloalkenyl or 4-12 membered heterocyclic alkyl groups, wherein the C5-C 12 The substituents on the cycloalkyl group are C1-C6 alkyl, phenyl, or benzo[a]yl group;

[0013] In formula (II), R3 and R4 are independently selected from H, C1-C6 alkyl or C1-C6 alkoxy.

[0014] This invention employs a novel system for synthesizing aldehydes or ketones, which has the following advantages: (1) Inexpensive raw materials and simple structure: Compared with AZADO and its fluorinated derivatives, oxonium nitrate compounds have significantly lower costs and are suitable for large-scale industrial applications; (2) No other auxiliary agents are required, and the reaction can be carried out in conventional organic solvents, making the operation simpler; (3) High atom economy with oxygen as the sole oxidant: The system does not rely on metal oxidants or peroxides, is environmentally friendly, and produces few byproducts; (4) High selectivity and high yield: The complete conversion of various primary and secondary alcohols can be achieved with a relatively low catalyst dosage, and the yield of the target product can reach 99%. In summary, this invention has significant improvements over existing technologies in terms of catalyst configuration, synthesis cost, environmental friendliness, process simplicity, and substrate adaptability. It is suitable for the selective oxidation reaction of various alcohol substrates and has good industrialization prospects.

[0015] Preferably, in R1 and R2, the substituted or unsubstituted C6~C 12 The aryl group is an ortho-, meta-, or para-phenyl group, or a naphthyl group, having an electron-donating or electron-withdrawing substituent, wherein the electron-donating or electron-withdrawing substituent is methyl, ethyl, isopropyl, methoxy, ethoxy, nitro, hydroxy, cyano, F, Cl, or Br.

[0016] The substituted or unsubstituted 5-12-membered heteroaryl group is thienyl, furanyl or pyridyl, or thienyl, furanyl or pyridyl with electron-donating or electron-withdrawing substituents, wherein the electron-donating or electron-withdrawing substituents are methyl, ethyl, isopropyl, methoxy, ethoxy, nitro, hydroxy, cyano, F, Cl or Br;

[0017] The heteroatoms contained in the 4-12 membered heterocyclic alkyl groups are O, S or N.

[0018] Preferably, the oxidant is pure oxygen gas or a mixture of gases containing oxygen.

[0019] According to some preferred embodiments of the present invention, the molar ratio of the alcohol compound to the oxonium nitrate compound is 5:1 to 1000:1. More specifically, the molar ratio of the alcohol compound to the oxonium nitrate compound is 5:1 to 20:1.

[0020] Preferably, the reaction solvent is one or a mixture of benzene, toluene, dichloromethane (DCM), 1,2-dichloroethane (DCE), 1,2-dichloropropane, acetonitrile, acetic acid, acetone, water, dioxane, ethyl acetate, tetrahydrofuran, etc.; preferably, it is acetonitrile; wherein, based on the amount of the alcohol compound used, the amount of the organic solvent used is 1.0-10.0 ml / mmol; preferably 2.0 ml / mmol.

[0021] Preferably, the reaction temperature is 0~80℃, and more preferably 50℃~60℃.

[0022] Preferably, the reaction pressure of the oxidation reaction is 0.01~40 MPa, more preferably 0.05~10 MPa, and even more preferably 0.1~0.5 MPa.

[0023] In this invention, the oxidation reaction time is 0.1 to 96 hours; more preferably 1 to 24 hours, and the reaction time can be determined by monitoring the reaction progress of the substrate.

[0024] In this invention, the reaction is carried out under stirring conditions, and the stirring speed is not particularly strictly limited.

[0025] The present invention also provides a catalyst for the oxidation of alcohols to prepare aldehydes or ketones, which is an oxonium nitrate compound represented by the following formula:

[0026]

[0027] R is a C1-C6 alkyl, C1-C6 alkamido group, or C6-C6 alkyl group. 12 Aryl, hydroxyl, carboxyl, or C1-C6 alkoxy groups.

[0028] The method for preparing the oxonium nitrate compound includes the following steps:

[0029] The reaction involves the reaction of 4-R-2,2,6,6-tetramethylpiperidin-1-oxy radical with nitrite esters. The general formula for nitrite esters is R5-O-NO, where R5 is selected from branched or straight-chain C3-C8 alkyl, phenyl, cyclohexyl, or combinations thereof. Examples include, but are not limited to, tert-butyl nitrite and isopropyl nitrite. The reaction temperature is 20℃-50℃. The reaction time is 1-3 hours. A yellow precipitate forms after the reaction; after filtration and drying, the product is obtained. The reaction process is shown in the following formula (using tert-butyl nitrite as an example):

[0030]

[0031] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0032] This invention proposes a method for preparing aldehydes or ketones from alcohols by oxidizing alcohols in an organic solvent using an oxonium nitrate compound as a catalyst and oxygen or oxygen from the air as the oxidant. This invention minimizes the introduction of other atoms, ensuring minimal byproducts in the reaction. It is suitable not only for the highly selective oxidation of reactive alcohols to aldehydes and ketones, but also for the highly selective oxidation of aliphatic alcohols and alicyclic alcohols to aldehydes and ketones, and is particularly suitable for the oxidation of alcohols containing heteroatoms (N, S, etc.). Attached Figure Description

[0033] Figure 1 Photograph of 2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0034] Figure 2 Photograph of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0035] Figure 3 Photograph of 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0036] Figure 4 Photograph of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0037] Figure 5 Photograph of 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0038] Figure 6 It has a single crystal structure of 2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0039] Figure 7 It has a single crystal structure of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0040] Figure 8 It has a single crystal structure of 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0041] Figure 9 High-resolution ESI image of 2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0042] Figure 10 High-resolution ESI image of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0043] Figure 11 High-resolution ESI image of 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0044] Figure 12 High-resolution ESI image of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate;

[0045] Figure 13 High-resolution ESI image of 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxonium nitrate. Detailed Implementation

[0046] The above-mentioned solution will be further described below with reference to specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions used in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0047] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared by conventional methods in the art.

[0048] Unless otherwise specified, all reaction conversions and yields below were determined by gas chromatography (using commercially available raw materials and products to establish standard curves).

[0049] Gas chromatography conditions:

[0050] The gas chromatography column was a SHIMADAZU SH-5. The initial temperature was set to 70°C and held for 3 minutes, then increased to 120°C at a rate of 5°C per minute and held for 2 minutes, followed by an increase to 300°C at a rate of 100°C per minute and held for 5 minutes.

[0051] Example 1

[0052] This example provides a method for preparing the [TEMPO][NO3]oxonium nitrate compound, which uses the following synthetic route:

[0053]

[0054] The method comprises: dissolving 2,2,6,6-tetramethyl-1-piperidinoxy radical (TEMPO, 3 mmol, 470 mg) in tert-butyl nitrite (2 mL) in a 25 mL round-bottom flask; stirring the mixture at room temperature for 2 hours to form a yellow precipitate. After the reaction is complete, the precipitate is collected by filtration through a sintered glass funnel and dried under vacuum at room temperature (25 °C) for 12 hours to obtain a yellow solid of [TEMPO][NO3] (621 mg, yield 95%). See the photograph below. Figure 1 Single crystal structure is shown Figure 6 High-resolution ESI image can be found Figure 9 .

[0055] Example 2

[0056] This example provides a method for preparing the [4-OH-TEMPO][NO3]oxonium nitrate compound, which uses the following synthetic route:

[0057]

[0058] The method comprises: dissolving 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinoxy radical (TEMPO, 3 mmol, 517 mg) in tert-butyl nitrite (2 mL) in a 25 mL round-bottom flask; stirring the mixture at room temperature for 2 hours to form a yellow precipitate. After the reaction is complete, the precipitate is collected by filtration through a sintered glass funnel and dried under vacuum at room temperature for 12 hours to obtain a yellow solid of [4-OH-TEMPO][NO3] (646 mg, yield 92%). See the photograph below. Figure 2 High-resolution ESI image can be found Figure 10 .

[0059] Example 3

[0060] This example provides a method for preparing the [4-AcNH-TEMPO][NO3]oxonium nitrate compound, which uses the following synthetic route:

[0061]

[0062] The method comprises: dissolving 4-acetamido-2,2,6,6-tetramethyl-1-piperidinoxy radical (4-AcNH-TEMPO, 3 mmol, 639 mg) in tert-butyl nitrite (2 mL) in a 25 mL round-bottom flask; stirring the mixture at room temperature for 2 hours to form a yellow precipitate. After the reaction is complete, the precipitate is collected by filtration through a sintered glass funnel and dried under vacuum at room temperature for 12 hours to obtain a yellow solid of [4-AcNH-TEMPO][NO3] (751 mg, yield 91%). See the photograph below. Figure 3 High-resolution ESI image can be found Figure 11 .

[0063] Example 4

[0064] This example provides a method for preparing the [4-OCH3-TEMPO][NO3]oxonium nitrate compound, which uses the following synthetic route:

[0065]

[0066] The method comprises: dissolving 4-carboxy-2,2,6,6-tetramethyl-1-piperidinoxy radical (4-OCH3-TEMPO, 3 mmol, 558 mg) in tert-butyl nitrite (2 mL) in a 25 mL round-bottom flask; stirring the mixture at room temperature for 2 hours to form a yellow precipitate. After the reaction is complete, the precipitate is collected by filtration through a sintered glass funnel and dried under vacuum at room temperature for 12 hours to obtain a yellow solid of [4-OCH3-TEMPO][NO3] (669 mg, 90% yield). See the photograph below. Figure 4 Single crystal structure is shown Figure 7High-resolution ESI image can be found Figure 12 .

[0067] Example 5

[0068] This example provides a method for preparing the [4-COOH-TEMPO][NO3]oxonium nitrate compound, which uses the following synthetic route:

[0069]

[0070] The method comprises: dissolving 4-carboxy-2,2,6,6-tetramethyl-1-piperidinoxy radical (4-COOH-TEMPO, 3 mmol, 600 mg) in tert-butyl nitrite (2 mL) in a 25 mL round-bottom flask; stirring the mixture at room temperature for 2 hours to form a yellow precipitate. After the reaction is complete, the precipitate is collected by filtration through a sintered glass funnel and dried under vacuum at room temperature for 12 hours to obtain a yellow solid of [4-COOH-TEMPO][NO3] (700 mg, yield 89%). See the photograph below. Figure 5 Single crystal structure is shown Figure 8 High-resolution ESI image can be found Figure 13 .

[0071] Example 6

[0072] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0073]

[0074] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OCH3-TEMPO][NO3] (0.075 mmol, 18.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 100% and the yield of cyclohexanone is 96%.

[0075] Example 7

[0076] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0077]

[0078] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [COOH-TEMPO][NO3] (0.075 mmol, 19.7 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 100% and the yield of cyclohexanone is 98%.

[0079] Example 8

[0080] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0081]

[0082] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 100% and the yield of cyclohexanone is 99%.

[0083] Example 9

[0084] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0085]

[0086] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.2 MPa for 3 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 100% and the yield of cyclohexanone is 98%.

[0087] Example 10

[0088] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0089]

[0090] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.05 MPa for 6 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 100% and the yield of cyclohexanone is 85%.

[0091] Example 11

[0092] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0093]

[0094] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of toluene to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 62% and the yield of cyclohexanone is 58%.

[0095] Example 12

[0096] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0097]

[0098] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of dichloroethane to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 100% and the yield of cyclohexanone is 95%.

[0099] Example 13

[0100] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0101]

[0102] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetic acid to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 92% and the yield of cyclohexanone is 85%.

[0103] Example 14

[0104] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0105]

[0106] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of tetrahydrofuran to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 75% and the yield of cyclohexanone is 69%.

[0107] Example 15

[0108] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0109]

[0110] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours with stirring at 30 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 92% and the yield of cyclohexanone is 86%.

[0111] Example 16

[0112] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0113]

[0114] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours with stirring at 80 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 89% and the yield of cyclohexanone is 80%.

[0115] Example 17

[0116] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0117]

[0118] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.005 mmol, 1.17 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 42% and the yield of cyclohexanone is 38%.

[0119] Example 18

[0120] This example provides a method for the efficient preparation of cyclohexanone by oxygen oxidation of cyclohexanol, which uses the following synthetic route:

[0121]

[0122] The method includes: adding cyclohexanol (0.5 mmol, 50 mg), [OH-TEMPO][NO3] (0.05 mmol, 11.7 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexanol is 96% and the yield of cyclohexanone is 92%.

[0123] Example 19

[0124] This example provides a method for the efficient preparation of o-methylbenzaldehyde by oxygen oxidation of o-methylbenzyl alcohol, which adopts the following synthetic route:

[0125]

[0126] The method includes: adding o-toluene (0.5 mmol, 61 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of o-toluene is 100%, and the yield of the product o-tolualdehyde is 99%.

[0127] Example 20

[0128] This example provides a method for the efficient preparation of 3-methylbenzaldehyde by oxygen oxidation of 3-methylbenzyl alcohol, which adopts the following synthetic route:

[0129]

[0130] The method includes: adding 3-methylbenzyl alcohol (0.5 mmol, 61 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 3-methylbenzyl alcohol is 100%, and the yield of the product 3-methylbenzaldehyde is 98%.

[0131] Example 21

[0132] This example provides a method for the efficient preparation of 4-methylbenzaldehyde by oxygen oxidation of 4-methylbenzyl alcohol, which adopts the following synthetic route:

[0133]

[0134] The method includes: adding 4-methylbenzyl alcohol (0.5 mmol, 61 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 4-methylbenzyl alcohol is 100%, and the yield of the product 4-methylbenzaldehyde is 98%.

[0135] Example 22

[0136] This example provides a method for the efficient preparation of p-nitrobenzaldehyde by oxygen oxidation of p-nitrobenzyl alcohol, which adopts the following synthetic route:

[0137]

[0138] The method includes: adding p-nitrobenzyl alcohol (0.5 mmol, 77 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 3 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-nitrobenzyl alcohol is 100%, and the yield of the product p-nitrobenzaldehyde is 99%.

[0139] Example 23

[0140] This example provides a method for the efficient preparation of m-nitrobenzaldehyde by oxygen oxidation of m-nitrobenzyl alcohol, which adopts the following synthetic route:

[0141]

[0142] The method includes: adding m-nitrobenzyl alcohol (0.5 mmol, 77 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 3 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of m-nitrobenzyl alcohol is 100%, and the yield of the product m-nitrobenzaldehyde is 99%.

[0143] Example 24

[0144] This example provides a method for the efficient preparation of o-nitrobenzaldehyde by oxygen oxidation of o-nitrobenzyl alcohol, which adopts the following synthetic route:

[0145]

[0146] The method includes: adding o-nitrobenzyl alcohol (0.5 mmol, 77 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of o-nitrobenzyl alcohol is 100%, and the yield of the product o-nitrobenzaldehyde is 96%.

[0147] Example 25

[0148] This example provides a method for the efficient preparation of p-hydroxybenzaldehyde by oxygen oxidation of p-hydroxybenzyl alcohol, which adopts the following synthetic route:

[0149]

[0150] The method includes: adding p-hydroxybenzyl alcohol (0.5 mmol, 62 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 12 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-hydroxybenzyl alcohol is 100%, and the yield of the product p-hydroxybenzaldehyde is 93%.

[0151] Example 26

[0152] This example provides a method for the efficient preparation of p-cyanobenzaldehyde by oxygen oxidation of p-cyanobenzyl alcohol, which adopts the following synthetic route:

[0153]

[0154] The method includes: adding p-cyanobenzyl alcohol (0.5 mmol, 67 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 3 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-cyanobenzyl alcohol is 100%, and the yield of the product p-cyanobenzaldehyde is 99%.

[0155] Example 27

[0156] This example provides a method for the efficient preparation of p-ethylbenzyl alcohol by oxygen oxidation, which uses the following synthetic route:

[0157]

[0158] The method includes: adding p-ethylbenzyl alcohol (0.5 mmol, 62 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-ethylbenzyl alcohol is 100%, and the yield of the product p-ethylbenzaldehyde is 99%.

[0159] Example 28

[0160] This example provides a method for the efficient preparation of p-isopropylbenzaldehyde by oxygen oxidation of p-isopropylbenzyl alcohol, which adopts the following synthetic route:

[0161]

[0162] The method includes: adding p-isopropylbenzyl alcohol (0.5 mmol, 75 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-isopropylbenzyl alcohol is 100%, and the yield of the product p-isopropylbenzaldehyde is 98%.

[0163] Example 29

[0164] This example provides a method for the efficient preparation of p-cyclohexaneformin by oxygen oxidation of cyclohexylethanol, which employs the following synthetic route:

[0165]

[0166] The method includes: adding cyclohexylethanol (0.5 mmol, 57 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclohexylethanol is 100% and the yield of the product cyclohexylformaldehyde is 99%.

[0167] Example 30

[0168] This example provides a method for the efficient preparation of p-methoxybenzaldehyde by oxygen oxidation of p-methoxybenzyl alcohol, which adopts the following synthetic route:

[0169]

[0170] The method includes: adding p-methoxybenzyl alcohol (0.5 mmol, 69 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-methoxybenzyl alcohol is 100%, and the yield of the product p-methoxybenzaldehyde is 99%.

[0171] Example 31

[0172] This example provides a method for the efficient preparation of furfural by oxygen oxidation of furfuryl alcohol, which adopts the following synthetic route:

[0173]

[0174] The method includes: adding furfuryl alcohol (0.5 mmol, 49 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of furfuryl alcohol is 100% and the yield of furfural is 98%.

[0175] Example 32

[0176] This example provides a method for the efficient preparation of 2-thiopheneformaldehyde by oxygen oxidation of 2-thiophene methanol, which adopts the following synthetic route:

[0177]

[0178] The method includes: adding 2-thiophene methanol (0.5 mmol, 57 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 2-thiophene methanol is 100%, and the yield of the product 2-thiophene formaldehyde is 99%.

[0179] Example 33

[0180] This example provides a method for the efficient preparation of E-cinnamaldehyde by oxygen oxidation of E-cinnamyl alcohol, which adopts the following synthetic route:

[0181]

[0182] The method includes: adding E-cinnamyl alcohol (0.5 mmol, 67 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of E-cinnamyl alcohol is 100%, and the yield of the product E-cinnamaldehyde is 91%.

[0183] Example 34

[0184] This example provides a method for the efficient preparation of 2-cyclohexen-1-one by oxygen oxidation of 2-cyclohexen-1-ol, which adopts the following synthetic route:

[0185]

[0186] The method includes: adding 2-cyclohexen-1-ol (0.5 mmol, 49 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 3 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 2-cyclohexen-1-ol is 100%, and the yield of the product 2-cyclohexen-1-one is 98%.

[0187] Example 35

[0188] This example provides a method for the efficient preparation of acetophenone by the oxygen oxidation of 1-phenylethanol, which uses the following synthetic route:

[0189]

[0190] The method includes: adding 1-phenylethanol (0.5 mmol, 61 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 1-phenylethanol is 100%, and the yield of acetophenone is 99%.

[0191] Example 36

[0192] This example provides a method for the efficient preparation of menthone by oxygen oxidation of menthol, which uses the following synthetic route:

[0193]

[0194] The method includes: adding menthol (0.5 mmol, 78 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of menthol is 100% and the yield of the product menthone is 99%.

[0195] Example 37

[0196] This example provides a method for the efficient preparation of 1-naphthaldehyde by oxygen oxidation of 1-naphthylmethanol, which adopts the following synthetic route:

[0197]

[0198] The method includes: adding 1-naphthylethanol (0.5 mmol, 79 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 1-naphthylethanol is 100%, and the yield of the product 1-naphthaldehyde is 99%.

[0199] Example 38

[0200] This example provides a method for the efficient preparation of benzaldehyde by oxygen oxidation of benzyl alcohol, which uses the following synthetic route:

[0201]

[0202] The method includes: adding benzyl alcohol (0.5 mmol, 54 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of benzyl alcohol is 100% and the yield of benzaldehyde is 99%.

[0203] Example 39

[0204] This example provides a method for the efficient preparation of p-nitroacetophenone by oxygen oxidation of p-nitrophenylethanol, which uses the following synthetic route:

[0205]

[0206] The method includes: adding p-nitrophenylethanol (0.5 mmol, 84 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-nitrophenylethanol is 100%, and the yield of the product p-nitroacetophenone is 99%.

[0207] Example 40

[0208] This example provides a method for the efficient preparation of p-methoxyacetophenone by oxygen oxidation of p-methoxyphenylethanol, using the following synthetic route:

[0209]

[0210] The method includes: adding p-methoxyphenylethanol (0.5 mmol, 76 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-methoxyphenylethanol is 100%, and the yield of the product p-methoxyacetophenone is 99%.

[0211] Example 41

[0212] This example provides a method for the efficient preparation of p-methylacetophenone by oxygen oxidation of p-methylphenylethanol, which uses the following synthetic route:

[0213]

[0214] The method includes: adding p-toluene (0.5 mmol, 67 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 1 hour under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-toluene is 100%, and the yield of p-toluene acetophenone is 99%.

[0215] Example 42

[0216] This example provides a method for the efficient preparation of p-chloroacetophenone by oxygen oxidation of p-chlorophenylethanol, which adopts the following synthetic route:

[0217]

[0218] The method includes: adding p-chlorophenylethanol (0.5 mmol, 78 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 3 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of p-chlorophenylethanol is 100%, and the yield of the product p-chloroacetophenone is 99%.

[0219] Example 43

[0220] This example provides a method for the efficient preparation of phenylcyclopropyl methyl ketone by oxygen oxidation of phenylcyclopropyl methanol, using the following synthetic route:

[0221]

[0222] The method includes: adding phenylcyclopropylmethanol (0.5 mmol, 74 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours under stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of phenylcyclopropylmethanol is 100%, and the yield of the product phenylcyclopropyl methyl ketone is 99%.

[0223] Example 44

[0224] This example provides a method for the efficient preparation of 2-furan ethanol by oxygen oxidation, which adopts the following synthetic route:

[0225]

[0226] The method includes: adding 2-furan ethanol (0.5 mmol, 56 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 2-furan ethanol is 100%, and the yield of the product 2-furan ethyl ketone is 99%.

[0227] Example 45

[0228] This example provides a method for the efficient preparation of 2-adamantanone by oxygen oxidation of 2-adamantanol, which adopts the following synthetic route:

[0229]

[0230] The method includes: adding 2-adamantanol (0.5 mmol, 76 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 6 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 2-adamantanol is 100%, and the yield of the product 2-adamantanone is 95%.

[0231] Example 46

[0232] This example provides a method for the efficient preparation of camphor by oxidizing isoborneol with oxygen. The method adopts the following synthetic route:

[0233]

[0234] The method includes: adding isoborneol (0.5 mmol, 77 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa at 50 °C for 24 hours with stirring. After the reaction is completed, gas chromatography analysis showed that the conversion rate of isoborneol was 100% and the yield of camphor was 99%.

[0235] Example 47

[0236] This example provides a method for the efficient preparation of 3-oxetane by oxygen oxidation of oxetane-3-ol, using the following synthetic route:

[0237]

[0238] The method includes: adding oxetane-3-ol (0.5 mmol, 37 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 48 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of oxetane-3-ol is 100%, and the yield of the product 3-oxetane is 99%.

[0239] Example 48

[0240] This example provides a method for the efficient preparation of n-hexanol by oxygen oxidation of n-hexanol, which uses the following synthetic route:

[0241]

[0242] The method includes: adding n-hexanol (0.5 mmol, 51 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of n-hexanol is 100% and the yield of the product n-hexanal is 95%.

[0243] Example 49

[0244] This example provides a method for the efficient preparation of 3-hexanone by oxygen oxidation of 3-hexanol, which adopts the following synthetic route:

[0245]

[0246] The method includes: adding 3-hexanol (0.5 mmol, 51 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 3-hexanol is 100%, and the yield of the product 3-hexanone is 94%.

[0247] Example 50

[0248] This example provides a method for the efficient preparation of trans-2-pentenol by oxygen oxidation of trans-2-pentenol, which adopts the following synthetic route:

[0249]

[0250] The method includes: adding trans-2-pentenol (0.5 mmol, 43 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 3 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of trans-2-pentenol is 100%, and the yield of the product trans-2-pentenal is 99%.

[0251] Example 51

[0252] This example provides a method for the efficient preparation of 1-methoxyacetone by oxygen oxidation of 1-methoxy-2-propanol, which adopts the following synthetic route:

[0253]

[0254] The method includes: adding 1-methoxy-2-propanol (0.5 mmol, 45 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 1-methoxy-2-propanol is 100%, and the yield of the product 1-methoxyacetone is 95%.

[0255] Example 52

[0256] This example provides a method for the efficient preparation of 2-ethylhexanal by oxygen oxidation of 2-ethylhexanol, which adopts the following synthetic route:

[0257]

[0258] The method includes: adding 2-ethylhexanol (0.5 mmol, 65 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 2-ethylhexanol is 100%, and the yield of the product 2-ethylhexanal is 95%.

[0259] Example 53

[0260] This example provides a method for the efficient preparation of propanal by oxygen oxidation of propanol, which uses the following synthetic route:

[0261]

[0262] The method includes: adding propanol (0.5 mmol, 30 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of propanol is 100% and the yield of propionaldehyde is 96%.

[0263] Example 54

[0264] This example provides a method for the efficient preparation of octanal by oxygen oxidation of octanol, which uses the following synthetic route:

[0265]

[0266] The method includes: adding octanol (0.5 mmol, 65 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of octanol is 100% and the yield of octanal is 99%.

[0267] Example 55

[0268] This example provides a method for the efficient preparation of 2-ethylhexanal by oxygen oxidation of 2-ethylhexanol, which adopts the following synthetic route:

[0269]

[0270] The method includes: adding 2-ethylhexanol (0.5 mmol, 65 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 2-ethylhexanol is 100%, and the yield of the product 2-ethylhexanal is 99%.

[0271] Example 56

[0272] This example provides a method for the efficient preparation of cyclopropylformaldehyde by oxygen oxidation of cyclopropylmethanol, which adopts the following synthetic route:

[0273]

[0274] The method includes: adding cyclopropylmethanol (0.5 mmol, 36 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of cyclopropylmethanol is 100% and the yield of the product cyclopropylformaldehyde is 98%.

[0275] Example 57

[0276] This example provides a method for the efficient preparation of 2-octanone by oxygen oxidation of 2-octanol, which adopts the following synthetic route:

[0277]

[0278] The method includes: adding 2-octanol (0.5 mmol, 65 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of 2-octanol is 100%, and the yield of the product 2-octanone is 98%.

[0279] Example 58

[0280] This example provides a method for the efficient preparation of isopentenyl alcohol by oxygen oxidation, which adopts the following synthetic route:

[0281]

[0282] The method includes: adding isopentenol (0.5 mmol, 43 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa at 50 °C for 24 hours with stirring. After the reaction is completed, gas chromatography analysis showed that the conversion rate of isopentenol was 100% and the yield of the product isopentenaldehyde was 99%.

[0283] Example 59

[0284] This example provides a method for the efficient preparation of ethyl pyruvate from ethyl 2-hydroxypropionate by oxygen oxidation, using the following synthetic route:

[0285]

[0286] The method includes: adding ethyl 2-hydroxypropionate (0.5 mmol, 59 mg), [OH-TEMPO][NO3] (0.075 mmol, 17.6 mg), and 2 mL of acetonitrile to a 20 mL reaction flask, adding a magnetic stir bar, evacuating the flask, introducing oxygen, and reacting at a pressure of 0.1 MPa for 24 hours with stirring at 50 °C. After the reaction is completed, gas chromatography analysis shows that the conversion rate of ethyl 2-hydroxypropionate is 100%, and the yield of ethyl pyruvate is 99%.

[0287] Example 60

[0288] This example provides a method for the efficient preparation of diphenylmethyl ketone by the oxidation of diphenylmethanol with oxygen. The method adopts the following synthetic route:

[0289]

[0290] The difference between this example and Example 8 is that 50 mg of cyclohexanol was replaced with 92 mg of diphenylmethanol, while the other reaction conditions remained unchanged. After the reaction, the conversion rate of diphenylmethanol was 100%, and the yield of diphenyl ketone was 89%.

[0291] Example 61

[0292] This example provides a method for the efficient preparation of 4,4-dimethoxybenzophenone by oxygen oxidation of 4,4-dimethoxybenzoethanol, which adopts the following synthetic route:

[0293]

[0294] The difference between this example and Example 8 is that 50 mg of cyclohexanol was replaced with 122 mg of 4,4-dimethoxydiphenylmethanol, while the other reaction conditions remained unchanged. After the reaction, the conversion rate of 4,4-dimethoxydiphenylmethanol was 100%, and the yield of 4,4-dimethoxydibenzophenone was 76%.

[0295] Example 62

[0296] This example provides a method for the efficient preparation of bibenzoyl by the oxygen oxidation of 1,2-diphenylethane-1,2-diol, which adopts the following synthetic route:

[0297]

[0298] The difference between this example and Example 8 is that 50 mg of cyclohexanol was replaced with 107 mg of 1,2-diphenylethane-1,2-diol, while the other reaction conditions remained unchanged. After the reaction, the conversion rate of 1,2-diphenylethane-1,2-diol was 100%, and the yield of bibenzoyl was 99%.

[0299] Example 63

[0300] This example provides a method for the efficient preparation of 10,11-dihydro-5H-dibenzocyclohepten-5-one by oxygen oxidation of 10,11-dihydro-5H-dibenzocyclohepten-5-one, which adopts the following synthetic route:

[0301]

[0302] The difference between this example and Example 8 is that 50 mg of cyclohexanol was replaced with 105 mg of 10,11-dihydro-5H-dibenzocyclohepten-5-ol, while the other reaction conditions remained unchanged. After the reaction, the conversion rate of 10,11-dihydro-5H-dibenzocyclohepten-5-ol was 98%, and the yield of 10,11-dihydro-5H-dibenzocyclohepten-5-one was 91%.

Claims

1. A method for catalytic oxidation of alcohols to prepare aldehydes or ketones, characterized in that, include: In the presence of oxonium nitrate compounds, alcohols undergo oxidation reactions to produce the corresponding aldehydes or ketones; The reaction is as shown in formula (I) or (II): （I） (II) R is a C1-C6 alkyl, C1-C6 alkamido group, or C6-C6 alkyl group. 12 Aryl, hydroxyl, carboxyl, or C1-C6 alkoxy groups; In formula (I), R1 and R2 are independently selected from H, substituted or unsubstituted C1~C 20 Alkyl, C3~C 20 cycloalkyl, C2~C 20 alkenyl or phenyl substituted C2~C 20 alkenyl, C2~C 20 Alkyne, C1-C6 alkoxycarbonyl, substituted or unsubstituted C6-C 12 aryl, substituted or unsubstituted 5-12 heteroaryl groups, wherein C6-C 12 The substituents on the aryl group or the 5-12-membered heteroaryl group are selected from C1-C6 alkyl, C1-C6 alkoxy, nitro, hydroxyl, cyano, or halogen, wherein the C1-C6 group... 20 The substituents on the alkyl group are hydroxyl, C1-C6 alkoxy, or phenyl; or R1, R2, together with the carbons connecting R1 and R2, form substituted or unsubstituted C5-C groups. 12 cycloalkyl, C5~C 12 Cycloalkenyl or 4-12 membered heterocyclic alkyl groups, wherein the C5-C 12 The substituents on the cycloalkyl group are C1-C6 alkyl, phenyl, or benzo[a]yl group; In formula (II), R3 and R4 are independently selected from H, C1-C6 alkyl or C1-C6 alkoxy.

2. The method for catalytic oxidation of alcohols to prepare aldehydes or ketones according to claim 1, characterized in that, The oxidation reaction is carried out in a solvent selected from one or more of acetonitrile, acetic acid, dichloroethane, toluene, water, acetone, tetrahydrofuran, benzene, dioxane, and ethyl acetate.

3. The method for preparing aldehydes or ketones by catalytic oxidation of alcohols according to claim 1, characterized in that: The oxidation reaction is carried out in the presence of an oxidant, which is pure oxygen gas or a mixture of gases containing oxygen.

4. The method for preparing aldehydes or ketones by catalytic oxidation of alcohols according to claim 1, characterized in that: The reaction takes place in a neutral, acidic, or slightly alkaline environment.

5. The method for preparing aldehydes or ketones by catalytic oxidation of alcohols according to claim 1, characterized in that: The molar ratio of the alcohol compound to the oxonium nitrate compound is 5:1 to 1000:

1.

6. The method for preparing aldehydes or ketones by catalytic oxidation of alcohols according to claim 1, characterized in that: The molar ratio of the alcohol compound to the oxonium nitrate compound is 5:1 to 20:

1.

7. The method for preparing aldehydes or ketones by catalytic oxidation of alcohols according to claim 1, characterized in that: The oxidation reaction temperature is 0~80℃; the oxidation reaction pressure is 0.01~40MPa; and the oxidation reaction time is 0.1~96 hours.

8. The method for preparing aldehydes or ketones by catalytic oxidation of alcohols according to claim 1, characterized in that: The oxidation reaction temperature is 50℃~60℃; the oxidation reaction pressure is 0.05~10 MPa, preferably 0.1~0.5 MPa.

9. The method for preparing aldehydes or ketones by catalytic oxidation of alcohols according to claim 1, characterized in that: The alcohol compound is benzyl alcohol or its derivatives, thiophene methanol or its derivatives, C3-C 20 Straight-chain or branched primary alcohols, cyclopentanol or cyclohexanol.

10. A catalyst for the oxidation of alcohols to prepare aldehydes or ketones, characterized in that, The following is an oxonium nitrate compound: ； R is a C1-C6 alkyl, C1-C6 alkamido group, or C6-C6 alkyl group. 12 Aryl, hydroxyl, carboxyl, or C1-C6 alkoxy groups.

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