A palladium catalyzed carbonyl reduction method regulated by quaternary ammonium salt

Abstract

The application discloses a kind of palladium catalytic carbonyl reduction method regulated by quaternary ammonium salt, belongs to organic synthesis application technical field.The palladium salt catalyst, quaternary ammonium salt additive, solvent and aryl ketone are mixed, and aryl alcohol or alkane is obtained by carrying out reaction under hydrogen environment;The quaternary ammonium salt additive is tetrabutylammonium iodide, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium fluoride, tetrabutylammonium hexafluorophosphate, tetrabutylammonium perchlorate, dipdecyldimethylammonium chloride, methyltrioctylammonium chloride or decyldimethylammonium chloride.The catalytic activity of palladium catalyst and the chemical selectivity of palladium catalytic hydrogenation reaction are regulated by using quaternary ammonium salt as key additive in the application.In addition, the reaction condition of the application is milder, reaction can occur under normal pressure, and the use of high-toxic heavy metal reagent is avoided, which is more in line with the characteristics of environment-friendly chemistry, has the potential of industrial application, and is expected to produce significant social and economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis application technology, specifically relating to a palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salts. Background Technology

[0002] Selective hydrogenation reduction of aryl ketones is one of the core transformation pathways for constructing fine chemicals and pharmaceutical intermediates. By precisely controlling the reaction process, this reaction can selectively generate high-value-added aryl alcohols or alkanes.

[0003] Currently, traditional methods for the deep reduction of aryl ketones to aryl alkanes mainly include Clemmensen reduction under acidic conditions and Wolff-Kishner-Huang reduction under basic conditions. Although these two classic methods are widely used, their inherent limitations are significant: the reaction conditions are extremely harsh (requiring strong acid or high-temperature, strong-base environments), and the reagents used often pose high toxicity and environmental pollution risks. These shortcomings make it difficult for traditional methods to meet the urgent need in modern organic synthesis for the mild and highly selective transformation of complex, multifunctional molecules.

[0004] In terms of catalytic system optimization, quaternary ammonium salts have been successfully applied as phase transfer catalysts in liquid-liquid two-phase reactions. However, their role in metal-catalyzed hydrogenation has long been limited to auxiliary regulation of physical properties such as substrate solubility. Those skilled in the art generally believe that the interaction between quaternary ammonium salt cations and metal centers is weak, making it difficult to directly control the electronic structure and steric hindrance of the active metal center through coordination bonds, unlike phosphine ligands. Therefore, they have never been considered as selective regulators that can replace traditional ligands. Furthermore, no existing literature suggests that the directional conversion of aryl ketones to different products (alcohols or alkanes) can be achieved under mild conditions (such as 60 °C and atmospheric pressure) through simple structural selection of quaternary ammonium salts.

[0005] This limitation in technological understanding has led to a long-standing reliance on expensive and structurally complex specialized ligands for the selective control of hydrogenation reactions, often accompanied by harsh reaction conditions, severely hindering the development of green synthesis processes. Therefore, exploring a novel catalytic system that achieves precise selective control using only inexpensive quaternary ammonium salts without the need for traditional ligands is not only a significant breakthrough from existing technological approaches but also crucial for solving the challenge of greening hydrogenation reactions. Summary of the Invention

[0006] To address or partially resolve problems in related technologies, this invention proposes a palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salts. Using aryl ketones as raw materials, and under conditions of room temperature and a hydrogen atmosphere at one atmosphere, this invention employs palladium salts as catalysts and quaternary ammonium salts as additives to adjust catalyst activity. This avoids the use of heavy metals and achieves highly efficient and selective reduction to yield alcohols or alkyl products. This method holds promise for technological applications, promoting the development of related industries, and meeting the needs of scientific research.

[0007] This invention provides a palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt, comprising the following steps: mixing palladium salt catalyst, quaternary ammonium salt additive, solvent and aryl ketone, reacting in a hydrogen atmosphere, removing the volatile solvent after the reaction, purifying the concentrated reaction solution using column chromatography, and obtaining the reduction product after purification. When the quaternary ammonium salt additive is at least one of tetrabutylammonium iodide, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium fluoride, tetrabutylammonium hexafluorophosphate, and tetrabutylammonium perchlorate, the reduction product is an aryl alcohol. When the quaternary ammonium salt additive is at least one of diecryldimethylammonium chloride, tetradecyltrimethylammonium chloride, methyltrioctylammonium chloride, or decadecyltrimethylammonium chloride, the reduction product is an alkane.

[0008] More preferably, the quaternary ammonium salt additive is tetrabutylammonium fluoride, and the reduction product is an aryl alcohol; even more preferably, the quaternary ammonium salt additive is decaalkyltrimethylammonium chloride, and the reduction product is an alkane.

[0009] Preferably, when the palladium salt catalyst is at least one of palladium acetate, tetra(triphenylphosphine)palladium, tris(dibenzylacetone)dipalladium, palladium bromide, palladium chloride, palladium trifluoroacetate, palladium on carbon, and palladium tetrafluoroborate tetraacetonitrile, the reduction product is an aryl alcohol.

[0010] When the palladium salt catalyst is at least one of palladium acetate, palladium bromide, palladium chloride, palladium trifluoroacetate, palladium on carbon, or palladium tetrafluoroborate tetraacetonitrile, the reduction product is an alkane.

[0011] More preferably, the palladium salt catalyst is palladium acetate, and the reduction product is an aryl alcohol; the palladium salt catalyst is palladium acetate, and the reduction product is an alkane.

[0012] When the solvent is at least one of dioxane, tetrahydrofuran, toluene, methanol, and dichloroethane, the reduction product is an aryl alcohol; when the solvent is at least one of dioxane, tetrahydrofuran, and dichloroethane, the reduction product is an alkane. More preferably, when the solvent is methanol, the reduction product is an aryl alcohol; when the solvent is dichloroethane, the reduction product is an alkane.

[0013] Preferably, the reaction temperature is 20-80°C, the reaction time is 2-48 hours, and the reaction is carried out under standard atmospheric pressure. More preferably, the reaction time is 12 hours.

[0014] Preferably, the molar ratio of the palladium salt catalyst, the quaternary ammonium salt additive and the aryl ketone is (0.01-0.1):(0.05-0.3):1.

[0015] More preferably, the molar ratio of the palladium salt catalyst, the quaternary ammonium salt additive and the aryl ketone is 0.05:0.1:1.

[0016] Preferably, the molar concentration of the aryl ketone in the solvent is 0.1 mmol / ml.

[0017] The technical solution provided by the present invention includes the following beneficial effects: the present invention uses quaternary ammonium salt as a key additive to regulate the catalytic activity of the palladium catalyst, and exhibits good chemoselectivity and stereoselectivity. In addition, the reaction conditions of the present invention are milder, the reaction can occur under normal pressure, no high-temperature and high-pressure equipment is required, the energy consumption is lower, the safety is higher, the production cost can be greatly reduced, the present invention has industrial application potential, and is expected to produce significant social and economic benefits. Moreover, the use of highly toxic heavy metal reagents is avoided, which is more in line with the characteristics of environmentally friendly chemistry. Brief Description of the Drawings

[0018] Figure 1 is 2-naphthaleneethanol 1 H nuclear magnetic resonance spectrum.

[0019] Figure 2 is 2-naphthaleneethanol 13 C nuclear magnetic resonance spectrum.

[0020] Figure 3 is 2-ethylnaphthalene 1 H nuclear magnetic resonance spectrum.

[0021] Figure 4 is 2-ethylnaphthalene 13 C nuclear magnetic resonance spectrum.

[0022] Figure 5 is 9-fluorenol 1 H nuclear magnetic resonance spectrum.

[0023] Figure 6 is 9-fluorenol 13 C nuclear magnetic resonance spectrum.

[0024] Figure 7 is fluorene 1 H nuclear magnetic resonance spectrum.

[0025] Figure 8 is fluorene 13 C nuclear magnetic resonance spectrum.

[0026] Figure 9 It is 4-fluorodiphenylmethanol 1 H NMR spectrum.

[0027] Figure 10 It is 4-fluorodiphenylmethanol 13 C NMR spectrum.

[0028] Figure 11 It is 4-fluorodiphenylmethane 1 H NMR spectrum.

[0029] Figure 12 It is 4-fluorodiphenylmethane 13 C NMR spectrum.

[0030] Figure 13 4-Biphenylmethanol 1 H NMR spectrum.

[0031] Figure 14 4-Biphenylmethanol 13 C NMR spectrum.

[0032] Figure 15 4-Methylbiphenyl 1 H NMR spectrum.

[0033] Figure 16 4-Methylbiphenyl 13 C NMR spectrum. Detailed Implementation

[0034] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate this invention.

[0035] Example 1 (1) Place a clean, dry Schlenk flask equipped with a clean magnetic stir bar into a glove box. Inside the glove box, add Pd(OAc)2 (2.3 mg, 5 mol%: 5% of the amount of aryl ketone 1a) and tetrabutylammonium fluoride (TBAF) (5.2 mg, 10 mol%: 10% of the amount of aryl ketone 1a) to the Schlenk flask in sequence.

[0036] (2) Accurately weigh 1a (39.2 mg, 0.2 mmol) into the Schlenk flask from step (1), and then add 2 ml of methanol (MeOH) as a mixed solvent. Then remove the Schlenk flask from the glove box.

[0037] (3) Open the Schlenk flask, introduce H2 into the Schlenk flask, and carry out the reaction at 60 °C and atmospheric pressure (1 atm) for 7 hours.

[0038] (4) The reaction process was monitored by TLC and GC-MS. After the reaction was completed, the volatile solvent in the reaction solution was removed by vacuum concentration using a rotary evaporator. Then, the concentrated reaction solution was purified by column chromatography. The eluent was ethyl acetate / petroleum ether = 1 / 5. After purification, the reduced product naphthaleneethanol 2a was obtained. It was a white solid with a yield of 96%.

[0039] The 1H NMR characterization data of the aryl alcohol product in Example 1 are as follows: Figure 1 , 2 : 1 H NMR (400 MHz, Chloroform-d) δ 7.87 – 7.73 (m, 4H), 7.52 – 7.39 (m, 3H), 5.01 (q, J = 6.5Hz, 1H), 2.21 (s, 1H), 1.54 (d, J = 6.5 Hz, 3H). 13 C NMR (101 MHz, Chloroform-d) δ 143.2, 133.3, 132.9, 128.3, 128.0, 127.7, 126.2, 125.8, 123.9, 123.8,70.5, 25.2. Example 2 (1) Place a clean, dry Schlenk bottle equipped with a clean magnetic stir bar into a glove box. Inside the glove box, add Pd(OAc)2 (2.3 mg, 5 mol%: 5% of the amount of aryl ketone 1a) and decaalkyltrimethylammonium chloride (5.2 mg, 10 mol%: 10% of the amount of aryl ketone 1a) to the Schlenk bottle in sequence.

[0040] (2) Accurately weigh 1a (39.2 mg, 0.2 mmol) into the Schlenk flask from step (1), and then add 2 ml of dichloroethane (DCE) as a solvent. Then remove the Schlenk flask from the glove box.

[0041] (3) Open the Schlenk flask, introduce H2 into the Schlenk flask, and react for 2 hours at 60 °C and atmospheric pressure (1 atm).

[0042] (4) The reaction process was monitored using TLC and GC-MS. After the reaction was completed, the volatile solvent in the reaction solution was removed by vacuum concentration using a rotary evaporator. Then, the concentrated reaction solution was purified by column chromatography using pure petroleum ether as the eluent. The purified product 2-ethylnaphthalene 3a was obtained as a colorless liquid with a yield of 98%.

[0043] The 1H NMR characterization data of the alkane product in Example 2 are as follows: Figure 3 , 4 : 1 H NMR (400 MHz, Chloroform-d) δ 7.84 – 7.72 (m, 3H), 7.61 (s, 1H), 7.48 – 7.28 (m, 3H), 2.80 (q, J = 7.6 Hz, 2H), 1.31 (t, J = 7.6 Hz, 3H). 13 C NMR (101 MHz, Chloroform-d)δ 141.8, 133.7, 132.0, 127.9, 127.7, 127.5, 127.2, 125.9, 125.6, 125.1, 29.1,15.7. Example 3 (1) Place a clean, dry Schlenk bottle equipped with a clean magnetic stir bar into a glove box. Inside the glove box, add Pd(OAc)2 (2.3 mg, 5 mol%: 5% of the amount of aryl ketone 1b) and tetrabutylammonium fluoride (TBAF) (5.2 mg, 10 mol%: 10% of the amount of aryl ketone 1b) to the Schlenk bottle in sequence.

[0044] (2) Accurately weigh 1b (36 mg, 0.2 mmol) into the Schlenk flask from step (1), and then add 2 ml of methanol (MeOH) as a mixed solvent. Then send the Schlenk flask out of the glove box.

[0045] (3) Open the Schlenk flask, introduce H2 into the Schlenk flask, and carry out the reaction at 60 °C and atmospheric pressure (1 atm) for 4 hours.

[0046] (4) The reaction process was monitored using TLC and GC-MS. After the reaction was completed, the volatile solvent in the reaction solution was removed by vacuum concentration using a rotary evaporator. Then, the concentrated reaction solution was purified by column chromatography using ethyl acetate / petroleum ether = 1 / 5 as the eluent. The purified product 9-fluorenol 2b was obtained as a white solid with a yield of 97%.

[0047] The 1H NMR characterization data of the aryl alcohol product in Example 3 are as follows: Figure 5 , 6 : 1 H NMR (400 MHz, Chloroform-d) δ 7.60 (dd, J = 10.8, 7.4 Hz, 4H), 7.33 (dtd, J = 28.6, 7.4,1.2 Hz, 4H), 5.50 (d, J = 8.3 Hz, 1H), 2.08 (d, J = 8.8 Hz, 1H). 13 C NMR (101MHz, Chloroform-d) δ 145.6, 140.0, 129.1, 127.8, 125.2, 120.0, 75.2. Example 4 (1) Place a clean, dry Schlenk bottle equipped with a clean magnetic stir bar into a glove box. Inside the glove box, add Pd(OAc)2 (2.3 mg, 5 mol%: 5% of the amount of aryl ketone 1b) and decaalkyltrimethylammonium chloride (5.2 mg, 10 mol%: 10% of the amount of aryl ketone 1b) to the Schlenk bottle in sequence.

[0048] (2) Accurately weigh 1b (36 mg, 0.2 mmol) into the Schlenk flask from step (1), and then add 2 ml of dichloroethane (DCE) as a solvent. Then send the Schlenk flask out of the glove box.

[0049] (3) Open the Schlenk flask, introduce H2 into the Schlenk flask, and carry out the reaction at 60 °C and atmospheric pressure (1 atm) for 10 hours.

[0050] (4) The reaction process was monitored using TLC and GC-MS. After the reaction was completed, the volatile solvent in the reaction solution was removed by vacuum concentration using a rotary evaporator. Then, the concentrated reaction solution was purified by column chromatography using pure petroleum ether as the eluent. The purified product fluorene (3b) was obtained as a white solid with a yield of 98%.

[0051] The 1H NMR characterization data of the alkane product in Example 4 are as follows: Figure 7 , 8 : 1 H NMR (400 MHz, Chloroform-d) δ 7.78 (d, J = 7.5 Hz, 2H), 7.53 (d, J = 7.2 Hz, 2H), 7.36 (td,J = 7.5, 1.2 Hz, 2H), 7.29 (td, J = 7.4, 1.2 Hz, 2H), 3.88 (s, 2H). 13 C NMR (101 MHz, Chloroform-d) δ 143.3, 141.7, 126.8, 126.8, 125.1, 119.9, 37.0. Example 5 (1) Place a clean, dry Schlenk bottle equipped with a clean magnetic stir bar into a glove box. Inside the glove box, add Pd(OAc)2 (2.3 mg, 5 mol%: 5% of the amount of aryl ketone 1c) and tetrabutylammonium fluoride (TBAF) (5.2 mg, 10 mol%: 10% of the amount of aryl ketone 1c) to the Schlenk bottle in sequence.

[0052] (2) Accurately weigh 1 c (40 mg, 0.2 mmol) into the Schlenk flask from step (1), and then add 2 ml of methanol (MeOH) as a mixed solvent. Then send the Schlenk flask out of the glove box.

[0053] (3) Open the Schlenk flask, introduce H2 into the Schlenk flask, and carry out the reaction at 60 °C and atmospheric pressure (1 atm) for 8 hours.

[0054] (4) The reaction process was monitored using TLC and GC-MS. After the reaction was completed, the volatile solvent in the reaction solution was removed by vacuum concentration using a rotary evaporator. Then, the concentrated reaction solution was purified by column chromatography using ethyl acetate / petroleum ether = 1 / 5 as the eluent. The purified product 4-fluorodiphenylethanol 2c was obtained as a white solid with a yield of 97%.

[0055] The 1H NMR characterization data of the aryl alcohol product in Example 5 are as follows: Figure 9 , 10 : 1H NMR (400 MHz, Chloroform-d) δ 7.26 – 7.14 (m, 7H), 6.90 (t, J = 8.7 Hz, 2H), 5.66 (d, J =2.2 Hz, 1H), 2.45 (d, J = 3.0 Hz, 1H). 13 C NMR (101 MHz, Chloroform-d) δ 162.2(d, J = 245.6 Hz), 143.7, 139.6 (d, J = 3.0 Hz), 128.6, 128.3 (d, J = 8.1Hz), 127.8, 126.5, 115.3 (d, J = 21.4 Hz), 75.6. Example 6 (1) Place a clean, dry Schlenk bottle equipped with a clean magnetic stir bar into a glove box. Inside the glove box, add Pd(OAc)2 (2.3 mg, 5 mol%: 5% of the amount of aryl ketone 1c) and decaalkyltrimethylammonium chloride (5.2 mg, 10 mol%: 10% of the amount of aryl ketone 1c) to the Schlenk bottle in sequence.

[0056] (2) Accurately weigh 1 c (40 mg, 0.2 mmol) into the Schlenk flask from step (1), and then add 2 ml of dichloroethane (DCE) as a solvent. Then send the Schlenk flask out of the glove box.

[0057] (3) Open the Schlenk flask, introduce H2 into the Schlenk flask, and carry out the reaction at 60 °C and atmospheric pressure (1 atm) for 24 hours.

[0058] (4) The reaction process was monitored using TLC and GC-MS. After the reaction was completed, the volatile solvent in the reaction solution was removed by vacuum concentration using a rotary evaporator. Then, the concentrated reaction solution was purified by column chromatography using pure petroleum ether as the eluent. The purified product 4-fluorodiphenylmethane 3c was obtained as a colorless liquid with a yield of 88%.

[0059] The 1H NMR characterization data of the alkane product in Example 6 are as follows: Figure 11 , 12 : 1H NMR (400 MHz, Chloroform-d) δ 7.29 (dd, J = 8.2, 6.7 Hz, 2H), 7.21 (d, J = 7.3 Hz, 1H), 7.14 (ddd, J = 14.2, 6.9, 1.9 Hz, 4H), 6.96 (t, J = 8.7 Hz, 2H), 3.94 (s,2H), 1.25 (s, 1H). 13 C NMR (101 MHz, Chloroform-d) δ 161.4 (d, J = 243.9 Hz), 141.0, 136.8 (d, J = 3.2 Hz), 130.3 (d, J = 7.8 Hz), 128.7 (d, J = 29.4 Hz), 126.2, 115.2 (d, J = 21.2 Hz), 41.1, 29.8. Example 7 (1) Place a clean, dry Schlenk bottle equipped with a clean magnetic stir bar into a glove box. Inside the glove box, add Pd(OAc)2 (2.3 mg, 5 mol%: 5% of the amount of aryl ketone 1d) and tetrabutylammonium fluoride (TBAF) (5.2 mg, 10 mol%: 10% of the amount of aryl ketone 1d) to the Schlenk bottle in sequence.

[0060] (2) Accurately weigh 1 d (36.4 mg, 0.2 mmol) into the Schlenk flask from step (1), and then add 2 ml of methanol (MeOH) as a mixed solvent. Then send the Schlenk flask out of the glove box.

[0061] (3) Open the Schlenk flask, introduce H2 into the Schlenk flask, and carry out the reaction at 60 °C and atmospheric pressure (1 atm) for 4 hours.

[0062] (4) The reaction process was monitored using TLC and GC-MS. After the reaction was completed, the volatile solvent in the reaction solution was removed by vacuum concentration using a rotary evaporator. Then, the concentrated reaction solution was purified by column chromatography using ethyl acetate / petroleum ether = 1 / 5 as the eluent. The purified product 4-biphenylmethanol was obtained as a white solid with a yield of 96%.

[0063] The 1H NMR characterization data of the aryl alcohol product in Example 7 are as follows: Figure 13 , 14 : 1H NMR (400 MHz, Chloroform-d) δ 7.62 – 7.52 (m, 4H), 7.47 – 7.37 (m, 4H), 7.37 – 7.30 (m,1H), 4.69 (s, 2H), 2.08 (s, 1H). 13 C NMR (101 MHz, Chloroform-d) δ 140.8,140.6, 139.9, 128.8, 127.5, 127.4, 127.3, 127.1, 65.1. Example 8 (1) Place a clean, dry Schlenk bottle equipped with a clean magnetic stir bar into a glove box. Inside the glove box, add Pd(OAc)2 (2.3 mg, 5 mol%: 5% of the amount of aryl ketone 1d) and decaalkyltrimethylammonium chloride (5.2 mg, 10 mol%: 10% of the amount of aryl ketone 1d) to the Schlenk bottle in sequence.

[0064] (2) Accurately weigh 1 d (40 mg, 0.2 mmol) into the Schlenk flask from step (1), and then add 2 ml of dichloroethane (DCE) as a solvent. Then send the Schlenk flask out of the glove box.

[0065] (3) Open the Schlenk flask, introduce H2 into the Schlenk flask, and carry out the reaction at 60 °C and atmospheric pressure (1 atm) for 4 hours.

[0066] (4) The reaction process was monitored using TLC and GC-MS. After the reaction was completed, the volatile solvent in the reaction solution was removed by vacuum concentration using a rotary evaporator. Then, the concentrated reaction solution was purified by column chromatography using pure petroleum ether as the eluent. The purified product 4-methylbiphenyl 3d was obtained as a white solid with a yield of 99%.

[0067] The 1H NMR characterization data of the alkane product in Example 8 are as follows: Figure 15 , 16 : 1H NMR (400 MHz, Chloroform-d) δ 7.59 – 7.53 (m, 2H), 7.51 – 7.46 (m, 2H), 7.41 (dd, J = 8.4,6.9 Hz, 2H), 7.34 – 7.27 (m, 1H), 7.23 (d, J = 7.9 Hz, 2H), 2.38 (s, 3H). 13 CNMR (101 MHz, Chloroform-d) δ 141.2, 138.4, 137.1, 129.6, 128.8, 127.1,127.1, 21.2. Comparative Example 1 (1) Place a clean, dry Schlenk flask equipped with a clean magnetic stir bar into a glove box. Inside the glove box, add Pd(OAc)2 (2.3 mg, 5 mol%: 5% of the amount of aryl ketone 1a) to the Schlenk flask in sequence.

[0068] (2) Accurately weigh 1a (39.2 mg, 0.2 mmol) into the Schlenk flask from step (1), and then add 2 ml of methanol (MeOH) as a mixed solvent. Then remove the Schlenk flask from the glove box.

[0069] (3) Open the Schlenk flask, introduce H2 into the Schlenk flask, and carry out the reaction at 60 °C and atmospheric pressure (1 atm) for 7 hours.

[0070] (4) The reaction process was monitored by TLC and GC-MS. After the reaction was completed, the volatile solvent in the reaction solution was removed by vacuum concentration using a rotary evaporator. Then, the concentrated reaction solution was purified by column chromatography with ethyl acetate / petroleum ether = 1 / 5 as the eluent. After purification, aryl alcohol reduction product 2a was obtained, which was a white solid with a yield of 24%. At the same time, alkane reduction product 3a was obtained, which was a colorless liquid with a yield of 38%.

[0071] The various embodiments of the present invention 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 improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salts, characterized in that, The process includes the following steps: mixing palladium salt catalyst, quaternary ammonium salt additive, solvent and aryl ketone, reacting in a hydrogen atmosphere, removing the volatile solvent after the reaction is complete, purifying the concentrated reaction solution using column chromatography, and obtaining the reduction product after purification. When the quaternary ammonium salt additive is at least one of tetrabutylammonium iodide, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium fluoride, tetrabutylammonium hexafluorophosphate, and tetrabutylammonium perchlorate, the reduction product is an aryl alcohol. When the quaternary ammonium salt additive is at least one of diecryldimethylammonium chloride, tetradecyltrimethylammonium chloride, methyltrioctylammonium chloride, or decadecyltrimethylammonium chloride, the reduction product is an alkane.

2. The palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt as described in claim 1, characterized in that, When the quaternary ammonium salt additive is tetrabutylammonium fluoride, the reduction product is an aryl alcohol; When the quaternary ammonium salt additive is decaalkyltrimethylammonium chloride, the reduction product is an alkane.

3. The palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt as described in claim 1, characterized in that, When the palladium salt catalyst is at least one of palladium acetate, tetra(triphenylphosphine)palladium, tris(dibenzylacetone)dipalladium, palladium bromide, palladium chloride, palladium trifluoroacetate, palladium on carbon, or palladium tetrafluoroborate tetraacetonitrile, the reduction product is an aryl alcohol. When the palladium salt catalyst is at least one of palladium acetate, palladium bromide, palladium chloride, palladium trifluoroacetate, palladium on carbon, or palladium tetrafluoroborate tetraacetonitrile, the reduction product is an alkane.

4. The palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt as described in claim 1, characterized in that, The palladium salt catalyst is palladium acetate, and the reduction product is an aryl alcohol; the palladium salt catalyst is palladium acetate, and the reduction product is an alkane.

5. The palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt as described in claim 1, characterized in that, When the solvent is at least one of dioxane, tetrahydrofuran, toluene, methanol, and dichloroethane, the reduction product is an aryl alcohol; when the solvent is at least one of dioxane, tetrahydrofuran, and dichloroethane, the reduction product is an alkane.

6. The palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt as described in claim 1, characterized in that, The solvent is methanol, and the reduction product is an aryl alcohol; the solvent is dichloroethane, and the reduction product is an alkane.

7. The palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt as described in claim 1, characterized in that, The reaction is carried out at a temperature of 20-80℃ for 2-48 hours under standard atmospheric pressure.

8. The palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt as described in claim 1, characterized in that, The molar ratio of the palladium salt catalyst, the quaternary ammonium salt additive, and the aryl ketone is (0.01-0.1):(0.05-0.3):

1.

9. The palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt as described in claim 1, characterized in that, The molar ratio of the palladium salt catalyst, the quaternary ammonium salt additive, and the aryl ketone is 0.05:0.1:1; the molar concentration of the aryl ketone in the solvent is 0.1 mmol / ml.

10. The aryl alcohol or aryl alkane prepared by the palladium-catalyzed carbonyl reduction method controlled by quaternary ammonium salt as described in claim 1.

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