Preparation of alcohols by deoxygenation catalyzed by a pyrylium salt 18 Process for the marking of ketones

Abstract

This invention discloses a pyran salt-catalyzed alcohol deoxygenation preparation method. 18 This invention relates to a method for labeling ketones with O, belonging to the field of organic synthesis technology. The process uses tertiary benzyl alcohol as a raw material and triphenylpyran salt as a catalyst, under visible light irradiation, with H2... 18 O is 18 O source, can be obtained in high yield 18 O-labeled ketones. This invention does not require acids or high temperatures, and avoids the residue of transition metals. It uses a novel, inexpensive organic photocatalyst to catalyze the oxidation of alcohols to ketones under mild reaction conditions. 18 O mark.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a pyran salt-catalyzed method for the deoxygenation preparation of alcohols. 18 A method for labeling ketones with O. Background Technology

[0002] The oxidation of alcohols to carbonyl compounds is an important reaction in organic synthesis. Generally, primary and secondary alcohols are readily oxidized to ketones in the presence of strong oxidizing agents. Currently, with the development of electrocatalytic synthetic chemistry, primary and secondary alcohols can be synthesized into ketones through electrooxidation. Chem. Eur. J. 2024, 30, e202402986; J. Org. Chem. 2024, 89, 15864).

[0003] However, for tertiary alcohols, achieving the synthesis of ketones under green and mild conditions via C / C bond cleavage remains a significant challenge. Besides Knowles' achievement of photocatalytic oxidation of p-methoxy-substituted aryl tertiary alcohols to ketones (…),… J. Am. Chem. Soc. 2016, 138, 10794), current strategies all require transition metals and equivalent amounts of oxidant ( Chin. Chem. Lett. 2023, 34, 108454; Chin. Chem. Lett. 2024, 35, 108835). Given the important role of isotope labeling in chemistry, biology, and medicinal chemistry, commercially available H2 was utilized. 18 Developing a green and mild 18-O isotope-labeled ketone synthesis method is of great research value. Summary of the Invention

[0004] The purpose of this invention is to provide a pyran salt-catalyzed alcohol deoxygenation preparation method. 18 The method for O-labeled ketones is specifically implemented through the following technical solution:

[0005] A pyran salt-catalyzed alcohol deoxygenation preparation 18 The method of O-labeled ketones, using tertiary benzyl alcohol As raw material, triarylpyran salt As a photocatalyst, it simultaneously oxidizes to ketones under visible light irradiation. 18 O mark.

[0006] Furthermore, raw materials The R1, R2, and R3 groups are various substituted aryl, heteroaryl, or alkyl groups.

[0007] Furthermore, the triarylpyran salt is a triphenylpyran salt. .

[0008] Further, the amount of the photocatalyst added is 5-20% of the molar amount of the raw material.

[0009] Further, the reaction is carried out in an acetonitrile solvent in an air atmosphere.

[0010] Further, the visible light is white light, blue light or sunlight.

[0011] Further, 18 O is H2 18 O.

[0012] The synthetic route of the present application is as follows:

[0013]

[0014] A typical reaction is as follows:

[0015]

[0016] The present application has the following advantages:

[0017] The present application has the following advantages: 18 O is H2 DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely in combination with examples. If the specific conditions are not mentioned in the examples, the conventional conditions or the conditions suggested by the manufacturers are used. If the reagents or instruments are not mentioned by the manufacturers, they are the conventional products which can be purchased in the market.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0020] The photocatalyst triphenylpyrylium salt used in the present application is synthesized by the following method:

[0021]

[0022] The synthesis is carried out according to the literature and repeated test research, and the specific steps are as follows:

[0023] In a 100 mL distillation flask, a magnetic stirrer was added, then chalcone (21.0 g, 100 mmol) weighed on an analytical balance was added, 20 mL of DCE (1,2-dichloroethane) was added under air, then a syringe was used to add acetophenone (6.1 g, 50 mmol) to it, and the mixture was stirred on a magnetic stirrer until dissolved. After the reflux device was assembled, it was preheated to 110°C, then an HBF4 solution (about 20 mL, 100 mmol) was drawn into a syringe and added to the distillation flask, then the reaction was carried out for 1.5 h. After the reaction was completed, it was cooled to room temperature and the solvent was evaporated, about 80 mL of Et2O solution was added, stirred for 20 min, filtered, washed with 20 mL of Et2O, and dried to obtain a light yellow solid.

[0024] The raw material benzyl alcohol used in the present application is synthesized by the following method:

[0025]

[0026] According to the literature (Cicco L., Rodríguez-Álvarez M. J., Perna F. M., García-Álvarez J., Capriati V.. Green Chem., 2017, 19, 3069-3077), the specific steps are as follows:

[0027] (1) Synthesis of secondary alcohol: First, prepare a dry round-bottom flask with a magnetic stirrer, add the reaction raw material ketone (1.0 equivalent) and methanol (0.8 mmol / mL) to the round-bottom flask, stir and cool to 0°C for about 15 minutes, then slowly add sodium borohydride (1.01 equivalent) to the solution, stir the mixture for 14 hours while warming the reaction liquid to room temperature. After the reaction is completed, quench the reaction with H2O (2 mL / mmol). The aqueous phase is extracted with EA three times, the combined organic phase is washed with brine, and finally the combined organic phase is dried with anhydrous MgSO4, and the solution is concentrated under reduced pressure to obtain the desired product.

[0028] (2) The synthesis of tertiary alcohols: First, prepare a dry reaction bottle with a branch, the upper end is tightly plugged with a rubber plug, and the branch is connected to a nitrogen device. Place the reaction bottle in an ice water bath and maintain at 0 °C. Maintain N2 atmosphere in the reaction bottle. Then add the raw material ketone (1.0 equivalent) and anhydrous tetrahydrofuran (1.0 mmol / mL) to the reaction container (if the raw material ketone is a solid, we can first add the ketone to the reaction bottle and then connect the device). Then use a syringe to slowly add the Grignard reagent (1.5 equivalents) from the rubber plug to the reaction solution. Stir the mixture overnight while warming the reaction solution to room temperature. After the reaction is complete, quench the reaction with an aqueous solution of ammonium chloride, extract the aqueous phase with EA three times, then dry the mixed liquid with anhydrous MgSO4, monitor the position of the product spot using thin layer chromatography, and finally purify using silica gel column chromatography to obtain the desired product.

[0029] Example 1

[0030] Weigh the photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) into a reaction tube, and add 2 mL of super-dry acetonitrile under an air atmosphere. Then carefully add (39.6 mg, 0.2 mmol), and then add H2 18 O (120.0 mg, 6 mmol), and then place it under two 18 W white light lamps for irradiation at room temperature for 6 h. Dry loading, column chromatography (300-400 mesh chromatographic silica gel) to obtain the product 24.4 mg, yield 78%, 18 O labeling rate 88%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.90 (d, J = 8.4 Hz, 2H), 7.44 (d, J = 8.5 Hz, 2H),2.60 (s, 3H).

[0031] Example 2

[0032] Weigh the photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) into a reaction tube, and add 2 mL of super-dry acetonitrile under an air atmosphere. Then carefully add (45.6 mg, 0.2 mmol), and then add H2 18 O (120.0 mg, 6 mmol), and then place it under two 18 W white light lamps for irradiation at room temperature for 6 h. Dry loading, column chromatography (300-400 mesh chromatographic silica gel) to obtain the product 36.6 mg, yield 92%, 18 O labeling rate 90%.1 H NMR (400 MHz, Chloroform- d ) δ 7.8 (d, J = 8.4 Hz, 2H), 7.6 (d, J = 6.9 Hz, 2H), 2.6 (s, 3H).

[0033] Example 3

[0034] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (39.6 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 31.6 mg, yield 93%, 18 O labeling rate: 93%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.9 (d, J = 8.2 Hz, 2H), 7.4 (d, J = 8.2 Hz, 2H), 3.0 (q, J = 7.3Hz, 2H), 1.2 (t, J = 7.2 Hz, 3H).

[0035] Example 4

[0036] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (36.0 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 24.9 mg, yield 69%, 18 O labeling rate: 94%. 1 H NMR (400 MHz, Chloroform- d ) δ 8.1 (s, 1H), 7.8 (d, J= 7.9 Hz, 1H), 7.7 (d, J = 8.6Hz, 1H), 7.4 (td, J = 7.8, 3.0 Hz, 1H), 2.6 (s, 3H), 2.2 (s, 1H), 1.6 (s, 6H).

[0037] Example 5

[0038] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (33.8 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 18.5 mg, yield 66%, 18 O labeling rate 85%. 1 H NMR (400 MHz, Chloroform- d ) δ 3.02 (q, J = 7.2 Hz, 2H), 1.23 (t, J = 7.3 Hz, 3H).

[0039] Example 6

[0040] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (48.0 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 40.1 mg, yield 94%, 18 O labeling rate: 89%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.8 (d, J = 8.5 Hz, 2H), 7.6 (d, J = 8.6 Hz, 2H), 3.0 (q, J = 7.2Hz, 2H), 1.2 (t,J = 7.2 Hz, 3H).

[0041] Example 7

[0042] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (56.4 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 30.7 mg, yield 72%, 18 O labeling rate was 91%. 1 HNMR (400 MHz, Chloroform- d ) δ 7.9 (d, J = 8.1 Hz, 2H), 7.4 (d, J = 8.2 Hz, 2H), 2.9 (t, J = 7.5 Hz, 2H), 1.7 (m, J = 9.0, 8.1 Hz, 2H), 1.4 – 1.3 (m, 4H), 0.9 (t, J = 7.1 Hz, 3H).

[0043] Example 8

[0044] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (48.4 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 40.6 mg, yield 84%, 18 O labeling rate: 89%.

[0045] Example 9

[0046] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (54.0 mg, 0.2 mmol), followed by H2 18 O (120.0 mg, 6 mmol) and then placed under irradiation from two 18 W white light lamps for 6 h at room temperature. Dry loading and column chromatography (300-400 mesh silica gel) gave the product 44.7 mg, yield 92%, 18 O labeling rate 84%.

[0047] Example 10

[0048] The photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) was weighed into a reaction tube, 2 mL of super-dry acetonitrile was added under an air atmosphere. Then, 4- methoxyphenylboronic acid (54.8 mg, 0.2 mmol) was carefully added, followed by H2 (54.0 mg, 0.2 mmol), followed by H2 18 O (40.0 mg, 2 mmol) and then placed under irradiation from two 18 W white light lamps for 6 h at room temperature. Dry loading and column chromatography (300-400 mesh silica gel) gave the product 34.9 mg, yield 95%, 18 O labeling rate 60%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.84 - 7.76 (m, 4H), 7.61 - 7.55 (m, 2H), 7.47 (t, J = 7.7 Hz, 4H).

[0049] Example 11

[0050] The photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) was weighed into a reaction tube, 2 mL of super-dry acetonitrile was added under an air atmosphere. Then, 4- methoxyphenylboronic acid (54.8 mg, 0.2 mmol) was carefully added, followed by H2 (38.4 mg, 0.2 mmol), followed by H2 18 O (40.0 mg, 2 mmol) and then placed under irradiation from two 18 W white light lamps for 6 h at room temperature. Dry loading and column chromatography (300-400 mesh silica gel) gave the product 19.1 mg, yield 64%, 18 O labeling rate 80%. 1 H NMR (400 MHz, Chloroform- d ) δ 8.01 - 7.86 (m, 2H), 7.55 (t, J= 7.3 Hz, 1H), 7.50 – 7.41 (m,2H), 2.95 (t, J = 7.3 Hz, 2H), 1.78 (h, J = 7.4 Hz, 2H), 1.01 (t, J = 7.4 Hz, 3H).

[0051] Example 12

[0052] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (54.0 mg, 0.2 mmol), then add H2 18 O (40.0 mg, 2 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 20.7 mg, yield 76%, 18 O labeling rate 80%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.97 (d, J = 8.2 Hz, 2H), 7.60 – 7.51 (m, 1H), 7.46 (t, J = 7.8Hz, 2H), 3.01 (q, J = 7.3 Hz, 2H), 1.23 (t, J = 7.2 Hz, 3H).

[0053] Example 13

[0054] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (49.2 mg, 0.2 mmol), then add H2 18 O (40.0 mg, 2 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 22.4 mg, yield 68%, 18 O labeling rate was 77%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.96 (d,J = 7.7 Hz, 2H), 7.55 (t, J = 7.5 Hz, 1H), 7.45 (t, J =7.6 Hz, 2H), 2.96 (t, J = 7.5 Hz, 2H), 1.73 (q, J = 7.4 Hz, 2H), 1.41 (q, J = 7.6Hz, 2H), 0.95 (t, J = 7.5 Hz, 3H).

[0055] Example 14

[0056] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (57.6 mg, 0.2 mmol), then add H2 18 O (30.0 mg, 1.5 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 30.0 mg, yield 76%, 18 O labeling rate was 76%. 1 H NMR (400 MHz, Chloroform- d ) δ 8.1 – 7.9 (m, 2H), 7.5 (q, J = 6.2, 5.0 Hz, 1H), 7.5– 7.4 (m, 2H), 7.4 – 7.2 (m, 5H), 4.3 (s, 2H).

[0057] Example 15

[0058] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (50.8 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 12 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 42.9 mg, yield 95%, 18 O labeling rate: 79%. 1H NMR (400 MHz, Chloroform- d ) δ 7.9 (d, J = 8.8 Hz, 2H), 7.6 (d, J = 6.2 Hz, 2H), 2.7 – 2.5 (m,1H), 1.3 – 1.2 (m, 2H), 1.1 – 1.0 (m, 2H).

[0059] Example 16

[0060] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (27.2 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 12 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 16.6 mg, yield 68%, 18 O labeling rate: 89%.

[0061] Example 17

[0062] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (67.6 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 12 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 41.5 mg, yield 67%, 18 O labeling rate: 81%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.89 (d, J = 1.8 Hz, 1H), 7.83 (dd, J =7.9, 1.8 Hz, 1H), 7.37 – 7.32 (m, 2H), 7.33 – 7.25 (m, 3H), 3.03 (q, J = 7.2Hz, 2H), 2.32 (s, 3H), 1.25 (t, J= 7.2 Hz, 3H).

[0063] Example 18

[0064] The photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) was weighed into a reaction vial and 2 mL of super-dry acetonitrile was added under an air atmosphere. Then, 4- methoxyphenylboronic acid (39.6 mg, 0.2 mmol) was carefully added followed by H2O2(120.0 mg, 6 mmol) and the reaction was left to stir under the irradiation of two 18 W white light lamps for 12 h at room temperature. The product was obtained after dry loading and column chromatography (300-400 mesh chromatographic silica gel). 18 The photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) was weighed into a reaction vial and 2 mL of super-dry acetonitrile was added under an air atmosphere. Then, 4- methoxyphenylboronic acid (39.6 mg, 0.2 mmol) was carefully added followed by H2O2(120.0 mg, 6 mmol) and the reaction was left to stir under the irradiation of two 18 W white light lamps for 12 h at room temperature. The product was obtained after dry loading and column chromatography (300-400 mesh chromatographic silica gel). 23.9 mg, 70% yield, 18 79% O-labeling yield. 1 H NMR (500 MHz, DMSO- d 6) δ 8.16 (t, J = 2.0 Hz, 1H), 7.85 (tt, J = 7.3, 2.0 Hz, 2H), 7.67 (t, J =7.4 Hz, 1H), 3.41 (q, J = 8.0 Hz, 2H), 1.18 (t, J = 8.0 Hz, 3H).

[0065] Example 19

[0066] The photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) was weighed into a reaction vial and 2 mL of super-dry acetonitrile was added under an air atmosphere. Then, 4- methoxyphenylboronic acid (39.6 mg, 0.2 mmol) was carefully added followed by H2O2(120.0 mg, 6 mmol) and the reaction was left to stir under the irradiation of two 18 W white light lamps for 12 h at room temperature. The product was obtained after dry loading and column chromatography (300-400 mesh chromatographic silica gel). 18 The photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) was weighed into a reaction vial and 2 mL of super-dry acetonitrile was added under an air atmosphere. Then, 4- methoxyphenylboronic acid (39.6 mg, 0.2 mmol) was carefully added followed by H2O2(120.0 mg, 6 mmol) and the reaction was left to stir under the irradiation of two 18 W white light lamps for 12 h at room temperature. The product was obtained after dry loading and column chromatography (300-400 mesh chromatographic silica gel). 43.1 mg, 95% yield, 18 88% O-labeling yield. 1 HNMR (400 MHz, Chloroform- d ) δ 7.98 (d, J = 8.7 Hz, 2H), 7.27 (dp, J = 15.4, 7.5Hz, 5H), 6.91 (d, J ​​= 8.8 Hz, 2H), 4.22 (s, 2H), 3.83 (s, 3H).

[0067] Example 20

[0068] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (50.8 mg, 0.2 mmol), then add H2 18 O (40.0 mg, 2 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 12 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 33.8 mg, yield 85%, 18 O labeling rate: 78%. 1 H NMR (400MHz, Chloroform- d ) δ 7.9 (d, J = 8.1 Hz, 2H), 7.4 (d, J = 8.2 Hz, 2H), 2.8 (d, J =6.8 Hz, 2H), 2.3 (dp, J = 20.7, 6.8 Hz, 1H), 1.0 (d, J = 5.4 Hz, 6H).

[0069] Example 21

[0070] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (50.6 mg, 0.2 mmol), then add H2 18 O (40.0 mg, 2 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 12 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 28.2 mg, yield 77%, 18 O labeling rate: 66%. 1 H NMR (400MHz, Chloroform- d ) δ 2.99 – 2.94 (m, 2H), 1.74 (p, J = 7.5 Hz, 2H), 1.37 (h, J=3.7 Hz, 4H), 0.91 (td, J = 6.9, 3.3 Hz, 3H).

[0071] Example 22

[0072] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (52.8 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 24 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 26.8 mg, yield 57%, 18 O labeling rate: 78%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.99 (d, J = 8.4 Hz, 2H), 7.74 (d, J = 8.4 Hz, 2H), 3.01 (q, J = 7.2 Hz, 2H), 1.24 (t, J = 7.2 Hz, 3H).

[0073] Example 23

[0074] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (33.6 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 24 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 17.0 mg, yield 55%, 18 O labeling rate was 77%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.87 – 7.71 (m, 2H), 7.04 (t, J = 8.9 Hz, 1H), 2.56 (d, J = 1.4Hz, 3H), 2.31 (s, 3H).

[0075] Example 24

[0076] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (52.0 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 24 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 18.8 mg, yield 60%, 18 O labeling rate: 73%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.90 (d, J = 8.4 Hz, 2H), 7.44 (d, J = 8.5 Hz, 2H), 2.60 (s, 3H).

[0077] Example 25

[0078] Weigh out 15.8 mg (0.02 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (42.4 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 24 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). The gas phase yield was 70%. 18 O labeling rate: 69%.

[0079] Example 26

[0080] Weigh out 15.8 mg (0.02 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (45.2 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 24 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). The gas phase yield was 65%. 18 O labeling rate: 65%.

[0081] Example 27

[0082] Weigh out 15.8 mg (0.02 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (53.6 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 24 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 17.7 mg, yield 39%, 18 O labeling rate 70%. 1 HNMR (400 MHz, Chloroform- d ) δ 8.06 – 8.02 (m, 2H), 7.71 – 7.66 (m, 2H), 7.65 – 7.60 (m, 2H), 7.51 – 7.44 (m, 2H), 7.43 – 7.37 (m, 1H), 2.98 (t, J = 7.3 Hz, 2H), 1.80 (h, J = 7.4 Hz, 2H), 1.03 (t, J = 7.4 Hz, 3H).

[0083] Example 28

[0084] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (67.3 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 6 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 30.0 mg, yield 61%, 18 O labeling rate: 83%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.70 (d, J = 1.8 Hz, 1H), 7.35 (d, J = 1.8 Hz, 1H), 3.18 (t, J= 7.2 Hz, 2H), 2.60 (s, 3H), 1.93 (t, J = 7.2 Hz, 2H), 1.36 (s, 9H), 1.26 (s,6H).

[0085] Example 29

[0086] The photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) was weighed into a reaction vial and 2 mL of super-dry acetonitrile was added under an air atmosphere. Then, the photocatalyst was carefully added to the reaction vial. (70.1 mg, 0.2 mmol) was added, followed by H2 18 O (120.0 mg, 6 mmol) and placed under two 18 W white light lamps for 6 h at room temperature. Dry loading and column chromatography (300-400 mesh chromatographic silica gel) gave the product 45.8 mg, 88% yield, 18 O-labeling yield 81%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.66 (s, 1H), 7.20 (s, 1H), 2.57 (s, 3H), 2.50 (s,3H), 1.88 (dqd, J = 13.4, 6.8, 2.6 Hz, 1H), 1.64 (t, J = 13.3 Hz, 1H), 1.40 (dd, J = 13.6, 2.7 Hz, 1H), 1.33 (s, 6H), 1.27 (s, 3H), 1.07 (s, 3H), 1.00 (d, J = 6.8 Hz, 3H).

[0087] Example 30

[0088] The photocatalyst triphenylpyrylium salt (7.9 mg, 0.01 mmol) was weighed into a reaction vial and 2 mL of super-dry acetonitrile was added under an air atmosphere. Then, the photocatalyst was carefully added to the reaction vial. (68.4 mg, 0.2 mmol) was added, followed by H2 18 O (120.0 mg, 6 mmol) and placed under two 18 W white light lamps for 6 h at room temperature. Dry loading and column chromatography (300-400 mesh chromatographic silica gel) gave the product 41.1 mg, 82% yield, 18 O-labeling yield 34%. 1HNMR (400 MHz, Chloroform- d ) δ 7.75 – 7.71 (m, 4H), 7.49 – 7.45 (m, 4H).

[0089] Example 31

[0090] Weigh out 15.8 mg (0.02 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (39.6 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under a 456 nm blue light lamp and reacted at room temperature for 12 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). The gas phase yield is 45%. 18 O labeling rate: 66%.

[0091] Example 32

[0092] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (48.0 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was then placed under two 18 W white light lamps and reacted at room temperature for 24 h. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). The gas phase yield was 27%. 18 O labeling rate: 69%.

[0093] Example 33

[0094] Weigh out 7.9 mg (0.01 mmol) of the photocatalyst triphenylpyran salt and add it to a reaction tube. Then, under air atmosphere, add 2 mL of ultra-dry acetonitrile. Then carefully add... (39.6 mg, 0.2 mmol), then add H2 18 O (120.0 mg, 6 mmol) was added and then placed under sunlight for 6 h at room temperature. The product was obtained by dry loading and column chromatography (300-400 mesh silica gel). 21.9 mg, yield 70%, 18 O labeling rate: 93%. 1 H NMR (400 MHz, Chloroform- d ) δ 7.90 (d,J = 8.4 Hz, 2H), 7.44 (d, J = 8.5 Hz, 2H), 2.60 (s, 3H).

[0095] Example 34

[0096] The photocatalyst triphenylpyrylium salt (23.8 mg, 0.03 mmol) was weighed into a reaction tube and 6 mL of super-dry acetonitrile was added under an air atmosphere. Then, the photocatalyst was carefully added to the reaction mixture. (59.4 mg, 0.3 mmol) was added, followed by H2 18 O (180.0 mg, 6 mmol) was added and the reaction was collected over a continuous flow reactor under irradiation from two 23 W white lamps for 2 hours to give 4 mL (0.2 mmol). This was dried down and purified by column chromatography (300-400 mesh silica gel) to give the product 26.6 mg, 78% yield, 18 O labelling efficiency 61%. 1 H NMR (500 MHz, DMSO- d 6) δ 8.16 (t, J = 2.0 Hz, 1H),7.85 (tt, J = 7.3, 2.0 Hz, 2H), 7.67 (t, J = 7.4 Hz, 1H), 3.41 (q, J = 8.0 Hz, 2H),1.18 (t, J = 8.0 Hz, 3H).

[0097] The above described embodiments only express several preferred embodiments of the present application, which are described in more detail and in more detail, but are not used to limit the present application. It should be noted that for those skilled in the art, the present application can also have various changes and modifications, any modification, equivalent replacement, improvement, etc. within the concept and principle of the present application, should be included in the protection scope of the present application.

Claims

1. A pyran salt-catalyzed alcohol deoxygenation preparation method 18 The method for O-labeled ketones is characterized by... With tertiary benzyl alcohol Using triphenylpyran salt as raw material As a photocatalyst, it simultaneously oxidizes to ketones under visible light irradiation. 18 O mark; The raw material, tertiary benzyl alcohol, and the product are selected from one of the following groups: when the raw material is... The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is When the raw material is The product is ; 18 O originates from H2 18 O.

2. The method for preparing alcohols by pyran salt catalysis according to claim 1 18 The method for O-labeled ketones is characterized by... The amount of photocatalyst added is 5%-20% of the raw material molar amount.

3. The method for preparing alcohols by pyran salt catalysis according to claim 1 18 The method for O-labeled ketones is characterized by... The reaction was carried out in an air atmosphere using acetonitrile as a solvent.

4. The method for preparing alcohols by pyran salt catalysis according to claim 1 18 The method for O-labeled ketones is characterized by... The visible light is white light, blue light, or sunlight.

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