Method for preparing 2-arylhydrazone substituted arylethyl phosphine oxide compound

Abstract

The invention provides a high-efficiency and high-selectivity method for synthesizing 2-arylhydrazone substituted arylethyl phosphine oxide compounds containing different substituted functional groups, which comprises the following steps: by taking eosin Y as a catalyst and taking styrene compounds, diaryl / alkyl substituted phosphorus oxide compounds and aromatic hydrazine compounds as reaction substrates, synthesizing the 2-arylhydrazone substituted arylethyl phosphine oxide compounds containing different substituted functional groups by using a one-pot method, thereby obtaining the 2-arylhydrazone substituted arylethyl phosphine oxide compounds containing different substituted functional groups. Oxygen in air is used as an oxidizing agent, a 12 W green light LED lamp is used as a light source, and an organic solvent is added into a reaction system. The method has the advantages that the catalyst is cheap and easily available; the substrate applicability is high; reaction conditions are mild, safe and reliable; the selectivity of the obtained target product is close to 100%, and the yield is high. The method overcomes the defects of poor reaction selectivity, tedious reaction steps, low yield, high cost, need of a transition metal catalyst and the like in the traditional synthesis of the 2-arylhydrazone substituted arylethyl phosphine oxide compound, and has a good industrial application prospect. The invention also provides the corresponding 2-arylhydrazone substituted arylethyl phosphine oxide derivatives containing different substituted functional groups at the same time.

Description

Technical Field

[0001] The present invention relates to the field of catalytic synthesis of organic phosphonate compounds, and in particular to a synthesis method for preparing 2-arylhydrazone-substituted arylethylphosphine oxide compounds by a bifunctionalization reaction of a styrene compound with a diaryl / alkyl-substituted phosphorus oxide and an aromatic hydrazine compound under photocatalysis. Background Art

[0002] Organic phosphonates are an important class of organic synthesis intermediates, widely used in pharmaceutical intermediates, pesticides, biological agents, optoelectronic materials, high-efficiency flame retardants, and catalyst ligands. 2-Aromatic hydrazone-substituted arylethyl phosphine oxide compounds, in particular, exhibit unique biological activity due to the presence of unique hydrazone and phosphoryl substituents within their molecules, demonstrating unique advantages in anti-cancer and antibacterial applications.

[0003] During the phosphylation reaction, tetracoordinate organophosphorus reagents can transform into tricoordinate organophosphorus compounds through intramolecular tautomerism, where the high-energy phosphoryl group (P=O) and the PH bond are converted into a P-OH bond. During the reaction, tricoordinate organophosphorus reagents often use pentacoordinate phosphorus compounds as intermediates or transition states. It is precisely because of this interconversion between compounds of different coordination numbers that organophosphorus reagents are widely used in organic synthesis, becoming an important component of organophosphorus chemistry, especially synthetic organic chemistry.

[0004] The methods for synthesizing 2-arylhydrazono-substituted arylethylphosphine oxide compounds reported in the literature mainly include: (1) Transition metal-catalyzed difunctionalization of styrene compounds: Zou et al. reported that styrene compounds were reacted with diaryl / alkyl-substituted phosphorus oxide and ester-substituted hydrazine compounds under the catalysis of copper salts to prepare the corresponding 2-arylhydrazono-substituted arylethylphosphine oxide compounds. However, in this system, 2.0 equivalents of silver nitrate were required as the oxidant, and 0.5 equivalents of potassium hydroxide were required as the reaction aid. The reaction cost is high, the hydrazine compounds are limited (only 3 cases), and there may be transition metal residues in the obtained target product, which cannot be directly used for biological activity testing (J. Org. Chem., 2022, 87, 15820-15829); (2) Dehydration condensation reaction: 2-phosphoryl-substituted 1-acetophenone compounds and hydrazine compounds are used to react with the ketone carbonyl group and the amino group on the hydrazine molecule under the catalysis of transition metals and acids to produce the corresponding target product. However, the above methods generally use transition metal catalysts and special ligands (phosphine ligands, ferrocene ligands, carbene ligands, etc.), and there are also disadvantages such as cumbersome experimental steps, expensive and difficult to recycle catalysts, harsh reaction conditions, cross-substrate applicability, low yield, and high environmental pollution.

[0005] To date, the efficient synthesis of 2-arylhydrazone-substituted arylethylphosphine oxide compounds has encountered several challenges, including raw material quality, production safety (acids are highly corrosive, silver nitrate has poor stability, etc.), and product stability and purity. The synthesis technology is quite difficult, and currently only a few companies in the United States, Germany, the United Kingdom, and Japan are producing them. my country's high-end or specialty organic phosphonate products currently rely mainly on imports.

[0006] In view of the shortcomings of the existing synthesis process of heterocyclic-substituted organic phosphonate compounds, the industry is focusing on the development of new methods for synthesizing the corresponding 2-arylhydrazone-substituted aromatic ethyl phosphine oxide compounds from stable, inexpensive and readily available phosphating agents using inexpensive catalysts or auxiliary agents for efficient catalysis. Summary of the Invention

[0007] The purpose of the present invention is to provide a new method for efficiently and selectively synthesizing the corresponding 2-arylhydrazone-substituted aromatic ethyl phosphine oxide compounds by photocatalytic bifunctionalization reaction using cheap and readily available styrene compounds, diaryl / alkyl-substituted phosphorus oxides and aromatic hydrazine compounds as raw materials, so as to overcome the above-mentioned defects in the prior art.

[0008] The present invention comprises the following steps: taking a reaction amount of a styrene compound, an aromatic hydrazine, a diaryl / alkyl substituted phosphorus oxide, a catalyst and an organic solvent, placing them in a reaction vessel under an air atmosphere, mixing them, and heating them at 25-100°C under irradiation of a 12 W green LED lamp. o C and stirred for 3-12 hours to obtain the corresponding 2-arylhydrazono-substituted arylethylphosphine oxide compounds containing different substituted functional groups. The specific reaction formula is as follows: （I） in, The catalyst is Eosin Y and the organic solvent is acetonitrile; Ar 1 is selected from phenyl, 4-methylphenyl, 3-methylphenyl, 4-tert-butylphenyl, 4-methoxyphenyl, 4-fluorophenyl, 3-fluorophenyl, 4-chlorophenyl, 3-chlorophenyl, 4-bromophenyl, 3-bromophenyl, 4-trifluoromethylphenyl, and 2-naphthyl; Ar 2 is selected from phenyl, 4-methylphenyl, 3-methylphenyl, 2,5-dimethylphenyl, 4-ethylphenyl, 4-isopropylphenyl, 4-methoxyphenyl, 4-fluorophenyl, 4-chlorophenyl, 2-chlorophenyl, 4-bromophenyl, 3-bromophenyl, 2,4-dichlorophenyl, 4-iodophenyl, 4-trifluoromethylphenyl, 3-trifluoromethylphenyl, and 2-trifluoromethylphenyl; R 1is selected from phenyl, 4-methylphenyl, 3-methylphenyl, 3,5-dimethylphenyl, 4-ethylphenyl, 4-butylphenyl, 4-tert-butylphenyl, 2,4-dimethylphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 4-fluorophenyl, 3-fluorophenyl, 4-chlorophenyl, 4-phenylphenyl, 3-phenylphenyl, 2-naphthyl, 1-naphthyl, and benzyl; R 2 is selected from phenyl, 4-methylphenyl, 3-methylphenyl, 3,5-dimethylphenyl, 4-ethylphenyl, 4-butylphenyl, 4-tert-butylphenyl, 2,4-dimethylphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 4-fluorophenyl, 3-fluorophenyl, 4-chlorophenyl, 4-phenylphenyl, 3-phenylphenyl, 2-naphthyl, 1-naphthyl, and benzyl.

[0009] In the above-mentioned method for synthesizing 2-arylhydrazono-substituted aromatic ethyl phosphine oxide compounds by reacting photocatalytic styrene compounds with diaryl / alkyl-substituted phosphorus oxides and aromatic hydrazines, the styrene compound is selected from styrene, 4-methylstyrene, 3-methylstyrene, 4-tert-butylstyrene, 4-methoxystyrene, 4-fluorostyrene, 3-fluorostyrene, 4-chlorostyrene, 3-chlorostyrene, 4-bromostyrene, 3-bromostyrene, 4-trifluoromethylstyrene, and 2-naphthylene.

[0010] In the above method for synthesizing 2-arylhydrazine-substituted arylethylphosphine oxide compounds by reacting a photocatalytic styrene compound with a diaryl / alkyl-substituted phosphorus oxide and an aromatic hydrazine, the aromatic hydrazine compound is selected from phenylhydrazine, 4-methylphenylhydrazine, 3-methylphenylhydrazine, 2,5-dimethylphenylhydrazine, 4-ethylphenylhydrazine, 4-isopropylphenylhydrazine, 4-methoxyphenylhydrazine, 4-fluorophenylhydrazine, 4-chlorophenylhydrazine, 2-chlorophenylhydrazine, 4-bromophenylhydrazine, 3-bromophenylhydrazine, 2,4-dichlorophenylhydrazine, 4-iodophenylhydrazine, 4-trifluoromethylphenylhydrazine, 3-trifluoromethylphenylhydrazine, and 2-trifluoromethylphenylhydrazine.

[0011] In the above method for synthesizing 2-arylhydrazono-substituted arylethylphosphine oxide compounds by reacting photocatalytic styrene compounds with diaryl / alkyl substituted phosphine oxides and aromatic hydrazines, the diaryl / alkyl substituted phosphine oxide compounds are selected from diphenylphosphine oxide, di(4-methylphenyl)phosphine oxide, di(3-methylphenyl)phosphine oxide, di(3,5-dimethylphenyl)phosphine oxide, di(4-ethylphenyl)phosphine oxide, di(4-butylphenyl)phosphine oxide, di(4-tert-butylphenyl)phosphine oxide, di(2,4 2-dimethylphenyl)phosphine oxide, bis(4-methoxyphenyl)phosphine oxide, bis(3-methoxyphenyl)phosphine oxide, bis(4-fluorophenyl)phosphine oxide, bis(3-fluorophenyl)phosphine oxide, bis(4-chlorophenyl)phosphine oxide, bis(4-phenylphenyl)phosphine oxide, bis(3-phenylphenyl)phosphine oxide, di(2-naphthyl)phosphine oxide, di(1-naphthyl)phosphine oxide, phenyl(2,4-dimethylphenyl)phosphine oxide, phenyl(4-fluorophenyl)phosphine oxide, phenyl(4-chlorophenyl)phosphine oxide, dibenzylphosphine oxide.

[0012] In the above-mentioned method for synthesizing 2-arylhydrazono-substituted arylethyl phosphine oxide compounds by reacting photocatalytic styrene compounds with diaryl / alkyl-substituted phosphine oxides and aromatic hydrazines, the molar ratio of the styrene compounds to the aromatic hydrazines and diaryl / alkyl-substituted phosphine oxide compounds is 1:[1.0-2.0]:[1.0-3.0]; the molar ratio of the styrene compounds to Eosin Y is 1:[0.01-0.1].

[0013] The present invention provides a method for efficiently and selectively synthesizing 2-arylhydrazono-substituted arylethylphosphine oxide compounds from styrene compounds, diaryl / alkyl-substituted phosphine oxides, and aromatic hydrazines under photocatalytic reaction conditions. The reaction process is mild and easy to control. While achieving high yields and 100% selectivity, the method is simple and easy to implement, uses inexpensive and readily available additives, and is straightforward to prepare, promising promising industrial applications. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the embodiments of the present invention: 1. Testing and Analysis The structures of the reaction products in the following examples were analyzed using an Agilent GC / MS (6890N / 5973N) equipped with an HP-5MS capillary column (30 m × 0.45 mm × 0.8 μm) and a Bruker Avance-III 500 nuclear magnetic resonance analyzer. The selectivity and yield of the target products were analyzed using a Bruker Avance-III 500 nuclear magnetic resonance analyzer. 2. Example Example 1

[0015] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 84%. Example 2

[0016] 59 mg (0.5 mmol) of 4-methylstyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 75%. Example 3

[0017] 59 mg (0.5 mmol) of 3-methylstyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 71%. Example 4

[0018] 80 mg (0.5 mmol) of 4-tert-butylstyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 73%. Example 5

[0019] 67 mg (0.5 mmol) of 4-methoxystyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. oC was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 69%. Example 6

[0020] 61 mg (0.5 mmol) of 4-fluorostyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 85%. Example 7

[0021] 61 mg (0.5 mmol) of 3-fluorostyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 82%. Example 8

[0022] 69 mg (0.5 mmol) of 4-chlorostyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 83%. Example 9

[0023] 69 mg (0.5 mmol) of 3-chlorostyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 81%. Example 10

[0024] 92 mg (0.5 mmol) of 4-bromostyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 79%. Example 11

[0025] 92 mg (0.5 mmol) of 3-bromostyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 81%. Example 12

[0026] 86 mg (0.5 mmol) of 4-trifluoromethylstyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 91%. Example 13

[0027] 77 mg (0.5 mmol) of 4-trifluoromethylstyrene, 108 mg (1.0 mmol) of phenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 75%. Example 14

[0028] 52 mg (0.5 mmol) of styrene, 122 mg (1.0 mmol) of 4-methylphenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. oC was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 73%. Example 15

[0029] 52 mg (0.5 mmol) of styrene, 122 mg (1.0 mmol) of 3-methylphenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 72%. Example 16

[0030] 52 mg (0.5 mmol) of styrene, 136 mg (1.0 mmol) of 2,5-dimethylphenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 69%. Example 17

[0031] 52 mg (0.5 mmol) of styrene, 136 mg (1.0 mmol) of 4-ethylphenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 73%. Example 18

[0032] 52 mg (0.5 mmol) of styrene, 150 mg (1.0 mmol) of 4-isopropylphenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 75%. Example 19

[0033] 52 mg (0.5 mmol) of styrene, 138 mg (1.0 mmol) of 4-methoxyphenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 68%. Example 20

[0034] 52 mg (0.5 mmol) of styrene, 126 mg (1.0 mmol) of 4-fluorophenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 84%. Example 21

[0035] 52 mg (0.5 mmol) of styrene, 142 mg (1.0 mmol) of 4-chlorophenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 85%. Example 22

[0036] 52 mg (0.5 mmol) of styrene, 142 mg (1.0 mmol) of 2-chlorophenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 78%. Example 23

[0037] 52 mg (0.5 mmol) of styrene, 187 mg (1.0 mmol) of 4-bromophenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. oC was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 81%. Example 24

[0038] 52 mg (0.5 mmol) of styrene, 187 mg (1.0 mmol) of 3-bromophenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 77%. Example 25

[0039] 52 mg (0.5 mmol) of styrene, 177 mg (1.0 mmol) of 2,4-dichlorophenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 81%. Example 26

[0040] 52 mg (0.5 mmol) of styrene, 234 mg (1.0 mmol) of 4-iodophenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 84%. Example 27

[0041] 52 mg (0.5 mmol) of styrene, 176 mg (1.0 mmol) of 4-trifluoromethylphenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 88%. Example 28

[0042] 52 mg (0.5 mmol) of styrene, 176 mg (1.0 mmol) of 3-trifluoromethylphenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 83%. Example 29

[0043] 52 mg (0.5 mmol) of styrene, 176 mg (1.0 mmol) of 2-trifluoromethylphenylhydrazine and 303 mg (1.5 mmol) of diphenylphosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 81%. Example 30

[0044] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 345 mg (1.5 mmol) of di(4-methylphenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 61%. Example 31

[0045] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 345 mg (1.5 mmol) of di(3-methylphenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 64%. Example 32

[0046] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 387 mg (1.5 mmol) of bis(3,5-dimethylphenyl)phosphine were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added.o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 67%. Example 33

[0047] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 387 mg (1.5 mmol) of di(4-ethylphenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 73%. Example 34

[0048] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 471 mg (1.5 mmol) of di(4-butylphenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 69%. Example 35

[0049] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 471 mg (1.5 mmol) of di(4-tert-butylphenyl)phosphine were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 65%. Example 36

[0050] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 387 mg (1.5 mmol) of bis(2,4-dimethylphenyl)phosphine were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 66%. Example 37

[0051] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 393 mg (1.5 mmol) of bis(4-methoxyphenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 63%. Example 38

[0052] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 393 mg (1.5 mmol) of bis(3-methoxyphenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 69%. Example 39

[0053] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 357 mg (1.5 mmol) of bis(4-fluorophenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 69%. Example 40

[0054] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 357 mg (1.5 mmol) of bis(3-fluorophenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 79%. Example 41

[0055] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 407 mg (1.5 mmol) of bis(4-chlorophenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. oC was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 81%. Example 42

[0056] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 531 mg (1.5 mmol) of bis(4-phenylphenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 72%. Example 43

[0057] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 531 mg (1.5 mmol) of bis(3-phenylphenyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 73%. Example 44

[0058] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 453 mg (1.5 mmol) of di(2-naphthyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 67%. Example 45

[0059] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 453 mg (1.5 mmol) of di(1-naphthyl)phosphine oxide were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 62%. Example 46

[0060] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 345 mg (1.5 mmol) of phenyl(2,4-dimethylphenyl)phosphine were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 64%. Example 47

[0061] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 330 mg (1.5 mmol) of phenyl (4-fluorophenyl) phosphine were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 68%. Example 48

[0062] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 354 mg (1.5 mmol) of phenyl (4-chlorophenyl) phosphine were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 71%. Example 49

[0063] 52 mg (0.5 mmol) of styrene, 108 mg (1.0 mmol) of phenylhydrazine and 345 mg (1.5 mmol) of dibenzylphosphine were placed in a Schlenk tube under air, and then 2.0 mL of acetonitrile was added. o C was stirred and reacted for 12 hours under irradiation with a 12 W green LED light. After the reaction was completed, the product was separated and purified by column chromatography, and the yield of the target product was 68%.

[0064] As can be seen from the above examples, the method employed in the present invention for efficiently reacting styrene compounds with diaryl / alkyl-substituted phosphine oxides and aromatic hydrazines under photocatalysis to prepare the corresponding 2-arylhydrazono-substituted arylethylphosphine oxide compounds containing various substituted functional groups has the advantages of mild reaction conditions, readily available and inexpensive catalysts, and simple preparation. Furthermore, this method offers advantages such as wide substrate applicability and high yield, providing a highly efficient method for synthesizing 2-arylhydrazono-substituted arylethylphosphine oxide compounds containing various substituted functional groups.

[0065] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing a styrene compound having a structural formula by reacting a photocatalytic styrene compound with a diaryl / alkyl substituted phosphorus oxide and an aromatic hydrazine. （I） The preparation method of 2-arylhydrazone-substituted arylethylphosphine oxide compounds is as follows: （I） It is characterized by: The following steps are included: The reaction amount of styrene compound, aromatic hydrazine, diaryl / alkyl substituted phosphorus oxide, catalyst and organic solvent were placed in a reaction vessel under air atmosphere and mixed, and the mixture was heated at 25-100°C under irradiation of 12 W green LED light. o C and stirring for 3-12 hours to obtain the corresponding 2-arylhydrazone-substituted arylethylphosphine oxide compounds containing different substituted functional groups; in, The catalyst is Eosin Y and the organic solvent is acetonitrile; Ar 1 is selected from phenyl, 4-methylphenyl, 3-methylphenyl, 4-tert-butylphenyl, 4-methoxyphenyl, 4-fluorophenyl, 3-fluorophenyl, 4-chlorophenyl, 3-chlorophenyl, 4-bromophenyl, 3-bromophenyl, 4-trifluoromethylphenyl, and 2-naphthyl; Ar 2 is selected from phenyl, 4-methylphenyl, 3-methylphenyl, 2,5-dimethylphenyl, 4-ethylphenyl, 4-isopropylphenyl, 4-methoxyphenyl, 4-fluorophenyl, 4-chlorophenyl, 2-chlorophenyl, 4-bromophenyl, 3-bromophenyl, 2,4-dichlorophenyl, 4-iodophenyl, 4-trifluoromethylphenyl, 3-trifluoromethylphenyl, and 2-trifluoromethylphenyl; R 1 is selected from phenyl, 4-methylphenyl, 3-methylphenyl, 3,5-dimethylphenyl, 4-ethylphenyl, 4-butylphenyl, 4-tert-butylphenyl, 2,4-dimethylphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 4-fluorophenyl, 3-fluorophenyl, 4-chlorophenyl, 4-phenylphenyl, 3-phenylphenyl, 2-naphthyl, 1-naphthyl, and benzyl; R 2 is selected from phenyl, 4-methylphenyl, 3-methylphenyl, 3,5-dimethylphenyl, 4-ethylphenyl, 4-butylphenyl, 4-tert-butylphenyl, 2,4-dimethylphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 4-fluorophenyl, 3-fluorophenyl, 4-chlorophenyl, 4-phenylphenyl, 3-phenylphenyl, 2-naphthyl, 1-naphthyl, and benzyl.

2. The preparation method according to claim 1, characterized in that The styrene compound is selected from styrene, 4-methylstyrene, 3-methylstyrene, 4-tert-butylstyrene, 4-methoxystyrene, 4-fluorostyrene, 3-fluorostyrene, 4-chlorostyrene, 3-chlorostyrene, 4-bromostyrene, 3-bromostyrene, 4-trifluoromethylstyrene, and 2-naphthylene.

3. The preparation method according to claim 1, characterized in that The aromatic hydrazine compound is selected from phenylhydrazine, 4-methylphenylhydrazine, 3-methylphenylhydrazine, 2,5-dimethylphenylhydrazine, 4-ethylphenylhydrazine, 4-isopropylphenylhydrazine, 4-methoxyphenylhydrazine, 4-fluorophenylhydrazine, 4-chlorophenylhydrazine, 2-chlorophenylhydrazine, 4-bromophenylhydrazine, 3-bromophenylhydrazine, 2,4-dichlorophenylhydrazine, 4-iodophenylhydrazine, 4-trifluoromethylphenylhydrazine, 3-trifluoromethylphenylhydrazine, and 2-trifluoromethylphenylhydrazine.

4. The preparation method according to claim 1, characterized in that The diaryl / alkyl substituted phosphine oxide compound is selected from diphenyl phosphine oxide, di(4-methylphenyl)phosphine oxide, di(3-methylphenyl)phosphine oxide, di(3,5-dimethylphenyl)phosphine oxide, di(4-ethylphenyl)phosphine oxide, di(4-butylphenyl)phosphine oxide, di(4-tert-butylphenyl)phosphine oxide, di(2,4-dimethylphenyl)phosphine oxide, di(4-methoxyphenyl)phosphine oxide, di(3-methoxyphenyl)phosphine oxide, di(4-fluorophenyl)phosphine oxide, di(3-fluorophenyl)phosphine oxide, di(4-chlorophenyl)phosphine oxide, di(4-phenylphenyl)phosphine oxide, di(3-phenylphenyl)phosphine oxide, di(2-naphthyl)phosphine oxide, di(1-naphthyl)phosphine oxide, phenyl(2,4-dimethylphenyl)phosphine oxide, phenyl(4-fluorophenyl)phosphine oxide, phenyl(4-chlorophenyl)phosphine oxide, and dibenzylphosphine oxide.

5. The preparation method according to claim 1, characterized in that The molar ratio of the styrene compound to the aromatic hydrazine compound and the diaryl / alkyl substituted phosphine oxide compound is 1:[1.0-2.0]:[1.0-3.0]; the molar ratio of the styrene compound to Eosin Y is 1:[0.01-0.1].

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