Method for preparing phosphino compound through catalysis of organic iodine compound

Abstract

The invention discloses a method for preparing a phosphino compound through catalysis of an organic iodine compound, and belongs to the field of organic chemical synthesis, and the method comprises the following steps: adding pyrophosphorous acid and organic iodine into a phosphine oxide (sulfur) compound Y, fully stirring and mixing, heating, carrying out a heat preservation reaction, and carrying out water washing, liquid separation, extraction and purification to obtain a phosphino compound X; wherein the molar ratio of the pyrophosphorous acid to the phosphine oxide (sulfur) compound is (1-2): 1; and the molar percentage of the added catalyst organic iodine is 0.1-10 mol%. According to the method, organic iodine is introduced as a catalyst, so that the use amount of pyrophosphorous acid is remarkably reduced, and the production cost is effectively reduced; in addition, the phosphino compound prepared by the method has relatively high yield and shows remarkable industrial application potential.

Description

Technical Field

[0001] The invention relates to the field of organic chemical synthesis, and more specifically to a method for preparing a phosphine-based compound by catalysis of an organic iodine compound. Background Art

[0002] In the process of preparing phosphine-based compounds, the reduction method of traditional iodine, diphenyl phosphite and trimethyl phosphite often requires a large amount of iodine. Although such a method is effective, iodine is expensive, toxic, and difficult to recycle after the reaction. In addition, iodine has a strong corrosive effect on production equipment, which not only leads to an increase in production cost but also causes environmental pollution, and this feature limits its application in large-scale industrial production.

[0003] In order to solve this problem, the Chinese patent with publication number CN117866009A published on April 12, 2024, provides a method for preparing phosphine-based compounds based on pyrophosphorous acid;The method reduces the usage of iodine by the addition of pyrophosphorous acid. Although this method can reduce the consumption of iodine to a certain extent, it is impossible to fundamentally solve the above-mentioned defects of using iodine. In addition, since iodine is volatile when heated, it will have an adverse effect on the reduction reaction of phosphine oxide (sulfur) compounds, thereby reducing the yield and selectivity of phosphine-based compounds.

[0004] Therefore, there is an urgent need to provide an economical and efficient method for preparing phosphine-based compounds without using elemental iodine, which aims to reduce the amount of pyrophosphorous acid used while improving the reaction conversion rate and reaction selectivity to achieve cost-effectiveness and environmental sustainability. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the inventors conducted in-depth research on catalysts and unexpectedly found that organic iodine compounds containing CI bonds can catalyze the reduction reaction more efficiently. Therefore, the present invention provides a method for preparing phosphine-based compounds by catalysis of organic iodine compounds. The method uses an organic iodine catalyst, which can not only avoid the problems of corrosion and recovery caused by iodine, but also greatly reduce the amount of pyrophosphorous acid used, effectively reducing production costs; in addition, the yield of phosphine-based compounds prepared using this method is higher.

[0006] To solve the above problems, the present invention adopts the following technical solutions.

[0007] A method for preparing a phosphine-based compound by catalysis of an organic iodine compound, comprising adding pyrophosphorous acid and organic iodine to a phosphine oxide (sulfur) compound Y, fully stirring and mixing, heating, and heat preservation for reaction, followed by water washing, liquid separation, extraction, and purification to obtain a phosphine-based compound X;

[0008] The molar ratio of the phosphine oxide (sulfur) compound to the pyrophosphorous acid is 1-2:1; and the added molar percentage of the catalyst organic iodine is 0.1-10 mol%.

[0009] Further, the organic iodine is diiodomethane, benzyl iodide, isopropyl iodide, methyl iodide, 1-iodobutane, 1-iodooctane, iodobenzene, (1-iodoethyl)benzene, tert-butyl iodide, iodoform, tetraiodomethane, methyltriphenylphosphonium iodide or tetraphenylphosphonium iodide.

[0010] Furthermore, the organic iodine is diiodomethane, benzyl iodide, isopropyl iodide, methyl iodide, 1-iodobutane, 1-iodooctane, iodobenzene, (1-iodoethyl)benzene or tert-butyl iodide.

[0011] Furthermore, the heating is performed to a temperature of 130-150°C.

[0012] Furthermore, the reaction time is 5 to 20 hours.

[0013] Furthermore, an organic solvent is added, and the organic solvent is a mixture of one or more of benzene, toluene and p-xylene.

[0014] Furthermore, the added molar percentage of the organic iodine is 0.5 to 3.0 mol%.

[0015] Furthermore, the added molar percentage of the organic iodine is 1.0-2.0 mol%.

[0016] Furthermore, the reaction takes place under a nitrogen atmosphere.

[0017] Furthermore, the phosphine oxide (sulfur) compound Y contains an aromatic group.

[0018] Furthermore, the structural formula of the phosphine oxide (sulfur) compound Y is When the phosphine compound X is The reaction equation is:

[0019] When the structure of the phosphine oxide (sulfur) compound Y is When the structural formula of the phosphine compound X is When

[0020] wherein Z is selected from O or S;

[0021] R 1 , R 2 , R 3 Each is independent; R 1 and R 2 are all aromatic; R 3 is selected from cycloalkyl, alkyl, aryl or alkyl substituted by aryl;

[0022] R 4 It is selected from cycloalkyl, alkyl, aryl or alkyl substituted by aryl.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] First, the present invention uses organic iodine to replace iodine as a catalyst, which can not only effectively reduce the generation of harmful byproducts, but also reduce the risk of corrosion to production equipment. In addition, the method can also greatly improve the yield of the product. Since organic iodine is not easily volatilized by heat, it not only reduces the amount of organic iodine used as a catalyst, but also maintains its catalytic efficiency and reduces the amount of pyrophosphorous acid in a high temperature environment. DETAILED DESCRIPTION

[0025] Embodiment 1:

[0026] Preparation of the phosphine compound triphenylphosphine Ph3P: Under the protection of nitrogen, triphenylphosphine oxide Ph3P(O) (1.0 g, 3.59 mmol), benzyl iodide (0.0157 g, 0.0718 mmol), pyrophosphorous acid H4P2O5 (0.524 g, 3.59 mmol) and p-xylene (5.0 mL) were placed in a 50 mL Schlenk tube, heated to 100 ° C, and kept warm for 16 h. After the reaction, water (5 mL) was added to the reaction solution, followed by extraction with ethyl acetate to obtain an organic phase. The concentrated organic phase was subjected to silica gel column chromatography under nitrogen protection to obtain triphenylphosphine Ph3P (0.556 g, 2.12 mmol) with a yield of 59%.

[0027] Example 2-Example 27:

[0028] On the basis of Example 1, different organic iodine was added as catalyst, and the amount of catalyst, the molar ratio of pyrophosphorous acid H4P2O5 and triphenylphosphine oxide Ph3P(O), reaction temperature and reaction time were adjusted to obtain triphenylphosphine Ph3P.

[0029] Table 1 Different reaction conditions and yields of preparing triphenylphosphine Ph3P using triphenylphosphine oxide, pyrophosphorous acid and organic iodine

[0030]

[0031]

[0032] It can be seen from Examples 1 to 5 that, under the same conditions, the reaction temperature is changed; it can be seen from Example 3 that when the reaction temperature is 130°C, the yield is 81%; it can be seen from Example 4 that when the temperature is 150°C, the yield is 93%; it can be seen from Example 5 that when the temperature is 170°C, the yield is 73%; therefore, the reaction temperature of 150°C is the optimal reaction temperature, and increasing or decreasing the reaction temperature cannot increase the yield; therefore, the preferred reaction temperature is 130-150°C.

[0033] It can be seen from Examples 3 and 6 to 13 that under the same conditions, the type of catalyst is changed. It can be seen from Example 13 that when the catalyst is diiodomethane, the yield is the highest, which can reach 91%; and it can be seen from Example 10 that when the catalyst is iodobenzene, the yield is the lowest, which is 8%. When the catalyst is other organic iodine except diiodomethane, the yield cannot be improved, so the catalyst is most preferably diiodomethane.

[0034] It can be seen from Examples 13 and 14 that under the same conditions, the reaction temperature is changed: from Example 13, when the temperature is 130°C and the catalyst is diiodomethane, the yield can reach 91%; from Example 14, when the temperature is 150°C and the catalyst is diiodomethane, the yield can reach 93%. Therefore, one of the best reaction conditions for preparing phosphine-based compounds using organic iodine catalysis is: the reaction temperature is 150°C, the catalyst is diiodomethane and the amount of diiodomethane added is 2 mol%.

[0035] It can be seen from Example 14 to Example 16 that under the same conditions, when the reaction time is changed and the temperature is 150°C, the optimal reaction time is 16 h, and extending or shortening the reaction time cannot increase the yield.

[0036] It can be seen from Examples 13, 17 and 19 that under the same conditions, the amount of diiodomethane used is changed: from Example 18, when the amount of catalyst diiodomethane is reduced to 1.0 mol%, the yield can reach 90%; from Example 17, it can be seen that the amount of diiodomethane is further reduced to 0.5 mol%, and the yield of the final product drops sharply to 71%; from Example 19, it can be seen that the yield cannot be improved by further increasing the amount of catalyst diiodomethane. Therefore, the amount of catalyst diiodomethane is 1.0-2.0 mol%; the added amount is preferably 2.0 mol%.

[0037] It can be seen from Example 20-Example 21 that when the molar ratio of pyrophosphorous acid and triphenylphosphine oxide is 1:2, under the same conditions, the reaction temperature is changed: from Example 20, when the reaction temperature is 130°C, the yield is 60%; from Example 21, when the reaction temperature is 150°C, the yield is 66%; therefore, the reaction temperature is preferably 150°C.

[0038] It can be seen from Example 14 and Example 21 that, under the same conditions, reducing the molar ratio of pyrophosphorous acid to triphenylphosphine oxide cannot increase the yield.

[0039] It can be seen from Examples 21 to 26 that, under the same conditions, the molar ratio of pyrophosphorous acid to triphenylphosphine oxide is 1:2, the amount of catalyst used is 2.0 mol%, and the type of catalyst is changed: it can be seen from Example 24 that when the catalyst is tetraiodomethane, the yield is 34%; it can be seen from Example 21 that when the catalyst is diiodomethane, the yield is 66%; when the catalyst is other organic iodine except diiodomethane, the yield cannot be improved.

[0040] Example 27-Example 29:

[0041] Preparation of phosphine compounds using different phosphine oxide (sulfur) compounds:

[0042] On the basis of the optimal embodiment 14 among embodiments 1 to 27, different phosphine oxide compounds and phosphine sulfur compounds, pyrophosphorous acid and phosphine oxide (sulfur) compounds with a molar ratio of 1:1, 2 mol% of the catalyst diiodomethane and 5 mL of p-xylene solvent were selected respectively, and the reaction was kept warm at 150°C for 16 hours to obtain the corresponding phosphine-based compounds.

[0043] The reaction conditions of Example 27 to Example 29 were used to prepare Table 2: Different reactions for preparing phosphine-based compounds using diiodomethane and different phosphine oxide (sulfur) compounds.

[0044] Table 2 Different reaction conditions and yields of phosphine-based compounds prepared using different phosphine oxide (sulfur) compounds

[0045]

[0046]

[0047] It can be seen from Example 15 and Example 27 to Example 29 that Z can be O or S. Therefore, it can be further inferred that both phosphine oxide compounds and phosphine sulfur compounds can be reduced in the H4P2O5 / organic iodine system to prepare phosphine compounds.

[0048] Example 30-Example 31:

[0049] On the basis of the optimal embodiment 14 among embodiments 1 to 27, different phosphine oxide compounds containing multiple phosphine oxide bonds, pyrophosphorous acid and phosphine oxide compounds with a molar ratio of 1:1, 2 mol% of the catalyst diiodomethane and 5 mL of p-xylene solvent were selected respectively, and the reaction was kept warm at 150°C for 16 hours to obtain the corresponding phosphine-based compounds.

[0050] Table 3 Different reaction conditions and yields using diiodomethane and phosphine oxide compounds containing multiple phosphine oxide bonds

[0051]

[0052]

[0053] It can be seen from Example 30 and Example 31 that under the same conditions, reacting at 150°C for 16 hours in the presence of 2 mol% diiodomethane can effectively promote the generation of phosphine-based compounds from phosphine oxide compounds containing multiple phosphine oxide groups, and both have relatively high yields.

[0054] Comparative Example 1:

[0055] Preparation of phosphine compound triphenylphosphine Ph3P: Under the protection of nitrogen, triphenylphosphine oxide Ph3P(O) (1.0 g, 3.59 mmol), iodine I2 (0.03 g, 0.15 mol), pyrophosphorous acid H4P2O5 (0.524 g, 3.59 mmol) and p-xylene (5.0 mL) were placed in a 50 mL Schlenk tube, heated to 150 ° C, and kept warm for 16 hours. After the reaction, water (5 mL) was added to the reaction mixture, followed by extraction with ethyl acetate to obtain an organic phase. The concentrated organic phase was subjected to silica gel column chromatography under nitrogen protection to obtain triphenylphosphine Ph3P with a yield of 15%.

Claims

1. A method for preparing a phosphine-based compound by catalysis of an organic iodine compound, characterized in that: The process comprises adding pyrophosphorous acid and organic iodine to a phosphine oxide (sulfur) compound Y, fully stirring and mixing, heating, keeping the mixture warm for reaction, washing with water, separating the liquids, extracting, and purifying to obtain a phosphine compound X; The molar ratio of the phosphine oxide (sulfur) compound to the pyrophosphorous acid is 1-2:1; and the added molar percentage of the catalyst organic iodine is 0.1-10 mol%.

2. The method for preparing a phosphine-based compound by catalysis of an organic iodine compound according to claim 1, characterized in that: The organic iodine is diiodomethane, benzyl iodide, isopropyl iodide, methyl iodide, 1-iodobutane, 1-iodooctane, iodobenzene, (1-iodoethyl)benzene, tert-butyl iodide, iodoform, tetraiodomethane, methyltriphenylphosphonium iodide or tetraphenylphosphonium iodide.

3. The method for preparing a phosphine-based compound by catalysis of an organic iodine compound according to claim 2, characterized in that: The organic iodine is diiodomethane, benzyl iodide, isopropyl iodide, methyl iodide, 1-iodobutane, 1-iodooctane, iodobenzene, (1-iodoethyl)benzene or tert-butyl iodide.

4. The method for preparing a phosphine-based compound by catalysis of an organic iodine compound according to claim 1, characterized in that: The heating temperature is 130-150° C. and the reaction time is 5-20 hours.

5. The method for preparing a phosphine-based compound by catalysis of an organic iodine compound according to claim 1, characterized in that: An organic solvent is also added, and the organic solvent is a mixture of one or more of benzene, toluene and p-xylene.

6. The method for preparing a phosphine-based compound by catalysis of an organic iodine compound according to claim 1, characterized in that: The added molar percentage of the organic iodine is 0.5-3.0 mol%.

7. The method for preparing a phosphine-based compound by catalysis of an organic iodine compound according to claim 6, characterized in that: The added molar percentage of the organic iodine is 1.0-2.0 mol%.

8. The method for preparing a phosphine-based compound by catalysis of an organic iodine compound according to claim 1, characterized in that: The reaction took place under nitrogen atmosphere.

9. The method for preparing a phosphine-based compound by catalysis of an organic iodine compound according to claim 1, characterized in that: The phosphine oxide (sulfur) compound Y contains an aromatic group.

10. The method for preparing phosphine-based compounds by catalysis of organic iodine compounds according to claim 1, characterized in that: The structural formula of the phosphine oxide (sulfur) compound Y is When the phosphine compound X is The reaction equation is When the structure of the phosphine oxide (sulfur) compound Y is When the structural formula of the phosphine compound X is When wherein Z is selected from O or S; R 1 , R 2 , R 3 Each is independent; R 1 and R 2 are all aromatic; R 3 is selected from cycloalkyl, alkyl, aryl or alkyl substituted by aryl; R 4 It is selected from cycloalkyl, alkyl, aryl or alkyl substituted by aryl.

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