Method for olefin hydroformylation using iridium-based catalyst

Abstract

Provided in the present invention is an iridium-based catalyst, which is characterized in that the chemical structural formula of the iridium-based catalyst is: ##STR00001## wherein Ph is a phenyl, R is a methyl or an ethyl, and X is one or more of CH.sub.3CO.sub.2, NO.sub.3, Cl, BF.sub.4, PF.sub.6 and SbF.sub.6. In the present invention, a rhodium-based catalyst in the prior art is replaced with the iridium-based catalyst, such that the reaction cost is reduced, and the yield of reactants is increased.

Claims

1. A method for olefin hydroformylation using an iridium-based catalyst, comprising the following steps: under a condition that the iridium-based catalyst is existed, olefins, carbon monoxide, and hydrogen are used as raw materials to perform a catalytic reaction; before the catalytic reaction, the iridium-based catalyst is dissolved in a solvent; the solvent is one of n-butyraldehyde, iso-butyraldehyde, toluene or tetraxofuran; characterized in that a chemical structural formula of the iridium-based catalyst is: ##STR00003## wherein Ph is a phenyl, R is a methyl or an ethyl, and X is one or more of CH.sub.3CO.sub.2, NO.sub.3, BF.sub.4, PF.sub.6 and SbF.sub.6; wherein a preparation method of the iridium-based catalyst comprises the following steps: mixing and stirring 4,5-bis(diphenylphosphoryl)-9,9-dimethylxanthene, solvent and iridium compound, and then heating and stirring to obtain the iridium-based catalyst; wherein a time for mixing and stirring 4,5-bis(diphenylphosphoryl)-9,9-dimethylxanthene, solvent and iridium compound is 2 h; wherein during the heating and stirring process, a temperature is raised to 50? C., and then stirring for 2 h; when X in the iridium-based catalyst is CH.sub.3CO.sub.2, NO.sub.3, BF.sub.4, PF.sub.6 or SbF.sub.6, the temperature is first raised and stirred to obtain a substance to be substituted, and then a compound containing an X-based group is added to replace the substance to be substituted.

2. The method for olefin hydroformylation according to claim 1, wherein a reaction temperature of the catalytic reaction is between 70?120? C.

3. The method for olefin hydroformylation according to claim 1, wherein a reaction temperature of the catalytic reaction is between 80? C.?110? C.

4. The method for olefin hydroformylation according to claim 1, wherein a reaction pressure of the catalytic reaction is 0.5 Mpa?3.0 Mpa.

5. The method for olefin hydroformylation according to claim 1, wherein a reaction pressure of the catalytic reaction is between 1.0 Mpa?2.0 Mpa.

6. The method for olefin hydroformylation according to claim 1, wherein a partial pressure ratio of the olefin to the carbon monoxide is 10:1-1:10.

7. The method for olefin hydroformylation according to claim 1, wherein a partial pressure ratio of the olefin to the carbon monoxide is 5:1-1:5.

8. The method for olefin hydroformylation according to claim 1, wherein a partial pressure ratio of the olefin to the hydrogen is 10:1-1:10.

9. The method for olefin hydroformylation according to claim 1, wherein a partial pressure ratio of the olefin to the hydrogen is 5:1-1:5.

10. The method for olefin hydroformylation according to claim 1, where a mass of the iridium-based catalyst is 0.005 wt %-2.0 wt % of a mass of the solvent.

11. The method for olefin hydroformylation according to claim 1, where a mass of the iridium-based catalyst is 0.05 wt %-1.0 wt % of a mass of the solvent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating preferred embodiments only and are not to be construed as limiting the present invention. Also, throughout the drawings, the same reference characters are used to designate the same components. In the drawings:

(2) FIG. 1 is a chromatogram of the reaction product in Embodiment 6 of the present invention.

(3) FIG. 2 is a chromatogram of the reaction product in Embodiment 10 of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) The schemes of the present invention will be described in detail below with reference to embodiments, however, those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. If the specific conditions are not specified in the embodiments, the conditions should be carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not indicated, they are all conventional products that can be purchased commercially.

Embodiment 1

(5) The preparation method of iridium-based catalyst is as follows:

(6) Synthesis of POP(CH.sub.3)IrCl: under nitrogen protection, 100 ml of tetrahydrofuran, 5.0 g of cyclooctadiene iridium chloride, and 8.6 g of 4,5-bis(diphenylphosphonyl)-9,9-dimethylxanthene are added into a 250 ml reaction bottle. Stirring and reacting at room temperature for 2 hours, and then raising the temperature to 50? C., and stirring and reacting for 2 hours. The solvent is evaporated to dryness, and the obtained solid is washed twice with 20 ml of n-hexane and dried to obtain 11.9 g of POP(CH.sub.3)IrCl.

Embodiment 2

(7) The specific operating steps are the same as those in Embodiment 1. The differences between them are that the mixing and stirring time is 1.5 h, the heating and stirring temperature is 40? C., and the stirring time is 1.5 h. Finally, 11.4 g of POP(CH.sub.3)IrCl is obtained.

Embodiment 3

(8) The specific operating steps are the same as those in Embodiment 1. The differences between them are that the mixing and stirring time is 3 h, the heating and stirring temperature is 60? C., and the stirring time is 3 h. Finally, 11.5 g of POP(CH.sub.3)IrCl is obtained.

Embodiment 4

(9) Synthesis of POP(CH.sub.3)IrNO.sub.3: 150 ml of tetrahydrofuran, 5.0 g of POP(CH.sub.3)IrCl prepared in Embodiments 1-3, 0.92 g of silver nitrate, and 20 ml of water are added into a 250 ml reaction bottle. Stirring and reacting at room temperature in the dark for 6 hours, and then the insoluble matter is filtered off. The solvent is evaporated to dryness, and the obtained solid is washed twice with 20 ml of n-hexane and dried to obtain 4.5 g of POP(CH.sub.3)IrNO.sub.3.

Embodiment 5

(10) Synthesis of POP(CH.sub.3)IrCH.sub.3CO.sub.2: 150 ml of tetrahydrofuran, 5.0 g of POP(CH.sub.3)IrCl prepared in Embodiments 1-3, 0.90 g of silver acetate, and 20 ml of water are added into a 250 ml reaction bottle. Stirring and reacting at room temperature in the dark for 6 hours, and then the insoluble matter is filtered off. The solvent is evaporated to dryness, and the obtained solid is washed twice with 20 ml of n-hexane and dried to obtain 4.6 g of POP(CH.sub.3)IrCH.sub.3CO.sub.2.

Embodiment 6

(11) The operating steps of the aldehyde reaction are as follows:

(12) The 81 mg of POP(CH.sub.3)IrCH.sub.3CO.sub.2 obtained from Embodiment 5 and 12 ml of toluene are added into a 50 ml high-pressure reaction kettle. After replacing it with hydrogen for three times, 3 bar of propylene, 8 bar of carbon monoxide, and 8 bar of hydrogen are added in sequence, and then the temperature is raised to 90? C. with stirring. Stirring and reacting it at this temperature for 8 hours, and the reaction solution is cooled to 0? C. After slowly releasing the pressure, samples are taken for gas chromatography analysis. According to the gas phase results, it can be calculated that the catalyst conversion number TON is 78.8, and the selectivity of n-butyraldehyde and iso-butyraldehyde is 99.8% (n-butyraldehyde/iso-butyraldehyde=29.1:1).

Embodiments 7-11

(13) The propylene hydroformylation reaction method of Embodiment 6 is adopted while changing different temperatures to carry out the reaction, and the results are shown in Table 1.

(14) TABLE-US-00001 TABLE 1 Effects of temperature on propylene hydroformylation reaction. Selectivity of n- n-buty- Catalyst butyraldehyde raldehyde/ Tem- conversion and iso- Embod- perature number iso-buty- buty- iment (? C.) TON raldehyde (%) raldehyde 7 70 29.6 99.8 19.8:1 8 80 51.1 99.7 23.1:1 9 100 123.6 99.5 16.9:1 10 110 162.1 99.6 14.3:1 11 120 192.7 99.5 12.0:1

Embodiments 12-17

(15) The propylene hydroformylation reaction method of Embodiment 6 is adopted while changing the pressure of gas, and the results are shown in Table 2.

(16) TABLE-US-00002 TABLE 2 Effects of pressure on propylene hydroformylation reaction. Catalyst Selectivity of n- Reaction conversion butyraldehyde and pressure Propylene CO H.sub.2 number iso-butyraldehyde n-butyraldehyde/ Embodiment (MPa) (bar) (bar) (bar) TON (%) iso-butyraldehyde 12 0.5 3 1 1 35.3 99.5 26.1:1 13 1.0 2 4 4 53.5 99.6 26.7:1 14 2.2 2 10 10 110.9 99.5 22.5:1 15 1.4 10 2 2 36.6 99.7 26.5:1 16 2.0 10 5 5 93.1 99.5 23.2:1 17 3.0 14 8 8 50.1 99.3 22.4:1

Comparative Example 1

(17) Other operating steps are the same as those in Embodiment 6, and the differences between them are that: the catalyst used is tris[2,4-di-tert-butylphenyl] phosphite-rhodium disclosed in the patent CN111348995A. The results are as follows:

(18) TABLE-US-00003 TABLE 3 Effects of different catalysts on hydroformylation reaction. Catalyst Selectivity of n- conversion butyraldehyde and n-butyraldehyde/ number TON iso-butyraldehyde (%) iso-butyraldehyde Embodiment 6 78.8 99.8 29.1:1 Comparative 60.2 98.5 25.4:1 Example 1

(19) As can be seen from the above tables that: during the process of using the iridium-based catalyst for hydroformylation reaction, the hydroformylation reaction is best when the temperature is 80? C. and the propylene gas pressure is 3 bar, and the present invention obtains the highest n-butyraldehyde/iso-butyraldehyde ratio of 29.1:1. This shows that the present invention still has good reaction selectivity and reaction conversion rate under low temperature and low pressure conditions. By comparing with the rhodium-based catalyst of Comparative Example 1, it can be known that the new catalyst of the present invention not only reduces the cost, but also has better catalytic effect than the traditional catalyst.

(20) Therefore, the present invention adopts a new iridium-based catalyst to conduct the catalytic reaction and explores the reaction conditions, thereby realizing the reaction under the conditions of low energy consumption and good reaction efficiency.

(21) Finally, it should be noted that the above embodiments are merely used to illustrate the technical schemes of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the above-mentioned embodiments, those of ordinary skill in the art should understand that they can still modify the technical schemes recorded in the above-mentioned embodiments or make equivalent substitutions for some or all of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical scheme to depart from the scope of the technical scheme of each embodiment of the present invention.