Method of preparing gamma-ketene from alpha, gamma-unsaturated diketene

A technology for unsaturated and dienone, applied in the field of preparing γ-ketene, can solve the problems of high selectivity and yield of target product, large amount of catalyst, complicated operation, etc. Small volume and simple operation

Active Publication Date: 2020-03-27
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It solves the shortcomings of large amount of catalyst used, high cost, and complicated operation in the prior art, and can realize the silicon hydrogen reduction of α, γ-unsaturated dienone to obtain γ-enone and the reaction operation with a catalyst with low cost and small amount Simple, target product selectivity and high yield

Method used

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  • Method of preparing gamma-ketene from alpha, gamma-unsaturated diketene
  • Method of preparing gamma-ketene from alpha, gamma-unsaturated diketene
  • Method of preparing gamma-ketene from alpha, gamma-unsaturated diketene

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Experimental program
Comparison scheme
Effect test

Embodiment 1-18

[0039] Selective hydrogenation of β-ionone to dihydro-β-ionone:

[0040] Add tetrakis(triphenylphosphine)palladium (176.87mg, 0.15mmol), triethoxysilane (55.32g, 0.33mol), lanthanum trifluoromethanesulfonate (358.84mg, 0.6mmol) into a 500mL autoclave and tetrahydrofuran (176.60g), the reactor is sealed, and replaced with nitrogen three times, and the nitrogen pressure in the reactor is 0MPa (gauge pressure). Under the protection of nitrogen, pump β-ionone (58.87g, 0.3mol) into the autoclave with an advection pump, turn on the stirring device and heating device of the autoclave, and start timing when the inner temperature of the autoclave reaches 40°C , keep the reaction for 3 hours, take samples for analysis, and detect the conversion rate of β-ionone and the selectivity of dihydro-β-ionone by GC.

[0041] When carrying out embodiment 2-6, monohydrosilane is triethoxysilane, solvent is tetrahydrofuran, and Lewis acid is lanthanum trifluoromethanesulfonate, with respect to embod...

Embodiment 19

[0048] Selective hydrogenation of β-ionone to dihydro-β-ionone:

[0049] Add tetrakis(triphenylphosphine)palladium (35.37mg, 0.03mmol), triethoxysilane (150.8g, 0.9mol), lanthanum trifluoromethanesulfonate (897.11mg, 1.5mmol) into a 1000mL autoclave and tetrahydrofuran (176.60g), the reactor is sealed, and replaced with nitrogen three times, and the nitrogen pressure in the reactor is 0MPa (gauge pressure). Under nitrogen protection, β-ionone (58.87g, 0.3mol) is pumped into the autoclave with a convection pump, and the autoclave stirring device and heating device are turned on. When the inner temperature of the autoclave reaches 60°C, start timing. After incubation and reaction for 6 hours, sample analysis was carried out. GC detection showed that the conversion rate of β-ionone was 98.92%, and the selectivity of dihydro-β-colorone was 98.19%.

Embodiment 20

[0051] Selective hydrogenation of β-ionone to dihydro-β-ionone:

[0052] Add tetrakis(triphenylphosphine)palladium (353.75mg, 0.3mmol), triethoxysilane (50.29g, 0.3mol), lanthanum trifluoromethanesulfonate (179.42mg, 0.3mmol) into a 1000mL autoclave and tetrahydrofuran (294.34g), the reactor was sealed, and replaced three times with nitrogen, and the nitrogen pressure in the reactor was 0MPa (gauge pressure). Under nitrogen protection, β-ionone (58.87g, 0.3mol) was pumped into the autoclave with a convection pump, and the high-pressure autoclave stirring device was turned on. The inner temperature of the autoclave was 20°C, and the temperature was kept for 1 hour, and the sample was analyzed. GC detection showed that the conversion rate of β-ionone was 99.92%, and the selectivity of dihydro-β-ionone was 97.26%.

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Abstract

The invention provides a method of preparing gamma-ketene from alpha, gamma-unsaturated diketene. According to the method, single hydrogen silane is used as a silicon hydrogen reducing agent, a palladium complex is used as a catalyst, a Lewis acid is used as an auxiliary agent, and alpha, gamma-unsaturated diketene are subjected to silicon hydrogen reduction reactions to obtain gamma-ketene through a one-step method. The method has the advantages of mild conditions, simple operation, high product selectivity and yield, cheap and easily available silicon hydrogen reducing agent, high catalystactivity, little using amount, and low cost, and has potential of industrial scale-up.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a method for preparing gamma-enone from alpha, gamma-unsaturated dienone. Background technique [0002] Selective reduction of α, β-carbon-carbon double bonds of conjugated α, γ-dienones is an important class of reactions, which can obtain a series of high value-added fine chemical products, such as selective reduction of 6-methyl-3 , the α, β-carbon-carbon double bond of 5-heptadien-2-one can get 6-methyl-5-hepten-2-one, which is linalool, citral, citronellal, An important synthetic intermediate of spices such as ionone; while β-ionone selectively reduces α, β-carbon-carbon double bonds to obtain dihydro β-ionone, which is a key intermediate for the synthesis of ambergris. Because α,γ-dienone contains three unsaturated double bonds, there are many different hydrogenation products in theory, and it is extremely challenging to control the selectivity of this type of r...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C49/21C07C45/62
CPCC07C45/62C07C49/21
Inventor 沈稳黄文学于斌成谢硕张永振黎源
Owner WANHUA CHEM GRP CO LTD
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