JPS637532B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for producing α,β-unsaturated carbonyl compounds, and more specifically, to a method for producing α,β-unsaturated carbonyl compounds by a novel reaction using alkenylsilyl ether and allyl carbonate as starting materials. Relating to a method of manufacturing. Unsaturated carbonyl compounds such as cyclopentenone derivatives, cyclohexenone derivatives, cyclododecenone derivatives, etc. are useful chemical substances in the fields of fragrances, medicines, chemicals, etc. As a method for synthesizing such unsaturated carbonyl compounds, a method using isomerization of a compound having an extracyclic double bond such as alkylidene cyclopentanone has been known (for example, in JP-A No. 51
In this case, the reactivity was not uniform depending on the type of side chain, and it was practically unsuitable for the synthesis of compounds having unsaturated bonds in the side chains such as alkenylcyclopentenones. Therefore, the present inventors conducted intensive studies to develop a method that would enable the synthesis of the desired unsaturated carbonyl compound regardless of the type of side chain.
We have discovered a new reaction using alkenylsilyl ether and allyl carbonate as starting materials, and have completed the present invention. Thus, according to the present invention, an alkenylsilyl ether and an allyl carbonate represented by the following general formula [] are prepared from a platinum group metal compound and an α,ω-alkylene di(disubstituted) phosphine (hereinafter abbreviated as ADP). Provided is a method for producing an α,β-unsaturated carbonyl compound represented by the following general formula [], which comprises contacting the compound in the presence of a catalyst consisting essentially of the following: (In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are hydrogen or hydrocarbon residues, X is a trihydrocarbylsilyl group, and R ₁ , R ₂ , R ₃ and R ₄ are chain-like In the present invention, an alkenylsilyl ether represented by the general formula [ ] is used as the first starting material. In the formula, R ₁ is a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group, a pentyl group, etc., or a ring such as a cyclopentane ring, a cyclohexane ring, a cyclododecane ring by bonding with R ₂ , R ₃ or R ₄ Refers to the forming alkylene group or aryl group such as phenyl group, trityl group, etc., and R ₂ , R ₃ and R ₄ mean a hydrogen atom or the same alkyl group, alkylene group, or aryl group as R ₁ . , and further, X means a trihydrocarbylsilyl group. Among the above substituents, R ₁ , R ₂ , R ₃ and R ₄ may each form a ring in any combination. As a specific example, for example 1-
Cyclohexenyltrimethylsilyl ether, 1
-cyclopentenyltrimethylsilyl ether,
2-Methyl-1-cyclohexenyltrimethylsilyl ether, 6-methyl-1-cyclohexenyltrimethylsilyl ether, 1-cyclododecenyltrimethylsilyl ether, 1-cyclohexenyltriethylsilyl ether, 1-cyclohexenyltripropylsilyl ether, 2 -Pentenyl-1-cyclohexenyltrimethylsilyl ether, 2-propyl-1-cyclohexenyltrimethylsilyl ether, 2-pentyl-1-
Cyclohexenyltrimethylsilyl ether, 2
-Pentyl-1-cyclopentenyl trimethylsilyl ether, 2-pentenyl-1-cyclopentenyl trimethylsilyl ether, 2-pentynyl-1-cyclopentenyl trimethylsilyl ether, 1-phenyl-1-putenyl trisilyl ether, 1-propenyl trimethylsilyl ether, 1-hexenyltrimethylsilyl ether,
Examples include 2-methyl-1-butenyltrimethylsilyl ether, 3-methyl-1-butenyltrimethylsilyl ether, and 3-phenyl-1-propenyltrimethylsilyl ether. These compounds can be synthesized by conventional methods; for example, 1-cyclohexenyltrimethylsilyl ether can be easily synthesized by reacting cyclohexanone and trimethylsilyl chloride in the presence of a base. can. The allyl carbonate ester used as the second starting material is a carbonate ester having at least one allyl residue, and usually has the following general formula []
This is a compound represented by (In the formula, R ₅ represents a hydrocarbon residue, R ₆ , R ₇ ,
R ₈ and R ₉ represent hydrogen or hydrocarbon residues. ) Specific examples of such compounds include diallyl carbonate, dicrotyl carbonate, dimethallyl carbonate, methylallyl carbonate, ethylallyl carbonate, propylallyl carbonate, butylallyl carbonate, pentylallyl carbonate, methylcrotyl carbonate, ethylmethallyl carbonate, and the like. Among these, allyl esters, crotyl esters, and methallyl esters in which R ₅ is a lower alkyl group or lower alkenyl group having 4 or less carbon atoms are preferred. In the present invention, a catalyst consisting essentially of a platinum group metal compound and ADP is used in the reaction. The platinum group metal compound is a salt or complex of palladium, platinum, rhodium, iridium, or ruthenium, and any compound that can form a complex with ADP can be used. Specific examples of such compounds include tris(tribenzylideneacetylacetone)dipalladium(0), tris(tribenzylideneacetylacetone)tripalladium(0),
Examples include palladium acetate, palladium acetylacetonate, palladium nitrate, palladium sulfate, palladium chloride, and the like. When using a strong inorganic acid salt among these compounds, it is desirable to coexist a base such as potassium acetate, sodium alcoholate, or tertiary amine. Among the platinum group metals, palladium is particularly preferred in terms of reactivity.
Among these, it is preferable to use zero-valent compounds or divalent organic compounds. On the other hand, specific examples of ADP include α,
β-ethylenedi(diphenyl)phosphine, α,
β-ethylene di(diethyl)phosphine, α, β
-ethylene di(dibutyl)phosphine, α, β-
Ethylene di(butylphenyl) phosphine, α,
γ-propylene di(diphenyl)phosphine,
Examples include α, δ-butylene di(diphenyl)phosphine, among which α, β-ethylene diphosphine, especially α, β-ethylene di(diphenyl) phosphine is used. Incidentally, α,β-ethylenedi(diphenyl)phosphine is represented by the following structural formula. (In the formula, Ph represents a phenyl group.) The ratio of these two components to be used is selected as appropriate, but
Usually, the amount of ADP is 0.5 mol or more, preferably 0.7 to 1.5 mol per 1 mol of platinum group metal compound, and the catalyst consisting of these two components has a ratio such that the platinum group metal compound is usually 0.01 to 10 mol per 100 mol of raw material. used in Although these two components may be reacted in advance, the catalyst is usually prepared by bringing both components into contact in a reaction system. The reaction of the present invention proceeds easily by bringing two starting materials into contact with a catalyst. For example, the reaction formula when 1-cyclohexyltrimethylsilyl ether and diallyl carbonate are used as starting materials is as follows. The ratio of raw materials used is 1 part alkenyl silyl ether
The amount of allyl carbonate ester is usually 0.8 to 5 moles, preferably 1 to 2 moles per mole, the reaction temperature is usually 50°C or higher, preferably 60 to 150°C, and the reaction time is usually 10 minutes to 10 hours. Further, during the reaction, it is preferable to have a diluent present from the viewpoint of improving selectivity, and specific examples thereof include acetonitrile, propionitrile, benzonitrile, dimethylformamide, dioxane, and the like. These diluents are usually used in proportions such that the concentration of the starting materials is 1 to 50% by weight. After the reaction is completed, a highly purified α,β-unsaturated carbonyl compound, i.e., α,β-unsaturated ketone or α,β-unsaturated aldehyde, is obtained by separating the target product from the reaction solution using a conventional method. can get. Such unsaturated carbonyl compounds are used as intermediates for the synthesis of various useful compounds, particularly for perfumes, medicines, and the like. Thus, according to the present invention, an α,β-unsaturated carbonyl compound can be efficiently produced by utilizing a novel reaction. The present invention will be explained in more detail below by giving examples. Example 1 1-Cyclohexenyltrimethylsilyl ether in a container

[Formula] 2 moles of diallyl carbonate, 8 moles of acetonitrile, 0.05 moles of palladium acetate, and 0.05 moles of α,β-ethylenedi(diphenyl)phosphine are charged per mole;
After stirring rapidly at room temperature, the temperature was raised to the boiling point of the solvent, and the reaction was carried out under reflux in an argon atmosphere for 1 hour. After the reaction was completed, the product was distilled under reduced pressure according to a conventional method, and as a result, 2-cyclohexen-1-one was 87
% yield. Note that these compounds were identified using IR, NMR, and mass spectra. Examples 2 to 6 Reactions were carried out in the same manner as in Example 1 except that the compounds shown in Table 1 were used as starting materials. The results are shown in Table 1.

【table】

[Table] Example 9 A reaction was carried out in the same manner as in Example 1 except that the amount of catalyst used was reduced to 1/5 and the reaction time was extended to 5 hours.
The yield of 1-one was 60%. Example 10 A reaction was carried out according to Example 1 except that palladium acetylacetonate was used in place of palladium acetate, and almost the same results as in Example 1 were obtained. Example 11 A reaction was carried out according to Example 2 except that tris(dibenzylideneacetone)dipalladium (0) was used in place of palladium acetate, and almost the same results as in Example 2 were obtained. Example 12 The reaction was carried out in accordance with Example 1 except for using 1-cyclopentenyltrimethylsilyl ether as a raw material and changing the solvent from acetonitrile to benzonitrile. 2-cyclopenten-1-one was obtained in a yield of 70%. obtained at a rate. Example 13 A reaction was carried out according to Example 1 except that α, γ-propylene di(diphenyl) phosphine was used in place of α, β-ethylene di(diphenyl) phosphine, and 2-cyclohexen-1-one was obtained. Obtained with a yield of 70%.

Claims (1)

[Claims] 1. General formula [] (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are hydrogen or hydrocarbon residues, X is a trihydrocarbylsilyl group, and R ₁ , R ₂ , R ₃ and R ₄ are chain-like and Alkenyl silyl ethers and allyl carbonates represented by A general formula characterized by contacting in the presence of a catalyst consisting of [] A method for producing an α,β-unsaturated carbonyl compound represented by the formula (wherein R ₁ , R ₂ , R ₃ and R ₄ are the same as above).