Process for double carbonylation of allyl ethers to corresponding diesters
View Patent ↗The invention relates to a process for doubly carbonylating allyl ethers to the corresponding diesters, wherein a linear or branched allyl ether is reacted with a linear or branched alkanol (alcohol) with supply of CO and in the presence of a catalytic system composed of a palladium complex and at least one organic phosphorus ligand and in the presence of a hydrogen halide selected from HCl, HBr and HI.
1. Process for doubly carbonylating allyl ethers to diesters, comprising: reacting, in a single step, a linear or branched allyl ether with a linear or branched alkanol with supply of CO and in the presence of a catalytic system composed of a palladium complex and at least one organic phosphorus ligand and in the presence of a hydrogen halide selected from HCl, HBr and HI,
wherein both the allyl portion and the ether portion of the allyl ether are reacted with the CO.
2. Process according to claim 1 ,
characterized in that the allyl ethers are compounds of the general formula (1):
where R 1 , R 2 and R 3 are independently hydrogen or a C 1 to C 10 alkyl radical and
R′ is hydrogen, or a saturated or unsaturated, branched or unbranched, aliphatic, cycloaliphatic or cycloaliphatic-aliphatic hydrocarbyl radical having up to 12 carbon atoms, in which C—C bonds may be interrupted by oxygen or the —O—CO— group, or a phenyl radical, where the phenyl radical may be substituted as follows: C 1 - to C 10 -alkyl or C 1 - to C 10 -alkoxy groups,
R″ is a saturated or unsaturated, branched or unbranched, aliphatic, cycloaliphatic, araliphatic or cycloaliphatic-aliphatic hydrocarbyl radical having up to 12 carbon atoms, in which C—C bonds may be interrupted by oxygen or the —O—CO— group.
3. Process according to claim 1 ,
characterized in that the alkanols are compounds of the general formula ROH where R is a C 1 - to C 10 -alkyl, a C 4 - to C 20 -cycloalkyl or a C 7 - to C 11 -aralkyl group.
4. Process according to claim 1 ,
characterized in that the reaction is conducted in the liquid phase at a temperature of 70 to 250° C.
5. Process according to claim 1 ,
characterized in that reaction is conducted under a pressure of 2 to 100 bar.
6. Process according to claim 1 ,
characterized in that the palladium complex is formed in situ proceeding from a pre-complex, using, as palladium source, palladium-containing salts and complexes as precursor.
7. Process according to claim 6 ,
characterized in that the palladium complex is selected from the group comprising Pd acetates, Pd acetonates, Pd halides and Pd halide complexes, and also Pd-halogen-1,5-cyclooctadienes, Pd nitrates and Pd oxide.
8. Process according to claim 1 ,
characterized in that the phosphine ligands have a mono- or bidentate structure, preferably selected from the group comprising
L1—(9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphine),
L2—(oxybis(2,1-phenylene))bis(di-tert-butylphosphine),
L3—1,2-bis((di-tert-butylphosphinyl)methyl)benzene,
L4—triphenylphosphine,
L5—di(1-adamantyl)-n-butylphosphine.
9. Process according to claim 1 ,
characterized in that the hydrogen halide used is hydrogen chloride.
10. Process according to claim 1 ,
characterized in that the ratio of palladium to hydrogen halide is in the range from 1:1 to 1:20.