Ruthenium-phenol catalysts and method of preparing menthone from isopulegol

Patent metadata

Field	Value
Publication number	US-9790157-B2
Application number	US-201515123271-A
Country	US
Kind code	B2
Filing date	Mar 4, 2015
Priority date	Mar 5, 2014
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

The present invention is directed towards a catalyst which is obtainable by contacting in situ a ruthenium precursor and a phenol derivative. Furthermore, the present invention is directed towards the use of said catalyst in transfer hydrogenation reactions. In particular, the present invention is directed to a method for preparing menthone starting from isopulegol.

First claim

The invention claimed is:

1. A method for preparing menthone comprising conducting a transfer hydrogenation reaction in the presence of a liquid medium that includes isopulegol, a ruthenium precursor and a phenol derivative,
wherein the phenol derivative:isopulegol is present at a weight ratio of 1:10, and the transfer hydrogenation reaction is carried out at a temperature in range from 150 to 200° C., and the phenol derivative is of the formulae (Ia) or (Ic)

wherein
R 1 , R 2 , R 3 , R 4 independently are hydrogen, alkyl, or hydroxy, or
R 3 , R 4 together with the carbon atoms to which they are bound form an anellated aromatic ring;
R 5a is hydrogen, alkyl, or hydroxy;
R 6 , R 7 , R 8 , R 9 independently are hydrogen or alkyl, or
R 6 , R 7 together with the carbon atoms to which they are bound form an anellated aromatic ring;
R 10 is hydrogen or hydroxy, and
X is a chemical bond; alkylene optionally substituted by 1, 2 or 3 substituents which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, cycloalkyl, aryl, and OH; or arylene optionally substituted by 1, 2, 3 substituents which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, alkoxy and OH; —O—; and —S—;
and the ruthenium precursor does not possess nitrogen or phosphorous donor ligands.

2. The method of claim 1 wherein
R 1 , R 2 , R 3 , R 4 independently are hydrogen, branched or linear alkyl, or hydroxy, or
R 3 , R 4 together with the carbon atoms to which they are bound form an anellated aromatic ring;
R 5a is hydrogen, alkyl branched or linear alkyl, or hydroxy;
R 6 , R 7 , R 8 , R 9 independently are hydrogen, or branched or linear alkyl, or
R 6 , R 7 together with the carbon atoms to which they are bound form an anellated aromatic ring;
R 10 is hydrogen or hydroxy, and
X is a chemical bond, alkylene optionally substituted by 1, 2 or 3 substituents which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, cycloalkyl, aryl, OH, or —O—.

3. The method of claim 1 wherein therein the phenol derivative is of the formula (Ia)

wherein R 1 , R 2 , R 3 , R 4 and R 5a independently are hydrogen, alkyl, or hydroxy.

4. The method of claim 1 wherein the phenol derivative is of the formula (Ic)

wherein
R 1 , R 2 , R 3 , R 4 independently are hydrogen or alkyl, or
R 3 , R 4 together with the carbon atoms to which they are bound form an anellated aromatic ring;
R 6 , R 7 , R 8 , R 9 independently are hydrogen or alkyl, or
R 6 , R 7 together with the carbon atoms to which they are bound form an anellated aromatic ring;
R 10 is hydrogen or hydroxy, and
X is a chemical bond; alkylene optionally substituted by 1, 2 or 3 substituents which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, cycloalkyl, aryl, and OH; arylene optionally substituted by 1, 2, 3 substituents which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, alkoxy and OH; —O—, or —S—.

5. The method of claim 4 wherein
R 1 , R 2 , R 3 , R 4 independently are hydrogen, linear C 1 -C 10 -alkyl, or branched C 3 -C 10 -alkyl, or
R 3 , R 4 together with the carbon atoms to which they are bound form an anellated aromatic ring;
R 6 , R 7 , R 8 , R 9 independently are hydrogen, linear C 1 -C 10 -alkyl, or branched C 3 -C 10 -alkyl, or
R 6 , R 7 together with the carbon atoms to which they are bound form an anellated aromatic ring;
R 10 is hydrogen or hydroxy, and
X is a chemical bond or alkylene.

6. The method of claim 1 wherein the ruthenium precursor having labile ligands is of formula (II) or a salt thereof
[RuL m ] n   (II)

wherein
Ru is in the oxidation state (+II), (+III) or (+IV);
each L independently is selected from the group consisting
a. hydride;
b. halide;
c. alkyl;
d. aliphatic olefins optionally substituted by 1, 2 or 3 substituents which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, cycloalkyl, aryl, and OH;
e. cyclic olefins optionally substituted by 1, 2 or 3 substituents which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, cycloalkyl, aryl, and OH;
f. —CO;
g. 1,3-dialkyldionate;
h. alkanoate and
i. aryl optionally substituted by 1, 2, 3, 4 or 5 which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, alkoxy and OH;
m is an integer in a range from 2 to 6;
n is at least 1.

7. The method of claim 5 wherein the ruthenium precursor having labile ligands is of formula (II) or a salt thereof
[RuL m ] n   (II)

wherein
Ru is in the oxidation state (+II), (+III) or (+IV);
each L independently is selected from the group consisting
a. hydride;
b. halide;
c. alkyl;
d. aliphatic olefins optionally substituted by 1, 2 or 3 substituents which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, cycloalkyl, aryl, and OH;
e. cyclic olefins optionally substituted by 1, 2 or 3 substituents which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, cycloalkyl, aryl, and OH;
f. —CO;
g. 1,3-dialkyldionate;
h. alkanoate and
i. aryl optionally substituted by 1, 2, 3, 4 or 5 which are independently selected from the group consisting of halogen, alkyl, substituted alkyl, alkoxy and OH;
m is an integer in a range from 2 to 6;
n is at least 1.

8. The method of claim 1 wherein the ruthenium precursor is selected from the group consisting of
Bis(2,4-dimethylpentadienyl)ruthenium(II);
Bis(2-methylallyl)(1,5-cyclooctadiene)ruthenium(II);
Bis(2,2,6,6-tetramethyl-3,5-heptanedionato)(1,5-cyclooctadiene)ruthenium(II);
Chloro(1,5-cyclooctadiene)(pentamethylcyclopentadienyl)ruthenium(II);
Chloro(pentamethylcyclopentadienyl)ruthenium(II) tetramer;
Cyclopentadienyl(p-cymene)ruthenium(II) hexafluorophosphat;
Dicarbonylcyclopentadienylruthenium(II) dimer;
Dichloro(benzene)ruthenium(II);
Di-μ-chlorobis[(p-cymene)chlororuthenium(II)];
Dichloro(1,5-cyclooctadiene)ruthenium(II);
Dichlorotricarbonylruthenium (dimer);
Dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer;
Ruthenium(III) acetylacetonate;
Ruthenium(III) bromide;
Ruthenium(III) chloride;
Ruthenium(III) iodide;
Acetatodicarbonylruthenium(IV) polymer;
Ammonium hexachlororuthenate(IV);
Dichloro(μ-chloro)bis[(1,2,3,6,7,8-η)-2,7-dimethyl-2,6-octadien-1,8-diyl]diruthenium(IV); and
Dichloro(2,6,10-dodecatriene-1,12-diyl)ruthenium(IV).

Assignees

• Basf Se
• Basf Se (Reitstötter Kinzebach & Partner)

Inventors

• Limburg Carolin
• Paciello Rocco

Classifications

• B01J31/2226

  Anionic ligands, i.e. the overall ligand carries at least one formal negative charge · CPC title

• B01J31/223

  At least two oxygen atoms present in one at least bidentate or bridging ligand · CPC title

• C07C2601/14

  The ring being saturated · CPC title

• B01J2231/645

  of C=C or C-C triple bonds · CPC title

• B01J2531/821

  Ruthenium · CPC title