JP2015124156A - Method for manufacturing alcohol by hydrogenation of carboxylic acid compound and ester compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for obtaining alcohol by hydrogenation of carboxylic acid compound efficiently by using a homogeneous system catalyst, especially a method for obtaining alcohol by hydrogenation of various carboxylic acid compound and ester compound by the homogeneous system catalyst efficiently even under alleviation condition.SOLUTION: A carboxylic acid compound and/or an ester compound is hydrogenated in a presence of a rhenium complex represented by ReXYZ, where X is a halogen atom, Y is same or different and each a ligand containing one or more phosphorus atom, Z is a ligand other than X and Y, m is an integer of 1 to 6, p is an integer of 0 to 2 and the sum of m, n and p is an integer of 2 to 6, and a specific alkali metal salt.

Description

  The present invention relates to a method for producing an alcohol by hydrogenation of a carboxylic acid compound and an ester compound.

  Hydrogen transfer reactions such as hydrogenation reactions are widely used for the synthesis of low molecular and high molecular organic compounds.

  For example, Non-Patent Document 1 shows that a specific ruthenium complex is useful for synthesizing an alcohol by hydrogenating an ester or carbon dioxide. Other examples of hydrogenating amides are also known.

  However, there are few examples of hydrogenation of carboxylic acid compounds using molecular catalysts. This is because the carboxylic acid compound has a carboxyl group that is stable with respect to the hydrogenation reaction, so that the hydrogenation reaction is generally difficult. In addition, in the conventional carboxylic acid compound hydrogenation method, when a homogeneous catalyst is used, the substrate dependency is high. Therefore, depending on the type of substrate, the central metal, ligand, reaction conditions, etc. of the catalyst are changed each time. It was necessary to change significantly.

  For this reason, not only amides and esters but also carboxylic acid compounds can be applied to the synthesis of low-molecular and high-molecular organic compounds as long as the alcohol can be synthesized by a hydrogenation reaction. It is more useful because it can be synthesized.

  For example, when a heterogeneous binuclear metal cluster catalyst or a heterogeneous catalyst is used, there are reported examples (Non-Patent Documents 2 to 3). However, in Non-Patent Document 2, when a homogeneous catalyst composed of a single metal is used, hydrogenation of the carboxylic acid compound is difficult, and a high pressure is required, and further, ring reduction proceeds. Moreover, in nonpatent literature 3, since it is accompanied by decarboxylation depending on a substrate, substrate generality and selectivity are scarce. For this reason, it cannot be said that it is the method excellent in the generality of the substrate which can be made to advance on moderate conditions.

  As described above, it is difficult to obtain an alcohol by directly reducing the carboxylic acid compound, and an undesirable side reaction occurs depending on the substrate. Therefore, after the intracarboxylic esterification of the carboxylic acid compound, the reduction is usually performed. The reaction is going on. As for the hydrogenation of ester compounds, almost no reaction using a rhenium complex is known. For example, in Non-Patent Document 2, it is known that a hydrogenation reaction can proceed in the case of a mixed catalyst instead of a single catalyst. It is to the extent that has been done.

  For this reason, a method for hydrogenating various carboxylic acid substrates under mild conditions using a homogeneous catalyst has not yet been achieved. In addition, a method for obtaining an alcohol by hydrogenating various ester substrates under mild conditions using a single homogeneous rhenium catalyst has not yet been achieved. For this reason, such a method is required.

Angew. Chem. Int. Ed. 2012, 51, 7499-7502 Tetrahedron Lett. 1995, 36, 1059-1062 Chem. Commun. 2010, 46, 6279-6281

  In general, the hydrogenation reaction of a substrate having an inactive carbonyl group such as an ester or amide is generally effective when carried out under basic conditions. However, when a carboxylic acid compound is used as the substrate, the reaction system is in an acidic condition, and the conditions for hydrogenating esters and amides cannot be applied as they are.

  Under such circumstances, an object of the present invention is to provide a method for efficiently hydrogenating a carboxylic acid compound to obtain an alcohol using a single homogeneous catalyst. Specifically, an object of the present invention is to provide a method for efficiently hydrogenating various carboxylic acid compounds and ester compounds using a homogeneous catalyst under mild conditions to obtain an alcohol.

The present inventors have intensively studied to solve the above problems. As a result, it was found that by adding an alkali metal salt to a specific rhenium complex, the carboxylic acid compound can be efficiently hydrogenated to obtain an alcohol even under mild conditions. Further, it has also been found that even when an ester compound is produced during the above reaction, the ester compound can be hydrogenated to obtain an alcohol. For this reason, in this invention, it can apply not only to the manufacturing method of alcohol by hydrogenation of a carboxylic acid compound but to the manufacturing method of alcohol by hydrogenation of an ester compound. Based on such knowledge, the present inventors have further studied and completed the present invention. That is, this invention includes the manufacturing method of the following alcohol.
Item 1. A method for producing an alcohol by hydrogenating a carboxylic acid compound and / or an ester compound,
Comprising a step of hydrogenating a carboxylic acid compound and / or an ester compound in a hydrogen atmosphere in the presence of a rhenium complex and an alkali metal salt,
The rhenium complex has the general formula (1):
ReX _m Y _n Z _p
[Wherein X is a halogen atom; Y is the same or different and each contains one or more phosphorus atoms; Z is a ligand other than X and Y; m is an integer of 1 to 6; P is an integer of 0-2; the sum of m, n and p is an integer of 2-6. ]
The manufacturing method which is a compound shown by these.
Item 2. Item 2. The production method according to Item 1, wherein in the rhenium complex, rhenium is trivalent to trivalent.
Item 2-1. Item 3. The method according to Item 1 or 2, wherein in the general formula (1), X is the same or different and each is a chlorine atom.
Item 3. Item 2. The production method according to any one of Items 1 to 2-1, wherein Y in the general formula (1) is a phosphine ligand.
Item 3-1. Item 4. The production method according to any one of Items 1 to 3, wherein in General Formula (1), Y is the same or different and is a phosphine ligand having an optionally substituted aryl group.
Item 3-2. In the general formula (1), Y represents triphenylphosphine, bis (diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane, 1,4 -Bis (diphenylphosphino) butane, 1,5-bis (diphenylphosphino) pentane, 1,6-bis (diphenylphosphino) hexane, 1,1'-bis (diphenylphosphino) ferrocene, 1,2- Bis (dipentafluorophenylphosphino) ethane, 1,2-bis (dicyclohexylphosphino) ethane, 1,3-bis (dicyclohexylphosphino) propane, 1,4-bis (dicyclohexylphosphino) butane, 1,2 -Bis (diphenylphosphino) benzene, 1,2-bis (bis (3,5-dimethylphenyl) ) Phosphino) ethane, 1,3-bis (bis (3,5-dimethylphenyl) phosphino) propane, 1,4-bis (bis (3,5-dimethylphenyl) phosphino) butane, 1,2-bis (cyclohexyl) Phosphino) ethane, 1,4-bis (bis (3,5-di-t-butylphenyl) phosphino) butane, 1,4-bis (bis (3,5-dimethoxyphenyl) phosphino) butane, 2,2 '-Bis (diphenylphosphino) -1,1'-binaphthyl, 2,2'-bis (bis (3,5-dimethylphenyl) phosphino) -1,1'-binaphthyl, (2S, 3S)-(- ) -Bis (diphenylphosphino) butane, (S, S) -1,2-bis [(2-methoxyphenyl) phenylphosphino] ethane ((S, S) -DIPAMP), (R, R)-( ) -2,3-bis (tert-butylmethylphosphino) quinoxaline (QuinoxP *), (R, R) -1,2-bis (tert-butylmethylphosphino) benzene (BenzP *), 1,1, 1-tris (diphenylphosphinomethyl) ethane, 1,1,1-tris (bis (3,5-dimethylphenyl) phosphinomethyl) ethane, 1,1,1-tris (diphenylphosphino) methane, tris ( 2-diphenylphosphinoethyl) phosphine, (oxydi-2,1-phenylene) bis (diphenylphosphine), 4,5-bis (diphenylphosphino) -9,9-dimethylxanthene, or triphenylphosphine oxide. The manufacturing method in any one of claim | item 1-3.
Item 4. In the general formula (1), Z is a ligand containing at least one selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom (coordination containing one or more phosphorus atoms). The manufacturing method in any one of claim | item 1-3 which is a child except).
Claim | item 4-1. In the said General formula (1), m is an integer of 1-3, n is an integer of 1-3, p is 0 or 1, and the sum total of m, n, and p is 5 or 6. Item 5. The production method according to any one of Items 1 to 4.
Item 5. The rhenium complex has the general formula (1A):

[In the formula, Z is the same as above; X ^{1 to} X ³ are the same or different, and each is a halogen atom; R ^{1 to} R ² are the same or different, and each is an optionally substituted aryl group; The bond represented is a single bond or a double bond; one R ¹ and one R ² may be bonded to each other to form a ring together with adjacent —P—Re—P—. ]
A compound represented by
The manufacturing method in any one of claim | item 1-4-1.
Item 6. The alkali metal salt has the general formula (2):
MBR ³ ₄
[Wherein, M is an alkali metal; R ³ is the same or different and each represents an optionally substituted alkyl group or an optionally substituted aryl group. ]
Item 6. The production method according to any one of Items 1 to 5, which is a salt represented by:
Item 7. Item 7. The production method according to any one of Items 1 to 6, wherein a ligand Y ′ containing one or more phosphorus atoms is added in the hydrogenation reaction step.
Item 8. Item 8. The production method according to Item 7, wherein Y ′ in the general formula (1) is a phosphine ligand.
Item 8-1. Item 9. The production method according to any one of Items 1 to 8, wherein the hydrogenation step is performed in the presence of a solvent.
Item 8-2. Item 8. The production method according to Item 8-1, wherein the solvent is at least one selected from the group consisting of cyclic ethers, cyclic hydrocarbons, and halogenated hydrocarbons.
Item 8-3. The said hydrogenation process is a manufacturing method in any one of claim | item 1 -8-2 which is a process made to react at 0-200 degreeC under the hydrogen pressure of 0.1-20 Mpa.

  According to the present invention, high temperature and high pressure are not required for the carboxylic acid compound, that is, even under mild conditions, hydrogenation can proceed efficiently and alcohol can be obtained. Is expensive.

  In addition, it is possible to obtain an alcohol in a very high yield by selecting a substrate, a complex and an alkali metal salt. In this case, since the selectivity of alcohol is high, there is a high possibility that it will lead to an energy conservation law.

  Furthermore, in the production method of the present invention, since it is easy to handle even at room temperature and in the air, and a readily available catalyst can be used, it is economical and highly practical and convenient.

  Further, even when an ester compound is generated during the hydrogenation reaction of the carboxylic acid compound, it is possible to obtain an alcohol by hydrogenating the ester compound. For this reason, in this invention, since it can apply not only to the manufacturing method of alcohol by hydrogenation of a carboxylic acid compound but to the manufacturing method of alcohol by hydrogenation of an ester compound, practicality and convenience are high.

  The method for producing an alcohol of the present invention includes a step of hydrogenating a carboxylic acid compound and / or an ester compound in a hydrogen atmosphere in the presence of a rhenium complex and an alkali metal salt.

1. Rhenium Complex The rhenium complex used in the present invention has the general formula (1):
ReX _m Y _n Z _p
[Wherein X is a halogen atom; Y is the same or different and each contains one or more phosphorus atoms; Z is a ligand other than X and Y; m is an integer of 1 to 6; P is an integer of 0-2; the sum of m, n and p is an integer of 2-6. ]
It is a compound shown by these.

  As the valence of rhenium in the rhenium complex used in the present invention, for example, 3 to 7 valences can be adopted. From the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound and / or the ester compound, the valence of 3 Preference is given to pentavalent, heptavalent, etc. Trivalent or pentavalent is more preferred, and pentavalent is even more preferred. In addition, even when the valence of rhenium is unknown in the reaction system, it is included in the category of the rhenium complex of the present invention.

  In the general formula (1), the group represented by X is a halogen atom.

  Examples of the halogen atom represented by X include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. From the viewpoint of the yield of alcohol by hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound, A chlorine atom or an iodine atom is preferable, and a chlorine atom is more preferable.

  In the general formula (1), the ligand represented by Y is a ligand containing one or more phosphorus atoms. As such a ligand, any of monodentate ligands, bidentate ligands, tridentate ligands and tetradentate ligands can be used, but hydrogenation (reduction of carboxylic acid compounds and / or ester compounds). From the viewpoint of the yield of alcohol due to), a monodentate ligand or a bidentate ligand is preferred, and a bidentate ligand is more preferred.

  In addition, examples of the ligand containing one or more phosphorus atoms represented by Y include a phosphine ligand and a phosphorane ligand. Hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound is also possible. The phosphine ligand is preferred from the viewpoint of alcohol yield by

  Furthermore, as a ligand containing one or more phosphorus atoms represented by Y, an aryl group which may be substituted from the viewpoint of the yield of alcohol by hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound A ligand having is preferred.

  When the ligand containing one or more phosphorus atoms represented by Y has an optionally substituted aryl group, examples of the aryl group include a phenyl group, a naphthyl group, a pyrenyl group, a toluyl group, a xylyl group, Examples include mesityl group, pyridyl group, furyl group, thiophenyl group, and pyrrolyl group. The substituent in the case where the aryl group is substituted is not particularly limited, but halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; alkyl groups such as methyl group, ethyl group and tert-butyl group; phenyl Group, naphthyl group, pyrenyl group, toluyl group, xylyl group, mesityl group, pyridyl group, furyl group, thiophenyl group, aryl group such as pyrrolyl group, alkoxy group such as methoxy group, ethoxy group; nitro group; amino group; hydroxy group A cyano group; a silyl group such as a trimethylsilyl group; and a thiol group. The number of substituents when substituted with a substituent can be, for example, about 1 to 3.

Specific examples of the ligand Y containing at least one phosphorus atom that can be used in the present invention include monodentate ligands such as trialkylphosphine such as trimethylphosphine; tricyclohexylphosphine (PCy ₃ ) and the like. Tricycloalkylphosphine; triarylphosphine such as triphenylphosphine and tri (4-fluoromethylphenyl) phosphine; triheteroarylphosphine such as tri-2-furanylphosphine; phosphorane ligand such as triphenylphosphine oxide Examples of the bidentate ligand include bis (diphenylphosphino) methane (dppm), 1,2-bis (diphenylphosphino) ethane (dppe), and 1,3-bis (diphenylphosphino) propane (dppp). ), 1,4-bis (diphenylphosphino) buta (Dppb), 1,5-bis (diphenylphosphino) pentane (dpppe), 1,6-bis (diphenylphosphino) hexane, 1,1′-bis (diphenylphosphino) ferrocene, 1,2-bis ( Dipentafluorophenylphosphino) ethane, 1,2-bis (dicyclohexylphosphino) ethane, 1,3-bis (dicyclohexylphosphino) propane, 1,4-bis (dicyclohexylphosphino) butane, 1,2-bis (Diphenylphosphino) benzene, 1,2-bis (bis (3,5-dimethylphenyl) phosphino) ethane, 1,3-bis (bis (3,5-dimethylphenyl) phosphino) propane, 1,4-bis (Bis (3,5-dimethylphenyl) phosphino) butane, 1,2-bis (cyclohexylphosphino) Tan, 1,4-bis (bis (3,5-di-t-butylphenyl) phosphino) butane, 1,4-bis (bis (3,5-dimethoxyphenyl) phosphino) butane, 2,2′-bis (Diphenylphosphino) -1,1′-binaphthyl, 2,2′-bis (bis (3,5-dimethylphenyl) phosphino) -1,1′-binaphthyl, (2S, 3S)-(−)-bis (Diphenylphosphino) butane, (S, S) -1,2-bis [(2-methoxyphenyl) phenylphosphino] ethane ((S, S) -DIPAMP), (R, R)-(−) — 2,3-bis (tert-butylmethylphosphino) quinoxaline (QuinoxP *), (R, R) -1,2-bis (tert-butylmethylphosphino) benzene (BenzP *), 1,1,1- Tris (Gifeni Ruphosphinomethyl) ethane, 1,1,1-tris (bis (3,5-dimethylphenyl) phosphinomethyl) ethane, 1,1,1-tris (diphenylphosphino) methane, tris (2-diphenylphosphine) Finoethyl) phosphine, (oxydi-2,1-phenylene) bis (diphenylphosphine), 4,5-bis (diphenylphosphino) -9,9-dimethylxanthene, 4,5-bis (diphenylphosphino) -9 , 9-dimethylxanthene, etc., and tridentate ligands include bis (2-diphenylphosphinoethyl) phenylphosphine, 1,1,1-tris (diphenylphosphinomethyl) ethane, and the like. Examples of the tetradentate ligand include tris (2-diphenylphosphinoethyl) phenylphosphine. Among them, from the viewpoint of the yield of alcohol by hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound, triphenylphosphine, bis (diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane, 1,4-bis (diphenylphosphino) butane, 1,5-bis (diphenylphosphino) pentane, 1,6-bis (diphenylphosphino) hexane, 1, 1′-bis (diphenylphosphino) ferrocene, 1,2-bis (dipentafluorophenylphosphino) ethane, 1,2-bis (dicyclohexylphosphino) ethane, 1,3-bis (dicyclohexylphosphino) propane, 1,4-bis (dicyclohexylphosphino) butane, 1,2-bis (diphenyl) Ruphosphino) benzene, 1,2-bis (bis (3,5-dimethylphenyl) phosphino) ethane, 1,3-bis (bis (3,5-dimethylphenyl) phosphino) propane, 1,4-bis (bis ( 3,5-dimethylphenyl) phosphino) butane, 1,2-bis (cyclohexylphosphino) ethane, 1,4-bis (bis (3,5-di-t-butylphenyl) phosphino) butane, 1,4- Bis (bis (3,5-dimethoxyphenyl) phosphino) butane, 2,2′-bis (diphenylphosphino) -1,1′-binaphthyl, 2,2′-bis (bis (3,5-dimethylphenyl) Phosphino) -1,1′-binaphthyl, (2S, 3S)-(−)-bis (diphenylphosphino) butane, (S, S) -1,2-bis [(2-methoxyphenyl) fe Nylphosphino] ethane ((S, S) -DIPAMP), 1,1,1-tris (diphenylphosphinomethyl) ethane, 1,1,1-tris (bis (3,5-dimethylphenyl) phosphinomethyl) ethane 1,1,1-tris (diphenylphosphino) methane, tris (2-diphenylphosphinoethyl) phosphine, (oxydi-2,1-phenylene) bis (diphenylphosphine), 4,5-bis (diphenylphosphino) ) -9,9-dimethylxanthene, triphenylphosphine oxide and the like, and triphenylphosphine, bis (diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) ) Propane, 1,2-bis (diphenylphosphino) benzene, 1,1,1 Tris (diphenylphosphinomethyl) ethane, 4,5-bis (diphenylphosphino) -9,9-dimethylxanthene, triphenylphosphine oxide and the like are more preferable, and bis (diphenylphosphino) methane, 1,2-bis ( Diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane, 1,2-bis (diphenylphosphino) benzene, 4,5-bis (diphenylphosphino) -9,9-dimethylxanthene and the like preferable.

  These ligands Y may be included in the rhenium complex to be charged, or may be formed in the rhenium complex in the system.

In the general formula (1), the ligand represented by Z is a ligand other than X and Y, and is not particularly limited as long as it can coordinate to a rhenium atom. For example, the ligand etc. which contain at least 1 sort (s) chosen from the group which consists of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom are mentioned. Examples of the ligand containing an oxygen atom include an oxygen atom (oxo group; O ²⁻ ), a water molecule (H ₂ O), carbon monoxide (CO), carbon dioxide (CO ₂ ), a lower alkoxy group (methoxy group, etc. C1-4 alkoxy group, etc.), ether (tetrahydrofuran, 1,4-dioxane, cyclopentylmethyl ether, etc.), triflate (CF ₃ SO ₃ ⁻ ), tosylate (p-CH ₃ C ₆ H ₄ SO ₃ ⁻ ), oxygen molecules (O ₂₎ and the like, and as the ligand containing a nitrogen atom, nitrile (acetonitrile etc.), isocyanides, triethylamine, amine (ammonia, triethylamine, etc.), heterocyclic compounds (pyridine, thiophene, THF, etc.) , nitric oxide (NO), tri-furyl imide _{((CF 3 SO 2) 2} N -), molecular nitrogen _{(N 2),} and the like The ligand containing a sulfur atom, dimethyl sulfide, dimethyl sulfoxide, thiophenol, thiophene, isocyanates, and the like. In addition, hydrogen atoms (hydride; H ⁻ ), aromatic hydrocarbons (benzene, naphthalene, pyrene, cyclopentadiene, etc.), unsaturated hydrocarbons (cyclooctadiene, acetylene, ethylene, 2-methylallyl), carbonyl compounds ( Formaldehyde, acetone, ethyl acetate, DMF, etc.), hydrogen molecules (H ₂ ), etc. can also be used. Among these, a ligand containing at least one selected from the group consisting of an oxygen atom, a nitrogen atom, and a sulfur atom is preferable, and an oxygen atom (oxo group; O ²⁻ ) and a ligand containing a nitrogen atom ( Acetonitrile and the like, and a ligand containing a sulfur atom (dimethyl sulfide, etc.) is more preferable,
In the general formula (1), m is an integer of 1 to 6, and an integer of 1 to 5 is preferable from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound and / or ester compound. An integer of 3 is more preferable.

  In the general formula (1), n is an integer of 1 to 6, and an integer of 1 to 4 is preferable from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound and / or ester compound. An integer of 3 is more preferable.

  In General formula (1), p is an integer of 0-2, and 0 or 1 is preferable from a viewpoint of the yield of the alcohol by hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound.

  In the general formula (1), the sum of m, n and p is an integer of 2 to 6, and from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound and / or ester compound, 4 to 6 is Preferably 5 or 6 is more preferable.

  As a preferable example of the rhenium complex used in the present invention, from the viewpoint of the yield of alcohol by hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound, for example, the general formula (1A):

[In the formula, Z is the same as above; X ^{1 to} X ³ are the same or different, and each is a halogen atom; R ^{1 to} R ² are the same or different, and each is an optionally substituted aryl group; The bond represented is a single bond or a double bond; one R ¹ and one R ² may be bonded to each other to form a ring together with adjacent —P—Re—P—. ]
(Hereinafter sometimes referred to as rhenium complex (1A)).

  In the above general formula (1A), the bond is shown for convenience, but a coordinated bond is also included.

In the general formula (1A), X ¹ ~X ³ is a halogen atom, e.g., fluorine atom, chlorine atom, bromine atom, and an iodine atom, preferably a chlorine atom or iodine atom, a chlorine atom is more preferable.

In the general formula (1A), R ^{1 and} R ² are the same or different and each is an optionally substituted aryl group, such as a phenyl group, a naphthyl group, a pyrenyl group, a toluyl group, a xylyl group, a mesityl group, A pyridyl group, a furyl group, a thiophenyl group, a pyrrolyl group etc. are mentioned, A phenyl group is preferable.

However, one R ¹ and one R ² may be bonded to each other to form a ring together with adjacent —P—Re—P—. In the case of forming a ring, the ring that can be formed is not particularly limited, but specifically,

[R ^{1 to} R ² are the same or different and the same as above. ]
Etc.

Thus, when one R ¹ and one R ² form a ring, the other R ^{1 to} R ² are each an optionally substituted aryl group, for example, a phenyl group or a naphthyl group. , Pyrenyl group, toluyl group, xylyl group, mesityl group, pyridyl group, furyl group, thiophenyl group, pyrrolyl group, and the like, and a phenyl group is preferable.

  Examples of the rhenium complex (1A) described above include:

[Ph is a phenyl group;
From the viewpoint of the yield of alcohol by hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound, a rhenium complex (1A-2), a rhenium complex (1A-3), a rhenium complex (1A-4) ), Rhenium complex (1A-5) and the like are preferable, and rhenium complex (1A-3) and rhenium complex (1A-5) are more preferable.

  As such a rhenium complex, a known or commercially available one can be used.

(2) Alkali metal salt In the present invention, an alkali metal salt is used to obtain an alcohol without hydrogenating a carboxylic acid compound and through an intermediate such as an ester or cyclic ester. By forming a cationic rhenium complex, an alcohol can be obtained by hydrogenating a carboxylic acid compound even under acidic conditions. In the production method of the present invention, even if not only an alcohol but also an ester compound is produced, the ester compound can be hydrogenated to obtain an alcohol.

  From such a viewpoint, the alkali metal salt is preferably one having low basicity and high ionicity. However, if an excessive amount of carboxylic acid is used, the reaction can proceed even if a strong base (NaH or the like) is used.

As such an alkali metal salt, the general formula (2):
MBR ³ ₄
[Wherein, M is an alkali metal; R ³ is the same or different and each represents an optionally substituted alkyl group or an optionally substituted aryl group. ]
Is preferred.

  Examples of the alkali metal include lithium, sodium, potassium, rubidium, cesium and the like. From the viewpoint of the yield of alcohol by hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound, lithium, sodium, potassium, Cesium and the like are preferable, and sodium, potassium, cesium and the like are more preferable.

R ³ in the general formula (2) is an optionally substituted alkyl group or an optionally substituted aryl group.

As the alkyl group represented by R ³ , for example, a saturated linear or branched aliphatic alkyl group having 1 to 20 carbon atoms (particularly 1 to 12, more preferably 1 to 6, particularly 1 to 4) is preferable. , Methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group and the like.

The substituent in the case where the alkyl group represented by R ³ is substituted is not particularly limited, but halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; methyl group, ethyl group, tert-butyl group and the like Alkyl group; aryl group such as phenyl group, naphthyl group, pyrenyl group, toluyl group, xylyl group, mesityl group, pyridyl group, furyl group, thiophenyl group and pyrrolyl group; alkoxy group such as methoxy group and ethoxy group; nitro group; Amino group; hydroxy group; cyano group; silyl group such as trimethylsilyl group; thiol group and the like. The number of substituents when substituted with substituents can be, for example, about 1 to 5.

In addition, examples of the aryl group represented by R ³ include the same aryl groups as those possessed by a ligand containing one or more phosphorus atoms represented by Y. Examples of the substituent are the same.

Among these, R ³ is preferably a substituted or unsubstituted aryl group, particularly a substituted or unsubstituted phenyl group from the viewpoint of the yield of alcohol by hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound. preferable.

Examples of the alkali metal salt that satisfies such conditions include LiBPh ₄ , NaBPh ₄ , KBPh ₄ , CsBPh ₄ , LiB (3,5- (CF ₃ ) ₂ Ph) ₄ , NaB (3,5- (CF ₃ ) ₂ Ph) ₄ , KB (3,5- (CF ₃ ) ₂ Ph) ₄ , CsB (3,5- (CF ₃ ) ₂ Ph) ₄ , LiB (3,5- (CH ₃ ) ₂ Ph) ₄ , NaB (3,5- (CH ₃ ) ₂ Ph) ₄ , KB (3,5- (CH ₃ ) ₂ Ph) ₄ , CsB (3,5- (CH ₃ ) ₂ Ph) ₄ , LiB (3 5-F ₂ Ph) ₄ , NaB (3,5-F ₂ Ph) ₄ , KB (3,5-F ₂ Ph) ₄ , CsB (3,5-F ₂ Ph) ₄ , LiB (C ₆ F _{5 ) 4, NaB (C 6 F} 5) 4, KB (C 6 F 5) 4, CsB (C 6 F _{) 4, LiB (4-FPh} ) 4, NaB (4-FPh) 4, KB (4-FPh) 4, CsB (4-FPh) 4, LiB (4-CF 3 Ph) 4, NaB (4-CF ₃ Ph) ₄ , KB (4-CF ₃ Ph) ₄ , CsB (4-CF ₃ Ph) _{4 and the} like, and the viewpoint of the yield of alcohol by hydrogenation (reduction) of a carboxylic acid compound and / or an ester compound Therefore, NaBPh ₄ , KBPh ₄ , CsBPh _{4 and the} like are preferable. When KBPh ₄ is used as the alkali metal salt, the production method of the present invention can be performed more efficiently even when the hydrogen pressure is lowered. Moreover, these alkali metal salts may be used independently and may be used in combination of 2 or more type. In addition, the alkali metal salt can be used as it is, or may be used as a hydrate or a solvate. However, it is preferably used as it is from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound and / or ester compound.

(3) Ligand Y ′ containing at least one phosphorus atom
In the production method of the present invention, as described above, a ligand may be introduced into the rhenium complex, but separately from the rhenium complex, a ligand Y ′ containing one or more phosphorus atoms is added. May be. As the ligand Y ′ that can be used in this case, for example, the same ligand as the ligand Y described above can be used.

  That is, any of a monodentate ligand, a bidentate ligand, a tridentate ligand, and a tetradentate ligand can be used. The ligand Y ′ is preferably a phosphine ligand. Furthermore, the ligand Y ′ preferably has an optionally substituted aryl group. Among them, triphenylphosphine, bis (diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane, 1,4-bis (diphenylphosphino) butane 1,5-bis (diphenylphosphino) pentane, 1,6-bis (diphenylphosphino) hexane, 1,1′-bis (diphenylphosphino) ferrocene, 1,2-bis (dipentafluorophenylphosphino) ) Ethane, 1,2-bis (dicyclohexylphosphino) ethane, 1,3-bis (dicyclohexylphosphino) propane, 1,4-bis (dicyclohexylphosphino) butane, 1,2-bis (diphenylphosphino) benzene 1,2-bis (bis (3,5-dimethylphenyl) phosphino) ethane 1,3-bis (bis (3,5-dimethylphenyl) phosphino) propane, 1,4-bis (bis (3,5-dimethylphenyl) phosphino) butane, 1,2-bis (cyclohexylphosphino) ethane, 1,4-bis (bis (3,5-di-t-butylphenyl) phosphino) butane, 1,4-bis (bis (3,5-dimethoxyphenyl) phosphino) butane, 2,2′-bis (diphenyl) Phosphino) -1,1′-binaphthyl, 2,2′-bis (bis (3,5-dimethylphenyl) phosphino) -1,1′-binaphthyl, (2S, 3S)-(−)-bis (diphenyl) Phosphino) butane, (S, S) -1,2-bis [(2-methoxyphenyl) phenylphosphino] ethane ((S, S) -DIPAMP), (R, R)-(−)-2, 3-bi (Tert-Butylmethylphosphino) quinoxaline (QuinoxP *), (R, R) -1,2-bis (tert-butylmethylphosphino) benzene (BenzP *), 1,1,1-tris (diphenylphosphino) Methyl) ethane, 1,1,1-tris (bis (3,5-dimethylphenyl) phosphinomethyl) ethane, 1,1,1-tris (diphenylphosphino) methane, tris (2-diphenylphosphinoethyl) Phosphine, (oxydi-2,1-phenylene) bis (diphenylphosphine), 4,5-bis (diphenylphosphino) -9,9-dimethylxanthene, triphenylphosphine oxide and the like are preferable, and triphenylphosphine and bis (diphenyl). Phosphino) methane, 1,2-bis (diphenylphosphino) ethane, , 3-bis (diphenylphosphino) propane, 1,2-bis (diphenylphosphino) benzene, 1,1,1-tris (diphenylphosphinomethyl) ethane, 4,5-bis (diphenylphosphino) -9 , 9-dimethylxanthene, triphenylphosphine oxide, etc. are more preferable, and bis (diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane, 1,2 More preferred are -bis (diphenylphosphino) benzene, 4,5-bis (diphenylphosphino) -9,9-dimethylxanthene and the like.

(4) Hydrogenation reaction In the production method of the present invention, specifically, hydrogen is added to a substrate (carboxylic acid compound and / or ester compound) in the presence of a rhenium complex, an alkali metal salt and, if necessary, a ligand. To cause a hydrogenation reaction to obtain an alcohol.

  The substrate used for the reaction is not particularly limited as long as it is a carboxylic acid compound and / or an ester compound, and a wide variety of carboxylic acid compounds and / or ester compounds can be used. In this respect, the present invention is useful in comparison with the prior art in which hydrogenation reaction can only occur on a special substrate and the complex needs to be changed depending on the substrate.

  As the carboxylic acid compound used in the present invention, not only a carboxylic acid having only one carboxyl group but also a carboxylic acid compound having a plurality of these groups can cause a hydrogenation reaction to obtain an alcohol. That is, alcohols can be obtained by hydrogenating a wide variety of carboxylic acid compounds, including carboxylic acids that cannot be intramolecularly esterified.

  In addition, when the carboxylic acid compound has a functional group (ketone group, double bond, etc.) other than the carboxyl group as a substrate, it can be hydrogenated in the same manner as the carboxyl group, and the functional group other than the carboxyl group can be protected. In addition, only the carboxyl group can be hydrogenated (reduced). The protection of the functional group can be performed according to a conventional method. The same applies when the substrate has a plurality of carboxyl groups. In addition, when the carboxylic acid compound has a specific functional group (ether group) in addition to the carboxyl group, it is possible to hydrogenate only the carboxyl group preferentially over the functional group. It can be maintained at least.

  A wide variety of carboxylic acid compounds can be used as the carboxylic acid compound as such a substrate.

[In the above formula, Me is a methyl group; Cy is a cyclohexyl group. The same applies below. ]
Any of these can be hydrogenated to obtain an alcohol.

  In addition, according to the manufacturing method of this invention, although not only alcohol but ester may produce | generate as a by-product, it can isolate easily by a conventional method. Even when an ester is produced, the resulting ester can be separated into a starting carboxylic acid and a target alcohol by subjecting it to an alkali treatment. For this reason, while the yield of alcohol can be raised more, the produced | generated carboxylic acid can be reused for the manufacturing method of this invention.

  Further, according to the production method of the present invention, when the above-exemplified carboxylic acid compounds (b1) to (b50) are hydrogenated to obtain an alcohol, the ester compound is obtained even when the ester compound is obtained as a by-product. Alternatively, alcohol can be obtained by hydrogenation according to the production method of the present invention. The conditions in this case are the same as in the case of hydrogenating the carboxylic acid compound.

  The amount of rhenium complex used can be appropriately selected according to the type of substrate (carboxylic acid compound and / or ester compound), and the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound and / or ester compound. From the viewpoint, for example, usually about 0.0001 to 1 mol, preferably about 0.001 to 0.1 mol, more preferably 0.003 to 1 mol of the substrate (carboxylic acid compound and / or ester compound). It can be about -0.07 mol.

  The amount of the alkali metal salt used is usually 0.02 to 10 with respect to 1 mol of the substrate (carboxylic acid compound) from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound and / or ester compound. Mol, preferably 0.03 to 5 mol, more preferably 0.04 to 2 mol.

    In the production method of the present invention, the reaction system is preferably set to acidic reaction conditions. Specifically, the amount of the substrate (carboxylic acid compound) is preferably excessive with respect to the alkali metal salt. Specifically, the amount of the alkali metal salt used is preferably an excess amount relative to the rhenium complex, and specifically, the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound and / or ester compound. From the above viewpoint, it can be usually 2 to 1000 mol, preferably 3 to 500 mol, more preferably 4 to 200 mol, per 1 mol of the rhenium complex.

  When the ligand is introduced, the amount of the ligand used is usually from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound and / or ester compound, for example, relative to 1 mole of rhenium complex. 0.05 to 100 mol, preferably 0.5 to 10 mol, more preferably 1 to 5 mol.

  The hydrogenation of the present invention is preferably performed in a solvent.

  Examples of the solvent include aliphatic ethers such as diethyl ether, diisopropyl ether, t-butyl methyl ether, cyclopentyl methyl ether, 1,2-dimethoxyethane, diglyme and triglyme; tetrahydrofuran (THF), 2-methyltetrahydrofuran, dioxane ( 1,4-dioxane and the like; cyclic hydrocarbons such as benzene, toluene, xylene, mesitylene, cyclopentane and cyclohexane; chain hydrocarbons such as pentane, hexane, heptane, octane, nonane, decane and petroleum ether Halogenated hydrocarbons such as trifluorotoluene; branched C3-6 alcohols such as isopropanol, n-butyl alcohol, tert-butyl alcohol, sec-butyl alcohol; dimethyl sulfoxide ( MSO), and the like. These solvents may be used alone or in combination of two or more. Among these, from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound, cyclic ether, cyclic hydrocarbon, halogenated hydrocarbon and the like are preferable, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, toluene, cyclohexane, Trifluorotoluene and the like are more preferable, and tetrahydrofuran, toluene, cyclohexane and the like are more preferable. In the production method of the present invention, the hydrogenation reaction can proceed even if water is contained in the solvent, but the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound. Therefore, the amount of water in the solvent is preferably 10% by volume or less, and more preferably does not contain water.

  The amount of the solvent is not particularly limited, but is adjusted so that the concentration of the substrate (carboxylic acid compound) is 0.01 to 2 mol / L from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound. It is preferable to adjust, and it is more preferable to adjust so that it may become 0.05-1 mol / L, and it is still more preferable to adjust so that it may become 0.07-0.3 mol / L.

  In the hydrogenation step of the present invention, hydrogen is added to the substrate (carboxylic acid compound), and hydrogen gas can be used as the hydrogen. The hydrogen partial pressure during hydrogenation (hydrogen pressure) is usually about 0.1 to 20 MPa, preferably about 0.5 to 10 MPa, from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound. More preferably, it can be about 1.5 to 8 MPa. For example, when the reaction temperature is higher, it is possible to reduce the hydrogen pressure to make the conditions milder.

  Although the reaction temperature and reaction time may vary depending on the type of substrate (carboxylic acid compound), the reaction temperature is usually about 0 to 200 ° C. from the viewpoint of the yield of alcohol by hydrogenation (reduction) of the carboxylic acid compound. The temperature may be about 50 to 195 ° C, more preferably about 100 to 190 ° C, and still more preferably about 145 to 185 ° C. The reaction time is usually about 10 minutes to 50 hours, preferably about 1 to 30 hours, from the viewpoint of alcohol yield in hydrogenation (reduction). In this reaction, usually an autoclave or the like can be used.

  In the hydrogenation of the present invention, a rhenium complex, an alkali metal salt and a ligand as required are reacted in the presence or absence of hydrogen, and then a substrate (carboxylic acid compound) is reacted in the presence of hydrogen. You can also. A catalytically active species having a high hydrogenation-reducing ability is once prepared by reaction of a rhenium complex, an alkali metal salt, and a ligand as required. Therefore, hydrogen can be efficiently produced by reacting this with a substrate (carboxylic acid compound). An additive reaction product can be obtained. In this case, in any reaction, the conditions can be the same as described above.

  After completion of the reaction, a hydrogenated reaction product (alcohol) can be obtained through normal isolation and purification steps.

  Next, the present invention will be described with reference to examples, but the present invention is not limited to the following examples.

  [Example 1: Effect of rhenium complex (part 1)]

Example 1-1
Reduction (hydrogenation) of 3-phenylpropionic acid was performed by the following method.

  A stir bar was placed in a dry glass tube (25 mL), and 3-phenylpropionic acid (75.09 mg, 0.5 mmol), the rhenium complex 3 (6.93 mg, 0.010 mmol), sodium tetraphenylborate (17.11 mg). 0.05 mmol) and a tube containing this mixture was inserted into the autoclave. Next, the inside of the autoclave was replaced with an argon gas atmosphere, and then dehydrated toluene (2.0 mL) was added while the argon gas was kept flowing. Hydrogen gas was introduced into this autoclave from a hydrogen gas cylinder connected via a stainless steel tube, the inside of the autoclave was replaced with hydrogen gas, and then the hydrogen gas pressure was released from the leak valve. This operation (substitution-replacement) was repeated 5 times. Finally, the hydrogen gas pressure in the autoclave was set to 8 MPa, and the reaction was performed at 160 ° C. for 24 hours using a thermostatic bath.

After completion of the reaction, the autoclave was immersed in an ice bath and cooled to room temperature. Then, the hydrogen gas inside was carefully released in the draft. After removal of the solvent, the reaction product was analyzed by ¹ H NMR using mesitylene (60.1 mg, 0.5 mmol) as an internal standard. As a result, the yields of 3-phenylpropyl alcohol and 3-phenylpropyl 3-phenylpropionate were 23% and 7%, respectively.

  The result of Example 1-1 corresponds to entry 4 in Table 1 described later.

Example 1-2
In Example 1-1, the rhenium complex was reduced (hydrogenated) in the same manner as in Example 1-1 except that the conditions described in Table 1 were adopted. However, entry 1 in Table 1 did not use sodium tetraphenylborate. In addition, each raw material used what was synthesize | combined by the commercial item or the well-known method. The results are shown in Table 1.

  [Example 2: Effect of solvent]

  In Example 1-1, reduction (hydrogenation) was performed in the same manner as in Example 1-1 except that the conditions described in Table 2 were adopted for the solvent. However, in entry 10 of Table 2, the reaction time was 36 hours. In addition, each raw material used what was synthesize | combined by the commercial item or the well-known method. Example 1-1 corresponds to entry 1 in Table 2. The results are shown in Table 2.

  [Example 3: Effect of rhenium complex (2)]

Example 3-1
Reduction (hydrogenation) of 3-phenylpropionic acid was performed by the following method.

  A stir bar was placed in a dry glass tube (25 mL), and 3-phenylpropionic acid (75.09 mg, 0.5 mmol), rhenium complex 4 (7.07 mg, 0.010 mmol), sodium tetraphenylborate (17.11 mg). 0.05 mmol) and a tube containing this mixture was inserted into the autoclave. Subsequently, after the inside of the autoclave was replaced with an argon gas atmosphere, dehydrated toluene (4.0 mL) was added while the argon gas was kept flowing. Hydrogen gas was introduced into this autoclave from a hydrogen gas cylinder connected via a stainless steel tube, the inside of the autoclave was replaced with hydrogen gas, and then the hydrogen gas pressure was released from the leak valve. This operation (substitution-replacement) was repeated 5 times. Finally, the hydrogen gas pressure in the autoclave was set to 8 MPa, and the reaction was performed at 160 ° C. for 24 hours using a thermostatic bath.

After completion of the reaction, the autoclave was immersed in an ice bath and cooled to room temperature. Then, the hydrogen gas inside was carefully released in the draft. After removal of the solvent, the reaction product was analyzed by ¹ H NMR using mesitylene (60.1 mg, 0.5 mmol) as an internal standard. As a result, the yields of 3-phenylpropyl alcohol and 3-phenylpropyl 3-phenylpropionate were 99% and 2%, respectively.

  The result of Example 3-1 corresponds to entry 1 in Table 3 described later.

Example 3-2
In Example 3-1, the rhenium complex was reduced (hydrogenated) in the same manner as in Example 3-1, except that the conditions described in Table 3 were adopted. In addition, each raw material used what was synthesize | combined by the commercial item or the well-known method. The results are shown in Table 3.

  [Example 4: Effect of hydrogenation conditions (1)]

  In Example 3-1, reduction (hydrogenation) was performed in the same manner as in Example 3-1, except that the conditions described in Table 4 were adopted as the hydrogenation conditions. Example 3-1 corresponds to entry 1 in Table 4. The results are shown in Table 4.

  [Example 5: Effect of alkali metal salt]

Example 5-1
Reduction (hydrogenation) of 3-phenylpropionic acid was performed by the following method.

  A stir bar was placed in a dry glass tube (25 mL), and 3-phenylpropionic acid (75.09 mg, 0.5 mmol), rhenium complex 4 (7.07 mg, 0.010 mmol), sodium tetraphenylborate (17.11 mg). 0.05 mmol) and a tube containing this mixture was inserted into the autoclave. Subsequently, after the inside of the autoclave was replaced with an argon gas atmosphere, dehydrated toluene (4.0 mL) was added while the argon gas was kept flowing. Hydrogen gas was introduced into this autoclave from a hydrogen gas cylinder connected via a stainless steel tube, the inside of the autoclave was replaced with hydrogen gas, and then the hydrogen gas pressure was released from the leak valve. This operation (substitution-replacement) was repeated 5 times. Finally, the hydrogen gas pressure in the autoclave was set to 4 MPa, and the reaction was carried out at 150 ° C. for 24 hours using a thermostatic bath.

After completion of the reaction, the autoclave was immersed in an ice bath and cooled to room temperature. Then, the hydrogen gas inside was carefully released in the draft. After removing the solvent, the reaction product was analyzed by ¹ H NMR using mesitylene (60.1 mg, 0.5 mmol) as an internal standard substance. As a result, the yields of 3-phenylpropyl alcohol and 3-phenylpropyl 3-phenylpropionate were 55% and 2%, respectively.

  The result of Example 5-1 corresponds to entry 1 in Table 5 described later.

Example 5-2
In Example 5-1 above, reduction (hydrogenation) was performed in the same manner as in Example 5-1, except that the conditions described in Table 5 were adopted for the alkali metal salt. However, in entry 5 of Table 5, the reaction time was 30 hours. In addition, each raw material used what was synthesize | combined by the commercial item or the well-known method. The results are shown in Table 5.

  [Example 6: Effect of hydrogenation conditions (2)]

Example 6-1
Reduction (hydrogenation) of 3-phenylpropionic acid was performed by the following method.

  A stir bar was placed in a dry glass tube (25 mL), and 3-phenylpropionic acid (75.09 mg, 0.5 mmol), rhenium complex 4 (7.07 mg, 0.010 mmol), potassium tetraphenylborate (17.92 mg). 0.05 mmol) and a tube containing this mixture was inserted into the autoclave. Subsequently, after the inside of the autoclave was replaced with an argon gas atmosphere, dehydrated toluene (4.0 mL) was added while the argon gas was kept flowing. Hydrogen gas was introduced into this autoclave from a hydrogen gas cylinder connected via a stainless steel tube, the inside of the autoclave was replaced with hydrogen gas, and then the hydrogen gas pressure was released from the leak valve. This operation (substitution-replacement) was repeated 5 times. Finally, the hydrogen gas pressure in the autoclave was set to 4 MPa, and the reaction was performed at 180 ° C. for 12 hours using a thermostatic bath.

After completion of the reaction, the autoclave was immersed in an ice bath and cooled to room temperature. Then, the hydrogen gas inside was carefully released in the draft. After removal of the solvent, the reaction product was analyzed by ¹ H NMR using mesitylene (60.1 mg, 0.5 mmol) as an internal standard. As a result, the yields of 3-phenylpropyl alcohol and 3-phenylpropyl 3-phenylpropionate were 98% and 1%, respectively.

  The result of Example 6-1 corresponds to entry 2 in Table 6 described later.

Example 6-2
In Example 6-1 above, reduction (hydrogenation) was performed in the same manner as in Example 6-1 except that the conditions described in Table 6 were adopted for the hydrogenation conditions (hydrogen pressure). The results are shown in Table 6.

  [Example 7: Effect of ligand addition]

  Reduction (hydrogenation) of 3-phenylpropionic acid was performed by the following method.

  A stir bar was placed in a dried glass tube (25 mL), and 3-phenylpropionic acid (75.1 mg, 0.50 mmol), the rhenium complex 8 (6.49 mg, 0.010 mmol), 1,2-bis (diphenylphosphine) was further added. Fino) benzene (4.46 mg, 0.010 mol), sodium tetraphenylborate (17.1 mg, 0.050 mmol) were accommodated, and a tube containing this mixture was inserted into the autoclave. Subsequently, after the inside of the autoclave was replaced with an argon gas atmosphere, dehydrated toluene (4.0 mL) was added while the argon gas was kept flowing. Hydrogen gas was introduced into this autoclave from a hydrogen gas cylinder connected via a stainless steel tube, the inside of the autoclave was replaced with hydrogen gas, and then the hydrogen gas pressure was released from the leak valve. This operation (substitution-replacement) was repeated 5 times. Finally, the hydrogen gas pressure in the autoclave was set to 4 MPa, and the reaction was performed at 140 ° C. for 24 hours using a thermostatic bath.

After completion of the reaction, the autoclave was immersed in an ice bath and cooled to room temperature. Then, the hydrogen gas inside was carefully released in the draft. After removal of the solvent, the reaction product was analyzed by ¹ H NMR using mesitylene (60.1 mg, 0.50 mmol) as an internal standard. As a result, the yields of 3-phenylpropyl alcohol and 3-phenylpropyl 3-phenylpropionate were 35% and 1%, respectively.

  [Example 8: Substrate generality]

  In Example 6-1 above, reduction was performed in the same manner as in Example 6-1 except that the conditions described in Tables 7 to 9 were adopted for the substrate (carboxylic acid compound) and the hydrogenation conditions (hydrogen pressure). (Hydrogenation) was performed. However, in entries 19 to 26 in Table 9, tetrahydrofuran (THF) was used as the solvent. The results are shown in Tables 7-9.

Claims (8)

A method for producing an alcohol by hydrogenating a carboxylic acid compound and / or an ester compound,
Comprising a step of hydrogenating a carboxylic acid compound and / or an ester compound in a hydrogen atmosphere in the presence of a rhenium complex and an alkali metal salt,
The rhenium complex has the general formula (1):
ReX _m Y _n Z _p
[Wherein X is a halogen atom; Y is the same or different and each contains one or more phosphorus atoms; Z is a ligand other than X and Y; m is an integer of 1 to 6; P is an integer of 0-2; the sum of m, n and p is an integer of 2-6. ]
The manufacturing method which is a compound shown by these. The manufacturing method of Claim 1 whose rhenium is 3-7 valence in the said rhenium complex. In the said General formula (1), Y is a phosphine ligand, The manufacturing method of Claim 1 or 2. In the said General formula (1), Z is a ligand containing at least 1 sort (s) chosen from the group which consists of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. The manufacturing method of crab. The rhenium complex has the general formula (1A):

[In the formula, Z is the same as above; X ^{1 to} X ³ are the same or different, and each is a halogen atom; R ^{1 to} R ² are the same or different, and each is an optionally substituted aryl group; The bond represented is a single bond or a double bond; one R ¹ and one R ² may be bonded to each other to form a ring together with adjacent —P—Re—P—. ]
A compound represented by
The manufacturing method in any one of Claims 1-4. The alkali metal salt has the general formula (2):
MBR ³ ₄
[Wherein, M is an alkali metal; R ³ is the same or different and each represents an optionally substituted alkyl group or an optionally substituted aryl group. ]
The manufacturing method in any one of Claims 1-5 which is a salt shown by these. The production method according to any one of claims 1 to 6, wherein a ligand Y 'containing one or more phosphorus atoms is added in the hydrogenation reaction step. In the said General formula (1), Y 'is a phosphine ligand, The manufacturing method of Claim 7.