JPH11300212A - Oxidation catalyst system and oxidation method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate an oxidation product in a high selectivity by oxidizing a substrate to be oxidized having a carbon-hydrogen bonding at a site adjacent to an unsaturated bonding to be oxidized in a high conversion rate in an oxygen atmosphere at a normal pressure by a method wherein an oxidation catalytic system composed of a specifically structured imide compound and a specific organic salt is used. SOLUTION: In the case where an oxidation catalyst useful in preparation of alcohols, carboxylic acids, or the like is prepared, an organic salt composed of an imide compound expressed by the formula (wherein, R<1> , R<2> are same or different, and are each hydrogen, a halogen, an alkyl group, an aryl group, a cycloalkyl group, a hydroxyl group or the like; and R<1> , R<2> may from a double bond, or an aromatic or nonaromatic ring by being linked to each other; X indicates an oxygen atom or hydroxyl group, and (n) indicates an integer of 1 to 3), a polyatomic cation or a polyatomic anion including periodic table group 15 or group 16 elements wherein at least one organic group is bonded, and a counterion, is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an oxidation catalyst system useful for producing alcohols, carbonyl compounds, carboxylic acids and the like, and an oxidation method using the catalyst system.

[0002]

2. Description of the Related Art Since an oxidation reaction is one of the most basic reactions in the organic chemical industry, various oxidation methods have been developed. From a resource and environmental point of view, a preferred oxidation method is a catalytic oxidation method using molecular oxygen or air directly as an oxidizing agent. However, in the catalytic oxidation method,
Usually, high temperature and high pressure are required to activate oxygen, and in order to react under mild conditions, it is necessary to react in the presence of a reducing agent such as aldehyde. Therefore, using a catalytic oxidation method, under mild conditions, alcohols,
It has been difficult to easily and efficiently produce carbonyl compounds and carboxylic acids. JP-A-8-38909 and JP-A-9-327626 disclose, as a catalyst for oxidizing a substrate by molecular oxygen, an imide compound having a specific structure or a mixture of the imide compound and a transition metal compound. A structured oxidation catalyst has been proposed.
When this catalyst is used, the organic substrate can be oxidized under mild conditions, and oxidation products such as alcohols can be produced in a relatively high yield. However, from an industrial point of view, it is not yet a satisfactory method in terms of conversion, selectivity, and catalyst life. Further, when a transition metal compound is used, a metal is liable to be mixed into a product of a target oxidation product. Therefore, a high degree of purification is required for use in a field where a metal adversely affects physical properties.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel compound capable of efficiently oxidizing a substrate with molecular oxygen under mild conditions and producing a target oxidation product with high selectivity. An object of the present invention is to provide an oxidation catalyst system and an oxidation method using the same. Another object of the present invention is to provide an oxidation catalyst system capable of oxidizing a substrate with molecular oxygen at a high conversion rate without using a metal catalyst, and an oxidation method using the same. Another object of the present invention is to provide an oxidation catalyst system having a long catalyst life. Still another object of the present invention is to provide an oxidation catalyst system and an oxidation method capable of producing alcohols, carbonyl compounds, and organic carboxylic acids at a high yield under mild conditions. Still another object of the present invention is to provide a simple method for producing α-hydroxycarboxylic acid or a derivative thereof, or α-ketocarboxylic acid or a derivative thereof.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, when an oxidation catalyst system composed of an imide compound having a specific structure and a specific organic salt is used, the oxidation catalyst system has a normal pressure. Under an oxygen atmosphere, an oxidizable substrate such as a compound having a carbon-hydrogen bond at a site adjacent to an unsaturated bond can be oxidized at a high conversion rate, and oxidation products such as alcohols are generated at a high selectivity. And completed the present invention.

That is, the oxidation catalyst system of the present invention comprises (A)
The following equation (1)

Embedded image (Wherein R ¹ and R ² are the same or different and each represents a hydrogen atom,
A halogen atom, an alkyl group, an aryl group, a cycloalkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or an acyl group; R ¹ and R ² are bonded to each other to form a double bond, or A non-aromatic ring may be formed. X represents an oxygen atom or a hydroxyl group, n represents an integer of 1 to 3), and (B) an element belonging to Group 15 or 16 of the periodic table to which at least one organic group is bonded. And an organic salt composed of a polyatomic cation or polyatomic anion and a counter ion. In the oxidation method of the present invention, the substrate is brought into contact with molecular oxygen in the presence of the above-mentioned oxidation catalyst system. Further, the present invention provides a method for reacting a carboxylic acid having 2 or more carbon atoms having at least one hydrogen atom at the α-position or a derivative thereof with molecular oxygen in the presence of the above-mentioned oxidation catalyst system to form a hydroxyl group at the α-position. Alternatively, the present invention provides a method for producing an α-hydroxycarboxylic acid or a derivative thereof, or an α-ketocarboxylic acid or a derivative thereof to obtain a corresponding carboxylic acid having 2 or more carbon atoms or a derivative thereof bonded to an oxo group.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION [Imide compound (A)] In the imide compound (A) represented by the above formula (1), halogen atoms among the substituents R ¹ and R ² include iodine, bromine, chlorine and Contains fluorine. In the alkyl group, for example,
C1-C1 such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, hexyl, heptyl, octyl and decyl groups
It contains about 0 linear or branched alkyl groups. Preferred alkyl groups include, for example, lower alkyl groups having about 1 to 6 carbon atoms, particularly about 1 to 4 carbon atoms.

The aryl group includes phenyl and naphthyl groups, and the cycloalkyl group includes cyclopentyl,
And a cyclohexyl group. The alkoxy group includes
For example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, t-butoxy, pentyloxy, hexyloxy group and the like about 1 to 10 carbon atoms, preferably about 1 to 6 carbon atoms, particularly about 1 to 4 carbon atoms Lower alkoxy groups.

The alkoxycarbonyl group includes, for example, a carbon atom of an alkoxy moiety such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, t-butoxycarbonyl, pentyloxycarbonyl and hexyloxycarbonyl. The number includes about 1 to 10 alkoxycarbonyl groups. Preferred alkoxycarbonyl groups include lower alkoxycarbonyl groups having about 1 to 6, particularly about 1 to 4, carbon atoms in the alkoxy moiety.

Examples of the acyl group include those having 1 to 6 carbon atoms such as formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl and pivaloyl groups.
A certain number of acyl groups can be exemplified.

The substituents R ¹ and R ² may be the same or different. In the formula (1), R ¹ and R ² may be bonded to each other to form a double bond or a ring having an aromatic or non-aromatic attribute. The preferred aromatic or non-aromatic ring is a 5- to 12-membered ring, particularly a 6- to 10-membered ring, and may be a heterocyclic ring or a fused heterocyclic ring, but is often a hydrocarbon ring. Such rings include, for example,
Non-aromatic alicyclic ring (cycloalkane ring optionally having a substituent such as cyclohexane ring, cycloalkene ring optionally having a substituent such as cyclohexene ring), non-aromatic bridge A bridged ring (eg, a bridged hydrocarbon ring which may have a substituent such as a 5-norbornene ring),
An aromatic ring (including a condensed ring) which may have a substituent such as a benzene ring and a naphthalene ring is included. The ring is
Often composed of aromatic rings. The ring is an alkyl group, a haloalkyl group, a hydroxyl group, an alkoxy group,
Carboxyl group, alkoxycarbonyl group, acyl group,
It may have a substituent such as a nitro group, a cyano group, an amino group, and a halogen atom.

The preferred imide compound (A) includes a compound represented by the following formula.

Embedded image (Wherein, R ^{3 to} R ⁶ are the same or different and each represents a hydrogen atom, an alkyl group, a haloalkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an acyl group, a nitro group, a cyano group, an amino group, R ^{3 to} R ⁶ may be a group in which adjacent groups are bonded to each other to form an aromatic or non-aromatic ring.
R ¹ , R ² and n are the same as described above) In the substituents R ^{3 to} R ⁶ , the alkyl group includes the same alkyl group as the above-described alkyl group, particularly an alkyl group having about 1 to 6 carbon atoms. A haloalkyl group having about 1 to 4 carbon atoms such as a trifluoromethyl group; an alkoxy group having the same alkoxy group as described above, particularly a lower alkoxy group having about 1 to 4 carbon atoms and an alkoxycarbonyl group; Includes the same alkoxycarbonyl group as described above, particularly a lower alkoxycarbonyl group having about 1 to 4 carbon atoms in the alkoxy moiety. Examples of the acyl group include the same acyl groups as described above, particularly an acyl group having about 1 to 6 carbon atoms. Examples of the halogen atom include fluorine,
Chlorine and bromine atoms can be exemplified. The substituents R ^{3 to} R ⁶ are usually a hydrogen atom, a lower alkyl group having about 1 to 4 carbon atoms, a carboxyl group, a nitro group, or a halogen atom in many cases. The ring formed by combining R ^{3 to} R ⁶ with each other is the same as the ring formed by combining R ¹ and R ² with each other, and in particular, an aromatic or non-aromatic 5- to 12-membered ring Is preferred.

In the general formula (1), X represents an oxygen atom or a hydroxyl group, and the bond between the nitrogen atom N and X is a single bond or a double bond. n is usually about 1 to 3,
Preferably it is 1 or 2. One or more compounds represented by the formula (1) can be used in the oxidation reaction.

The acid anhydride corresponding to the imide compound represented by the above formula (1) includes, for example, saturated or unsaturated aliphatic dicarboxylic anhydrides such as succinic anhydride and maleic anhydride, tetrahydrophthalic anhydride, Hexahydrophthalic anhydride (1,2-cyclohexanedicarboxylic anhydride),
1,2,3,4-cyclohexanetetracarboxylic acid 1,
Saturated or unsaturated non-aromatic cyclic polycarboxylic acid anhydrides such as 2-anhydrides (alicyclic polycarboxylic acid anhydrides), bridged cyclic polycarboxylic acids such as hetic anhydride and hymic anhydride Anhydrides (alicyclic polycarboxylic anhydrides), phthalic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, nitrophthalic anhydride, trimetic anhydride, methylcyclohexentricarboxylic anhydride, pyromellitic anhydride, anhydride Includes aromatic polycarboxylic anhydrides such as melitic acid, 1,8; 4,5-naphthalenetetracarboxylic dianhydride.

Preferred imide compounds include, for example,
N-hydroxysuccinimide, N-hydroxymaleimide, N-hydroxyhexahydrophthalimide, N, N'-dihydroxycyclohexanetetracarboxylic imide, N-hydroxyphthalimide, N-hydroxytetrabromophthalimide N-hydroxytetrachlorophthalic imide, N-hydroxyhetic imide, N-hydroxyhymic imide, N-hydroxytrimellitic imide, N, N'-dihydroxypyromellitic imide, N, N'-dihydroxy And naphthalenetetracarboxylic imide. Particularly preferred compounds are alicyclic polycarboxylic anhydrides or aromatic polycarboxylic anhydrides, especially N-hydroxyimide compounds derived from aromatic polycarboxylic anhydrides,
For example, N-hydroxyphthalimide is included. The imide compound can be prepared by a conventional imidization reaction, for example, the corresponding acid anhydride and hydroxylamine NH ₂ OH
And imidization via ring opening and ring closure of the acid anhydride group.

[Organic salt (B)] The feature of the present invention is that the imide compound (A) and a polyatomic cation or polyatomic compound containing an element belonging to Group 15 or 16 of the periodic table to which at least one organic group is bonded. The point is that an organic salt (B) composed of an anion and a counter ion is combined.

In the organic salt (B), Group 15 elements of the periodic table include N, P, As, Sb, and Bi. Periodic Table 1
Group 6 elements include O, S, Se, Te, and the like. Preferred elements include N, P, As, Sb, and S, and particularly preferred are N, P, and S.

The organic group bonded to the element atom includes a hydrocarbon group which may have a substituent, a substituted oxy group, and the like. Examples of the hydrocarbon group include about 1 to 30 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, hexyl, octyl, decyl, tetradecyl, hexadecyl, octadecyl, and allyl ( Preferably 1 to 2 carbon atoms
0) linear or branched aliphatic hydrocarbon groups (alkyl group, alkenyl group and alkynyl group); cyclopentyl, cyclohexyl and other alicyclic hydrocarbon groups having about 3 to 8 carbon atoms; phenyl, naphthyl 6-1 such as carbon number
About four aromatic hydrocarbon groups are exemplified. Examples of the substituent which the hydrocarbon group may have include, for example, a halogen atom, an oxo group, a hydroxyl group, a substituted oxy group (for example, an alkoxy group, an aryloxy group, an acyloxy group, etc.), a carboxyl group, a substituted oxycarbonyl group A substituted or unsubstituted carbamoyl group, a cyano group, a nitro group, a substituted or unsubstituted amino group, an alkyl group (for example, methyl,
Examples thereof include a C _1-4 alkyl group such as an ethyl group, a cycloalkyl group, an aryl group (eg, a phenyl and naphthyl group), and a heterocyclic group. Preferred hydrocarbon groups include alkyl groups having about 1 to 30 carbon atoms, and 6-1 to carbon atoms.
About 4 aromatic hydrocarbon groups (particularly, phenyl group or naphthyl group) are included. The substituted oxy group includes an alkoxy group, an aryloxy group, an aralkyloxy group and the like.

The polyatomic cation is represented, for example, by the following formula (2). The polyatomic cation forms an organic onium salt represented by the following formula (3) together with the counter anion.

[0019] _{^{[R a m A] + (}} 2) [R a m A] + Y - shows the (3) In the formula, R ^a is a hydrocarbon group or a hydrogen atom. Four R ^a may be the same or different from each other, at least one of R ^a is a hydrocarbon group. A represents an atom of a Group 15 or 16 element of the periodic table. Two R ^a may form a ring together with A adjacent bonded to each other, also, two R ^a is bonded to another R ^a to form the A and double bond together A And may form a ring. m represents 3 or 4. Y ^- represents a counter anion, and Y represents an acid group. In addition, the said hydrocarbon group may have the said substituent, for example.

[0020] As the ring two R ^a form with A adjacent bonded to each other, pyrrolidine ring, 3-8 membered piperidine ring (preferably 5- to 6-membered) about the nitrogen-containing (or phosphorus-containing ) Heterocycles and the like. Further, the two R ^a together form a double bond with A and also form a double bond with A by combining with other R ^a to form a 5- to 8-membered nitrogen-containing heterocyclic ring such as a pyridine ring. And the like. These rings may be condensed with a ring such as a benzene ring.
Examples of such a condensed ring include a quinoline ring. When A is an atom of a group 15 element in the periodic table, m is often 4, and when A is an atom of a group 16 element in the periodic table, m is 3 in many cases.

A is preferably N, P, As, S
b or S, and more preferably N, P or S
In particular, N or P is preferable. Further, in the preferred polyatomic cations, (including the case where the ring containing A is formed), all four R ^a is an organic group. Examples of the acid group Y include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; a nitrate group (NO ₃ ) and a sulfate group (S
Inorganic acid groups such as O ₄ ), phosphoric acid group (PO ₄ ) and perchloric acid group (ClO ₄ ); organic acid groups such as acetic acid group (CH ₃ CO ₂ ), methanesulfonic acid group and benzenesulfonic acid group Is mentioned. Preferred acid groups include a halogen atom and an inorganic acid group, and a halogen atom such as a chlorine atom or a bromine atom is particularly preferred.

Among the above-mentioned organic onium salts, organic ammonium salts, organic phosphonium salts, organic sulfonium salts and the like are particularly preferred. Specific examples of the organic ammonium salt include tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, tetrahexylammonium chloride, trioctylmethylammonium chloride, triethylphenylammonium chloride, tributyl (hexadecyl)
Quaternary ammonium chlorides, such as ammonium chloride, di (octadecyl) dimethylammonium chloride, and the corresponding quaternary ammonium bromides,
A quaternary ammonium salt in which four hydrocarbon groups are bonded to a nitrogen atom; and cyclic quaternary ammonium salts such as dimethylpiperidinium chloride, hexadecylpyridinium chloride, and methylquinolinium chloride.

Specific examples of the organic phosphonium salt include quaternary phosphonium chlorides such as tetramethylphosphonium chloride, tetrabutylphosphonium chloride, tributyl (hexadecyl) phosphonium chloride and triethylphenylphosphonium chloride, and corresponding quaternary phosphonium chlorides. 4 to the phosphorus atom, such as bromide
And quaternary phosphonium salts in which two hydrocarbon groups are bonded. Specific examples of the organic sulfonium salt include a sulfonium salt in which three hydrocarbon groups are bonded to a sulfur atom, such as triethylsulfonium iodide and ethyldiphenylsulfonium iodide.

The polyatomic anion is represented, for example, by the following formula (4). This polyatomic anion forms an organic salt represented by the following formula (5) together with the counter cation.

[R ^b AO ₃ ] ^q- (4) Z ^{q +} [R ^b AO ₃ ] ^q- (5) In the above formula, R ^b represents a hydrocarbon group or a hydrogen atom. A represents an atom of a Group 15 or 16 element of the periodic table. q represents 1 or 2, and Z ^{q +} represents a counter cation. Examples of the hydrocarbon group represented by R ^b include the same groups as described above,
Resins (polymer chains or branched chains thereof). Preferred A includes S, P and the like. When A is S or the like, q is 1; when A is P or the like, q is 2.
Examples of Z include alkali metals such as sodium and potassium; and alkaline earth metals such as magnesium and calcium. Preferred Z includes an alkali metal. Z ^{q +} may be a polyatomic cation as described above.

As the organic salt represented by the above formula (5),
Alkyl sulfonates such as methane sulfonate, ethane sulfonate, octane sulfonate, dodecane sulfonate; benzene sulfonate, p-toluene sulfonate, naphthalene sulfonate, decylbenzene sulfonate, dodecyl Aryl sulfonates which may be substituted with an alkyl group such as benzene sulfonate; sulfonic acid type ion exchange resins (ion exchangers); phosphonic acid type ion exchange resins (ion exchangers). Among them, a C _6-18 alkyl sulfonate and a C _6-18 alkyl-aryl sulfonate are often used. The organic salts (B) can be used alone or in combination of two or more. The catalyst system of the present invention may contain other catalyst components in addition to the components (A) and (B).

The catalyst system of the present invention may be a homogeneous system,
It may be heterogeneous. Further, the catalyst component may be used as a solid catalyst supported on a carrier. As the carrier, a porous carrier such as activated carbon, zeolite, silica, silica-alumina and bentonite is often used.

The amount of the imide compound (A) used can be selected in a wide range, for example, from 0.0001 mol (0.01 mol%) to 1 mol (100 mol) per 1 mol of the oxidizable substrate.
Mol%), preferably 0.001 mol (0.1 mol%)
0.5 mol (50 mol%), more preferably 0.0 mol
It is about 1 mol (1 mol%) to 0.30 mol (30 mol%), and 0.02 mol (2 mol%) to 0.25 mol (2 mol%).
5 mol%) in many cases.

The amount of the organic salt (B) to be used can be appropriately selected within a range that does not decrease the reactivity and the selectivity. For example, 0.0001 mol (0.01 mol) per 1 mol of the oxidizable substrate. %) To 0.7 mol (70 mol%), preferably 0.001 mol (0.1 mol%) to 0.5 mol (50 mol%), and more preferably 0.002 mol (0.2 mol%). ) To about 0.1 mol (10 mol%), and often about 0.005 mol (0.5 mol%) to 0.05 mol (5 mol%). If the amount of the organic salt (B) is too large, the reaction rate may decrease.

The imide compound (A) and the organic salt (B)
Can be selected to the extent that the reaction rate and selectivity are not impaired. For example, imide compound (A) / organic salt (B) (molar ratio) = 95/5 to 5/95, preferably 90/10 to 2
0/80, more preferably about 90/10 to 50/50.

When such an oxidation catalyst system is used, the decomposition of hydroperoxide generated by the reaction between the imide compound (A) and oxygen is remarkably promoted by the anion or cation of the organic salt (B), and the oxy radical generated there Probably because the substrate is rapidly oxidized, the oxidation reaction proceeds efficiently and an oxidation product is obtained in a high yield.
Further, compared to a conventional catalyst system combining the imide compound and a transition metal catalyst, degradation of the imide compound,
Deterioration is suppressed and high activity is maintained for a long time.

[Oxidation method] In the oxidation method of the present invention, molecular oxygen is brought into contact with a substrate in the presence of the catalyst system to oxidize. The substrate includes various oxidizable compounds that can be oxidized by molecular oxygen.

As preferred substrates, (a) a compound having a carbon-hydrogen bond at a site adjacent to an unsaturated bond, (b)
A compound having a methine carbon atom, (c) a non-aromatic cyclic hydrocarbon, (d) a non-aromatic heterocyclic compound having a carbon-hydrogen bond at a position adjacent to a hetero atom, (e) a conjugated compound,
(F) alcohols or thiols, (g) ethers or thioethers, (h) aldehydes or thioaldehydes, and (i) amines.
These compounds have various substituents such as halogen atom, oxo group, hydroxyl group, mercapto group, substituted oxy group (for example, alkoxy group, aryloxy group, acyloxy group, etc.), substituted thio group, carboxyl group, substituted Oxycarbonyl group, substituted or unsubstituted carbamoyl group, cyano group, nitro group, substituted or unsubstituted amino group, alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, aryl group (for example, phenyl, naphthyl group ), An aralkyl group, a heterocyclic group, and the like.

(A) a carbon atom at a site adjacent to an unsaturated bond
Compound having a hydrogen bond Compound (a) having a carbon-hydrogen bond at a site adjacent to an unsaturated bond includes (a1) an aromatic compound having a methyl group or a methylene group at a position adjacent to an aromatic ring (so-called benzyl position). Group compounds, and (a2) non-aromatic compounds having a methyl group or a methylene group at a position adjacent to an unsaturated bond (for example, a carbon-carbon unsaturated bond, a carbon-oxygen double bond, etc.).

In the aromatic compound (a1), the aromatic ring may be any of an aromatic hydrocarbon ring and an aromatic heterocyclic ring. The aromatic hydrocarbon ring includes a benzene ring, a condensed carbocyclic ring (for example, naphthalene, azulene, indacene, anthracene, phenanthrene, triphenylene,
A condensed carbocycle in which 2 to 10 4- to 7-membered carbocycles such as pyrene are condensed, and the like. Examples of the aromatic heterocyclic ring include, for example, a heterocyclic ring containing an oxygen atom as a hetero atom (for example, a 5-membered ring such as furan, oxazole, and isoxazole; a 6-membered ring such as 4-oxo-4H-pyran;
Benzofuran, isobenzofuran, 4-oxo-4H-
A fused ring such as chromene, etc.), a heterocyclic ring containing a sulfur atom as a hetero atom (for example, thiophene, thiazole,
5-membered rings such as isothiazole and thiadiazole, 6-membered rings such as 4-oxo-4H-thiopyran, condensed rings such as benzothiophene, etc., heterocycles containing a nitrogen atom as a hetero atom (for example, pyrrole, pyrazole, imidazole, 5-membered ring such as triazole, 6-membered ring such as pyridine, pyridazine, pyrimidine and pyrazine, indole,
Condensed rings of quinoline, acridine, naphthyridine, quinazoline, purine and the like) and the like.

The methylene group adjacent to the aromatic ring may be a methylene group constituting a non-aromatic ring fused to the aromatic ring. Further, the aromatic compound (a
In 1), both a methyl group and a methylene group may be present at positions adjacent to the aromatic ring.

Examples of the aromatic compound having a methyl group at the adjacent position of the aromatic ring include aromatic hydrocarbons having about 1 to 6 methyl groups substituted on the aromatic ring (for example, toluene, xylene, -Ethyl-4-methylbenzene, 1-
Ethyl-3-methylbenzene, 1-t-butyl-4-methylbenzene, 1-methoxy-4-methylbenzene, mesitylene, durene, methylnaphthalene, methylanthracene, 4,4'-dimethylbiphenyl, etc.) Heterocyclic compounds substituted with about 1 to 6 methyl groups (for example, 2-methylfuran, 3-methylfuran, 3-methylthiophene, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2,4 -Dimethylpyridine,
2,4,6-trimethylpyridine, 4-methylindole, 2-methylquinoline, etc.).

Examples of the aromatic compound having a methylene group at the adjacent position of the aromatic ring include aromatic hydrocarbons having an alkyl group or a substituted alkyl group having 2 or more carbon atoms (eg, ethylbenzene, propylbenzene, , 4-diethylbenzene, diphenylmethane, etc.), aromatic heterocyclic compounds having an alkyl group or a substituted alkyl group having 2 or more carbon atoms (eg, 2-ethylfuran, 3-propylthiophene, 4-ethylpyridine, 4-butylquinoline) Etc.), a compound in which a non-aromatic ring is fused to an aromatic ring, and a compound having a methylene group at a site adjacent to the aromatic ring among the non-aromatic rings (dihydronaphthalene,
Indene, indane, tetralin, fluorene, acenaphthene, phenalene, indanone, xanthene and the like).

The non-aromatic compound (a2) having a methyl group or a methylene group at a position adjacent to the unsaturated bond includes, for example,
(A2-1) Chain unsaturated hydrocarbons having a methyl group or a methylene group at an allyl position, and (a2-2) compounds having a methyl group or a methylene group at a position adjacent to a carbonyl group can be exemplified.

Examples of the chain unsaturated hydrocarbons (a2-1) include propylene, 1-butene, 2-butene,
Examples thereof include linear unsaturated hydrocarbons having about 3 to 20 carbon atoms, such as -pentene, 1-hexene, 2-hexene, 1,5-hexadiene, 1-octene, 3-octene, and undecatriene. The compound (a2-2) includes ketones (for example, chain ketones such as acetone, methyl ethyl ketone, 3-pentanone, and acetophenone; cyclic ketones such as cyclohexanone), carboxylic acids and derivatives thereof (for example, acetic acid and propion). Acids, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, phenylacetic acid, malonic acid, succinic acid, glutaric acid, and esters thereof).

Compound (a) having a carbon-hydrogen bond at a site adjacent to the unsaturated bond is converted to a compound (a) in the presence of the oxidation catalyst system.
When oxidized by molecular oxygen, the site adjacent to the unsaturated bond is efficiently oxidized to produce an alcohol, a carbonyl compound or a carboxylic acid. For example, from a compound having a methyl group at a site adjacent to an unsaturated bond, primary alcohols, aldehydes or carboxylic acids, particularly carboxylic acids, can be obtained in high yield. In particular,
For example, benzoic acid can be obtained in good yield from toluene.
From compounds having a methylene group at a site adjacent to the unsaturated bond, secondary alcohols or ketones, particularly ketones, can be obtained in high yield. For example, oxidation of tetralin produces mainly α-tetralone,
Oxidation of fluorene produces fluorenone. Further, when the ketones are oxidized, they are often cleaved to produce aldehydes or carboxylic acids. In particular, when a cyclic ketone such as cyclohexanone is used as a substrate, a dicarboxylic acid such as adipic acid can be obtained in a high yield.

The chain unsaturated hydrocarbons (a2-1)
When a compound having a carbon-carbon double bond is oxidized as in, for example, oxygen is introduced into the carbon-carbon double bond depending on the oxidation conditions, and a corresponding epoxy compound may be obtained.

In a preferred method of the present invention, a benzene derivative having a carboxyl group, which is an industrially useful compound (for example, Benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, etc.), aromatic hydrocarbons substituted with an alkyl group having about 2 to 6 carbon atoms (eg, ethylbenzene, etc.)
Is contacted with oxygen to produce a benzene derivative having a carbonyl group which is an industrially useful compound (for example, acetophenone).

(B) Compound having a methine carbon atom The compound (b) having a methine carbon atom (or a tertiary carbon atom) has a methine group (ie, a methine carbon-hydrogen bond) as a structural unit of the ring (b1). A) a cyclic compound containing (b)
2) Includes chain compounds having a methine carbon atom.

The cyclic compound (b1) includes (b1-1) a bridged cyclic compound having at least one methine group, (b1-2)
Non-aromatic cyclic compounds in which a hydrocarbon group is bonded to a ring (such as alicyclic hydrocarbons) are included. The bridged cyclic compound also includes a compound in which two rings share two carbon atoms, for example, a hydrogenated product of a condensed polycyclic aromatic hydrocarbon.

As the bridged cyclic compound (b1-1), for example, decalin, bicyclo [2.2.0] hexane, bicyclo [2.2.2] octane, bicyclo [3.2.1]
Octane, bicyclo [4.3.2] undecane, tuzeon, karan, pinan, pinene, bornane, bornylene,
Norbornane, norbornene, camphor, camphoric acid, camphene, tricyclene, tricyclo [4.3.
1.1 ^2,5 ] undecane, tricyclo [5.2.1.0
^3,8 ] decane, exotricyclo [5.2.1.0 ^2,6 ]
Decane, endotricyclo [5.2.1.0 ^2,6 ] decane, endotricyclo [5.2.2.0 ^2,6 ] undecane, adamantane, 1-adamantanol, 1-chloroadamantane, 1- Methyl adamantane, 1,3-dimethyl adamantane, 1-methoxy adamantane, 1-carboxy adamantane, 1-methoxy carbonyl adamantane, 1-nitro adamantane, tetracyclo [4.
4.0.1 ^2,5 . 1 ^7,10 ] 2- to 4-cyclic bridged cyclic hydrocarbons or bridges such as dodecane, perhydroanthracene, perhydroacenaphthene, perhydrophenanthrene, perhydrofluorene, perhydrophenalene, perhydroindene, quinuclidine and the like Heterocyclic compounds and their derivatives. These bridged cyclic compounds have a methine carbon atom at the bridgehead position (corresponding to the junction if two rings share two atoms).

Examples of the non-aromatic cyclic compound (b1-2) having a hydrocarbon group bonded to the ring include 1-methylcyclopentane,
1-methylcyclohexane, limonene, menthen, menthol, carbomentone, mentone, etc.
An alicyclic hydrocarbon having about 3 to 15 members in which about 20 (preferably 1 to 10) hydrocarbon groups (eg, an alkyl group or the like) are bonded to a ring and a derivative thereof are exemplified. Non-aromatic cyclic compound with a hydrocarbon group bonded to the ring (b1-2)
Has a methine carbon atom at the binding site between the ring and the hydrocarbon group.

Chain compound having methine carbon atom (b2)
As a chain hydrocarbon having a tertiary carbon atom, for example, isobutane, isopentane, isohexane,
Aliphatic having about 4 to 20 (preferably 4 to 10) carbon atoms such as methylpentane, 2,3-dimethylbutane, 2-methylhexane, 3-methylhexane, 3,4-dimethylhexane, and 3-methyloctane. Examples thereof include hydrocarbons and derivatives thereof.

When the above-mentioned oxidation catalyst system is used, the compound (b) having a methine carbon atom can be efficiently oxidized, and an alcohol derivative having a methine carbon with a hydroxyl group introduced can be obtained in a high yield. For example, when a bridged cyclic hydrocarbon (b1-1) such as adamantane is oxidized, an alcohol derivative having a hydroxyl group introduced at the bridgehead position, for example, 1-hydroxyadamantane (1, 1
3-Dihydroxyadamantane and 1,3,5-trihydroxyadamantane) are obtained in high yield. In addition,
In a compound having a methylene group at a site adjacent to the bridgehead position such as adamantane, a ketone derivative having an oxo group introduced into the methylene group (for example, 2-adamantanone) may be generated depending on oxidation conditions. Further, when a chain compound (b2) having a methine carbon atom such as isobutane is oxidized, a tertiary alcohol such as t-butanol can be obtained in a high yield.

(C) Non-aromatic cyclic hydrocarbon The non-aromatic cyclic hydrocarbon (c) includes (c1) cycloalkanes and (c2) cycloalkenes. As the cycloalkanes (c1), compounds having a 3 to 30-membered cycloalkane ring, for example, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane,
Examples thereof include cyclododecane, cyclotetradecane, cyclohexadecane, cyclotetracosane, cyclotriacontane, and derivatives thereof. Preferred cycloalkane rings include 5 to 30 membered, especially 5 to 20 membered cycloalkane rings.

When such cycloalkanes (c1) are oxidized in the presence of the oxidation catalyst system of the present invention, the corresponding dicarboxylic acid or cycloalkane can be obtained in a high yield even under an atmospheric air or oxygen atmosphere. Alkanone is produced. For example, oxidizing cyclohexane can provide adipic acid with high conversion and selectivity. In addition, even for macrocyclic cycloalkanes having 8 or more members, particularly 9 members or more, having low reactivity to oxidation, the reactivity to oxygen is improved, and ketones and dicarboxylic acids (particularly, macrocyclic monoketones) are obtained in high yield. , Long chain dicarboxylic acids). For example, oxidation of cyclooctane produces cyclooctanone and suberic acid.

The cycloalkenes (c2) include compounds having a 3- to 30-membered cycloalkene ring, for example, cyclopropene, cyclobutene, cyclopentene, cyclooctene, cyclohexene, 1-methyl-cyclohexene, isophorone, cycloheptene, cyclododeca In addition to ene and the like, cycloalkadienes such as cyclopentadiene, 1,3-cyclohexadiene and 1,5-cyclooctadiene, cycloalkatrienes such as cyclooctatriene, and derivatives thereof are included. Preferred cycloalkenes include compounds having a 3-20 membered ring, especially a 3-12 membered ring. When the cycloalkenes (c2) are oxidized using the oxidation catalyst system of the present invention, the corresponding oxides, particularly cycloalkenones and cycloalkenols, can be obtained in high yield. Further, depending on the reaction conditions, an epoxy compound in which oxygen is introduced into a carbon-carbon double bond can be obtained.

(D) Non-aromatic heterocyclic compound having a carbon-hydrogen bond adjacent to the hetero atom Non-aromatic heterocyclic compound having a carbon-hydrogen bond adjacent to the hetero atom (d) Group heterocycles include:
It includes a 3 to 20 membered (preferably 5 to 12 membered, more preferably 5 or 6 membered) heterocyclic ring having at least one hetero atom selected from a nitrogen atom, an oxygen atom and a sulfur atom. One or two or more aromatic or non-aromatic rings such as a benzene ring, a cyclohexane ring, and a pyridine ring may be condensed with the heterocyclic ring. Examples of the heterocycle include dihydrofuran, tetrahydrofuran, pyran, dihydropyran, tetrahydropyran, pyrrolidine, piperidine, piperazine, morpholine, indoline, chroman, isochroman and the like.

When the non-aromatic heterocyclic compound (d) is oxidized in the presence of the oxidation catalyst system of the present invention, a hydroxyl group or an oxo group is introduced at a position adjacent to the hetero atom, and the corresponding hydroxyl group or carbonyl group is introduced. A containing compound (eg, lactone, lactam, etc.) can be obtained.

(E) Conjugated Compound The conjugated compound (e) includes conjugated dienes (e1), α, β-
Unsaturated nitrile (e2), α, β-unsaturated carboxylic acid or derivative thereof (eg, ester, amide, acid anhydride, etc.)
(E3) and the like.

Examples of the conjugated dienes (e1) include butadiene, isoprene, 2-chlorobutadiene and 2-ethylbutadiene. The conjugated dienes (e1) include compounds in which a double bond and a triple bond are conjugated, for example, vinyl acetylene and the like. Oxidation of the conjugated dienes (e1) produces alkenediols and the like. For example, when butadiene is oxidized, 2
-Butene-1,4-diol, 1-butene-3,4-diol and the like are obtained.

As the α, β-unsaturated nitrile (e2),
For example, (meth) acrylonitrile and the like can be mentioned.
Examples of the α, β-unsaturated carboxylic acid or its derivative (e3) include (meth) acrylic acid; methyl (meth) acrylate,
(Meth) acrylic esters such as ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate; (meth) acrylamide, N-methylol (meth) And (meth) acrylamide derivatives. These α, β-unsaturated nitriles (e2), α, β-unsaturated carboxylic acids or derivatives thereof (e
When 3) is oxidized, the α, β-unsaturated bond site is selectively oxidized, the unsaturated bond becomes a single bond, and the β-position is a formyl group, an acetal group (when reacted in the presence of an alcohol) ) Or an acyloxy group (when reacted in the presence of a carboxylic acid).
More specifically, for example, when acrylonitrile and methyl acrylate are oxidized in the presence of methanol, 3,3-dimethoxypropionitrile and 3,3
-Methyl dimethoxypropionate is formed.

(F) Alcohols or thiols Alcohols include methanol, ethanol, 1-
Propanol, isopropanol, 1-butanol, 1
-Hexanol, 1-octanol, 1-decanol,
Myristyl alcohol, allyl alcohol, crotyl alcohol, propargyl alcohol, ethylene glycol, propylene glycol, 1,3-butanediol,
Aliphatic alcohols such as 1,4-butanediol, neopentyl glycol and glycerin; cyclopentanol, cyclohexanol, methylcyclohexanol,
Alicyclic alcohols such as cyclohexen-1-ol, 1,2-cyclohexanediol and 1,4-cyclohexanediol; and aromatic alcohols such as benzyl alcohol, salicyl alcohol, benzhydrol, and phenethyl alcohol. Preferred alcohols include alcohols having a hydroxyl group bonded to a carbon atom at a site adjacent to an unsaturated bond (eg, allyl alcohol, benzyl alcohol, etc.), alicyclic alcohols (eg, cyclohexanol, etc.), and the like. It is. Examples of thiols include thiols corresponding to the alcohols. When alcohols are oxidized,
Depending on the reaction conditions, the corresponding carbonyl compound (aldehyde or ketone) and / or carboxylic acid is produced.

(G) Ethers or thioethers Ethers include diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether,
Aliphatic ethers such as methyl ethyl ether, methyl butyl ether, ethyl butyl ether, diallyl ether, methyl vinyl ether, ethyl allyl ether;
And aromatic ethers such as anisole, phenetole, dibenzyl ether and phenylbenzyl ether. Examples of the thioethers include thioethers corresponding to the above ethers. When ethers are oxidized, adjacent positions of oxygen atoms forming an ether bond are oxidized to generate corresponding esters, acid anhydrides and the like.

(H) Aldehydes or thioaldehydes Examples of the aldehydes include aliphatic aldehydes such as acetaldehyde, propionaldehyde, hexanal, decanal, succinaldehyde, glutaraldehyde, and adipaldehyde; alicyclics such as formylcyclohexane, citral, and citronellal. Formula aldehydes; aromatic aldehydes such as benzaldehyde, nitrobenzaldehyde, cinnamaldehyde, salicylaldehyde, anisaldehyde, phthalaldehyde, isophthalaldehyde, and terephthalaldehyde; and heterocyclic aldehydes such as furfural and nicotinaldehyde.
The thioaldehydes include thioaldehydes corresponding to the aldehydes. Oxidation of the aldehyde gives the corresponding carboxylic acid in high yield.

(I) Amines As the amines (i), primary or secondary amines,
For example, methylamine, ethylamine, propylamine, butylamine, dimethylamine, diethylamine,
Examples thereof include aliphatic amines such as dibutylamine, ethylenediamine, 1,4-butanediamine, hydroxylamine, and ethanolamine; alicyclic amines such as cyclopentylamine and cyclohexylamine; and aromatic amines such as benzylamine and toluidine. Amines are
Oxidation converts it to the corresponding Schiff base, oxime and the like.

The molecular oxygen used for the oxidation of the substrate is not particularly limited, and pure oxygen may be used, or oxygen diluted with an inert gas such as nitrogen, helium, argon or carbon dioxide may be used. Is also good. It is preferable to use air from the viewpoint of economy as well as operability and safety.

The amount of the molecular oxygen to be used can be selected according to the type of the substrate and the target compound, and is usually 0.5 mol or more (for example, 1 mol or more), preferably 1 to 100 mol per 1 mol of the substrate. Mol, more preferably about 2 to 50 mol. Often, an excess of molecular oxygen is used relative to the substrate.

In the oxidation method of the present invention, water may be present in the reaction system. The presence of an appropriate amount of water increases the reaction rate. Note that water may be generated by the reaction depending on the type of the substrate and the like. The addition amount of water is, for example, 0.01 to 20 mol, preferably 0.1 to
It is about 10 mol, and is about 0.01 to 10 parts by weight, preferably about 0.05 to 5 parts by weight, based on 100 parts by weight of the reaction mixture. If the amount of water is too large, the reaction will be inhibited.

The oxidation method of the present invention is usually carried out in an organic solvent. Examples of the organic solvent include organic acids such as acetic acid and propionic acid; nitriles such as acetonitrile, propionitrile and benzonitrile; formamide;
Amides such as acetamide, dimethylformamide (DMF) and dimethylacetamide; t-butanol, t
-Alcohols such as amyl alcohol; aliphatic hydrocarbons such as hexane and octane; aromatic hydrocarbons such as benzene and toluene; halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, carbon tetrachloride, chlorobenzene and trifluoromethylbenzene. Nitro compounds such as nitrobenzene, nitromethane and nitroethane; esters such as ethyl acetate and butyl acetate; ethers such as diethyl ether and diisopropyl ether; mixed solvents thereof. As the solvent,
Organic acids such as acetic acid, nitriles such as benzonitrile, and halogenated hydrocarbons such as trifluoromethylbenzene are often used. In the method of the present invention, when an aromatic compound, for example, a benzene derivative is used,
High conversions are often obtained.

In the method of the present invention, the oxidation reaction proceeds smoothly even under relatively mild conditions. The reaction temperature can be appropriately selected according to the type of the substrate and the like.
Preferably from 30 to 250 ° C, more preferably from 40 to 2 ° C.
It is about 00 ° C., and usually reacts at about 50 to 150 ° C. in many cases. The oxidation reaction can proceed smoothly even at a relatively low temperature such as room temperature depending on the type of the substrate and the like. The reaction can be performed under normal pressure or under pressure,
When reacting under pressure, usually 1 to 100 atm
(For example, 1.5 to 80 atm), preferably 2 to 70 atm.
atm. The reaction time can be appropriately selected, for example, from a range of about 30 minutes to 48 hours depending on the reaction temperature and pressure.

The reaction can be carried out in the presence of molecular oxygen or in the flow of molecular oxygen by a conventional method such as a batch system, a semi-batch system or a continuous system. After completion of the reaction, the reaction product is easily separated and purified by a conventional method, for example, separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, and column chromatography, or a separation means combining these. it can.

[Production of α-hydroxycarboxylic acid or derivative thereof or α-ketocarboxylic acid or derivative thereof] By utilizing the oxidation method of the present invention, α
-Hydroxycarboxylic acid or a derivative thereof, or α-
Ketocarboxylic acid or a derivative thereof can be easily produced.

That is, in the presence of the oxidation catalyst system of the present invention, carbon atoms having at least one hydrogen atom at the α-position
By reacting the above carboxylic acid or its derivative with molecular oxygen, a corresponding carboxylic acid having 2 or more carbon atoms or a derivative thereof having a hydroxyl group or an oxo group bonded to the α-position can be obtained in a good yield. Can be. When an oxidation catalyst composed of the imide compound (A) and the transition metal compound is used, oxidation at the α-position proceeds very smoothly, probably because the metal compound is easily coordinated to the carbonyl group of the substrate. do not do. On the other hand, in the oxidation catalyst system composed of the imide compound (A) and the organic salt (B), the above-mentioned situation does not occur, and oxidation at the α-position proceeds extremely advantageously.

The carboxylic acid derivatives include carboxylic acid salts, carboxylic acid esters, carboxylic acid amides and the like. As a preferred "carboxylic acid or derivative thereof",
Carboxylic acid esters. The reaction and the purification of the reaction product can be performed by the method described in the section of the oxidation method of the present invention. From a carboxylic acid having one hydrogen atom bonded to an α carbon atom or a derivative thereof, a corresponding α-
Depending on the reaction conditions, the corresponding α-hydroxycarboxylic acid or a derivative thereof and / or α-hydroxycarboxylic acid or a derivative thereof may be produced from a carboxylic acid or a derivative thereof in which a hydroxycarboxylic acid or a derivative thereof is formed and two or three hydrogen atoms are bonded to the α carbon atom. Ketocarboxylic acid or a derivative thereof is formed. In particular, when two hydrogen atoms are bonded to the α carbon atom (when the α position is a methylene group), the corresponding α-ketocarboxylic acid or a derivative thereof can be obtained as a main product.

More specifically, for example, the following formula (6)

Embedded image (Wherein, R ^c and R ^d are the same or different and each represents a hydrogen atom,
A hydrocarbon group or a heterocyclic group, wherein R ^c and R ^d may combine with each other to form a ring together with adjacent carbon atoms;
R ^e represents a hydrocarbon group) from the carboxylic acid ester represented by the following formula (7) or (8)

Embedded image (Wherein R ^c , R ^d , and ^Re are as defined above)
A hydroxycarboxylic acid ester or an α-ketocarboxylic acid ester can be obtained.

The hydrocarbon groups for R ^c , R ^d and R ^e include:
Examples include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, and an aryl group.
Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, hexyl,
Alkyl groups having about 1 to 20 carbon atoms such as octyl, decyl, dodecyl, and hexadecyl groups (preferably having 1 to 20 carbon atoms)
10, more preferably an alkyl group having about 1 to 6 carbon atoms). Examples of the alkenyl group include alkenyl groups having about 2 to 20 carbon atoms (preferably having 2 to 20 carbon atoms) such as vinyl, allyl, 1-butenyl, 2-butenyl, 1-hexenyl, 1-decenyl and 1-hexadecenyl groups.
10, more preferably an alkenyl group having about 2 to 6 carbon atoms). Examples of the alkynyl group include ethynyl, 1-butynyl and 1-pentynyl groups having 2 to 2 carbon atoms.
About 20 alkynyl groups (preferably having 2 to 10 carbon atoms;
And more preferably about 2 to 6 alkynyl groups). Cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,
Examples thereof include a 3-20 membered cycloalkyl group such as a cyclooctyl group (preferably a 3-12 membered, more preferably a 5-8 membered cycloalkyl group). As the cycloalkenyl group, a 3- to 20-membered cycloalkenyl group such as cyclopentenyl and cyclohexenyl group (preferably
To 12-membered, more preferably a 5- to 8-membered cycloalkenyl group). The aryl group includes a phenyl group, a naphthyl group and the like.

The heterocyclic ring corresponding to the heterocyclic group in R ^c , R ^d and R ^e includes, for example, non-aromatic heterocyclic rings such as tetrahydrofuran, tetrahydropyran, pyrrolidine, piperidine, piperazine and morpholine, furan, oxazole, Benzofuran, isobenzofuran, thiophene, thiazole, isothiazole, thiadiazole, pyrrole, pyrazole, imidazole, triazole, pyridine, pyridazine, pyrimidine, pyrazine, indole,
It includes aromatic heterocycles such as quinoline and acridine.

The above-mentioned hydrocarbon group and heterocyclic group include various substituents, for example, halogen atom, oxo group, hydroxyl group, mercapto group, and substituted oxy group (for example, alkoxy group, aryloxy group, acyloxy group, etc.). A substituted thio group, a carboxyl group, a substituted oxycarbonyl group, a substituted or unsubstituted carbamoyl group, a cyano group, a nitro group, a substituted or unsubstituted amino group, an alkyl group (e.g.
About 4 alkyl groups), alkenyl groups, alkynyl groups,
It may have a cycloalkyl group, a cycloalkenyl group, an aryl group (for example, a phenyl or naphthyl group), an aralkyl group, a heterocyclic group, or the like.

Examples of the ring in which R ^c and R ^d are bonded to each other to form an adjacent carbon atom include a cyclopropane, cyclobutane, cyclopentane, cyclohexane, cyclooctane ring and the like. When one of R ^c and R ^d is a hydrogen atom, the other is preferably a 1-alkenyl group, a 1-alkynyl group, an aryl group, or an aromatic heterocyclic group. Preferred R ^e, include methyl, ethyl, isopropyl, an alkyl group having about 1-4 carbon atoms such as t- butyl group.

Representative compounds represented by the formula (6) include, for example, methyl acetate, methyl propionate, methyl butyrate, methyl 3-butenoate, methyl 3-pentenoate, methyl phenylacetate, 2-pyridylacetic acid Examples include methyl, methyl cyclohexanecarboxylate, methyl 2-methylpropionate, and corresponding _C2-4 alkyl esters. By subjecting these compounds to the production method of the present invention, the corresponding α-hydroxycarboxylic acid ester or α-ketocarboxylic acid ester can be obtained in good yield. For example, by oxidizing methyl phenylacetate, methyl 2-oxo-2-phenylacetate can be produced in a high yield.

[0077]

According to the present invention, the substrate can be efficiently oxidized by molecular oxygen under mild conditions, and the desired oxidation product can be produced with high selectivity. In addition, the substrate can be oxidized by molecular oxygen at a high conversion rate without using a metal catalyst. Furthermore, quinones can be produced in high yield by oxidizing aromatic hydrocarbons with molecular oxygen. Further, the activity of the oxidation catalyst system of the present invention does not decrease even when used for a long time, and the catalyst life is long. Furthermore, according to the present invention, alcohols, carbonyl compounds, and organic carboxylic acids can be produced in a high yield under mild conditions. Further, according to the production method of the present invention, α-hydroxycarboxylic acid or a derivative thereof, or α-ketocarboxylic acid or a derivative thereof can be obtained with a simple operation in a high yield.

[0078]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention thereto.

Example 1 A mixture of 2 mmol of tetralin, 0.2 mmol of N-hydroxyphthalimide, 1 drop of trioctylmethylammonium chloride and 6 ml of chlorobenzene was stirred at 80 ° C. for 14 hours in an oxygen atmosphere. When the product in the reaction solution was examined by gas chromatography analysis,
At a conversion of tetralin of 76%, α-tetralone and β-tetralone
Tetralone was formed in 49% and 8% yields, respectively.

Comparative Example 1 The same operation as in Example 1 was carried out except that trioctylmethylammonium chloride was not used. As a result, the conversion of α-tetralone and β-tetralone was 22% each at a conversion of tetralin of 36%. % And 8% yield.

Comparative Example 2 Cobalt acetylacetonate Co (acac) ₂ was used in place of trioctylmethylammonium chloride.
The same operation as in Example 1 was carried out except that 01 mmol was used. As a result, the conversion of tetralin was 47%, and α-tetralone and β-tetralone were 28% and 12%, respectively.
In a yield of

Example 2 The same operation as in Example 1 was carried out except that trifluoromethylbenzene was used instead of chlorobenzene and the reaction time was changed to 6 hours.
-Tetralone and β-tetralone were formed in 48% and 8% yields, respectively.

Comparative Example 3 Cobalt acetylacetonate Co (acac) ₂ was used in place of trioctylmethylammonium chloride.
The same operation as in Example 2 was performed except that 01 mmol was used. As a result, the conversion of tetralin was 13%, and α-tetralone and β-tetralone were formed in yields of 7% and 4%, respectively. .

Example 3 A mixture of 2 mmol of fluorene, 0.2 mmol of N-hydroxyphthalimide, 0.04 mmol of trioctylmethylammonium chloride and 6 ml of trifluoromethylbenzene was stirred at 80 ° C. for 6 hours in an oxygen atmosphere. . When the product in the reaction solution was examined by gas chromatography analysis, the conversion of fluorene was 56%,
Fluorenone was formed in a yield of 51%. Also, the amount of N-hydroxyphthalimide remaining in the reaction solution was measured by reversed-phase high-performance liquid chromatography.
It was found that 5% or more of N-hydroxyphthalimide remained.

Example 4 Example 3 except that hexadecylpyridinium chloride was used instead of trioctylmethylammonium chloride.
When the same operation as described above was performed, the conversion of fluorene was 44
%, Fluorenone was formed in a yield of 40%.

Example 5 Example 3 was repeated except that tetrabutylammonium bromide was used in place of trioctylmethylammonium chloride.
When the same operation as described above was performed, the conversion of fluorene was 50%.
%, Fluorenone was formed in a yield of 47%.

Example 6 The same operation as in Example 3 was carried out except that triethylphenylammonium chloride was used instead of trioctylmethylammonium chloride. The conversion of fluorene was 48% and the yield of fluorenone was 43%. Was generated by

Example 7 The same operation as in Example 3 was carried out except that tributyl (hexadecyl) phosphonium bromide was used instead of trioctylmethylammonium chloride. The conversion of fluorene was 50% and the content of fluorenone was 45%. It was produced in a yield.

Example 8 The same operation as in Example 3 was carried out except that di (octadecyl) dimethylammonium chloride was used instead of trioctylmethylammonium chloride. The conversion of fluorene was 55% and fluorenone was 51%. In a yield of

Example 9 The same operation as in Example 3 was carried out except that tetrahexylammonium chloride was used instead of trioctylmethylammonium chloride, and the conversion of fluorene was 6%.
At 1%, fluorenone had formed in a 60% yield.

Example 10 The same operation as in Example 3 was carried out except that tetrahexylammonium bromide was used instead of trioctylmethylammonium chloride, and the conversion of fluorene was found to be 4%.
At 0%, fluorenone had formed in a 34% yield.

Comparative Example 4 The same operation as in Example 3 was carried out except that trioctylmethylammonium chloride was not used. As a result, the conversion of fluorene was 10% and the yield of fluorenone was 7%. Was.

Comparative Example 5 The same operation as in Example 3 was carried out except that lithium bromide was used instead of trioctylmethylammonium chloride. The conversion of fluorene was 13% and the yield of fluorenone was 8%. Was generated by

Comparative Example 6 Instead of trioctylmethylammonium chloride, cobalt acetylacetonate Co (acac) ₂ was added to 0.0
The same operation as in Example 3 was performed except that 1 mmol was used,
When the amount of N-hydroxyphthalimide remaining in the reaction solution was measured by reversed-phase high performance liquid chromatography, only about 12% of N-hydroxyphthalimide remained.

Example 11 5 mmol of fluorene, 0.05 mmol of N-hydroxyphthalimide, 0.01 mmol of tetrabutylammonium bromide and trifluoromethylbenzene 1
5 ml of the mixture was stirred at 80 ° C. for 30 hours under an oxygen atmosphere. The conversion of fluorene 20 hours and 30 hours after the start of the reaction was determined by gas chromatography to be 19.3% and 24.1%, respectively. Was held.

Comparative Example 7 Cobalt acetylacetonate Co (acac) ₂ was replaced with tetrabutylammonium bromide by 0.0025.
The same operation as in Example 11 was performed except that mmol was used. The conversion of fluorene 20 hours and 30 hours after the start of the reaction was determined by gas chromatography to be 8.2% and 7.9%, respectively. In this catalyst system, it is considered that the catalyst is deactivated after a certain period of time.

Example 12 A mixture of 2 mmol of fluorene, 0.2 mmol of N-hydroxyphthalimide, 0.04 mmol of trioctylmethylammonium chloride, 1 drop of water (23.6 mg) and 6 ml of trifluoromethylbenzene was added to an oxygen atmosphere. The mixture was stirred at 80 ° C. for 6 hours. When the product in the reaction solution was examined by gas chromatography analysis, it was found that the conversion of fluorene was 73% and fluorenone was produced in a yield of 68%.

Example 13 The same operation as in Example 12 was carried out except that the amount of water was 34.7 mg and the reaction time was 18 hours, and the conversion of fluorene was 85% and the yield of fluorenone was 81%. Was generated at a rate.

Example 14 The same operation as in Example 13 was carried out except that the amount of water was changed to 73.3 mg. As a result, the conversion of fluorene was 83% and the yield of fluorenone was 81%.

Example 15 A mixture of 2 mmol of adamantane, 0.2 mmol of N-hydroxyphthalimide, 0.04 mmol of tetrabutylammonium bromide, 1 drop of water and 6 ml of trifluoromethylbenzene was added under oxygen atmosphere at 80 ° C. for 6 hours. Stirred for hours. The product in the reaction mixture was analyzed by gas chromatography to find that the conversion rate of adamantane was 73.
%, 1-adamantanol, 2-adamantanone and 1,3-adamantanediol were 41%, 8%, respectively.
% And 12% yield.

Comparative Example 8 The same operation as in Example 15 was carried out except that 0.01 mmol of cobalt acetylacetonate Co (acac) ₂ was used instead of tetrabutylammonium bromide, and the conversion of adamantane was 26%. , 1-adamantanol and 2-adamantanone were 17% and 2%, respectively.
% Yield.

Example 16 A mixture of 2 mmol of methyl phenylacetate, 0.2 mmol of N-hydroxyphthalimide, 0.04 mmol of tetrabutylammonium chloride, 1 drop of water and 6 ml of trifluoromethylbenzene was heated at 80 ° C. in an oxygen atmosphere. For 6 hours. When the product in the reaction solution was examined by gas chromatography analysis, methyl 2-oxo-2-phenylacetate was produced in a yield of 65%.

Comparative Example 9 The same operation as in Example 16 was carried out except that 0.01 mmol of cobalt acetylacetonate Co (acac) ₂ was used instead of tetrabutylammonium chloride, to obtain 2-oxo-2-phenyl. Methyl acetate yield 17%
Was generated by

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C07C 49/675 C07C 49/675 // C07B 61/00 300 C07B 61/00 300

Claims (5)

[Claims] (A) The following formula (1): (Wherein R ¹ and R ² are the same or different and each represents a hydrogen atom,
A halogen atom, an alkyl group, an aryl group, a cycloalkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or an acyl group; R ¹ and R ² are bonded to each other to form a double bond, or A non-aromatic ring may be formed. X represents an oxygen atom or a hydroxyl group, n represents an integer of 1 to 3), and (B) an element belonging to Group 15 or 16 of the periodic table to which at least one organic group is bonded. An oxidation catalyst system comprising an organic salt composed of a polyatomic cation or polyatomic anion and a counter ion. 2. The oxidation catalyst system according to claim 1, wherein the organic salt (B) is an organic onium salt. 3. An oxidation method comprising bringing a substrate into contact with molecular oxygen in the presence of the oxidation catalyst system according to claim 1. 4. A substrate comprising: (a) a compound having a carbon-hydrogen bond at a site adjacent to an unsaturated bond, (b) a compound having a methine carbon atom, (c) a non-aromatic cyclic hydrocarbon,
(D) a non-aromatic heterocyclic compound having a carbon-hydrogen bond at a position adjacent to a hetero atom, (e) a conjugated compound, (f) alcohol or thiol, (g) ether or thioether, (h) aldehyde or The oxidation method according to claim 3, which is a thioaldehyde or (i) an amine. 5. The method according to claim 1, wherein α
A carboxylic acid having 2 or more carbon atoms having at least one hydrogen atom at the position or a derivative thereof is reacted with molecular oxygen to form a corresponding carboxylic acid having 2 or more carbon atoms having a hydroxyl group or an oxo group bonded to the α-position or Α to obtain its derivative
-Hydroxycarboxylic acid or a derivative thereof, or α-
A method for producing ketocarboxylic acid or a derivative thereof.