JP4967098B2 - Cycloheptatrienylpalladium compound and process for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new palladium compound of sandwich type, to provide a method for producing the same, and to provide a catalyst comprising the same. <P>SOLUTION: The new palladium compound is represented by the general formula (wherein, R<SP>1</SP>and R<SP>2</SP>are each H, an alkyl, aryl, carboxy, hydroxy, an alkoxy, aryloxy, silyl or siloxy; m and n are each an integer of 1-7; and L is a ligand). Salts thereof are also provided. Further, the method for producing the new compound (salt) is provided. In addition, the catalyst comprising the new compound or a salt thereof is provided. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention mainly relates to a novel palladium compound, a process for producing the same, and a catalyst comprising the palladium compound.

  It is known that a palladium compound can be used as a catalyst for a wide range of organic synthesis reactions.

  As a conventional palladium catalyst, a molecular palladium compound containing a ligand such as phosphines, halides, and acetate and having a planar four-coordinate structure is known. Also known is a palladium compound in a multimerized form by cross-linking coordination of halides or acetates (see Non-Patent Document 1). In addition, it is also known that palladium black, supported palladium, palladium clusters, and compounds composed of organic polymers and palladium have catalytic activity (see Non-Patent Documents 2 and 3).

On the other hand, a sandwich type compound in which a metal atom is sandwiched between two cyclopentadienyl rings is known as a metallocene. Metallocene catalysts using this compound are widely used for olefin polymerization and the like. So far, many similar sandwich-type compounds have been made with iron, titanium, etc. as the central metal, but no compound has been known which can be handled as a stable compound with palladium as the central metal.
Palladium Reagents and Catalysts, J. Tsuji, John Wiley & Sons, 1995, p1-5. Coordination Chemistry Reviews, 2002, 231, 207-228 J. Am. Chem. Soc., 2005, 127, 2125-2135

  The main object of the present invention is to provide a sandwich-type palladium compound, a method for producing the same, and a catalyst comprising the compound.

  The present inventor has found that a stable sandwich type compound is formed by combining cycloheptatrienyls with three palladium atoms. Furthermore, it has been found that the compound can be prepared from known palladium compounds in one step under mild reaction conditions and can be used as a catalyst. The present invention has been completed based on such findings.

  That is, the present invention relates to the following compounds, production methods, and catalysts.

  Item 1: General formula

[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a carboxy group, a hydroxy group or a substituent. Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, a silyl group or a siloxy group, or R ¹ and R ² may be linked to form a bridging group;
m and n are the same or different and each represents an integer of 1 to 7. When m is 2 or more, R ¹ may be the same or different. when n is 2 or more, R ² may be the same or different;
L represents a ligand. ]
Or a salt thereof.

  Item 2: General formula

[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a carboxy group, a hydroxy group or a substituent. Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, a silyl group or a siloxy group, or R ¹ and R ² may be linked to form a bridging group;
m and n are the same or different and each represents an integer of 1 to 7. When m is 2 or more, R ¹ may be the same or different. when n is 2 or more, R ² may be the same or different;
L represents a ligand. ]
A method for producing a palladium compound or a salt thereof represented by:
A palladium zero-valent compound;
General formula

[Wherein R ¹ and m are the same as above; X ₁ represents a counter ion]
A compound represented by
General formula

[Wherein R ² and n are the same as above; X ₂ represents a counter ion]
The method of reacting the compound represented by these in the presence of a salt in an organic solvent.

  Item 3: General formula

[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a carboxy group, a hydroxy group or a substituent. Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, a silyl group or a siloxy group, or R ¹ and R ² may be linked to form a bridging group;
m and n are the same or different and each represents an integer of 1 to 7. When m is 2 or more, R ¹ may be the same or different. when n is 2 or more, R ² may be the same or different;
L represents a ligand. ]
The catalyst which consists of palladium compound represented by these, or its salt.

  Hereinafter, the present invention will be described in more detail.

1. Palladium Compound The present invention provides a palladium compound represented by the following general formula (1) or a salt thereof (hereinafter also referred to as the palladium compound of the present invention);
General formula

[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a carboxy group, a hydroxy group or a substituent. Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, a silyl group or a siloxy group, or R ¹ and R ² may be linked to form a bridging group;
m and n are the same or different and each represents an integer of 1 to 7. When m is 2 or more, R ¹ may be the same or different. when n is 2 or more, R ² may be the same or different;
L represents a ligand. ]

In the compound in the general formula (1), a binding interaction exists between cycloheptatrienyls and palladium.
In other words, the compound in the general formula (1) includes cases where cycloheptatrienyls and palladium are bonded in various forms.

  Specifically, each group shown in the general formula (1) is as follows.

The alkyl group which may have a substituent includes an alkyl group having no substituent (hereinafter also simply referred to as “alkyl group”) and an alkyl group having one or more substituents.
As the alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, etc., having a carbon number of about 1 to 20, preferably about 1 to 10, a straight chain or branched Mention may be made of chain or cyclic alkyl groups.
Examples of the substituent include an aryl group and a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.

The aryl group which may have a substituent includes an aryl group having no substituent (hereinafter also simply referred to as “aryl group”) and an aryl group having one or more substituents.
Examples of the aryl group include monocyclic or polycyclic aryl groups such as a phenyl group.
Examples of the substituent include an alkyl group having about 1 to 20 carbon atoms, a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.
Specific examples of the aryl group having a substituent include a tolyl group.

The alkoxy group which may have a substituent includes an alkoxy group having no substituent (hereinafter also simply referred to as “alkoxy group”) and an alkoxy group having one or more substituents.
As the alkoxy group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a tert-butoxy group or the like, which has a carbon number of about 1 to 20, preferably about 1 to 20, a linear or branched chain Or a cyclic alkoxy group can be mentioned.
Examples of the substituent include an aryl group and a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.

The aryloxy group which may have a substituent includes an aryloxy group having no substituent (hereinafter also simply referred to as “aryloxy group”) and an aryloxy group having one or more substituents. .
Examples of the aryloxy group include groups consisting of monocyclic or polycyclic aryl such as phenoxy group and oxygen.
Examples of the substituent include an alkyl group having about 1 to 20 carbon atoms, a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.

The silyl group has a general formula —SiR ³ ₃ (wherein each R ³ represents a hydrogen atom, an alkyl group or an aryl group, and two or more R ^{3 s} may be the same. The alkyl group and the aryl group are The same as the above). Specific examples include a trimethylsilyl group, a dimethyl (tert-butyl) silyl group, and a triphenylsilyl group.

The siloxy group has a general formula —OSiR ⁴ ₃ (wherein each R ⁴ represents a hydrogen atom, an alkyl group or an aryl group, and two or more R ^{4 s} may be the same. The alkyl group and the aryl group are The same as above). Specific examples include a trimethylsiloxy group, a dimethyl (tert-butyl) siloxy group, and a triphenylsiloxy group.

Examples of the bridging group formed by connecting R ¹ and R ² include an alkylene group that may have a substituent, an arylalkylene group that may have a substituent, and a substituent. And a good silylene (—SiH ₂ —) group.
Examples of the substituent include a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.
Specific examples include an ethylene group and a dimethylsilylene group.

In the general formula (1), when R ¹ is a hydrogen atom and m = 7, and R ² is a hydrogen atom and n = 7, the upper and lower cycloheptatrienyls sandwiching the palladium nucleus are both cycloheptatrienyl. (C ₇ H ₇ ).

  The ligand L can be appropriately selected from those generally used as a ligand for palladium.

  Specifically, each L is the same or different, halides, alkyls optionally having substituents, aryls optionally having substituents, alkynyls optionally having substituents, substituted Alkenyls which may have a group, hydrides, hydroxys, alkoxys which may have a substituent, aryloxys which may have a substituent, thiolates, carboxylates, phosphines, water , Amines, pyridines, nitriles, carbenes, CO, and isocyanides.

  Moreover, the case where two or more Ls are connected to form a ring can be mentioned.

  Examples of halides include chloride, bromide, and iodine.

The alkyls which may have a substituent include alkyls having no substituent (hereinafter also simply referred to as “alkyls”) and alkyls having one or more substituents.
Examples of the alkyl include linear, branched or cyclic alkyl having 1 to 20, preferably 1 to 10 carbon atoms. Specific examples include methyl, benzyl, neopentyl and the like.
Examples of the substituent include an aryl group and a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.

The aryls which may have a substituent include aryls having no substituent (hereinafter also simply referred to as “aryls”) and aryls having one or more substituents.
Examples of aryls include monocyclic or polycyclic aryl.
Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.
Specific examples of aryls that may have a substituent include phenyl and tolyl.

The alkynyls which may have a substituent include alkynyls having no substituent (hereinafter also simply referred to as “alkynyls”) and alkynyls having one or more substituents.
Examples of the alkynyls include linear or branched alkynyl having about 1 to about 20 carbon atoms, preferably about 2 to about 10 carbon atoms having one carbon-carbon triple bond. Specific examples include ethynyl and propynyl.
Examples of the substituent include an aryl group and a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.

The alkenyls which may have a substituent include alkenyls having no substituent (hereinafter also simply referred to as “alkenyls”) and alkenyls having one or more substituents.
Examples of the alkenyl include linear or branched alkenyl having about 2 to 20 carbon atoms, preferably about 2 to 10 carbon atoms, having one carbon-carbon double bond. Specific examples include vinyl and propenyl.
Examples of the substituent include an aryl group and a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.

  Examples of the hydrides include hydrides represented by the chemical formula H.

  Examples of hydroxys include hydroxy represented by the chemical formula OH.

Alkoxys which may have a substituent include alkoxys having no substituent (hereinafter also simply referred to as “alkoxys”) and alkoxys having one or more substituents.
Examples of alkoxy include linear, branched or cyclic alkoxy having about 1 to 20 carbon atoms, preferably about 1 to 10 carbon atoms. Specific examples include methoxy and tert-butoxy.
Examples of the substituent include an aryl group and a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.

The aryloxys which may have a substituent include aryloxys having no substituent (hereinafter also simply referred to as “aryloxys”) and aryloxys having one or more substituents. .
Examples of the aryloxys include aryloxy composed of monocyclic or polycyclic aryl and oxygen. Specific examples include phenoxy.
Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, a functional group containing a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like.

Examples of the thiolates include thiolates represented by the general formula SR ⁵ (wherein R ⁵ represents an alkyl group or an aryl group. The alkyl group and the aryl group are the same as described above). Specific examples include methyl thiolate and phenyl thiolate.

  Examples of the carboxylates include acetate and benzoate.

The phosphines of general formula PR ⁶ ₃ (wherein each R ⁶ represents an alkyl group or an aryl group, two or more R ⁶ may be the same. Alkyl and aryl groups are as defined above.) The phosphine represented by these can be mentioned. Specific examples include triphenylphosphine, trimethylphosphine, and triethylphosphine.

Examples of amines include those represented by the general formula NR ⁷ ₃ (wherein each R ⁷ represents a hydrogen atom, an alkyl group or an aryl group, and two or more R ^{7 s} may be the same. And alkylene diamines such as N, N, N, N-tetramethylethylenediamine.

The pyridines of the general formula C ₅ (R ⁸⁾ in _5-n H _n N (wherein, n represents an integer of 1 to 5. Each R ⁸ represents a hydrogen atom, an alkyl group or an aryl group, 2 The above R ⁸ may be the same. The alkyl group and the aryl group are the same as described above.) And bipyridine such as 2,2′-bipyridine.

Examples of nitriles include nitriles represented by the general formula R ⁹ CN (wherein R ⁹ represents an alkyl group or an aryl group. The alkyl group and the aryl group are the same as described above). Specific examples include acetonitrile and benzonitrile.

  Examples of the carbenes include carbene having a carbocyclic or heterocyclic ring, such as N-heterocyclic carbene.

Examples of the isocyanides include isocyanides represented by the general formula R ¹⁰ NC (wherein R ¹⁰ represents an alkyl group or an aryl group. The alkyl group and the aryl group are the same as described above). Specific examples include methyl isocyanide and phenyl isocyanide.

Examples of the case where two or more Ls are linked to form a ring include the case where L is linked to represent a multidentate ligand. Examples of the multidentate ligand include the diamine, the bipyridine, or Ph ₂ P (CH ₂ ) _n PPh ₂ (wherein Ph represents a phenyl group, n represents an integer of 1 or more). It is done.

  The salt of the compound represented by the general formula (1) refers to a palladium compound salt in which the structure represented by the general formula (1) has a charge and forms a salt.

  In other words, it refers to a compound represented by the following general formula (4).

  General formula

[Wherein R ¹ , R ² , m, n and L are the same as above;
Z represents the number of charges carried by the compound represented by the general formula (1);
X ₃ represents a counter ion]
The charge Z can take +2, +1, −1. In the case Z is 0 is identical to the compound represented by the general formula (1), in this case, the counter ion (X ₃₎ are not included.

The type and number of counter ions (X ₃ ) are not particularly limited as long as they form a salt with the compound represented by the general formula (1). Specific examples include BF ₄ ⁻ , PF ₆ ⁻ , PPh ₄ ⁺ , K ⁺ , Na ⁺ , Li ^{+ and the} like.

Specific examples of the salt of the compound represented by the general formula (1) include
[Pd ₃ (C ₇ H ₇ ) ₂ Cl ₃ ] [PPh ₄ ]
[Pd ₃ (C ₇ H ₇ ) ₂ (CH ₃ CN) ₃ ] [BF ₄ ] ₂
[Pd ₃ (C ₇ H ₇ ) ₂ (PPh ₃ ) ₃ ] [BF ₄ ] ₂
And so on.

  In the palladium compound of the present invention, three palladium atoms are assembled between cycloheptatrienyls to form a stable sandwich type (metallocene type) compound.

  The palladium compounds of the present invention are soluble in organic solvents and are often stable in the solid state and in solution. In such a case, it is stable in air at room temperature. Due to such properties, it is easy to obtain a high-purity substance that is easy to isolate, easy to store, and easy to handle even in industrial use.

  In addition, the palladium compound of the present invention is a binuclear complex having three palladium centers, and has a plurality of coordination sites in addition to the coordination site with cycloheptatrienyls, and various coordination sites are available in these coordination sites. It also has the feature that the ligand can be combined.

  The palladium compound of the present invention having such characteristics can be used for a wide range of organic synthesis reactions as a homogeneous catalyst. It can also be used as a reusable heterogeneous catalyst in combination with various polymers, activated carbon, oxides, and the like.

  The palladium compound of the present invention can be used not only as a catalyst, but also as an intermediate for preparing palladium compounds having different ligands, and as a molecular device material of a molecular assembly material.

2. Production Method The present invention further provides a production method of the palladium compound represented by the general formula (1) or a salt thereof.

That is, a method for producing a palladium compound represented by the general formula (1) or a salt thereof,
A palladium zero-valent compound;
General formula

[Wherein, R ¹ and m are the same as defined above. X ₁ represents a counter ion. ]
And a compound represented by the general formula

[Wherein R ² and n are the same as defined above. X ₂ represents a counter ion. ]
A method comprising a step of reacting a compound represented by formula (I) in an organic solvent in the presence of a salt:

  Palladium zero-valent compounds include palladium zero-valent compounds and palladium zero-valent compounds generated from other palladium raw materials.

The palladium zero-valent complex is not particularly limited as long as it is a complex formed by bonding an appropriate ligand to zero-valent palladium (Pd (0)). Specifically, [Pd ₂ (1,5-diphenyl-1,4-pentadien-3-one) ₃ ] (hereinafter also referred to as [Pd ₂ (dba) ₃ ]), Pd (PPh ₃ ) _4, etc. Is mentioned.

Examples of the palladium raw material capable of producing a palladium zero-valent compound include metal palladium, palladium black, and a palladium divalent complex. Specific examples of the palladium divalent complex include Pd (OAc) _{2 and the} like. A method for producing a palladium zero-valent compound from these palladium raw materials can be appropriately performed according to a known method.

  The compound represented by the general formula (2) or (3) is a compound that reacts with the palladium zero-valent compound to become a ligand composed of cycloheptatrienyls in the general formula (1).

The type of the counter ions X ₁ and X ₂ is not particularly limited as long as it forms a salt with cycloheptatrienyls, and examples thereof include BF ₄ ⁻ and PF ₆ ⁻ .

X ₁ and X ₂ may be the same or different. In other words, the compound represented by the general formula (2) and the compound represented by the general formula (3) may be the same or different.

  The total ratio of the compounds represented by the general formulas (2) and (3) to the palladium zero-valent compound is about 2 to 10 equivalents, preferably about 2 to 3 equivalents.

  The ratio of the compound represented by the general formula (2) and the compound represented by the general formula (3) is about 1: 1 in terms of molar ratio.

  The salt is not particularly limited as long as the salt itself can form a salt. For example, salts formed by anions such as halides and carboxylates with cations can be used.

  Examples of halides include chloride, bromide, and iodine.

  Examples of the carboxylates include acetate and benzoate.

The cations include alkali metal ions such as Na ⁺ , Li ⁺ , K ⁺ , general formula R ¹¹ ₄ N ⁺ (wherein R ¹¹ represents an alkyl group or an aryl group, and two or more R ¹¹ are the same, An ammonium ion represented by the general formula R ¹² ₄ P ⁺ (wherein R ¹² represents an alkyl group or an aryl group, and two or more R ¹² are the same) The alkyl group and the aryl group are the same as described above.) And the like.

Specific examples of the salt include Ph ₄ PCl, CH ₃ COONa (hereinafter also referred to as “NaOAc”) and the like.

  A part of these salts may be incorporated into the general formula (1) as the ligand L. For example, the anion in the salt may be a ligand L represented by the general formula (1).

  Although the ratio of a salt can be suitably set according to the kind, about 0.1-100, preferably about 1-10 equivalent is used with respect to a palladium zerovalent compound.

  The organic solvent is not particularly limited as long as it dissolves the raw material palladium zero-valent complex and the compounds represented by the general formulas (2) and (3) to some extent.

For example, methylene chloride (CH ₂ Cl ₂ ), acetonitrile (CH ₃ CN), acetone, tetrahydrofuran, diethyl ether, or a mixed solvent thereof can be used.

A part of these organic solvents may be incorporated into the general formula (1) as the ligand L. For example, CH ₃ CN used as the organic solvent may be the ligand L represented by the general formula (1).

  The amount of the organic solvent can be appropriately set, but is usually about 0.1 to 1 L, preferably about 0.2 to 0.5 L, with respect to 1 g of the palladium zero-valent compound.

  The reaction temperature can be appropriately set, but is usually 10 to 40 ° C, preferably about 20 to 30 ° C.

  The reaction time is not particularly limited, but is generally about 5 minutes to 12 hours.

  In the reaction system of this reaction, other components can be appropriately added as necessary.

  The reaction product obtained by the above reaction can be appropriately isolated and purified according to a conventional method. For example, after the reaction, the crude reaction product can be separated by an isolation operation such as filtration, concentration, and extraction, and purified by a normal purification operation such as recrystallization.

  Specific examples of the production method include a production method including a step represented by the following reaction formula 1.

  Reaction formula 1

[Wherein L, Z and X ₃ are the same as above; X ₄ represents the above X ₁ and X ₂ ; MX ′ represents a salt].

In Reaction Scheme 1, X ₃ in the product may be the same as the raw material X ₄ , that is, X ₁ and X ₂ , but may be the same as X ′ of the salt (MX ′) or the salt ( It may be the same as M in MX ′).

  The ligand L in the product may be taken from a salt or from an organic solvent.

  An example of the case where the ligand L is incorporated from the salt includes a case where the salt (MX ′) is represented by ML or LX ′. In this case, M and X ′ each represent an L counter ion.

  Moreover, as an example in case ligand L is taken in from an organic solvent, the case where the organic solvent is a solvent containing the compound L in Reaction formula 1 is mentioned.

  Specifically, as an example of the case where the ligand L is incorporated from the salt, a method including a step represented by the following reaction formula 2 can be mentioned.

  Reaction formula 2

[Wherein, L, X ₃ , X ₄ and Z are the same as above. M ¹ represents a counter ion of L].

  Moreover, as an example in case ligand L is taken in from an organic solvent, the method including the process represented by following Reaction formula 3 is mentioned.

  Reaction formula 3

[Wherein L, X ₃ , X ₄ , MX ′ and Z are the same as above].

  According to the production method including the step represented by the above reaction formula, the compound represented by the general formula (1) or a salt thereof is converted from a known palladium compound in one step, under mild conditions, and in a high yield. Can be manufactured.

  In addition to the above steps, the production method of the present invention includes a step of substituting all or part of the ligand of the obtained palladium compound, a step of bonding with another compound, and a palladium zero-valent compound from a palladium raw material. One or more steps selected from the group consisting of the steps of generating can be included.

  For example, as a specific example of the step of substituting the ligand, a reaction represented by the following reaction formula 4 can be shown.

  Reaction formula 4

[Wherein L ¹ and L ² each represent a ligand or a compound to be a ligand; n and X are the same as above].

3. catalyst
Furthermore, the present invention provides a catalyst comprising the compound represented by the general formula (1) or a salt thereof (hereinafter also referred to as “the palladium catalyst of the present invention”).

  Reactions in which the catalyst of the present invention can be used include oxidation reactions, reduction reactions, various bond formation reactions, polymerization reactions, and the like.

  Specifically, alcohol oxidation reaction, double bond or triple bond hydrogenation reaction, Suzuki-Miyaura coupling reaction, Heck reaction, olefin polymerization reaction, and other carbon-carbon bond formation reactions, carbon-nitrogen bonds Formation reaction, carbon-oxygen bond formation reaction, and the like.

  For example, the following reaction formula can be given as an example of the Suzuki-Miyaura coupling catalytic reaction.

  Reaction formula 5

[Wherein, Ar ¹ and Ar ² represent an aryl group which may have one or more substituents (—R ¹³ ). R ¹³ represents a halogen atom, an alkyl group or an alkoxy group. When there are multiple substituents, R ¹³ may be the same or different;
X represents a halogen atom].

  In Reaction Scheme 5, the alkyl group, aryl group and alkoxy group are as described above. Examples of the halogen atom include a chlorine atom, a bromine atom and an iodine atom.

  The amount of catalyst in each reaction can be appropriately set according to the reaction and the type of substrate.

  The palladium catalyst of the present invention can be used by being dissolved in various solvents as a homogeneous catalyst.

  In addition, the palladium catalyst of the present invention can be combined with various polymers, activated carbon, oxides such as silica, etc. to form a heterogeneous catalyst. Thereby, it is also possible to use as a catalyst that can be recovered and reused.

  Moreover, the palladium catalyst of this invention can also be utilized for stereoselective reaction by designing a ligand structure suitably.

  ADVANTAGE OF THE INVENTION According to this invention, the sandwich-type novel palladium compound which has palladium as a central metal and has cycloheptatrienyls as a ligand and is easy to handle is provided.

  The palladium compound of the present invention can be used as a palladium molecular catalyst in a wide range of organic synthesis reactions, and can also be used as a reusable catalyst in combination with various polymers, activated carbon, oxides, etc. It is.

  Moreover, the palladium compound of the present invention can be used not only as a catalyst but also as an intermediate for preparing palladium compounds having different ligands, and as a molecular element material in a molecular assembly material.

  Furthermore, according to this invention, the manufacturing method of the said palladium compound is provided. According to the production method of the present invention, the novel palladium compound of the present invention can be obtained from a known palladium compound in one step under mild reaction conditions and in a high yield.

  Furthermore, according to the present invention, there is provided a catalyst comprising the palladium compound of the present invention. The catalyst of the present invention can be used as a catalyst for various oxidation reactions, various reduction reactions, various bond formation reactions, polymerization reactions and the like.

  As described above, the present invention provides a novel palladium compound, a production method thereof, and a catalyst comprising the compound, and enables various organic synthesis reactions, high-performance catalysts, or development of new molecular materials. Is.

  The present invention will be further clarified by the following examples, but the present invention is not limited to these examples.

Unless specified experimental conditions , all reactions were performed under a nitrogen atmosphere. However, in practice, there are many cases where it can be performed in the air.

¹ H, ¹³ CNMR spectrum, 270- (JEOL GSX-270) , 400- (JEOL GSX-400, JEOL ECP-400) or _{600MH Z (Varian UNITY-INOVA 600} ) were obtained using the instrument. The chemical shift was matched with the residual resonance of the deuterated solvent.

  Elemental analysis was performed at the Analysis Center, Faculty of Engineering, Osaka University.

  All reagents were purchased commercially and used without purification unless otherwise specified. TCI represents Tokyo Chemical Industry Co., Ltd., and WAKO represents Wako Pure Chemical Industries, Ltd.

CH ₂ Cl ₂ , CD ₂ Cl ₂ , ClCH ₂ CH ₂ Cl, CH ₃ CN and CD ₃ CN were distilled using calcium hydride as a desiccant before use.

Pd ₂ (dba) ₃ was prepared according to the method described in the literature (J. Organomet. Chem. 1974, 65, 253).

  X-ray structural analysis was performed using a Rigaku RAXIS-Rapid Imaging Plate diffractometer. Diffraction data was collected at −150 ° C. using MoKα. The structure analysis was refined by the full-matrix least square method using the Patterson method.

In the following Examples and Production Examples, Tr represents cycloheptatrienyl (C ₇ H ₇ ). Ph represents a phenyl group.

Example 1: Synthesis of [Pd ₃ Tr ₂ Cl ₃ ] [PPh ₄ ] consisting of [C ₇ H ₇ ] [BF ₄ ] (46 mg, 0.257 mmol, TCI) and Ph ₄ PCl (361 mg, 0.965 mmol, TCI). To the solution was added Pd ₂ (dba) ₃ (200 mg, 0.193 mmol) in CH ₂ Cl ₂ (30 mL) and the mixture was stirred at room temperature (about 25 ° C.) for 10 minutes. The solution was filtered and the filtrate was concentrated and diethyl ether was added to give a dark pink precipitate. The product is dissolved in heated CH ₃ CN (60 ° C) and recrystallized by cooling to produce fine wine crystals of [Pd ₃ Tr ₂ Cl ₃ ] [PPh ₄ ] (88 mg, yield). Rate 72%).

  The analysis results of the obtained compound were as follows.

Elemental analysis
Anal.Calcd.for C ₃₈ H ₃₄ Cl ₈ PPd ₃ · H ₂ O: C, 47.28; H, 3.76.
Found: C, 47.42; H, 3.84.
NMR spectrum
¹ H-NMR (400 MHz, CD ₂ Cl ₂ , 25 ° C.):
δ7.93 (m, 4H, H4), 7.76 (m, 8H, H3), 7.62 (m, 8H, H2), 4.60 (s, 14H, H1).
¹³ C { ¹ H} -NMR (100.5 MHz, CD ₂ Cl ₂ , 25 ° C.):
δ136.4 (d, J = 3.0Hz, C5), 135.0 (d, J = 10.8Hz, C3), 131.2 (d, J = 13.1Hz, C4), 118.1 (d, J = 90.1Hz, C2), 75.9 (s, C1).
³¹ P { ¹ H} -NMR (CD ₂ Cl ₂ , 25 ° C.):
δ23.88 (s, P1).
Each symbol in parentheses corresponds to an atom of the following compound. :

The thermal vibration ellipsoid (50%) drawing of the X-ray structural analysis crystal is shown in FIG. For the sake of clarity, the water portion is omitted. Moreover, a part of bond length (A (angstrom)) and bond angle (deg) is shown below. The numbers in parentheses indicate standard deviation:
Pd1-Pd2, 2.7550 (5); Pd2-Pd3, 2.7446 (5); Pd3-Pd1, 2.7889 (5); Pd1-Cl1, 2.471 (1); Pd2-Cl2, 2.471 (1); Pd3-Cl3, 2.442 (1); Pd1-C1, 2.155 (5); Pd1-C2, 2.279 (5); Pd2-C3, 2.194 (5); Pd2-C4, 2.195 (5); Pd3-C5, 2.342 (6); Pd3 -C6, 2.149 (5); Pd3-C7, 2.610 (6); Pd1-C7, 2.760 (6); Pd1-C8, 2.145 (6); Pd1-C9, 2.465 (6); Pd2-C10, 2.176 ( 5); Pd2-C11, 2.229 (5); Pd3-C12, 2.246 (5); Pd3-C13, 2.150 (5); Pd3-C14, 2.794 (6); Pd1-C14, 2.530 (6); Pd1- Pd2-Pd3, 60.94 (1); Pd2-Pd3-Pd1, 59.71 (1); and Pd3-Pd1-Pd2, 59.34 (1).
When the bond distance was analyzed, the distance between the carbon and palladium atom forming the seven-membered ring of cycloheptatrienyl was about 2.1 angstrom to 2.8 angstrom, and the coordination between cycloheptatrienyl and palladium. There is a bond.

  As a result, it was confirmed that the obtained compound had the following structure.

  The above reaction example is represented by the reaction formula as follows.

  Reaction formula 6

Furthermore, no decomposition product was observed when the 1,2-dichloroethane solution of the obtained compound [Pd ₃ Tr ₂ Cl ₃ ] [PPh ₄ ] was left in the air at 60 ° C. for 1 week.

Example 2: Synthesis of [Pd ₃ Tr ₂ (CH ₃ CN) ₃ ] [BF ₄ ] ₂ [Pd ₃ Tr ₂ Cl ₃ ] [PPh ₄ ] (50 mg, 0.053 mmol) and AgBF obtained in Example 1 A mixture of ₄ (31 mg, 0.159 mmol, Aldrich) was stirred in CH ₃ CN (20 mL) at room temperature for 10 minutes. After filtration, toluene is added and the synthesized orange powder is recovered, washed with toluene and n-hexane, volatiles are removed in vacuo, and the analytically pure compound [Pd ₃ Tr ₂ (CH ₃ CN) _3] [obtain a _{BF 4] 2 (36mg, 85} % yield).

  The analysis results of the obtained compound were as follows.

Elemental analysis
_{Anal.Calcd.for C 20 H 23 B 2 F} 8 N 3 Pd 3 · H 2 O:. C, 29.43; H, 3.09; N, 5.15 Found: C, 29.20; H, 2.75; N, 4.71.
NMR spectrum
¹ H-NMR (400 MHz, CD ₃ OD, 25 ° C.):
δ4.93 (s, 14H, H1), 2.21 (s, 9H, H2).
¹³ C { ¹ H} -NMR (100.5 MHz, CD ₃ OD, 25 ° C.):
δ120.46 (s, C2), 81.67 (s, C1), 1.35 (s, C3).
Each symbol in parentheses corresponds to an atom of the compound shown below. :

  As a result, it was confirmed that the obtained compound had the following structure.

Example 3: Synthesis of [Pd ₃ Tr ₂ (CH ₃ CN) ₃ ] [BF ₄ ] ₂ [C ₇ H ₇ ] [BF ₄ ] (46 mg, 0.257 mmol, TCI) and NaOAc (79 mg, 0.965 mmol, WAKO ) Was added Pd ₂ (dba) ₃ (200 mg, 0.193 mmol) in CH ₂ Cl ₂ (20 mL) and CH ₃ CN (30 mL) and the mixture was stirred for 1 h at room temperature. The solution was filtered. Toluene was added to the filtrate to obtain an orange precipitate. The precipitate was washed with toluene and n-hexane to obtain analytically pure compound [Pd ₃ Tr ₂ (CH ₃ CN) ₃ ] [BF ₄ ] ₂ (91 mg, 89% yield).

  The analysis results of the obtained compound were as follows.

Elemental analysis
_{Anal.Calcd.for C 20 H 23 B 2 F} 8 N 3 Pd 3 · H 2 O:. C, 29.43; H, 3.09; N, 5.15 Found: C, 29.20; H, 2.75; N, 4.71.
NMR spectrum
¹ H-NMR (400 MHz, CD ₃ OD, 25 ° C.):
δ4.93 (s, 14H, H1), 2.21 (s, 9H, H2).
¹³ C { ¹ H} -NMR (100.5 MHz, CD ₃ OD, 25 ° C.):
δ120.46 (s, C2), 81.67 (s, C1), 1.35 (s, C3).
Each symbol in parentheses corresponds to an atom of the compound shown below. :

  As a result, it was confirmed that the obtained compound had the following structure.

  The above reaction example is represented by the reaction formula as follows.

  Reaction formula 7

Example 4: Synthesis of [Pd ₃ Tr ₂ (PPh ₃ ) ₃ ] [BF ₄ ] ₂
PPh ₃ (82.0 mg, 0.315 mmol, WAKO) and [Pd ₃ Tr ₂ (CH ₃ CN) ₃ ] [BF ₄ ] ₂ (50 mg, 0.063) obtained in Example 2 in CH ₂ Cl ₂ (20 mL). mmol) was added and the mixture was stirred at room temperature for 10 minutes. After filtration, toluene was added and added to the filtrate to obtain a red precipitate. The precipitate was washed with toluene and n-hexane and volatiles were removed in vacuo to give analytically pure compound [Pd ₃ Tr ₂ (PPh ₃ ) ₃ ] [BF ₄ ] ₂ (80 mg, Yield 87%).

  The analysis results of the obtained compound were as follows.

Elemental analysis
Anal.Calcd.for C ₆₈ H ₅₉ B ₂ F ₈ P ₃ Pd ₃・ H ₂ O: C, 55.18; H, 4.15.
Found: C, 54.66; H, 4.13.
NMR spectrum
¹ H-NMR (400 MHz, CD ₂ Cl ₂ , 25 ° C.):
δ7.60 (t, J = 7.6Hz, 9H, H4), 7.54 (t, J = 7.6Hz, 18H, H3), 7.25 (q, J = 6.8Hz, 18H, H2), 4.03 (s, 14H, H1)
¹³ C-NMR (100.5 MHz, CD ₂ Cl ₂ , 25 ° C.):
δ134.0 (q, J = 3.8Hz, C3), 132.8 (s, C5), 130.2 (q, J = 3.8Hz, C4), 129.4 (q, J = 11.5Hz, C2), 72.2 (s, C1 ).
³¹ P-NMR (CD ₂ Cl ₂ , 25 ° C.):
δ18.34 (s, P1)
Each symbol in parentheses corresponds to an atom of the compound shown below. :

  As a result, it was confirmed that the obtained compound had the following structure.

Test example 1
Using the compound [Pd ₃ Tr ₂ Cl ₃ ] [PPh ₄ ] obtained in Example 1 in a catalytic amount (3 mol%), 4-bromoacetophenone (TCI) and phenylboronic acid (TCI) ) And Miyaura reaction at 60 ° C. in the presence of Cs ₂ CO ₃ (WAKO), the reaction proceeded and the reaction time was 3 days, and the yield was 75% or more.

Moreover, it is the same except that the compound [Pd ₃ Tr ₂ (CH ₃ CN) ₃ ] [BF ₄ ] ₂ obtained in Example 2 is used instead of the compound [Pd ₃ Tr ₂ Cl ₃ ] [PPh ₄ ]. When the same reaction was performed, the reaction proceeded in the same manner.

  The reaction is represented by the following reaction formula.

  Reaction formula 8

₂ is a thermal vibration ellipsoid (50%) drawing in the X-ray structural analysis result of the compound [Pd ₃ Tr ₂ Cl ₃ ] [PPh ₄ ] obtained in Example 1. FIG. For the sake of clarity, the water portion is omitted.

Claims (3)

General formula

[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a carboxy group, a hydroxy group or a substituent. Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, a silyl group or a siloxy group, or R ¹ and R ² may be linked to form a bridging group;
m and n are the same or different and each represents an integer of 1 to 7. When m is 2 or more, R ¹ may be the same or different. when n is 2 or more, R ² may be the same or different;
L represents a ligand. ]
Or a salt thereof. General formula

[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a carboxy group, a hydroxy group or a substituent. Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, a silyl group or a siloxy group, or R ¹ and R ² may be linked to form a bridging group;
m and n are the same or different and each represents an integer of 1 to 7. When m is 2 or more, R ¹ may be the same or different. when n is 2 or more, R ² may be the same or different;
L represents a ligand. ]
A method for producing a palladium compound or a salt thereof represented by:
A palladium zero-valent compound;
General formula

[Wherein R ¹ and m are the same as above; X ₁ represents a counter ion]
A compound represented by
General formula

[Wherein R ² and n are the same as above; X ₂ represents a counter ion]
The method of reacting the compound represented by these in the presence of a salt in an organic solvent. General formula

[Wherein, R ¹ and R ² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a carboxy group, a hydroxy group or a substituent. Represents an optionally substituted alkoxy group, an optionally substituted aryloxy group, a silyl group or a siloxy group, or R ¹ and R ² may be linked to form a bridging group;
m and n are the same or different and each represents an integer of 1 to 7. When m is 2 or more, R ¹ may be the same or different. when n is 2 or more, R ² may be the same or different;
L represents a ligand. ]
The catalyst which consists of palladium compound represented by these, or its salt.

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