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DESCRIPTION
PROCESS FOR PRODUCING PHOSPHONIUM BORATE COMPOUND, NOVEL PHOSPHONIUM BORATE COMPOUND AND USE OF THE COMPOUND
FIELD OF THE INVENTION
[0001]
The present invention relates to a process for producing a phosphonium borate compound, a novel phosphonium borate compound, and use of the compound.
BACKGROUND OF THE INVENTION
[0002]
Transition metal complexes having alkylphosphine compounds as ligands are very important catalysts in carbon-carbon bond forming reactions such as Suzuki-Miyaura reaction, carbon-nitrogen bond forming reactions such as Buchwald-Hartwig amination, and carbon-oxygen bond forming reactions such as ether synthesis (see Nonpatent Document 1) . As an example, bis(tri-tert-butylphosphine)palladium (0) is used.
Many of the transition metal complexes having alkylphosphine ligands are very expensive, and the industrial availability thereof is low. Further, synthesis of the
transition metal complexes having alkylphosphine ligands is difficult because the raw-material alkylphosphine compounds are generally extremely susceptible to air oxidation and possess combustibility. [0003]
For such reasons, the alkylphosphine compounds are used together with transition metals, salts thereof, oxides thereof or complexes thereof in the reaction system, in place of the isolated transition metal complexes having alkylphosphine ligands (see Nonpatent Documents 1 and 3) . For example, di-tert-butylmethylphosphine, tri-tert-butylphosphine or tricyclohexylphosphine is used together with palladium (II) acetate or tris(dibenzylideneacetone)dipalladium (0) in the reaction system.
However, many of the alkylphosphine compounds are extremely susceptible to air oxidation and possess combustibility, and therefore are difficult to handle.
To improve the susceptibility to air oxidation, alkylphosphonium tetrafluoroborates, quaternary salts of alkylphosphines and boron compounds, have been studied. Examples of the alkylphosphonium tetraf luoroborates include:
(1) triethylphosphonium tetrafluoroborate (see
Nonpatent Document 2) ;
(2) tricyclohexylphosphonium tetrafluoroborate (see
Nonpatent Document 4) ;
(3) di-tert-butylmethylphosphonium tetrafluoroborate
(see Nonpatent Document 3);
(4) tri-n-butylphosphonium tetrafluoroborate (see
Nonpatent Document 5); and
(5) tri-tert-butylphosphonium tetrafluoroborate (see
Nonpatent Document 4).
These compounds are produced from alkylphosphine compounds and fluoroboric acid (see Nonpatent Document 5). [0004]
As known in the art, the above compounds are used together with transition metals, salts thereof, oxides thereof or complexes thereof in the carbon-carbon bond forming reactions such as Suzuki-Miyaura reaction (see Nonpatent Documents 3 and 5) . For example, di-tert-butylmethylphosphonium tetrafluoroborate or tri-tert-butylphosphonium tetraf luoroborate is used together with palladium (II) acetate, tris(dibenzylideneacetone)dipalladium (0) or bis(benzonitrile)dichloropalladium (II) in the reaction system.
Fluoroboric acid used as raw material in the production of the compounds (1) to (5) are corrosive and penetrate into the skin upon contact, and must be handled carefully. Furthermore, fluoroboric acid has acidity to corrode
production utility made of stainless steel, and when hydrofluoric acid is liberated, it will corrode production utility made of glass. Therefore, the actual use of the above compounds in the production causes problems. [0005]
Alkylphosphonium tetraarylborate compounds are also developed, and the following compounds are known:
(6) triethylphosphonium tetraphenylborate (see Patent
Document I);
(7) tri-n-butylphosphonium tetraphenylborate (see
Patent Document 1 and Nonpatent Document 6);
(8) tricyclohexylphosphonium tetraphenylborate (see
Nonpatent Documents 4 and 7) ; and
(9) tri-tert-butylphosphonium tetraphenylborate (see
Nonpatent Documents 4 and 7) .
Nonpatent Documents 4, 6 and 7 describe the production of the alkylphosphonium tetraarylborate compounds. Specifically, the documents describe the following production processes (10) to (12).
(10) Tricyclohexylphosphine is reacted with fluoroboric
acid to synthesize tricyclohexylphosphonium
tetrafluoroborate, which is reacted with sodium tetraphenylborate to produce tricyclohexylphosphonium tetraphenylborate (75% yield) .. A similar process is described
in which tri-tert-butylphosphine is used as starting material to produce tri-tert-butylphosphonium tetraphenylborate (11% yield) (see Nonpatent Document 4).
(11) Tri-tert-butylphosphine is reacted with
1, 1,1,3,3,3-hexafluoro-2-propanol and with sodium
tetraphenylborate to produce tri-tert-butylphosphonium
tetraphenylborate (77% yield) . A similar process is described
in which tricyclohexylphosphine is used as starting material
to produce tricyclohexylphosphonium tetraphenylborate (77%
yield) (see Nonpatent Document 7).
(12) Tri-n-butylphosphine is reacted with hydrochloric
acid in the presence of sodium tetraphenylborate to produce
tri-n-butylphosphonium tetraphenylborate (53% yield) (see
Nonpatent Document 6).
The four compounds (6) to (9) are the only compounds known as the alkylphosphonium tetraarylborate compounds, and the three processes (10) to (12) are the only known processes for producing them. [0006]
The processes (10) (Nonpatent Document 4) use fluoroboric acid and consequently have handling problems and problems of corrosion of production facility, and are not suited for industrial production.
The processes (11) (Nonpatent Document 7) use
1,1,1,3,3, 3-hexaf luoro-2-propanol which is expensive, and are not suited for industrial production. More inexpensive processes are desirable.
In the process (12) (Nonpatent Document 6) in which tri-n-butylphosphine is reacted with hydrochloric acid in the presence of sodium tetraphenylborate, the yield of tri-n-butylphosphonium tetraphenylborate is low (53% in terms of tri-n-butylphosphine) . The reason for the low yield is not clear but is probably that a side reaction takes place between the reaction product of sodium tetraphenylborate with hydrochloric acid, and tri-n-butylphosphine. [0007]
The documents recited above do not describe that the carbon-carbon bond forming reactions, carbon-nitrogen bond forming reactions and carbon-oxygen bond forming reactions wherein the transition metal complexes having phosphine ligands produce catalytic effects, may be catalyzed by phosphonium tetraarylborate compounds together with transition metals, salts thereof, oxides thereof or complexes thereof in place of the transition metal complexes having phosphine ligands.
Thus, there is a need for the development of alkylphosphine derivatives that are producible without special reaction equipment and by simple operations, and have
good handling properties.
Patent Document 1: JP-A-S62-149721 (pp. 2 and 3)
Nonpatent Document 1: Journal of American Chemical Society (U.S.A.) (2000, vol. 122, No. 17, pp. 4020-4028)
Nonpatent Document 2: Catalog of Strem Chemicals, Inc.
Nonpatent Document 3: Journal of American Chemical Society (U.S.A.) (2002, vol. 124, No. 46, pp. 13662-13663)
Nonpatent Document 4: Journal of American Chemical Society (U.S.A.) (1991, vol. 113, No. 3, pp. 875-883)
Nonpatent Document 5: Organic Letters (U.S.A.) (2001, vol. 3, No. 26, pp. 4295-4298)
Nonpatent Document 6: Organometallics (U.S.A.) (1999, vol. 18, No. 20, pp. 3981-3990)
Nonpatent Document 7: Journal of American Chemical Society (U.S.A.) (1997, vol. 119, No. 16, pp. 3716-3731)
DISCLOSURE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION
[0008]
It is an object of the present invention to provide a novel process whereby a phosphonium borate compound is produced safely on an industrial scale, by simple reaction operations and in a high yield. It is another object of the invention to provide a novel phosphonium borate compound that
is easily handled. It is a further object of the invention to provide a novel use of the phosphoniura borate compound in combination with a transition metal, salt thereof, oxide thereof or complex thereof in the carbon-carbon bond forming reactions, carbon-nitrogen bond forming reactions and carbon-oxygen bond forming reactions wherein a transition metal complex having a phosphine ligand produces catalytic effects, wherein the phosphonium borate compound in combination with the transition metal, salt thereof, oxide thereof or complex thereof is used in place of the transition metal complex having a phosphine ligand.
MEANS FOR SOLVING THE PROBLEMS
[0009]
The present inventors studied diligently to achieve the above objects, and they have found that a phosphonium borate compound can be produced safely, by simple reaction operations, and in a high yield by reacting a phosphine (II) with hydrochloric or sulfuric acid, and reacting the reaction product with a tetraarylborate compound (IV).
The inventors have also found a novel phosphonium borate compound which is highly resistance to oxidation as compared to alkylphosphine compounds. It has been also found that the phosphonium borate compound in combination with a transition
metal, salt thereof, oxide thereof or complex thereof can be used in the carbon-carbon bond forming reactions, carbon-nitrogen bond forming reactions and carbon-oxygen bond forming reactions wherein a transition metal complex having a phosphine ligand produces catalytic effects, wherein the phosphonium borate compound in combination with the transition metal, salt thereof, oxide thereof or complex thereof is used in place of the transition metal complex having a phosphine ligand. [0010]
In a first aspect of the present invention, there is provided a process for producing a phosphonium borate compound, which comprises:
reacting a phosphine with HCl to produce a phosphine hydrochloride, the phosphine being represented by Formula (II) :
(R1) (R2) (R3)P (II)
wherein R1 is a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms;
R2 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl
10
group of 3 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R3 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 30 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms; and
R1, R2 and R3 may be the same or different from one another;
the phosphine hydrochloride being represented by Formula (III):
(R1) (R2) (R3)PH-C1 (III)
wherein R1, R2 and R3 are as defined in Formula (II);
and
reacting the phosphine hydrochloride with a tetraarylborate compound represented by Formula (IV):
M-BAr4 (IV)
wherein M is lithium, sodium, potassium, magnesium halide or calcium halide, and Ar is an aryl group of 6 to 20 carbon atoms;
the phosphonium borate compound being represented by Formula (I): [0011]
(R1) (R2) (R3)PH-BAr4 (I)
wherein R1, R2 and R3 are as defined in Formula (II) , and Ar is as defined in Formula (IV).
In a second aspect of the present invention, there is provided a process for producing a phosphonium borate compound, which comprises:
reacting a phosphine with H2S04 to produce a phosphine
sulfate, the phosphine being represented by Formula (II):
(R1) (R2) (R3)P (II)
wherein R1 is a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms;
R2 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R3 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 30 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon
atoms, or an allyl group of 3 to 20 carbon atoms; and
R1, R2 and R3 may be the same or different from one another;
the phosphine sulfate being represented by Formula (V) :
[ (R1) (R2) (R3)PH](2_n)-HnS04 (V)
wherein R1, R2 and R3 are as defined in Formula (II) , and n is an integer of 0 or 1;
and
reacting the phosphine sulfate with a tetraarylborate compound represented by Formula (IV):
M-BAr,, (IV)
wherein M is lithium, sodium, potassium, magnesium halide or calcium halide, and Ar is an aryl group of 6 to 20 carbon atoms;
the phosphonium borate compound being represented by Formula (I) described above. [0012]
In a third aspect of the present invention, there is provided a novel phosphonium borate compound represented by Formula (I):
(R1) (R2) (R3)PH-BAr4 (I)
wherein R1 is a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms;
R2 is a hydrogen atom, a primary alkyl group of 1 to 20
carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R3 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 30 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R1, R2 and R3 may be the same or different from one another;
Ar is an aryl group of 6 to 20 carbon atoms; [0013]
R1, R2 and R3 cannot be tert-butyl groups simultaneously and Ar cannot be phenyl group at the same time; and
R1, R2 and R3 cannot be cyclohexyl groups simultaneously and Ar cannot be phenyl group at the same time.
In a fourth aspect of the present invention, there is provided use of a phosphonium borate compound in combination with a transition metal, transition metal salt, transition metal oxide or transition metal complex in carbon-carbon bond forming reactions, carbon-nitrogen bond forming reactions and carbon-oxygen bond forming reactions wherein a transition
metal complex having a phosphine ligand produces catalytic effects, wherein the phosphonium borate compound in combination with the transition metal, transition metal salt, transition metal oxide or transition metal complex is used in place of the transition metal complex having a phosphine ligand, the phosphonium borate compound being represented by Formula
(I) :
(R1) (R2) (R3) PH-BAr4 (I)
wherein R1 is a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms;
R2 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R3 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 30 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R1, R2 and R3 may be the same or different from one another; and
Ar is an aryl group of 6 to 20 carbon atoms.
EFFECTS OF THE INVENTION
[0014]
The process according to the present invention can produce a phosphonium borate compound safely, by simple reaction operations and in a high yield. In the production process, the specific phosphine hydrochloride or phosphine sulfate is reacted with the specific tetraarylborate compound, and consequently the novel phosphonium borate compound is produced safely, by simple reaction operations and in a high yield. The phosphonium borate compound provided in the invention is novel. The phosphonium borate compound in combination with a transition metal, salt thereof, oxide thereof or complex thereof can be used in the carbon-carbon bond forming reactions, carbon-nitrogen bond forming reactions and carbon-oxygen bond forming reactions wherein a transition metal complex having a phosphine ligand produces catalytic effects, wherein the phosphonium borate compound in combination with the transition metal, salt thereof, oxide thereof or complex thereof is used in place of the transition metal complex having a phosphine ligand.
PREFERRED EMBODIMENTS OF THE INVENTION
[0015]
The process for producing a phosphonium borate compound, novel phosphonium borate compound, and use of the compound will be described in detail hereinbelow.
[Process for producing phosphonium borate compound]
The process for producing a phosphonium borate compound will be described with reference to first and second production processes.
The first process for producing a phosphonium borate compound includes:
reacting a phosphine with HCl to produce a phosphine hydrochloride, the phosphine being represented by Formula (II) :
(R1) (R2) (R3)P (II)
wherein R1 is a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms;
R2 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl
group of 3 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R3 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 30 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms; and
R1, R2 and R3 may be the same or different from one another;
the phosphine hydrochloride being represented by Formula (III) :
(R1) (R2) (R3) PH-C1 (III)
wherein R1, R2 and R3 are as defined in Formula (II) ;
and
reacting the phosphine hydrochloride with a tetraarylborate compound represented by Formula (IV):
M-BAr4 (IV)
wherein M is lithium, sodium, potassium, magnesium halide or calcium halide, and Ar is an aryl group of 6 to 20 carbon atoms;
the phosphonium borate compound being represented by Formula (I) : [0016]
(R1) (R2) (R3)PH-BAr4 (I)
wherein R1, R2 and R3 are as defined in Formula (II) , and Ar is as defined in Formula (IV) .
Specifically, the first process for producing a phosphonium borate compound (I) includes:
a 1st step in which the phosphine (II) is reacted with HCl to give the phosphine hydrochloride (III); and
a 2nd step in which the compound (III) is reacted with the tetraarylborate compound (IV) to produce the phosphonium borate compound (I), as illustrated in the reaction formula below:
[0017] [Chem. 1] HCl
(R1)(R!XR3)PH-a M'BAr
[0018]
The first production process can produce the phosphonium borate compound (I) in a high yield. The reason for this effect is not clear, but is probably that a side reaction that takes place when the compound (II), HCl and the compound (IV) are added at the same time can be substantially avoided.
The first process for producing a phosphonium borate compound (I) will be described below with reference to an embodiment 1 for producing the trialkylphosphonium tetraphenylborate and an embodiment 2 for producing the novel
phosphonium borate compound. (Embodiment 1) [1st step]
In the 1st step, a trialkylphosphine (II) and HCl are reacted under predetermined conditions. These components will be described below. [0019]
The trialkylphosphine (II) used as a raw material in the
production process is represented by Formula (II):
(R1) (R2) (R3)P (II)
wherein R1, R2 and R3 are ethyl, n-butyl, tert-butyl or cyclohexyl groups, and are the same. Examples of the trialkylphosphines (II) include triethylphosphine, tri-n-butylphosphine, tri-tert-butylphosphine and tricyclohexylphosphine.
The trialkylphosphines (II) of Formula (II) may be produced by or according to known methods.
Examples of such methods include, but are not limited to, reaction of phosphinas halides and organo Grignard reagents, reaction of phosphinas halides and organolithium reagents, and reaction of phosphines and olefins. The trialkylphosphines (II) synthesized by the above reactions may be purified prior to use, or may be used without purification. [0020]
The trialkylphosphines (II) may be used in an undiluted form, or may be diluted with a solvent. Herein, the diluting solvents include solvents contained in the unpurified trialkylphosphines (II). The unpurified trialkylphosphines (II) may be further diluted with a solvent.
The solvents are not particularly limited as long as they can dissolve reaction substrates and are inert to the reaction substrates. Examples thereof include water; alcohol solvents such as methanol, ethanol and octanol; aliphatic hydrocarbon solvents such as hexane, heptane and isooctane; aromatic hydrocarbon solvents such as benzene, toluene and xylene; ether solvents such as tetrahydrofuran and dibutyl ether; halogenated hydrocarbon solvents such as chloroform and tetrachloromethane; dimethylsulfoxide and dimethylformamide. The solvents may be used singly or in combination of two or more kinds. [0021]
HC1 used in the production process may be hydrochloric acid or hydrogen chloride gas. The HC1 concentration in hydrochloric acid is not particularly limited, and is desirably in the range of 0.1 to 37% by weight, preferably 10 to 37% by weight.
The 1st step involving the above raw materials is performed in a reactor purged with an inert gas such as nitrogen
or argon. The addition sequence of the raw materials is not particularly limited. For example, HC1 may be added to the trialkylphosphine (II), or the trialkylphosphine (II) maybe added to HC1. When HCl is hydrochloric acid, the addition method is not particularly limited, and it may be added all at once or may be added dropwise intermittently or continuously, The hydrogen chloride gas may be easily added by being blown into the trialkylphosphine (II). [0022]
In the 1st step, the desirable HCl requirement, desirable temperature for smooth reaction, and desirable time to complete the reaction vary depending on the type of the trialkylphosphine (II) used, and are selected appropriately.
The HCl amount varies depending on the type of the trialkylphosphine (II), and is desirably in the range of 0.5 to 5 mol, preferably 0.8 to 1.6 mol per mol of phosphine. The HCl amount in this range enables the production of the trialkylphosphonium tetraphenylborate (I) in a high yield.
The reaction of HCl is desirably carried out while the solution is at -20 to 150°C, preferably 0 to 80°C and is continuously stirred for up to 24 hours, preferably 30 minutes to 5 hours at the temperature. The reaction under these conditions enables the production of the trialkylphosphonium tetraphenylborate (I) in a high yield.
The completion of the reaction in the 1st step may be determined by confirming the absence of unreacted trialkylphosphine (II). Specifically, the organic phase is analyzed by gas chromatography or the like to determine the trialkylphosphine (II) in the organic phase. When the analysis confirms substantial absence of the remaining trialkylphosphine (II), the reaction is terminated. When the trialkylphosphine (II) is still present in the organic phase, the reaction is preferably continued.
The reaction solution takes various forms depending on the solvent used. For example, the solution may contain crystals of trialkylphosphine hydrochloride (III) (described later), may be a uniform solution or a suspension, or may be a two-phase system consisting of an aqueous phase and an organic phase. In the case of the two-phase system consisting of an aqueous phase and an organic phase, the system is subjected to separation. In the case of other solution forms, separation may be performed as required by adding water, toluene, n-hexane, n-heptane or the like. The aqueous phase resulting from the separation may be washed with toluene, n-hexane, n-heptane or the like as required. [0024]
The aqueous phase obtained by the reaction of the 1st
step contains a reaction intermediate dissolved therein that is assumed to be a trialkylphosphine hydrochloride represented by Formula (III):
(R1) (R2) (R3) PH-C1 (III)
wherein R1, R2 and R3 are as defined in Formula (II) .
The formation of the trialkylphosphine hydrochloride (III) may be confirmed by, for example, a nuclear magnetic resonance spectrum ("""H-NMR) . [2nd step]
The reaction intermediate trialkylphosphine hydrochloride (III) obtained in the 1st step is reacted with a tetraphenylborate compound (IV) under predetermined conditions to produce a trialkylphosphonium tetraphenylborate represented by Formula (I):
(R1) (R2) (R3)PH-BAr4 (I)
wherein R1, R2 and R3 are ethyl, n-butyl, tert-butyl or cyclohexyl groups, and are the same; and Ar is phenyl group. [0025]
The tetraphenylborate compound (IV) used in the 2nd step is represented by Formula (IV):
M-BAr4 (IV)
wherein M is lithium, sodium, potassium, magnesium halide or calcium halide, and Ar is phenyl group.
In Formula (IV) , M may be a magnesium halide or a calcium
halide, with examples including magnesium fluoride, magnesium chloride, magnesium bromide, magnesium iodide, calcium fluoride, calcium chloride, calcium bromide and calcium iodide.
Specific examples of the tetraphenylborate compounds of Formula (IV) include lithium tetraphenylborate, sodium tetraphenylborate, potassium tetraphenylborate, tetraphenylborate magnesium fluoride, tetraphenylborate magnesium chloride, tetraphenylborate magnesium bromide, tetraphenylborate magnesium iodide, tetraphenylborate calcium fluoride, tetraphenylborate calcium chloride, tetraphenylborate calcium bromide and tetraphenylborate calcium iodide. The tetraphenylborate compounds (IV) may be used singly or in combination of two or more kinds. [0026]
Of the tetraphenylborate compounds (IV), sodium tetraphenylborate is particularly preferred. Sodium tetraphenylborate is preferable because of easy synthesis by known methods.
The tetraphenylborate compounds (IV) may be used in an undiluted form, or may be diluted with a solvent.
The solvent may be appropriately selected from the solvents used for dissolving the trialkylphosphines (II). The solvents may be used singly or in combination of two or more
kinds.
Specifically, the 2nd step involving the above raw materials is performed by mixing the aqueous solution of the reaction intermediate assumed to be the trialkylphosphine hydrochloride (III) , with the tetraphenylborate compound (IV) thereby to react the compound (III) with the compound (IV) under predetermined conditions. [0027]
The addition sequence of the aqueous solution obtained in the 1st step and the tetraphenylborate compound (IV) is not particularly limited. The addition method is not particularly limited, and the material may be added all at once or may be added dropwise intermittently or continuously.
In the 2nd step, the desirable requirement of the tetraphenylborate compound (IV), desirable temperature for smooth reaction, and desirable time to complete the reaction vary depending on the type of the raw material compound trialkylphosphine (II) used, amount of hydrogen chloride gas or hydrochloric acid, and type of the tetraphenylborate compound (IV), and are selected appropriately.
The amount of the tetraphenylborate compound (IV) varies depending on the type of the trialkylphosphine (II) used in the 1st step, and is desirably in the range of 0.55 to 5.5 mo I/ preferably 0.85 to 1. 65 mol per mol of phosphine . Particularly
preferably, the compound is used in an amount of at least 1 mol per mol of HCl used. The amount of the tetraphenylborate compound (IV) in this range enables the production of the trialkylphosphonium tetraphenylborate (I) in a high yield. [0028]
The reaction of the tetraphenylborate compound (IV) is desirably carried out while the reaction solution is at -20 to 150°C, preferably 0 to 80°C and is continuously stirred for up to 24 hours, preferably 1 to 5 hours at the temperature. The reaction under these conditions enables the production of the trialkylphosphonium tetraphenylborate (I) in a high yield.
After the completion of the reaction, purification such as recrystallization or column chromatography is performed, and consequently the objective trialkylphosphonium tetraphenylborate (I) of Formula (I) can be obtained with high purity:
(R1) (R2) (R3)PH-BAr4 (I)
wherein R1, R2 and R3 are ethyl, n-butyl, tert-butyl or cyclohexyl groups, and are the same; and Ar is phenyl group. [0029]
According to the embodiment I, the trialkylphosphonium tetraphenylborate (I) can be obtained in a high yield, specifically in a yield of about 87 to 93 mol% in terms of trialkylphosphine (II).
Examples of the trialkylphosphonium tetraphenylborates (I) of Formula (I) produced according to the embodiment 1 of the first production process include triethylphosphonium tetraphenylborate, tri-n-butylphosphonium tetraphenylborate, tri-tert-butylphosphonium tetraphenylborate and tricyclohexylphosphonium tetraphenylborate.
Next, the embodiment 2 for producing the novel phosphonium borate compound will be described. [0030]
(Embodiment 2) [1st step]
In the 1st step, a phosphine (II) and HCl are reacted under predetermined conditions. These components will be described below.
The phosphine (II) used as a raw material in the production process is represented by Formula (II):
(R1) (R2) (R3)P (II)
In Formula (II), R1 is as described below.
R1 may be a secondary alkyl group, desirably a secondary alkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The secondary alkyl groups include isopropyl, sec-butyl, 2-pentyl, 3-pentyl, 2-hexyl and 3-hexyl. [0031]
R1 may be a tertiary alkyl group, desirably a tertiary
alkyl group having 4 to 20, preferably 4 to 11 carbon atoms. The tertiary alkyl groups include tert-butyl, tert-amyl, 1, 1-dimethylbutyl, 3-methyl-3-pentyl and 1,1,2-trimethylpropyl.
R1 may be a cycloalkyl group, desirably a cycloalkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The cycloalkyl groups include cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl, 2-methylcyclohexyl, 1-adamantyl, 2-methyl-l-adamantyl, 2-adamantyl, l-methyl-2-adamantyl and 2-methyl-2-adamantyl. R1 is not limited to the groups described above. [0032]
In Formula (II), R2 is as described below.
R2 may be a primary alkyl group, desirably a primary alkyl group having 1 to 20, preferably 1 to 8 carbon atoms. The primary alkyl groups include methyl, ethyl, n-propyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, 2-methyl-l-pentyl, 2,2-diethyl-l-ethyl, n-heptyl and n-octyl.
R2 may be a secondary alkyl group, desirably a secondary alkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The secondary alkyl groups include isopropyl, sec-butyl, 2-pentyl, 3-pentyl, 2-hexyl and 3-hexyl. [0033]
R2 may be a tertiary alkyl group, desirably a tertiary
alkyl group having 4 to 20, preferably 4 to 11 carbon atoms. The tertiary alkyl groups include tert-butyl, tert-amyl, 1,1-dimethylbutyl, 3-methyl-3-pentyl and 1,1,2-trimethylpropyl.
R2 may be a cycloalkyl group, desirably a cycloalkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The cycloalkyl groups include cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl, 2-methylcyclohexyl, 1-adamantyl, 2-methyl-l-adamantyl, 2-adamantyl, l-methyl-2-adamantyl and 2-methyl-2-adamantyl. [0034]
R2 may be an aralkyl group, desirably an aralkyl group having 7 to 20, preferably 7 to 12 carbon atoms. The aralkyl groups include benzyl, 1-phenylethyl, 2-phenylethyl, 2-ethenylbenzyl, 3-ethenylbenzyl, 4-ethenylbenzyl, 4-(2-ethenylphenyl)butyl, 4-(3-ethenylphenyl)butyl and 4-(4-ethenylphenyl)butyl.
R2 may desirably be an allyl group having 3 to 20, preferably 3 to 8 carbon atoms. The allyl groups include allyl and 2-octenyl. R2 is not limited to the groups described above .
In Formula (II), R3 is as described below.
R3 may be a primary alkyl group, desirably a primary alkyl group having 1 to 20, preferably 1 to 8 carbon atoms. The primary alkyl groups include methyl, ethyl, n-propyl, n-butyl,
sobutyl, n-pentyl, isopentyl, n-hexyl, 2-methyl-l-pentyl,
2, 2-diethyl-l-ethyl, n-heptyl and n-octyl.
[0035]
R3 may be a secondary alkyl group, desirably a secondary alkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The secondary alkyl groups include isopropyl, sec-butyl, 2-pentyl, 3-pentyl, 2-hexyl and 3-hexyl.
R3 may be a tertiary alkyl group, desirably a tertiary alkyl group having 4 to 20, preferably 4 to 11 carbon atoms. The tertiary alkyl groups include tert-butyl, tert-amyl, 1, 1-dimethylbutyl, 3-methyl-3-pentyl and 1,1, 2-trimethylpropyl.
R3 may be a cycloalkyl group, desirably a cycloalkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The cycloalkyl groups include cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl, 2-methylcyclohexyl, 1-adamantyl, 2-methyl-l-adamantyl, 2-adamantyl, l-methyl-2-adamantyl and 2-methyl-2-adamantyl. [0036]
R3 may be an aryl group, desirably an aryl group having 6 to 30, preferably 6 to 22 carbon atoms. The aryl groups include phenyl, ortho-tolyl, meta-tolyl, para-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3,4-xylyl, 3,5-xylyl, mesityl, 2-tert-butylphenyl, 3-tert-butylphenyl,
4-tert-butylphenyl, 2-ethenylphenyl, 3-ethenylphenyl, 4-ethenylphenyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl, 1-naphthyl, 2-naphthyl, 1,1'-binaphthalene-2-yl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-tert-butoxyphenyl, 3-tert-butoxyphenyl, 4-tert-butoxyphenyl, 2-dimethylaminophenyl, 3-dimethylaminophenyl, 4-dimethylaminophenyl, 2' -dimethylamino-2-biphenylyl, 8-dimethylamino-l-naphthyl and 2'-dimethylamino-1,1'-binaphthalene-2-yl. [0037]
R3 may be an aralkyl group, desirably an aralkyl group having 7 to 20, preferably 7 to 12 carbon atoms. The aralkyl groups include benzyl, 1-phenylethyl, 2-phenylethyl, 2-ethenylbenzyl, 3-ethenylbenzyl, 4-ethenylbenzyl, 4-(2-ethenylphenyl)butyl, 4-(3-ethenylphenyl)butyl and 4-(4-ethenylphenyl)butyl.
R3 may be an alkenyl group, desirably an alkenyl group having 2 to 20, preferably 2 to 8 carbon atoms. The alkenyl groups include vinyl, methallyl and 1-octenyl.
R3 may be an alkynyl group, desirably an alkynyl group having 2 to 20, preferably 2 to 8 carbon atoms. The alkynyl groups include ethynyl, 1-propynyl and 1-octynyl. [0038]
R3 may desirably be an allyl group having 3 to 20,
preferably 3 to 8 carbon atoms. The allyl groups include allyl and 2-octenyl. R3 is not limited to the groups described above.
As long as R1, R2 and R3 are selected from the above groups, they may have an arbitrary combination in terms of carbon atom numbers.
Specific examples of the phosphines (II) represented by Formula (II) are shown in Tables 1-1 to 4-2 which will be presented later.
Specifically, preferred phosphines (II) include di-tert-butylmethylphosphine, tri-tert-butylphosphine, i-tert-butylethylphosphine, n-butyl-di-tert-butylphosphine, n-butyl-dicyclohexylphosphine, see-butyl-di-tert-butylphosphine, cyclohexyl-di-tert-butylphosphine, di-tert-butyl-n-octylphosphine, di-tert-butylphenylphosphine, 2-biphenylyl-di-tert-butylphosphine, di-tert-butyl-1-naphthylphosphine, benzyl-di-tert-butylphosphine, di-tert-butyl(4-ethenylbenzyl)phosphine,
di-tert-butylvinylphosphine, allyl-di-tert-butylphosphine, tricyclopentylphosphine, tricyclohexylphosphine and triisopropylphosphine. Di-tert-butylmethylphosphine,
tri-tert-butylphosphine, tricyclohexylphosphine and triisopropylphosphine are more preferable. These phosphines (II) are preferable because of easy availability of raw materials. [0039]
The phosphine compounds of Formula (II) may be produced by or according to known methods.
Examples of such methods include, but are not limited to, reaction of phosphinas halides and organo Grignard reagents, reaction of phosphinas halides and organolithium reagents, and reaction of phosphines and olefins. The phosphines (II) synthesized by the above reactions may be purified prior to use, or may be used without purification.
The phosphines (II) may be used in an undiluted form, or may be diluted with a solvent. Herein, the diluting solvents include solvents contained in the unpurified phosphines (II) . The unpurified phosphines (II) may be further diluted with a solvent. [0040]
The solvents are not particularly limited as long as they can dissolve reaction substrates and are inert to the reaction substrates. Examples thereof include water; alcohol solvents such as methanol, ethanol and octanol; aliphatic hydrocarbon solvents such as hexane, heptane and isooctane; aromatic
hydrocarbon solvents such as benzene, toluene and xylene; ether solvents such as tetrahydrofuran and dibutyl ether; halogenated hydrocarbon solvents such as chloroform and tetrachloromethane; dimethylsulfoxide and dimethylformamide . The solvents may be used singly or in combination of two or more kinds.
HC1 used in the production process may be hydrochloric acid or hydrogen chloride gas. The HC1 concentration in hydrochloric acid is not particularly limited, and is desirably in the range of 0.1 to 37% by weight, preferably 10 to 37% by weight. [0041]
The 1st step involving the above raw materials is performed in a reactor purged with an inert gas such as nitrogen or argon. The addition sequence of the raw materials is not particularly limited. For example, HC1 may be added to the phosphine (II), or the phosphine (II) may be added to HCl. When HC1 is hydrochloric acid, the addition method is not particularly limited, and it may be added all at once or may be added dropwise intermittently or continuously. The hydrogen chloride gas may be easily added by being blown into the phosphine (II).
In the 1st step, the desirable HCl requirement, desirable temperature for smooth reaction, and desirable time to
complete the reaction vary depending on the type of the phosphine (II) used, and are selected appropriately.
The HC1 amount varies depending on the type of the phosphine (II) , and is desirably in the range of 0.5 to 5 mol, preferably 0. 8 to 1. 6 mol per mol of phosphine. The HC1 amount in this range enables the production of the phosphonium borate compound (I) in a high yield. [0042]
The reaction of HC1 is desirably carried out while the solution is at -20 to 150°C, preferably 0 to 80°C and is continuously stirred for up to 24 hours, preferably 30 minutes to 5 hours at the temperature. The reaction under these conditions enables the production of the phosphonium borate compound (I) in a high yield.
The completion of the reaction in the 1st step may be determined by confirming the absence of unreacted phosphine (II) . Specifically, the organic phase is analyzed by gas chromatography or the like to determine the phosphine (II) in the organic phase. When the analysis confirms substantial absence of the remaining phosphine (II), the reaction is terminated. When the phosphine is still present in the organic phase, the reaction is preferably continued.
The reaction solution takes various forms depending on the solvent used. For example, the solution may contain
crystals of phosphine hydrochloride (III) (described later), may be a uniform solution or a suspension, or may be a two-phase system consisting of an aqueous phase and an organic phase. In the case of the two-phase system consisting of an aqueous phase and an organic phase, the phosphine hydrochloride (III) passes into the aqueous phase and therefore the aqueous phase is subjected to separation. In the case of other solution forms, separation may be performed as required by adding water, toluene, n-hexane, n-heptane or the like. The aqueous phase resulting from the separation may be washed with toluene, n-hexane, n-heptane or the like as required. [0043]
The aqueous phase obtained by the reaction of the 1st step contains a reaction intermediate dissolved therein that is assumed to be a phosphine hydrochloride (III) represented by Formula (III) :
(R1) (R2) (R3) PH-C1 (III)
wherein R1, R2 and R3 are as defined in Formula (II).
The formation of the phosphine hydrochloride (III) may be confirmed by, for example, a nuclear magnetic resonance spectrum 1HH-NMR). [2nd step]
The reaction intermediate that is assumed to be the phosphine hydrochloride (III) obtained in the 1st step is
reacted with a tetraarylborate compound (IV) under predetermined conditions to produce a novel phosphonium borate compound (I) of the present invention. [0044]
The tetraarylborate compound (IV) used in the 2nd step is represented by Formula (IV):
M-BAr4 (IV)
In Formula (IV) , M may be a magnesium halide or a calcium halide, with examples including magnesium fluoride, magnesium chloride, magnesium bromide, magnesium iodide, calcium fluoride, calcium chloride, calcium bromide and calcium iodide.
Ar is desirably an aryl group having 6 to 20, preferably 6 to 10 carbon atoms. Specific examples include phenyl, ortho-tolyl, meta-tolyl, para-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3,4-xylyl, 3,5-xylyl, mesityl, 2-tert-butylphenyl, 3-tert-butylphenyl, 4-tert-butylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-tert-butoxyphenyl, 3-tert-butoxyphenyl and 4-tert-butoxyphenyl. [0045]
The tetraarylborate compound (IV) is selected appropriately such that in the phosphonium borate compound (I) of Formula (I), R1, R2 and R3 are not tert-butyl groups
simultaneously and Ar is not phenyl group at the same time, and R1, R2 and R3 are not cyclohexyl groups simultaneously and Ar is not phenyl group at the same time.
Specific examples of the tetraarylborate compounds represented by Formula (IV) are shown in Tables 5 to 10 which will be presented later. These tetraarylborate compounds may be used singly or in combination of two or more kinds.
Of the tetraarylborate compounds (IV), sodium tetraphenylborate and sodium tetra-para-tolylborate are particularly preferable. The tetraarylborate compounds (IV) are preferable because of easy synthesis by known methods. [0046]
The tetraarylborate compounds (IV) may be used in an undiluted form, or may be diluted with a solvent.
The solvent may be appropriately selected from the solvents used for dissolving the phosphines (II). The solvents may be used singly or in combination of two or more kinds.
Specifically, the 2nd step involving the above raw materials is performed by mixing the aqueous solution of the reaction intermediate assumed to be the phosphine hydrochloride (III), with the tetraarylborate compound (IV) thereby to react the compound (III) with the compound (IV) under predetermined conditions.
The addition sequence of the aqueous solution obtained in the 1st step and the tetraarylborate compound (IV) is not particularly limited. The addition method is not particularly limited, and the material may be added all at once or may be added dropwise intermittently or continuously. [0047]
In the 2nd step, the desirable requirement of the tetraarylborate compound (IV), desirable temperature for smooth reaction, and desirable time to complete the reaction vary depending on the type of the raw material compound phosphine (II) used, amount of hydrogen chloride gas or hydrochloric acid, and type of the tetraarylborate compound (IV), and are selected appropriately.
The amount of the tetraarylborate compound (IV) varies depending on the type of the phosphine (II) used in the 1st step, and is desirably in the range of 0.55 to 5.5 mol, preferably 0 . 85 to 1. 65 mol per mol of phosphine . Particularly preferably, the compound is used in an amount of at least 1 mol per mol of HCl used. The amount of the tetraarylborate compound (IV) in this range enables the production of the phosphonium borate compound (I) in a high yield. [0048]
The reaction of the tetraarylborate compound (IV) is desirably carried out while the reaction solution is at -20
to 150°C, preferably 0 to 80°C and is continuously stirred for up to 24 hours, preferably 1 to 5 hours at the temperature. The reaction under these conditions enables the production of the phosphonium borate compound (I) in a high yield.
After the completion of the reaction, purification such as recrystallization or column chromatography is performed, and consequently the objective novel phosphonium borate compound (I) of Formula (I) can be obtained with high purity:
(R1) (R2) (R3) PH-BAr4 (I)
wherein R1, R2 and R3 are as defined in Formula (II) ; Ar is as defined in Formula (IV) ; R1, R2 and R3 cannot be tert-butyl groups simultaneously and Ar cannot be phenyl group at the same time; and R1, R2 and R3 cannot be cyclohexyl groups simultaneously and Ar cannot be phenyl group at the same time.
According to the embodiment 2, the novel phosphonium borate compound (I) can be obtained in a high yield, specifically in a yield of about 76 to 89 mol% in terms of phosphine (II). [0049]
The novel phosphonium borate compound produced according to the embodiment 2 of the first production process will be described later.
The second process for producing a phosphonium borate
compound includes:
reacting a phosphine with H2S04 to produce a phosphine sulfate, the phosphine being represented by Formula (II):
(R1) (R2) (R3)P (II)
wherein R1 is a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms;
R2 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R3 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 30 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms; and
R1, R2 and R3 may be the same or different from one another;
the phosphine sulfate being represented by Formula (V) :
[ (R1) (R2) (R3)PH](2-n)-HnS04 (V)
wherein R1, R2 and R3 are as defined in Formula (II) , and
n is an integer of 0 or 1;
and
reacting the phosphine sulfate with a tetraarylborate compound represented by Formula (IV):
M-BAr4 (IV)
wherein M is lithium, sodium, potassium, magnesium halide or calcium halide, and Ar is an aryl group of 6 to 20 carbon atoms;
the phosphonium borate compound being represented by Formula (I): [0050]
(R1) (R2) (R3)PH-BAr4 (I)
wherein R1, R2 and R3 are as defined in Formula (II) , and Ar is as defined in Formula (IV) .
Specifically, the second process for producing a phosphonium borate compound (I) includes:
a 1'st step in which the phosphine (II) is reacted with H2S04 to give the phosphine sulfate (V); and
a 2'nd step in which the compound (V) is reacted with the tetraarylborate compound (IV) to produce the phosphonium borate compound (I), as illustrated in the reaction formula below: [0051] [Chem. 2]
H2S04
(R1)(R2XR3)P 1H [ (R1)(R2XR3)PH I 2_n 'HnS04
(II) (V)
M-BAr4 (IV) « o 3
*- (R1 )(R XR )PH • BAr4
(I)
[0052]
The second production process can produce the phosphonium borate compound (I) in a high yield. The reason for this effect is not clear, but is probably that a side reaction that takes place when the compound (II), H2S04 and the compound (IV) are added at the same time can be substantially avoided.
The second process for producing a phosphonium borate compound (I) will be described below with reference to an embodiment 1 for producing the trialkylphosphonium tetraphenylborate and an embodiment 2 for producing the novel phosphonium borate compound. (Embodiment 1) [1'st step]
In the 1'st step, a trialkylphosphine (II) and H2S04 are reacted under predetermined conditions. [0053]
These components will be described below.
The trialkylphosphine (II) used as a raw material in the
production process is represented by Formula (II):
(R1) (R2) (R3)P (II)
wherein R1, R2 and R3 are ethyl, n-butyl, tert-butyl or cyclohexyl groups, and are the same. Examples of the trialkylphosphines (II) include those described in the embodiment 1 of the first production process.
H2S04 used in the production process may be sulfuric acid. The concentration thereof is not particularly limited, and is desirably in the range of 0.1 to 95% by weight, preferably 10 to 40% by weight. [0054]
The 1'st step involving the above raw materials is performed in a reactor purged with an inert gas such as nitrogen or argon. The addition sequence of the raw materials is not particularly limited. For example, sulfuric acid may be added to the trialkylphosphine (II), or the trialkylphosphine (II) may be added to sulfuric acid. The addition method is not particularly limited, and the material may be added all at once or may be added dropwise intermittently or continuously.
In the 1'st step, the desirable H2S04 requirement, desirable temperature for smooth reaction, and desirable time to complete the reaction vary depending on the type of the trialkylphosphine (II) used, and are selected appropriately.
The H2S04 amount varies depending on the type of the
trialkylphosphine (II), and is desirably in the range of 0.25 to 2.5 mol, preferably 0.4 to 0.8 mol per mol of phosphine. The H2S04 amount in this range enables the production of the trialkylphosphonium tetraphenylborate (I) in a high yield. [0055]
The reaction of sulfuric acid is desirably carried out while the solution is at -20 to 150°C, preferably 0 to 80°C and is continuously stirred for up to 24 hours, preferably 30 minutes to 5 hours at the temperature. The reaction under these conditions enables the production of the trialkylphosphonium tetraphenylborate (I) in a high yield.
The completion of the reaction in the 1'st step may be determined by confirming the absence of unreacted trialkylphosphine (II). Specifically, the organic phase is analyzed by gas chromatography or the like to determine the trialkylphosphine (II) in the organic phase. When the analysis confirms substantial absence of the remaining trialkylphosphine (II), the reaction is terminated. When the trialkylphosphine (II) is still present in the organic phase, the reaction is preferably continued. [0056]
The reaction solution takes various forms depending on the solvent used. For example, the solution may contain crystals of trialkylphosphine sulfate (V) (described later),
may be a uniform solution or a suspension, or may be a two-phase system consisting of an aqueous phase and an organic phase. In the case of the two-phase system consisting of an aqueous phase and an organic phase, the system is subjected to separation. In the case of other solution forms, separation may be performed as required by adding water, toluene, n-hexane, n-heptane or the like. The aqueous phase resulting from the separation may be washed with toluene, n-hexane, n-heptane or the like as required.
The aqueous phase obtained by the reaction of the 1'st step contains a reaction intermediate dissolved therein that is assumed to be a trialkylphosphine sulfate (V) represented by Formula (V):
[ (R1) (R2) (R3)PH](2-n)-HnS04 (V)
wherein R1, R2 and R3 are as defined in Formula (II) , and n is an integer of 0 or 1. [0057]
The formation of the trialkylphosphine sulfate (V) may be confirmed by, for example, a nuclear magnetic resonance spectrum 1HH-NMR) . [2'nd step]
The reaction intermediate trialkylphosphine sulfate (V) obtained in the 1'st step is reacted with a tetraphenylborate compound (IV) under predetermined conditions to produce a
trialkylphosphonium tetraphenylborate represented by Formula (I) :
(R1) (R2) (R3)PH-BAr4 (I)
wherein R1, R2 and R3 are ethyl, n-butyl, tert-butyl or cyclohexyl groups, and are the same; and Ar is phenyl group. [0058]
The tetraphenylborate compound (IV) used in the 2'nd step is represented by Formula (IV):
M-BAr4 (IV)
wherein M is lithium, sodium, potassium, magnesium halide or calcium halide, and Ar is phenyl group. Examples thereof include those described in the embodiment 1 of the first production process.
Specifically, the 2'nd step involving the above raw materials is performed by mixing the aqueous solution of the reaction intermediate assumed to be the trialkylphosphine sulfate (V), with the tetraphenylborate compound (IV) thereby to react the compound (V) with the compound (IV) under predetermined conditions.
The addition sequence of the aqueous solution obtained in the 1'st step and the tetraphenylborate compound (IV) is not particularly limited. The addition method is not particularly limited, and the material may be added all at once or may be added dropwise intermittently or continuously.
In the 2'nd step, the desirable requirement of the tetraphenylborate compound (IV), desirable temperature for smooth reaction, and desirable time to complete the reaction vary depending on the type of the raw material compound trialkylphosphine (II) used, amount of sulfuric acid, and type of the tetraphenylborate compound (IV), and are selected appropriately.
The amount of the tetraphenylborate compound (IV) varies depending on the type of the trialkylphosphine (II) used in the 1'st step, and is desirably in the range of 0.55 to 5.5 mol, preferably 0.85 to 1.65 mol per mol of phosphine. Particularly preferably, the compound is used in an amount of at least 2 mol per mol of H2S04 used. The amount of the tetraphenylborate compound (IV) in this range enables the production of the trialkylphosphonium tetraphenylborate (I) in a high yield. [0060]
The reaction of the tetraphenylborate compound (IV) is desirably carried out while the reaction solution is at -20 to 150°C, preferably 0 to 80°C and is continuously stirred for up to 24 hours, preferably 1 to 5 hours at the temperature. The reaction under these conditions enables the production of the trialkylphosphonium tetraphenylborate (I) in a high yield.
After the completion of the reaction, purification such as recrystallization or column chromatography is performed, and consequently the objective trialkylphosphonium tetraphenylborate (I) of Formula (I) can be obtained with high purity:
(R1) (R2) (R3)PH-BAr4 (I)
wherein R1, R2 and R3 are ethyl, n-butyl, tert-butyl or cyclohexyl groups, and are the same; and Ar is phenyl group. [0061]
According to the embodiment 1, the trialkylphosphonium tetraphenylborate (I) can be obtained in a high yield, specifically in a yield of about 87 to 93 mol% in terms of trialkylphosphine (II) .
Examples of the trialkylphosphonium tetraphenylborates (I) of Formula (I) produced according to the embodiment 1 of the second production process include triethylphosphonium tetraphenylborate, tri-n-butylphosphonium tetraphenylborate, tri-tert-butylphosphonium tetraphenylborate and tricyclohexylphosphonium tetraphenylborate.
Next, the embodiment 2 for producing the novel phosphonium borate compound will be described. [0062]
(Embodiment 2) [1'st step]
In the 1'st step, a phosphine (II) and H2S04 are reacted under predetermined conditions. These components will be described below.
The phosphine (II) used as a raw material in the production process is represented by Formula (II):
(R1) (R2) (R3)P (II)
wherein R1 is a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms;
R2 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R3 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 30 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms; and
R1, R2 and R3 may be the same or different from one another. Examples of the phosphines (II) include those described in the embodiment 2 of the first production process.
[0063]
H2S04 may be sulfuric acid. The concentration thereof is not particularly limited, and is desirably in the range of 0.1 to 95% by weight, preferably 10 to 40% by weight.
The 1'st step involving the above raw materials is performed in a reactor purged with an inert gas such as nitrogen or argon. The addition sequence of the raw materials is not particularly limited. For example, sulfuric acid may be added to the phosphine (II) , or the phosphine (II) may be added to sulfuric acid. The addition method is not particularly limited, and the material may be added all at once or may be added dropwise intermittently or continuously.
In the 1'st step, the desirable H2S04 requirement, desirable temperature for smooth reaction, and desirable time to complete the reaction vary depending on the type of the phosphine (II) used, and are selected appropriately. [0064]
The amount of sulfuric acid varies depending on the type of the phosphine (II), and is desirably in the range of 0.25 to 2.5 mol, preferably 0.4 to 0.8 mol per mol of phosphine. The H2SO
The reaction of H2S04 is desirably carried out while the solution is at -20 to 150°C, preferably 0 to 80°C and is
ontinuously stirred for up to 24 hours, preferably 30 minutes to 5 hours at the temperature. The reaction under these conditions enables the production of the phosphonium borate compound (I) in a high yield.
The completion of the reaction in the 1'st step may be determined by confirming the absence of unreacted phosphine (II). Specifically, the organic phase is analyzed by gas chromatography or the like to determine the phosphine (II) in the organic phase. When the analysis confirms substantial absence of the remaining phosphine (II), the reaction is terminated. When the phosphine is still present in the organic phase, the reaction is preferably continued. [0065]
The reaction solution takes various forms depending on the solvent used. For example, the solution may contain crystals of phosphine sulfate (V) (described later), may be a uniform solution or a suspension, or may be a two-phase system consisting of an aqueous phase and an organic phase. In the case of the two-phase system consisting of an aqueous phase and an organic phase, the phosphine sulfate (V) passes into the aqueous phase and therefore the aqueous phase is subjected to separation. In the case of other solution forms, separation may be performed as required by adding water, toluene, n-hexane, n-heptane or the like. The aqueous phase resulting from the
separation may be washed with toluene, n-hexane, n-heptane or the like as required.
The aqueous phase obtained by the reaction of the 1'st step contains a reaction intermediate dissolved therein that is assumed to be a phosphine sulfate (V) represented by Formula (V) :
[ (R1) (R2) (R3)PH](2-n)-HnS04 (V)
wherein R1, R2 and R3 are as defined in Formula (II) , and n is an integer of 0 or 1. [0066]
The formation of the phosphine sulfate (V) may be confirmed by, for example, a nuclear magnetic resonance spectrum 1HH-NMR). [2'nd step]
The reaction intermediate that is assumed to be the phosphine sulfate (V) obtained in the 1'st step is reacted with a tetraarylborate compound (IV) under predetermined conditions to produce a phosphonium borate compound (I) of the present invention.
The tetraarylborate compound (IV) used in the 2'nd step is represented by Formula (IV) :
M-BAr4 (IV)
wherein M is lithium, sodium, potassium, magnesium halide or calcium halide, and Ar is an aryl group of 6 to 20
carbon atoms. Examples of the tetraarylborate compounds include those described in the embodiment 2 of the first production process. [0067]
Specifically, the 2'nd step involving the above raw materials is performed by mixing the agueous solution of the reaction intermediate assumed to be the phosphine sulfate (V) , with the tetraarylborate compound (IV) thereby to react the compound (V) with the compound (IV) under predetermined conditions.
The addition sequence of the aqueous solution obtained in the 1'st step and the tetraarylborate compound (IV) is not particularly limited. The addition method is not particularly limited, and the material may be added all at once or may be added dropwise intermittently or continuously.
In the 2'nd step, the desirable requirement of the tetraarylborate compound (IV), desirable temperature for smooth reaction, and desirable time to complete the reaction vary depending on the type of the raw material compound phosphine (II) used, amount of sulfuric acid, and type of the tetraarylborate compound (IV), and are selected appropriately. [0068]
The amount of the tetraarylborate compound (IV) varies
depending on the type of the phosphine (II) used in the 1'st step, and is desirably in the range of 0.55 to 5.5 mol, preferably 0 . 85 to 1. 65 mol per mol of phosphine . Particularly preferably, the compound is used in an amount of at least 2 mol per mol of H2S04 used. The amount of the tetraarylborate compound (IV) in this range enables the production of the phosphonium borate compound (I) in a high yield.
The reaction of the tetraarylborate compound (IV) is desirably carried out while the reaction solution is at -20 to 150°C, preferably 0 to 80°C and is continuously stirred for up to 24 hours, preferably 1 to 5 hours at the temperature. The reaction under these conditions enables the production of the phosphonium borate compound (I) in a high yield. [0069]
After the completion of the reaction, purification such as recrystallization or column chromatography is performed, and consequently the objective novel phosphonium borate compound (I) of Formula (I) can be obtained with high purity.
The second production process can produce the novel phosphonium borate compound (I) in a high yield, specifically in a yield of about 80 to 85 mol% in terms of phosphine (II) . [Novel phosphonium borate compound]
The novel phosphonium borate compound (I) of the present Invention may be produced according to the embodiment 2 of the
irst production process and according to the embodiment 2 of
the second production process. The phosphonium borate
compound is represented by Formula (I):
(R1) (R2) (R3) PH-BAr4 (I)
wherein R1 is a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms;
R2 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R3 is a hydrogen atom, a primary alkyl group of 1 to 20 carbon atoms, a secondary alkyl group of 3 to 20 carbon atoms, a tertiary alkyl group of 4 to 20 carbon atoms, a cycloalkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 30 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon atoms, or an allyl group of 3 to 20 carbon atoms;
R1, R2 and R3 may be the same or different from one another;
Ar is an aryl group of 6 to 20 carbon atoms; [0070]
R1, R2 and R3 are not tert-butyl groups simultaneously and Ar is not phenyl group at the same time; and
R1, R2 and R3 are not cyclohexyl groups simultaneously and Ar is not phenyl group at the same time.
In Formula (I), R1 is as described below.
R1 may be a secondary alkyl group, desirably a secondary alkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The secondary alkyl groups include isopropyl, sec-butyl, 2-pentyl, 3-pentyl, 2-hexyl and 3-hexyl. [0071]
R1 may be a tertiary alkyl group, desirably a tertiary alkyl group having 4 to 20, preferably 4 to 11 carbon atoms. The tertiary alkyl groups include tert-butyl, tert-amyl, 1,1-dimethylbutyl, 3-methyl-3-pentyl and 1,1,2-trimethylpropyl.
R1 may be a cycloalkyl group, desirably a cycloalkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The cycloalkyl groups include cyclopropyl, cyclopentyl, cyclohexyl, l-methylcyclohexyl, 2-methylcyclohexyl, 1-adamantyl, 2-methyl-l-adamantyl, 2-adamantyl, l-methyl-2-adamantyl and 2-methyl-2-adamantyl. R1 is not limited to the groups described above. [0072]
2
R
In Formula (I), R2 is as described below.
R2 may be a primary alkyl group, desirably a primary alkyl group having 1 to 20, preferably 1 to 8 carbon atoms. The primary alkyl groups include methyl, ethyl, n-propyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, 2-methyl-l-pentyl, 2,2-diethyl-l-ethyl, n-heptyl and n-octyl.
R2 may be a secondary alkyl group, desirably a secondary alkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The secondary alkyl groups include isopropyl, sec-butyl, 2-pentyl, 3-pentyl, 2-hexyl and 3-hexyl. [0073]
R2 may be a tertiary alkyl group, desirably a tertiary alkyl group having 4 to 20, preferably 4 to 11 carbon atoms. The tertiary alkyl groups include tert-butyl, tert-amyl, 1,1-dimethylbutyl, 3-methyl-3-pentyl and 1,1,2-trimethylpropyl.
R2 may be a cycloalkyl group, desirably a cycloalkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The cycloalkyl groups include cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl, 2-methylcyclohexyl, 1-adamantyl, 2-methyl-l-adamantyl, 2-adamantyl, l-methyl-2-adamantyl and 2-methyl-2-adamantyl. [0074]
R2 may be an aralkyl group, desirably an aralkyl group having 7 to 20, preferably 7 to 12 carbon atoms. The aralkyl
groups include benzyl, 1-phenylethyl, 2-phenylethyl, 2-ethenylbenzyl, 3-ethenylbenzyl, 4-ethenylbenzyl, 4-(2-ethenylphenyl)butyl, 4-(3-ethenylphenyl)butyl and 4-(4-ethenylphenyl)butyl.
R2 may desirably be an allyl group having 3 to 20, preferably 3 to 8 carbon atoms. The allyl groups include allyl and 2-octenyl. R2 is not limited to the groups described above.
*!
In Formula (I), R3 is as described below.
[0075]
R3 may be a primary alkyl group, desirably a primary alkyl group having 1 to 20, preferably 1 to 8 carbon atoms. The primary alkyl groups include methyl, ethyl, n-propyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, 2-methyl-l-pentyl, 2,2-diethyl-l-ethyl, n-heptyl and n-octyl.
R3 may be a secondary alkyl group, desirably a secondary alkyl group having 3 to 20, preferably 3 to 11 carbon atoms. The secondary alkyl groups include isopropyl, sec-butyl, 2-pentyl, 3-pentyl, 2-hexyl and 3-hexyl.
R3 may be a tertiary alkyl group, desirably a tertiary alkyl group having 4 to 20, preferably 4 to 11 carbon atoms. The tertiary alkyl groups include tert-butyl, tert-amyl, 1, 1-dimethylbutyl, 3-methyl-3-pentyl and 1,1,2-trimethylpropyl.
R3 may be a cycloalkyl group, desirably a cycloalkyl group having 3 to 20, preferably 3 to 11 carbon atoms . The cycloalkyl groups include cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl, 2-methylcyclohexyl, 1-adamantyl, 2-methyl-l-adamantyl, 2-adamantyl, l-methyl-2-adamantyl and 2-methyl-2-adamantyl.
R3 may be an aryl group, desirably an aryl group having 6 to 30, preferably 6 to 22 carbon atoms. The aryl groups include phenyl, ortho-tolyl, meta-tolyl, para-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3,4-xylyl, 3,5-xylyl, mesityl, 2-tert-butylphenyl, 3-tert-butylphenyl, 4-tert-butylphenyl, 2-ethenylphenyl, 3-ethenylphenyl, 4-ethenylphenyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl, 1-naphthyl, 2-naphthyl, 1,1'-binaphthalene-2-yl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-tert-butoxyphenyl, 3-tert-butoxyphenyl, 4-tert-butoxyphenyl, 2-dimethylaminophenyl, 3-dimethylaminophenyl, 4-dimethylaminophenyl, 2'-dimethylamino-2-biphenylyl, 8-dimethylamino-l-naphthyl and 2'-dimethylamino-1,1'-binaphthalene-2-yl. [0077]
R3 may be an aralkyl group, desirably an aralkyl group having 7 to 20, preferably 7 to 12 carbon atoms. The aralkyl
groups include benzyl, 1-phenylethyl, 2-phenylethyl, 2-ethenylbenzyl, 3-ethenylbenzyl, 4-ethenylbenzyl, 4-(2-ethenylphenyl)butyl, 4-(3-ethenylphenyl)butyl and 4-(4-ethenylphenyl)butyl.
R3 may be an alkenyl group, desirably an alkenyl group having 2 to 20, preferably 2 to 8 carbon atoms. The alkenyl groups include vinyl, methallyl and 1-octenyl.
R3 may be an alkynyl group, desirably an alkynyl group having 2 to 20, preferably 2 to 8 carbon atoms. The alkynyl groups include ethynyl, 1-propynyl and 1-octynyl. [0078]
R3 may desirably be an allyl group having 3 to 20, preferably 3 to 8 carbon atoms. The allyl groups include allyl and 2-octenyl. R3 is not limited to the groups described above.
As long as R1, R2 and R3 are selected from the above groups, they may have an arbitrary combination in terms of carbon atom numbers. Ar
In Formula (I), Ar is desirably an aryl group of 6 to 20, preferably 6 to 10 carbon atoms.
The aryl groups include phenyl, ortho-tolyl, meta-tolyl, para-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3,4-xylyl, 3,5-xylyl, mesityl, 2-tert-butylphenyl, 3-tert-butylphenyl, 4-tert-butylphenyl, 2-methoxyphenyl,
3-methoxyphenyl, 4-methoxyphenyl, 2-tert-butoxyphenyl, 3-tert-butoxyphenyl and 4-tert-butoxyphenyl. Ar is not limited to the groups described above. [0079]
In Formula (I) , R1, R2 and R3 cannot be tert-butyl groups simultaneously and Ar cannot be phenyl group at the same time, and R1, R2 and R3 cannot be cyclohexyl groups simultaneously and Ar cannot be phenyl group at the same time.
The novel phosphonium borate compound preferably has Formula (I) given below for the reason that the raw material phosphine (II) and tetraarylborate compound (IV) can be synthesized easily by known methods:
(R1) (R2) (R3)PH-BAr4 (I)
wherein R1 is a secondary alkyl group of 3 to 6 carbon atoms, a tertiary alkyl group of 4 to 8 carbon atoms, or a cycloalkyl group of 3 to 8 carbon atoms;
R2 is a hydrogen atom, a primary alkyl group of 1 to 8 carbon atoms, a secondary alkyl group of 3 to 6 carbon atoms, a tertiary alkyl group of 4 to 8 carbon atoms, a cycloalkyl group of 3 to 8 carbon atoms, an aralkyl group of 7 to 9 carbon atoms, or an allyl group of 3 to 4 carbon atoms;
R3 is a hydrogen atom, a primary alkyl group of 1 to 8 carbon atoms, a secondary alkyl group of 3 to 6 carbon atoms, a tertiary alkyl group of 4 to 8 carbon atoms, a cycloalkyl
group of 3 to 8 carbon atoms, an aryl group of 6 to 15 carbon atoms, an aralkyl group of 7 to 9 carbon atoms, an alkenyl group of 2 to 4 carbon atoms, an alkynyl group of 2 to 4 carbon atoms, or an allyl group of 3 to 4 carbon atoms;
R1, R2 and R3 may be the same or different from one another;
Ar is an aryl group of 6 to 10 carbon atoms; [0080]
R1, R2 and R3 cannot be tert-butyl groups simultaneously and Ar cannot be phenyl group at the same time; and
R1, R2 and R3 cannot be cyclohexyl groups simultaneously and Ar cannot be phenyl group at the same time.
Specific examples of the novel phosphonium borate compounds (I) represented by Formula (I) are shown in Tables 11-1 to 18-3 which will be presented later.
Of the phosphonium borate compounds (I) , preferred are:
(1) di-tert-butylmethylphosphonium tetraphenylborate,
(2) di-tert-butylmethylphosphonium tetra-para-tolylborate,
(3) tri-tert-butylphosphonium tetra-para-tolylborate,
(4) di-tert-butylethylphosphonium tetraphenylborate,
(5) n-butyl-di-tert-butylphosphonium tetraphenylborate,
(6) sec-butyl-di-tert-butylphosphonium tetraphenylborate,
(7) cyclohexyl-di-tert-butylphosphonium tetraphenylborate,
(8) di-tert-butyl-n-octylphosphonium tetraphenylborate,
(9) di-tert-butylphenylphosphonium tetraphenylborate,
(10) 2-biphenylyl-di-tert-butylphosph1Hi1H tetraphenylborate,
(11) di-tert-butyl-1-naphthylphosphonium tetraphenylborate,
(12) benzyl-di-tert-butylphosphonium tetraphenylborate,
(13) di-tert-butyl(4-ethenylbenzyl)phosphonium
tetraphenylborate,
(14) di-tert-butylvinylphosphonium tetraphenylborate,
(15) allyl-di-tert-butylphosphonium tetraphenylborate,
(16) tricyclohexylphosphonium tetra-para-tolylborate,
(17) triisopropylphosphonium tetraphenylborate,
(18) tricyclopentylphosphonium tetraphenylborate and
(19) n-butyldicyclohexylphosphonium tetraphenylborate.
Of these, the compounds (1), (3), (16) and (17) are more preferable. [0081]
The phosphonium borate compounds (I) are particularly useful in combination with a transition metal, salt thereof, oxide thereof or complex thereof in the carbon-carbon bond forming reactions, carbon-nitrogen bond forming reactions and carbon-oxygen bond forming reactions wherein a transition metal complex having a phosphine ligand produces catalytic effects, wherein the phosphonium borate compounds in combination with the transition metal, salt thereof, oxide thereof or complex thereof are used in place of the transition metal complex having a phosphine ligand.
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