Reuse of homogeneous palladium catalysts

Abstract

The present invention relates to the field of catalysts, and more particularly to a method for recovering palladium in the form of a homogeneous palladium complex of formula (I) from a reaction mixture containing a homogeneous palladium complex.

Description

[Technical Field]

[0001] The present invention relates to the field of catalysts, and more particularly to a method for recovering palladium in the form of a homogeneous palladium complex of formula (I) from a reaction mixture containing a homogeneous palladium complex.

[0002] Background technology One of the major breakthroughs in organic chemistry was the discovery of catalytic reactions, particularly those occurring in the presence of metal complexes acting as catalysts. This discovery has enabled the development of novel reactions over several decades, including cross-coupling, CH activation, addition to unsaturated bonds, intramolecular or intermolecular cyclization, elimination, allyl substitution, hydrogenation, hydroformylation, and isomerization. Homogeneous palladium complexes are among the most widely developed and used catalysts.

[0003] With growing awareness of climate and environmental issues, the development of this type of reaction aligns with this trend. In fact, metal complex-catalyzed reactions are one of the twelve principles of green chemistry, which aim to reduce the environmental impact of organic chemistry. Reducing waste generated during chemical reactions is also highly desirable. The homogeneous palladium complex involved in such reactions is part of the waste and does not need to be recovered at the end of the reaction.

[0004] Today, there is a need to limit waste, and metal complexes must be recovered / reused as much as possible, even though they are only involved in small amounts in such transformations.

[0005] The present invention makes it possible to recover palladium in the form of a homogeneous palladium complex of formula (I) from a reaction mixture containing a homogeneous palladium complex, either during distillation of the reaction mixture or by adding phosphine to the distillation residue. To the best of the inventors' knowledge, the method of the present invention has not been reported in the prior art.

[0006] Modes for carrying out the invention Surprisingly, the method of the present invention allows for the easy and very productive recovery of palladium in the form of a homogeneous palladium complex of formula (I).

[0007] Thus, a first object of the present invention is formula (I) Pd(PR 3) x (PR 2 3) y (I) (wherein x is an integer from 1 to 4, y is an integer from 0 to 3, provided that the sum of x and y is equal to 4, and each R 1 is, independently of one another, a C1-C 12 alkyl group, a C1-C 12 alkoxy group, a C6-C 12 aryloxy group, or a C6-C 12 aryl group, each optionally being substituted by one or more halogen atoms, a C 1-6 alkyl group, a C 1-6 alkoxy group, a hydroxy group, an N-C 1-6 alkylaniline group, an N-C 1-6 alkyl-N-C 1-6 alkylaniline group, or a C 1-6 halo- or perhalohydrocarbon, and each R 2 is, independently of one another, a C1-C 12 alkyl group, a C1-C 12 alkoxy group, a C6-C 12 aryloxy group, or a C6-C 12 aryl group, each optionally being substituted by one or more halogen atoms, a C 1-6 alkyl group, a C 1-6 alkoxy group, a hydroxy group, an N-C 1-6 alkylaniline group, an N-C 1-6 alkyl-N-C 1-6 alkylaniline group, or a C 1-6 halo- or perhalohydrocarbon, provided that PR 1 3 is different from PR​​​A method for recovering palladium in the form of a palladium complex from a reaction mixture containing a homogeneous palladium complex, a) Add formula PR to the reaction mixture. 1 3 (wherein, R 1 (This has the same meaning as the definition above) at least one phosphine, and optionally formula PR 2 3 (wherein, R 2 The process involves adding another phosphine (which has the same meaning as the definition above), b) A step of distilling the reaction mixture obtained from step a) to obtain a distillate and a distillation residue, c) A step of filtering the distillation residue to obtain a palladium complex of formula (I) and This method includes [something].

[0008] To clarify, the statement "x is an integer between 1 and 4, and y is an integer between 0 and 3, provided that the sum of x and y is equal to 4" or a similar expression means what is commonly understood by those skilled in the art, namely that x may be 1, 2, 3, or 4, y may be 0, 1, 2, or 3, and x + y equals 4. For example, if x is 4, then y is 0; if x is 2, then y is 2; or if x is 3, then y is 1.

[0009] "Alkyl", "Alkoxy", "NC" 1-6 "Alkylaniline group", and NC 1-6 Alkyl-NC 1-6 The term alkylaniline group refers to branched and linear alkyl groups, alkoxy groups, and NC groups. 1-6 Alkylaniline group, and NC 1-6 Alkyl-NC 1-6 It is understood to contain an alkylaniline group.

[0010] "NC 1-6 The term "alkylaniline" is defined as having R' = C 1-6 It is understood as a secondary amine of the formula -NH-R', which is an alkyl group.

[0011] "NC1-6 Alkyl-NC 1-6 The term "alkylaniline" refers to a group where R' and R'' are independent of each other. 1-6 It is understood as a tertiary amine of the formula -NR'R'', which is an alkyl group.

[0012] The term "aryl" is understood to include any group containing at least one aromatic group, such as phenyl, indenyl, indanyl, benzodioxolyl, dihydrobenzodioxynyl, tetrahydronaphthalenyl, or a naphthalenyl group.

[0013] The term "optional" is understood to mean that a particular group that is optionally substituted may or may not be substituted by a particular functional group. The term "one or more" is understood to mean that the group is substituted by 1 to 7, preferably 1 to 5, and more preferably 1 to 3, particular functional groups.

[0014] The term "halo- or perhalo-hydrocarbon" is understood as a hydrocarbon group in which some or all of the hydrogen atoms are replaced by halogen atoms. Examples of "halo- or perhalo-hydrocarbons" are CClH2 or CF3.

[0015] Alternatively, formula PR 1 3 at least one type of phosphine, and optionally formula PR 2 Another phosphine of formula (I) may be added to the distillation residue after distillation. Therefore, a second object of the present invention is formula (I) Pd(PR 1 3) x (PR 2 3) y (I) (In the formula, x is an integer between 1 and 4, and y is an integer between 0 and 3, where the sum of x and y is equal to 4, and each R 1 These are independent of each other, C1~C 12 Alkyl alkyl groups, C1-C 12 Alkoxy group, C6~C 12 Aryloxy group, or C6~C12 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-6 Alkyl alkyl group, C 1-6 Alkoxy group, hydroxyl group, NC 1-6 Alkylaniline group, NC 1-6 Alkyl-NC 1-6 alkylaniline group, or C 1-6 Substituted by one or more halo- or perhalo-hydrocarbons, each R 2 These are independent of each other, C1~C 12 Alkyl alkyl groups, C1-C 12 Alkoxy group, C6~C 12 Aryloxy group, or C6~C 12 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-6 Alkyl alkyl group, C 1-6 Alkoxy group, hydroxyl group, NC 1-6 Alkylaniline group, NC 1-6 Alkyl-NC 1-6 alkylaniline group, or C 1-6 Substituted by one or more halo- or perhalo-hydrocarbons, however PR 1 3 is PR 2 (Different from 3) A method for recovering palladium in the form of a palladium complex from a reaction mixture containing a homogeneous palladium complex, i) A step of distilling a reaction mixture containing a homogeneous palladium complex to obtain a distillate and a distillation residue, ii) The distillation residue contains formula PR 1 3 (wherein, R 1 (This has the same meaning as the definition above) at least one phosphine, and optionally formula PR 2 3 (wherein, R 2 The process involves adding another phosphine (which has the same meaning as the definition above), iii) A step of mixing the distillation residue containing phosphine obtained from step ii) to obtain a distillation residue containing the palladium complex of formula (I), iv) A step of filtering the distillation residue containing the palladium complex of formula (I) to obtain the palladium complex of formula (I), This method includes [something].

[0016] The term "reaction mixture containing a homogeneous palladium complex" means, 1) A homogeneous palladium complex is used as a reagent, especially as a catalyst, to provide a crude product in chemical synthesis / reactions. It is understood as any mixture resulting from, 2) The crude product obtained in step 1) is washed by one or more optional washing steps to obtain a reaction mixture containing palladium.

[0017] The washing step may involve washing the crude product with water, one or more acidic aqueous solutions, and / or one or more basic aqueous solutions. The crude product may be washed several times with different types of aqueous solutions. In other words, the palladium-catalyzed reaction is carried out under conditions known to those skilled in the art. The crude product of the reaction obtained is optionally washed with water, one or more acidic aqueous solutions, and / or one or more basic aqueous solutions to provide a reaction mixture containing a homogeneous palladium complex. The method of the present invention is then carried out on the reaction mixture thus obtained. The palladium-catalyzed reaction may be any reaction catalyzed by the homogeneous palladium complex. Examples of suitable palladium-catalyzed reactions include, but are not limited to, cross-coupling reactions, e.g., Heck reaction, Sonogashira coupling, Negishi coupling, Still cross-coupling, Suzuki coupling, Kumada coupling, Hiyama coupling, Buchwald-Hartwig coupling, cyanation reactions, carbonylation reactions, CH activation, addition to unsaturated bonds, intramolecular or intermolecular cyclization, allyl substitution, and elimination. The palladium complexes used in such reactions are homogeneous palladium(O), palladium(I), or palladium(II) complexes. Suitable examples of homogeneous palladium(O) include, but are not limited to, palladium tetrakistriarylphosphine, palladium diphosphine, palladium triphosphine, bis(dibenzylideneacetone)palladium, or tris(dibenzylideneacetone)-dipalladium. Suitable examples of homogeneous palladium(I) include, but are not limited to, monophosphine palladium halide dimers. Suitable examples of homogeneous palladium(II) include, but are not limited to, palladium acetate, palladium acetylacetonate, allyl palladium chloride dimer, clotyl palladium chloride dimer, cinnamyl palladium chloride dimer, dihalobis(acetonitrile) palladium, dihalobis(benzonitrile) palladium, dichlorobisphosphine palladium, diphosphine palladium acetate, dichloro-diphosphine-palladium, dihalo(1,5-cyclooctadiene) palladium, or dihalo(1,10-phenanthroline) palladium.

[0018] Importantly, the present invention emphasizes that the reaction mixture is not the result of the palladium complex itself, in particular the preparation reaction of the palladium complex of formula (I).

[0019] According to any embodiment of the present invention, the palladium complex of formula (I) and the homogeneous palladium complex from the reaction mixture may be the same or different, and in particular may be different.

[0020] According to certain embodiments of the present invention, the reaction mixture containing a homogeneous palladium complex is obtained from a reaction catalyzed with a homogeneous palladium(II) or homogeneous palladium(O) complex, particularly palladium acetate or palladium tetrakistriphenylphosphine.

[0021] According to any embodiment of the present invention, distillation is carried out using a distillation column which may include plates, trays, or packing material. Those skilled in the art can select and size the distillation column according to the melting and boiling points of the starting and final products.

[0022] According to any embodiment of the present invention, distillation is carried out at atmospheric pressure or reduced pressure, particularly 5 × 10⁻⁶. 4 Pressures less than Pa (500 mbar), e.g., 100 Pa ~ 5 × 10 4 This can be done at pressures within the range of Pa (1 to 500 mbar).

[0023] According to any embodiment of the present invention, distillation may be carried out at a temperature within the range of 40°C to 300°C, more preferably 80°C to 250°C. Naturally, those skilled in the art can also select a preferred temperature depending on the boiling points of the starting and final products, as well as the boiling point of the solvent.

[0024] According to any embodiment of the present invention, distillation is carried out in the presence of a solvent having a high boiling point. The solvent is inert. In particular, the solvent has a boiling point above 200°C, and even above 300°C. Suitable solvents having a high boiling point include, but are not limited to, polyethylene glycol, dibenzyl toluene, and high-boiling point saturated and unsaturated hydrocarbons.

[0025] According to any embodiment of the present invention, a high-boiling point solvent can be added to the distillation medium at a wide range of concentrations. As a non-limiting example, the concentration of the high-boiling point solvent can range from 1 to 100 equivalents relative to the amount of homogeneous palladium complex in the reaction mixture. Preferably, the concentration of the high-boiling point solvent is in the range of 4 to 50 equivalents. More preferably, the concentration of the high-boiling point solvent is in the range of 5 to 20 equivalents. Needless to say, the method of the present invention also works with a larger amount of high-boiling point solvent. However, as is known to those skilled in the art, the optimal concentration of the high-boiling point solvent depends on the properties of the solvent, the properties of the palladium complex, the temperature, and the desired reaction time.

[0026] The temperature range in which the distillation residue containing phosphine obtained from step ii) can be mixed is within the range of 20°C to 100°C, more preferably 50°C to 90°C. Naturally, those skilled in the art may also select a preferred temperature depending on the properties of the distillation residue and the properties of the phosphine used.

[0027] According to any embodiment of the present invention, the mixing of the distillation residue containing phosphine obtained from step ii) is carried out under an inert atmosphere such as nitrogen or argon.

[0028] According to any embodiment of the present invention, the mixing of the distillation residue containing phosphine obtained from step ii) is carried out over a period of 30 to 240 minutes, preferably 60 to 150 minutes.

[0029] According to any embodiment of the present invention, filtration is gravity filtration, membrane filtration, or vacuum filtration.

[0030] According to any embodiment of the present invention, the palladium complex of formula (I) obtained after filtration is further washed with an organic solvent. Examples of suitable solvents for washing the palladium complex of formula (I) include, but are not limited to, aromatic solvents such as toluene, fluorobenzene, trifluorotoluene, ortho-difluorobenzene, ortho-dichlorobenzene, chlorobenzene, or xylene; hydrocarbon solvents such as hexane, heptane, or cyclohexane; ethers such as tetrahydrofuran, methyltetrahydrofuran, or MTBE; polar solvents such as isopropanol, primary or secondary alcohols such as ethanol, or methanol; or mixtures thereof.

[0031] According to any embodiment of the present invention, the method of the present invention is carried out in the absence of a base, additive, reducing agent, or oxidizing agent.

[0032] According to any embodiment of the present invention, formula PR 1 The phosphine of formula PR can be added to the reaction medium at a wide range of concentrations. As a non-limiting example, the complex concentration can be in the range of 4 to 15 equivalents relative to the amount of homogeneous palladium complex in the reaction mixture. Preferably, the phosphine concentration is in the range of 4 to 10 equivalents. More preferably, the phosphine concentration is in the range of 5 to 8 equivalents. Needless to say, the method of the present invention also works with higher concentrations of phosphine. However, formula PR 1 The optimal concentration of phosphine 3 depends, as is known to those skilled in the art, on the properties of the phosphine, the properties of the palladium complex, the temperature, and the desired reaction time.

[0033] According to any embodiment of the present invention, formula PR 2The phosphine of 3 can be added to the reaction medium at a wide range of concentrations. As a non-limiting example, values within the range of 0 to 15 equivalents relative to the amount of the homogeneous palladium complex contained in the reaction mixture can be cited as the complex concentration. Preferably, the phosphine concentration is included in 0 to 10 equivalents. More preferably, the phosphine concentration is included in 0 to 8 equivalents. Needless to say, the method of the present invention functions even with more phosphine. However, the optimum concentration of the phosphine of the formula PR 2 3 depends on the nature of the phosphine, the nature of the palladium complex, the temperature, and the desired reaction time, as known to those skilled in the art.

[0034] According to any embodiment of the present invention, each R 2 is, independently of one another, a C1-C 10 alkyl group, a C1-C 10 alkoxy group, a C6-C 10 aryloxy group, or a C6-C 10 aryl group, each optionally substituted by one or more of a halogen atom, a C 1-6 alkyl group, a C 1-6 alkoxy group, a hydroxy group, an N-C 1-6 alkyl aniline group, an N-C 1-6 alkyl-N-C 1-6 alkyl aniline group, or a C 1-6 halo- or perhalo hydrocarbon. In particular, each R 2 is, independently of one another, a C1-C8 alkyl group, a C1-C8 alkoxy group, a C6-C 10 aryloxy group, or a C6-C 10 aryl group, each optionally substituted by one or more of a halogen atom, a C 1-6 alkyl group, a C 1-6 alkoxy group, a hydroxy group, an N-C 1-6 alkyl aniline group, an N-C 1-6 alkyl-N-C 1-6 alkyl aniline group, or a C 1-6 halo- or perhalo hydrocarbon. In particular, each R 2 is, independently of one another, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C6-C10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-6 Alkyl alkyl group, C 1-6 Alkoxy group, hydroxyl group, NC 1-6 Alkylaniline group, NC 1-6 Alkyl-NC 1-6 alkylaniline group, or C 1-6 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 2 These are, independently of each other, a C1-C6 alkyl group, a C1-C6 alkoxy group, and a C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 2 These are, independently of each other, a C1-C4 alkyl group, a C1-C4 alkoxy group, and a C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 2 These are, independently of each other, C1-C3 alkyl groups, C1-C3 alkoxy groups, and C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 2 These are, independently of each other, a C1-C2 alkyl group, a C1-C2 alkoxy group, and a C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 2 These are, independently of each other, a methyl group, C6~C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 2 These are, independently of each other, a methyl group, a C6 aryloxy group, or a C6 aryl group, each optionally containing a halogen atom, C 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 2These are, independently of each other, a methyl group, or optionally a halogen atom, C 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 A phenyl group substituted with one or more halo- or perhalo-hydrocarbons. In particular, each R 2 These are, independently of each other, a methyl group, or optionally a halogen atom, C 1-3 Alkyl alkyl group, C 1-3 Alkoxy group, hydroxyl group, NC 1-3 Alkylaniline group, NC 1-3 Alkyl-NC 1-3 alkylaniline group, or C 1-3 A phenyl group substituted with one or more halo- or perhalo-hydrocarbons. In particular, each R 2 These are, independently of each other, a methyl group, or optionally a halogen atom, C 1-2 Alkyl alkyl group, C 1-2 Alkoxy group, hydroxyl group, NC 1-2 Alkylaniline group, NC 1-2 Alkyl-NC 1-2 A phenyl group substituted with an alkylaniline group or one or more perhalohydrocarbons. In particular, each R 2 These are, independently of each other, a methyl group, or optionally a halogen atom, C 1-2 Alkyl alkyl group, C 1-2 A phenyl group substituted with one or more alkoxy groups or perhalohydrocarbons. In particular, each R 2 These are phenyl groups that are independently of each other, either a methyl group or optionally substituted with one or more of the following: a chlorine atom, a fluorine atom, a bromine atom, a methyl group, a methoxy group, N,N-dimethylaniline, a hydroxyl group, or a trifluoromethyl group. In particular, each R 2These are, independently of each other, a methyl group, a phenyl group, an o-methoxyphenyl group, an m-methoxyphenyl group, a p-methoxyphenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 4-methoxy-3,5-dimethylphenyl group, a 2,4-dimethylphenyl group, a 3,5-dimethylphenyl group, a 2,4,6-trimethoxyphenyl group, a pentafluorophenyl group, an m-chlorophenyl group, a p-chlorophenyl group, a p-fluorophenyl group, a p-trifluoromethylphenyl group, a 4-(N,N-dimethylamino)phenyl group, a 2-hydroxyphenyl group, a 2-bromophenyl group, and a 2,4,6-trimethylphenyl group.

[0035] According to any embodiment of the present invention, PR 2 3 is triphenylphosphine, tris(o-methoxyphenyl)phosphine, tris(m-methoxyphenyl)phosphine, tris(p-methoxyphenyl)phosphine, tri(o-tolyl)phosphine, tri(m-tolyl)phosphine, tri(p-tolyl)phosphine, tris(4-methoxy-3,5-dimethylphenyl)phosphine, methyl(diphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethoxyphenyl The following can be selected from the group consisting of (phenyl)phosphine, tris(pentafluorophenyl)phosphine, tri(m-chlorophenyl)phosphine, tri(p-chlorophenyl)phosphine, tris(p-fluorophenyl)phosphine, tris(p-trifluoromethylphenyl)phosphine, diphenyl[4-(N,N-dimethylamino)phenyl]phosphine, (2-hydroxyphenyl)diphenylphosphine, 2-bromophenyldiphenylphosphine, and tris(2,4,6-trimethylphenyl)phosphine.

[0036] According to any embodiment of the present invention, x is 2, 3, or 4. Preferably, x is 4.

[0037] According to any embodiment of the present invention, y is 2, 1, or 0. Preferably, y is 0.

[0038] According to any embodiment of the present invention, the palladium complex of formula (I) is, Pd(PR 1 3)4(I') (wherein x and R in the formula) 1 (This has the same meaning as the definition above.) It is a complex of [the two compounds].

[0039] According to any embodiment of the present invention, each R 1 These are independent of each other, C1~C 10 Alkyl alkyl groups, C1-C 10 Alkoxy group, C6~C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-6 Alkyl alkyl group, C 1-6 Alkoxy group, hydroxyl group, NC 1-6 Alkylaniline group, NC 1-6 Alkyl-NC 1-6 alkylaniline group, or C 1-6 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, C1-C8 alkyl groups, C1-C8 alkoxy groups, and C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-6 Alkyl alkyl group, C 1-6 Alkoxy group, hydroxyl group, NC 1-6 Alkylaniline group, NC 1-6 Alkyl-NC 1-6 alkylaniline group, or C 1-6 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, a C1-C6 alkyl group, a C1-C6 alkoxy group, and a C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-6 Alkyl alkyl group, C 1-6 Alkoxy group, hydroxyl group, NC1-6 Alkylaniline group, NC 1-6 Alkyl-NC 1-6 alkylaniline group, or C 1-6 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, a C1-C6 alkyl group, a C1-C6 alkoxy group, and a C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, a C1-C4 alkyl group, a C1-C4 alkoxy group, and a C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, C1-C3 alkyl groups, C1-C3 alkoxy groups, and C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, a C1-C2 alkyl group, a C1-C2 alkoxy group, and a C6-C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, a methyl group, C6~C 10 Aryloxy group, or C6~C 10 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, a methyl group, a C6 aryloxy group, or a C6 aryl group, each optionally containing a halogen atom, C 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4 Alkyl-NC 1-4 alkylaniline group, or C 1-4 Substituted by one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, a methyl group, or optionally a halogen atom, C 1-4 Alkyl alkyl group, C 1-4 Alkoxy group, hydroxyl group, NC 1-4 Alkylaniline group, NC 1-4Alkyl-NC 1-4 alkylaniline group, or C 1-4 A phenyl group substituted with one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, a methyl group, or optionally a halogen atom, C 1-3 Alkyl alkyl group, C 1-3 Alkoxy group, hydroxyl group, NC 1-3 Alkylaniline group, NC 1-3 Alkyl-NC 1-3 alkylaniline group, or C 1-3 A phenyl group substituted with one or more halo- or perhalo-hydrocarbons. In particular, each R 1 These are, independently of each other, a methyl group, or optionally a halogen atom, C 1-2 Alkyl alkyl group, C 1-2 Alkoxy group, hydroxyl group, NC 1-2 Alkylaniline group, NC 1-2 Alkyl-NC 1-2 A phenyl group substituted with an alkylaniline group or one or more perhalohydrocarbons. In particular, each R 1 These are, independently of each other, a methyl group, or optionally a halogen atom, C 1-2 Alkyl alkyl group, C 1-2 A phenyl group substituted with one or more alkoxy groups or perhalohydrocarbons. In particular, each R 1 These are phenyl groups that are independently of each other, either a methyl group or optionally substituted with one or more of the following: a chlorine atom, a fluorine atom, a bromine atom, a methyl group, a methoxy group, N,N-dimethylaniline, a hydroxyl group, or a trifluoromethyl group. In particular, each R 1These are, independently of each other, a methyl group, a phenyl group, an o-methoxyphenyl group, an m-methoxyphenyl group, a p-methoxyphenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 4-methoxy-3,5-dimethylphenyl group, a 2,4-dimethylphenyl group, a 3,5-dimethylphenyl group, a 2,4,6-trimethoxyphenyl group, a pentafluorophenyl group, an m-chlorophenyl group, a p-chlorophenyl group, a p-fluorophenyl group, a p-trifluoromethylphenyl group, a 4-(N,N-dimethylamino)phenyl group, a 2-hydroxyphenyl group, a 2-bromophenyl group, and a 2,4,6-trimethylphenyl group. More specifically, each R 1 These are phenyl groups, independently of each other.

[0040] According to any embodiment of the present invention, PR 1 3 is triphenylphosphine, tris(o-methoxyphenyl)phosphine, tris(m-methoxyphenyl)phosphine, tris(p-methoxyphenyl)phosphine, tri(o-tolyl)phosphine, tri(m-tolyl)phosphine, tri(p-tolyl)phosphine, tris(4-methoxy-3,5-dimethylphenyl)phosphine, methyl(diphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(3,5-dimethylphenyl)-phosphine, tris(2,4,6-trimethoxyphenyl It can be selected from the group consisting of (phenyl)phosphine, tris(pentafluorophenyl)-phosphine, tri(m-chlorophenyl)phosphine, tri(p-chlorophenyl)phosphine, tris(p-fluorophenyl)phosphine, tris(p-trifluoromethylphenyl)phosphine, diphenyl[4-(N,N-dimethylamino)phenyl]phosphine, (2-hydroxyphenyl)diphenylphosphine, 2-bromo-phenyldiphenylphosphine, and tris(2,4,6-trimethylphenyl)phosphine. In particular, PR 1 3 is triphenylphosphine.

[0041] According to any embodiment of the present invention, the palladium complex of formula (I') is palladium tetrakiss(triphenylphosphine), tri(tris(o-methoxyphenyl)phosphine)phosphine, palladium tetrakiss(tris(m-methoxyphenyl)-phosphine), palladium tetrakiss(tris(p-methoxyphenyl)phosphine), palladium tetrakiss-(tri-(p-tolyl)phosphine), palladium tetrakiss(tris(4-methoxy-3,5-dimethylphenyl)phosphine), palladium tetrakiss(methyl(diphenyl)phosphine), palladium tetrakiss(tris(2,4-dimethylphenyl)phosphine), palladium tetrakiss(tris(3,5-dimethylphenyl)phosphine), palladium tetrakiss(tris(2,4,6-tri A selection may be made from the group consisting of methoxyphenyl)phosphine, palladium tetrakiss(tris(pentafluorophenyl)phosphine), palladium tetrakiss(tri(m-chlorophenyl)-phosphine), palladium tetrakiss(tri(p-chlorophenyl)phosphine), palladium tetrakiss(tris(p-fluorophenyl)phosphine), palladium tetrakiss(tris(p-trifluoromethylphenyl)phosphine), palladium tetrakiss(diphenyl[4-(N,N-dimethylamino)phenyl]phosphine), palladium tetrakiss((2-hydroxyphenyl)diphenylphosphine), palladium tetrakiss(2-bromophenyl-diphenylphosphine), and palladium tetrakiss(tris(2,4,6-trimethylphenyl)phosphine).

[0042] Another object of the present invention is a solvent having a high boiling point and formula (I) Pd(PR 1 3) x (PR 2 3) y (I) (In the formula, x is an integer between 1 and 4, and y is an integer between 0 and 3, where the sum of x and y is equal to 4, and each R 1 These are independent of each other, C1~C 12 Alkyl alkyl groups, C1-C 12 Alkoxy group, C6~C 12Aryloxy group, or C6~C 12 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-6 Alkyl alkyl group, C 1-6 Alkoxy group, hydroxyl group, NC 1-6 Alkylaniline group, NC 1-6 Alkyl-NC 1-6 alkylaniline group, or C 1-6 Substituted by one or more halo- or perhalo-hydrocarbons, each R 2 These are independent of each other, C1~C 12 Alkyl alkyl groups, C1-C 12 Alkoxy group, C6~C 12 Aryloxy group, or C6~C 12 These are aryl groups, each optionally containing a halogen atom and a carbon atom. 1-6 Alkyl alkyl group, C 1-6 Alkoxy group, hydroxyl group, NC 1-6 Alkylaniline group, NC 1-6 Alkyl-NC 1-6 alkylaniline group, or C 1-6 Substituted by one or more halo- or perhalo-hydrocarbons, however PR 1 3 is PR 2 (Different from 3) It is a distillation residue containing a palladium complex.

[0043] A solvent with a high boiling point is defined as described above.

[0044] Unless otherwise specified, all percentages refer to weight percentages based on the total weight of the referenced composition.

[0045] Typical methods for carrying out the process of the present invention are reported below in the examples provided herein.

[0046] Examples The present invention will now be described in more detail by the following examples, where abbreviations have their usual meanings in the art and temperatures are given in degrees Celsius (°C). The pre-catalyst and ligand solutions were prepared using the standard Schlenk technique under an inert atmosphere (argon). The solvent was dried by conventional procedures and distilled under an argon atmosphere. NMR spectra were recorded at 20°C using a Bruker AV300, AV400, or AV500 MHz spectrometer. Chemical shifts were measured against the solvent signal (chloroform, δ). H =7.26 ppm, δ C It is reported in ppm for (=77.0 ppm). The signal assignment is, 1 H, 1 H-COSY, -NOESY, 13 C, 1 This was confirmed by recording H-HSQC and HMBC experiments.

[0047] Example 1 Method for recovering [Pd(PPh3)4] from a reaction mixture containing a homogeneous palladium complex. 80 g of residue containing 3100 ppm of a homogeneous palladium complex (residue obtained by flash distillation of the crude product containing a trace amount of palladium complex; distilled under vacuum using a high-boiling solvent) was stirred under nitrogen with 4.0 g (6.5 equivalents) of triphenylphosphine at 80°C for 2 hours. After cooling to 30°C, 30 g of heptane was added to the mixture. The suspension was transferred to a frit filter under nitrogen and washed with 30 g of heptane, 30 g of methanol, and 30 g of heptane. After drying under vacuum, 2.57 g of palladiumtetrakis (triphenylphosphine) was obtained (yield 94.7 mol%).

Claims

1. Equation (I) Pd(PR １ ３ ) ｘ (PR ２ ３ ) ｙ (I) (where x is an integer included in 1 to 4, y is an integer included in 0 to 3, provided that the sum of x and y is equal to 4, and each R １ is, independently of one another, C １ to C １２ alkyl group, C １ to C １２ alkoxy group, C ６ to C １２ aryloxy group, or C ６ to C １２ aryl group, and each is, optionally, substituted by one or more of a halogen atom, C １－６ alkyl group, C １－６ alkoxy group, hydroxy group, N-C １－６ alkylaniline group, N-C １－６ alkyl-N-C １－６ alkylaniline group, or C １－６ halo- or perhalohydrocarbon, and each R ２ is, independently of one another, C １ to C １２ alkyl group, C １ to C １２ alkoxy group, C ６ to C １２ aryloxy group, or C ６ to C<​​​​​​​​​​​​​​​​​​​ A method for recovering palladium in the form of a palladium complex from a reaction mixture containing a homogeneous palladium complex, a) Add the formula PR to the reaction mixture １ ３ (In the formula, R １ (This has the same meaning as the definition above) at least one phosphine of formula PR ２ ３ (In the formula, R ２ The process involves adding another phosphine (which has the same meaning as the definition above), b) A step of distilling the reaction mixture obtained from step a) to obtain a distillate and a distillation residue, c) A step of filtering the distillation residue to obtain the palladium complex of formula (I) Methods that include...

2. Equation (I) Pd(PR １ ３ ) ｘ (PR ２ ３ ) ｙ (I) (In the formula, x is an integer between 1 and 4, and y is an integer between 0 and 3, provided that the sum of x and y is equal to 4, and each R １ They are independent of each other, C １ ~C １２ alkyl group, C １ ~C １２ Alkoxy group, C ６ ~C １２ Aryloxy group, or C ６ ~C １２ These are aryl groups, each optionally containing a halogen atom and C １－６ alkyl group, C １－６ Alkoxy group, hydroxyl group, N-C １－６ Alkylaniline group, N-C １－６ Alkyl-N-C １－６ Alkylaniline group, or C １－６ Substituted by one or more halos or perhalohydrocarbons, each R ２ They are independent of each other, C １ ~C １２ alkyl group, C １ ~C １２ Alkoxy group, C ６ ~C １２ Aryloxy group, or C ６ ~C １２ These are aryl groups, each optionally containing a halogen atom and C １－６ alkyl group, C １－６ Alkoxy group, hydroxyl group, N-C １－６ Alkylaniline group, N-C １－６ Alkyl-N-C １－６ Alkylaniline group, or C １－６ Substituted by one or more halos or perhalohydrocarbons, however PR １ ３ PR ２ ３ (Different from) A method for recovering palladium in the form of a palladium complex from a reaction mixture containing a homogeneous palladium complex, i) A step of distilling the reaction mixture containing the homogeneous palladium complex to obtain a distillate and a distillation residue, ii) adding to the distillation residue at least one phosphine of the formula PR １ ３ (wherein R １ has the same meaning as defined above), and optionally another phosphine of the formula PR ２ ３ (wherein R ２ has the same meaning as defined above); iii) A step of mixing the distillation residue containing phosphine obtained from step ii) to obtain a distillation residue containing the palladium complex of formula (I), iv) A step of filtering the distillation residue containing the palladium complex of formula (I) to obtain the palladium complex of formula (I). Methods that include...

3. The method according to claim 1 or 2, wherein the distillation is carried out in the presence of a solvent having a high boiling point.

4. The method according to any one of claims 1 to 3, wherein X is 4 and y is 0.

5. Each R １ is, independently of one another, C １ to C ６ alkyl group, C １ to C ６ alkoxy group, C ６ to C １０ aryloxy group, or C ６ to C １０ aryl group, and each is, optionally, substituted by one or more of a halogen atom, C １－４ alkyl group, C １－４ alkoxy group, hydroxy group, N-C １－４ alkylaniline group, N-C １－４ alkyl-N-C １－４ alkylaniline group, or C １－４ halo- or perhalohydrocarbon, and the method according to any one of claims 1 to 4.

6. Each R １ However, independently of each other, they are either methyl groups, or optionally, halogen atoms, C １－４ alkyl group, C １－４ Alkoxy group, hydroxyl group, N-C １－４ Alkylaniline group, N-C １－４ Alkyl-N-C １－４ Alkylaniline group, or C １－４ The method according to any one of claims 1 to 5, wherein the phenyl group is substituted with one or more halo or perhalohydrocarbons.

7. PR １ ３ The method according to any one of claims 1 to 6, wherein is triphenylphosphine.

8. The method according to any one of claims 1 to 7, wherein the reaction mixture containing the homogeneous palladium complex is derived from a reaction catalyzed by a homogeneous palladium (O), palladium (I), or palladium (II) complex.

9. The method according to any one of claims 1 to 8, wherein the homogeneous palladium(II) complex is selected from the group consisting of palladium acetate, palladium acetylacetonate, allyl palladium chloride dimer, clotyl palladium chloride dimer, cinnamyl palladium chloride dimer, dihalobis(acetonitrile)palladium, dihalo-bis(benzonitrile)palladium, dichlorobisphosphine palladium, diphosphine palladium acetate, dichlorodiphosphine palladium, dihalo(1,5-cyclooctadiene)palladium, and dihalo(1,10-phenanthroline)palladium; the homogeneous palladium(O) complex is selected from the group consisting of palladium tetrakistriarylphosphine, palladium diphosphine, palladium triphosphine, bis(dibenzylideneacetone)palladium, and tris(dibenzylideneacetone)dipalladium; and the homogeneous palladium(I) complex is selected from the group consisting of monophosphine palladium halide dimers.

10. The method according to any one of claims 1 to 9, wherein the palladium complex of formula (I) obtained after the filtration is further washed with an organic solvent.

11. The method according to any one of claims 1 to 10, carried out in the absence of a base, additive, reducing agent, or oxidizing agent.

12. Solvents with high boiling points and formula (I) Pd(PR １ ３ ) ｘ (PR ２ ３ ) ｙ (I) (In the formula, x is an integer between 1 and 4, and y is an integer between 0 and 3, provided that the sum of x and y is equal to 4, and each R １ They are independent of each other, C １ ~C １２ alkyl group, C １ ~C １２ Alkoxy group, C ６ ~C １２ Aryloxy group, or C ６ ~C １２ These are aryl groups, each optionally containing a halogen atom and C １－６ alkyl group, C １－６ Alkoxy group, hydroxyl group, N-C １－６ Alkylaniline group, N-C １－６ Alkyl-N-C １－６ Alkylaniline group, or C １－６ Substituted by one or more halos or perhalohydrocarbons, each R ２ They are independent of each other, C １ ~C １２ alkyl group, C １ ~C １２ Alkoxy group, C ６ ~C １２ Aryloxy group, or C ６ ~C １２ These are aryl groups, each optionally containing a halogen atom and C １－６ alkyl group, C １－６ Alkoxy group, hydroxyl group, N-C １－６ Alkylaniline group, N-C １－６ Alkyl-N-C １－６ Alkylaniline group, or C １－６ Substituted by one or more halos or perhalohydrocarbons, however PR １ ３ PR ２ ３ (Different from) Distillation residue containing palladium complex.

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