Selective hydrogenation

By using transition metal catalysts of specific bidentate phosphine ligand systems, the selectivity problem of selective hydrogenation of carbon-carbon triple bonds is solved, and efficient selectivity and efficiency of the reaction are achieved.

CN120569261APending Publication Date: 2025-08-29DSM IP ASSETS BV
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Patent Information

Application Number
CN202480008363.1
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Priority Date
2023-02-02
Filing Date
2024-02-02
Publication Date
2025-08-29

AI Technical Summary

Technical Problem

In the prior art, the selectivity of the carbon-carbon triple bond selective hydrogenation reaction is low, and it is difficult to effectively hydrogenate the alkyne to an olefin without affecting the double bond.

Method used

The transition metal catalyst of a specific bitodentate phosphine ligand system is used to selective hydrogenation under mild reaction conditions, using Rh or Ir as the catalyst, ligand L is (R)2-P-A-P-(R1)2, the bridge segment A is -(CH2)m, and X- is halogen, -OAc or -OH, which is used for selective hydrogenation of starting materials such as alkynol.

Benefits of technology

The selectivity and efficiency of the selectivity of the carbon-carbon triple bond selective hydrogenation reaction are improved, and efficient selective hydrogenation of compounds such as alkynols is achieved.

✦ Generated by Eureka AI based on patent content.

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Abstract

The present invention relates to partial (selective) hydrogenation of carbon-carbon triple bonds using specific homogeneous catalysts.
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Description

[0001] The present invention relates to the partial (selective) hydrogenation of carbon-carbon triple bonds using a specific homogeneous catalyst.

[0002] This catalyst is used for selective hydrogenation, i.e., the hydrogenation of alkynes to alkenes. Thus, if a compound contains both double and triple bonds, only the triple bond is reduced to a double bond.

[0003] Homogeneous catalysis refers to reactions in which the catalyst and reactants are in the same phase, primarily in solution.

[0004] The purpose of this study is to improve the selectivity of selective hydrogenation reactions catalyzed by this type of catalyst.

[0005] Studies have found that transition metal catalysts with specific bidentate phosphine ligand systems have good hydrogenation efficiency under mild reaction conditions.

[0006] According to the present invention, the catalyst for the selective hydrogenation reaction has the following formula (I),

[0007]

[0008] in

[0009] M is Rh or Ir, and

[0010] L is a bidentate phosphine ligand of formula (II)

[0011] (R)2-PAP-(R 1 )2(II),

[0012] in

[0013] R is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl or isopropyl, and

[0014] R 1 is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl or isopropyl, and

[0015] A is a bridging fragment selected from the group consisting of:

[0016] ---(CH2)m---, where m is an integer with a value of 1-6;

[0017]

[0018] and

[0019] X - It is halogen, -OAc, - OH or - OCH3;

[0020] And any dashed line in the structural formula represents the bond connecting the substituent to the rest of the molecule.

[0021] The catalyst of the present invention is used for the selective catalytic hydrogenation of starting materials, in particular starting materials containing carbon-carbon triple bonds, more particularly alkynol compounds, particularly preferably α-alkynol compounds.

[0022] Therefore, a first aspect of the present invention relates to the selective hydrogenation (H) using at least one catalyst of formula (I),

[0023]

[0024] in

[0025] M is Rh or Ir, and

[0026] L is a bidentate phosphine ligand of formula (II)

[0027] (R)2-PAP-(R 1 )2(II),

[0028] in

[0029] R is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl or isopropyl, and

[0030] R 1 is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl or isopropyl, and

[0031] A is a bridging fragment selected from the group consisting of:

[0032] ---(CH2) m ---, where m is an integer with a value of 1-6;

[0033]

[0034] and

[0035] X - It is halogen, - OAc, - OH or - OCH3;

[0036] And any dashed line in the structural formula represents the bond connecting the substituent to the rest of the molecule.

[0037] The present invention therefore also relates to a selective hydrogenation (H1), which is a selective hydrogenation (H), in which a starting material containing carbon-carbon triple bonds is selectively hydrogenated.

[0038] The present invention therefore also relates to a selective hydrogenation (H2), which is a selective hydrogenation (H) or (H1), in which an alkynol compound is selectively hydrogenated.

[0039] The present invention therefore also relates to a selective hydrogenation (H2′) which is a selective hydrogenation (H) or (H1), wherein an α-alkynol compound is selectively hydrogenated.

[0040] Preferably, the present invention also relates to a process for the selective hydrogenation of a compound of formula (III),

[0041]

[0042] in

[0043] R 2 Is a straight chain or branched C1-C 35 -alkyl; or a linear or branched C2-C 35 -alkenyl fragment, wherein the C chain may be substituted; and

[0044] R 3 is H or a linear or branched C1-C4-alkyl group, wherein the C chain may be substituted; and

[0045] R 4 is H or a cyclic, linear or branched C1-C6-alkyl group, wherein the C chain may be substituted; or a C3-C 12 - a cyclic aromatic moiety, which may be substituted; and

[0046] R 5 is H or OH or OC1-C4-alkyl; or O(CO)C1-C4-alkyl.

[0047] The product of the selective hydrogenation is a compound represented by formula (IV),

[0048]

[0049] in

[0050] R 2 、R 3 、R 4 and R 5 has the same meaning as defined in formula (III).

[0051] More preferably, the present invention also relates to a selective hydrogenation process in which a compound of formula (III) is selectively hydrogenated to a compound of formula (IV),

[0052]

[0053] in

[0054] R 2 Is a straight chain or branched C1-C 30 -alkyl; or a linear or branched C2-C 30 -alkenyl fragment, wherein the C chain may be substituted; and

[0055] R 3 is C1-C2-alkyl; and

[0056] R 4 is H or a cyclic, linear or branched C1-C6-alkyl group, wherein the C chain may be substituted; and

[0057] R 5 is OH or O(CO)C1-C2-alkyl.

[0058] Even more preferably, the present invention also relates to a selective hydrogenation process wherein a compound of formula (III) is selectively hydrogenated to a compound of formula (IV),

[0059]

[0060] in

[0061] R 2 Is a straight chain or branched C1-C 20 -alkyl; or linear or branched C2-C 20 -alkenyl fragment, wherein the C chain may be substituted; and

[0062] R 3 is C1-C2-alkyl; and

[0063] R 4 is H; and

[0064] R 5 is OH or O(CO)C1-C2-alkyl.

[0065] Among the most preferred compounds of formula (III) are the following compounds of formula (IIIa) to (IIId):

[0066]

[0067]

[0068] Therefore, the present invention also relates to a selective hydrogenation (H3), which is a selective hydrogenation (H), (H1) or (H2), wherein the compound of formula (III) is selectively hydrogenated.

[0069]

[0070] in

[0071] R 2 Is a straight chain or branched C1-C 35 -alkyl; or linear or branched C2-C 35 -alkenyl fragment, wherein the C chain may be substituted; and

[0072] R 3 is H or a linear or branched C1-C4-alkyl group, where the C chain may be substituted, and

[0073] R 4 is H or a cyclic, linear or branched C1-C6-alkyl group, where the C chain may be substituted; or a C5-C 12 - a cyclic aromatic fragment, which may be substituted, and

[0074] R 5 is H or OH or OC1-C4-alkyl or O(CO)C1-C4-alkyl,

[0075] Therefore, the present invention also relates to a selective hydrogenation (H3'), which is a selective hydrogenation (H), (H1), (H2) or (H2'), wherein the compound of formula (III) is selectively hydrogenated,

[0076]

[0077] in

[0078] R 2 Is a straight chain or branched C1-C 30 -alkyl; or linear or branched C2-C 30 -alkenyl fragment, wherein the C chain may be substituted; and

[0079] R 3 is C1-C2-alkyl; and

[0080] R 4 is H or a cyclic, linear or branched C1-C6-alkyl group, wherein the C chain may be substituted; and

[0081] R 5 is OH or O(CO)C1-C2-alkyl.

[0082] Therefore, the present invention also relates to a selective hydrogenation (H3"), which is a selective hydrogenation (H), (H1), (H2) or (H2'), wherein the compound of formula (III) is selectively hydrogenated,

[0083]

[0084] in

[0085] R 2 Is a straight chain or branched C1-C 20 -alkyl; or linear or branched C2-C 20 -alkenyl fragments, in which the C chain may be substituted, and

[0086] R 3 is C1-C2-alkyl, and

[0087] R 4 is H, and

[0088] R 5 is OH or O(CO)C1-C2-alkyl.

[0089] Therefore, the present invention also relates to a selective hydrogenation (H3″′), which is a selective hydrogenation (H), (H1), (H2) or (H2′), wherein a compound of formula (IIIa), (IIIb), (IIIc) or (IIId) is selectively hydrogenated to the corresponding compound of formula (IVa), (IVb), (IVc) or (IVd),

[0090]

[0091]

[0092] As mentioned above, the selective hydrogenation according to the invention is carried out using a specific catalyst of formula (I).

[0093] Preferred catalysts of formula (I) are those wherein M is Rh.

[0094] It is well known that catalysts usually change during the catalytic cycle, for example switching between monomers, dimers and oligomers. Therefore, the catalyst of formula (I) is the catalyst initially used in the selective hydrogenation reaction.

[0095] Therefore, the present invention also relates to a selective hydrogenation (H4), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3") or (H3'"), wherein a catalyst of formula (I) is used, wherein M is Rh.

[0096] Preferred catalysts of formula (I) are those wherein L is a bidentate phosphine ligand selected from the group consisting of ligands of the following formulae (IIa) to (III):

[0097]

[0098]

[0099] More preferred catalysts of formula (I) are those wherein L is a bidentate phosphine ligand selected from the group consisting of ligands represented by the following formulae:

[0100]

[0101] Therefore, the present invention also relates to a selective hydrogenation (H5), which is a selective hydrogenation of (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'") or (H4), wherein a catalyst of formula (I) is used, wherein L is a bidentate phosphine ligand selected from the group consisting of ligands of formulae (IIa) to (III):

[0102]

[0103]

[0104]

[0105] Therefore, the present invention also relates to a selective hydrogenation (H5′), which is a hydrogenation (H), (H1), (H2), (H2′), (H3), (H3′), (H3″), (H3′″) or (H4), wherein a catalyst of formula (I) is used, wherein

[0106] L is a bidentate phosphine ligand selected from the group consisting of:

[0107]

[0108]

[0109] Preferred catalysts are those wherein X - Cl - Br - , I - 、 - OAc, - OH or - Those of OCH3,

[0110] Among them X - Halogen, - OAc, - OH or - Those of OCH3.

[0111] More preferred catalysts are those wherein X - Cl - or Br - Those.

[0112] The most preferred catalyst is one in which X - Cl- Those.

[0113] Therefore, the present invention also relates to a selective hydrogenation (H6), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5) or (H5'), wherein a catalyst of formula (I) is used, wherein X - Selected from Cl - Br - , I - 、 - OAc, - OH and - OCH3 group.

[0114] Therefore, the present invention also relates to a selective hydrogenation (H6'), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5) or (H5'), wherein a catalyst of formula (I) is used, wherein X - Selected from Cl - and Br - The group composed of.

[0115] Therefore, the present invention also relates to a selective hydrogenation (H6"), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5) or (H5'), wherein a catalyst of formula (I) is used, wherein X - Cl - .

[0116] The hydrogenation according to the invention can be carried out without any solvent.

[0117] Therefore, the present invention also relates to a selective hydrogenation (H7), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6') or (H6"), wherein the hydrogenation is carried out in the absence of any solvent.

[0118] The hydrogenation according to the invention can be carried out in the presence of at least one inert solvent.

[0119] The hydrogenation can be carried out in a solvent (or a mixture of solvents). Suitable solvents include alkanes, esters, carbonates, lactones, ethers, amides, hydrocarbons, halogenated hydrocarbons, water, and alcohols. Preferred solvents include water, hexane, CH2Cl2, toluene, ethyl acetate, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-Me-THF), cyclopentyl methyl ether (CPME), methanol, ethanol, and isopropanol. Particularly preferred solvents are methanol, water, and hexane.

[0120] Therefore, the present invention also relates to a selective hydrogenation (H8), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6') or (H6"), wherein the hydrogenation is carried out in at least one solvent.

[0121] Therefore, the present invention also relates to a selective hydrogenation (H8'), which is a selective hydrogenation (H8), wherein the solvent is selected from the group consisting of alkanes, esters, carbonates, lactones, ethers, amides, hydrocarbons, halogenated hydrocarbons, water and alcohols.

[0122] Therefore, the present invention also relates to a selective hydrogenation (H8"), which is a selective hydrogenation (H8), wherein the solvent is selected from the group consisting of water, hexane, CH2Cl2, toluene, ethyl acetate, tetrahydrofuran, 2-methyltetrahydrofuran, cyclopentyl methyl ether, methanol, ethanol and isopropanol.

[0123] Therefore, the present invention also relates to a selective hydrogenation (H8'"), which is a selective hydrogenation (H8), wherein the solvent is selected from the group consisting of methanol, water and hexane.

[0124] The catalyst of formula (I) according to the present invention is usually used in an amount of 0.001 to 1 mol % (preferably 0.001 to 0.5 mol %) (based on the moles of the compound of formula (III)).

[0125] Therefore, the present invention also relates to a selective hydrogenation (H9), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8") or (H8'"), wherein the at least one catalyst of formula (I) is used in an amount of 0.001 to 1 mol% (based on the moles of the compound of formula (III)).

[0126] Therefore, the present invention also relates to a selective hydrogenation (H9'), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8") or (H8'"), wherein the at least one catalyst of formula (I) is used in an amount of 0.001 to 0.5 mol% (based on the moles of the compound of formula (III)).

[0127] The hydrogenation process can be carried out using (pure) H2 gas or a gas comprising H2. Preferably, the hydrogenation process according to the invention is carried out using (pure) H2 gas.

[0128] Therefore, the present invention also relates to a selective hydrogenation (H10), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8"), (H8"), (H9) or (H9'), wherein the hydrogenation process is carried out using (pure) H2 gas or a gas containing H2.

[0129] Therefore, the present invention also relates to a selective hydrogenation (H10'), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8"), (H8"), (H9) or (H9'), wherein the hydrogenation process is carried out using H2 gas.

[0130] The hydrogenation process can be carried out at ambient pressure or under pressure. Preferably, the hydrogenation process according to the present invention is carried out at a pressure of 1 to 50 bar, more preferably at a pressure of 1 to 30 bar. Typically, the reaction is carried out in an autoclave (or any other container capable of withstanding pressure).

[0131] Therefore, the present invention also relates to a selective hydrogenation (H11), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8"), (H8'"), (H9), (H9'), (H10) or (H10'), wherein the hydrogenation process is carried out at ambient pressure.

[0132] Therefore, the present invention also relates to a selective hydrogenation (H11'), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8"), (H8"), (H9), (H9'), (H10) or (H10'), wherein the hydrogenation process is carried out at a pressure of 1 to 50 bar, preferably at a pressure of 1 to 30 bar.

[0133] The hydrogenation is generally carried out at a temperature of -10 to 150°C (preferably 10 to 100°C).

[0134] Therefore, the present invention also relates to a selective hydrogenation (H12), which is a selective hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8"), (H8'"), (H9), (H9'), (H10), (H10'), (H11) or (H11'), wherein the hydrogenation process is carried out at a temperature of -10 to 150 ° C.

[0135] The following examples illustrate the present invention. Temperatures are given in ° C. and all percentages are by weight. Example

[0136] Synthesis of General Catalyst (Example 1) Synthesis of [Rh(DPPE)(μ2-Cl)]2

[0137] [Rh(cod)(μ2-Cl)]2 (185.6 mg, 0.376 mmol) (cod = 1,5-cyclooctadiene) was dissolved in 5 mL of toluene, placed in a Schlenk tube, and heated to 70°C. DPPE (300.0 mg, 0.753 mmol) was dissolved in 5 mL of toluene and slowly added dropwise over 2 hours. The reaction mixture was stirred at 125°C for 3 hours. The solvent was then evaporated, and the precipitate was dried under vacuum to yield the catalyst ([Rh(DPPE)(μ2-Cl)]2).

[0138] 1 H NMR (300MHz, THF-d8, 297K): δ = 1.98 (dd, J = 19.21Hz, J = 1.02Hz, 8H), 7.13–7.26 (m, 24H), 7.87–7.93 (m, 16H) ppm.

[0139] 31 P NMR (121MHz, THF-d8, 297K): δ = 72.9 (d, J P-Rh =198.3Hz)ppm.

[0140] All other catalysts used in the following examples were prepared according to a similar process to Example 1.

[0141] Hydrogenation Example

[0142] Example 2

[0143] 0.5 mmol of dehydroisophytol (compound of formula (IIIb)), 7.5 mL of methanol, and 0.005 mmol of [Rh(DPPE)(μ2-Cl)]2 prepared as described in Example 1 were placed in an autoclave. The mixture was stirred and H2 gas was introduced.

[0144] The autoclave temperature was controlled at 25°C, and the hydrogen pressure was released after 13 minutes to obtain isophytol in a yield of 94.2%.

[0145] Example 3

[0146] 440 mmol of dehydroisophytol (compound of formula (IIIb)), 650 ml of methanol and 0.044 mmol of [Rh(DPPE)(μ2-Cl)]2 prepared as described in Example 1 were placed in an autoclave. The mixture was stirred and hydrogen was added in the form of H2 gas until the pressure reached 3.5 bar.

[0147] The autoclave temperature was controlled at 25° C., and the hydrogen pressure was released after 102 minutes to obtain isophytol in a yield of 91.4%.

[0148] The following examples were all carried out in a manner similar to that of Example 2 (Tables 1-4 list the differences in reaction conditions).

[0149] Table 1

[0150]

[0151] Table 1. *DIP = dehydroisophytol; IP = isophytol; DiIP = perhydrodehydroisophytol; = 3,7,11,15-tetramethylhexadecane-3-ol.

[0152] Table 2

[0153]

[0154] Table 2. *DIP = dehydroisophytol; IP = isophytol; DiIP = fully hydrogenated dehydroisophytol; =

[0155] 3,7,11,15-Tetramethylhexadecane-3-ol.

[0156] Table 3

[0157]

[0158] Table 3. *DIP = dehydroisophytol; IP = isophytol; DiIP = perhydrodehydroisophytol; = 3,7,11,15-tetramethylhexadecane-3-ol.

[0159] Table 4

[0160]

[0161] Table 4. *DIP = dehydroisophytol; IP = isophytol; DiIP = perhydrodehydroisophytol; = 3,7,11,15-tetramethylhexadecane-3-ol.

Claims

1. Selective hydrogenation using at least one catalyst of formula (I), in M is Rh or Ir, and L is a bidentate phosphine ligand of formula (II) (R)2-PAP-(R 1 )2(II), in R is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl or isopropyl, and R 1 is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl or isopropyl, and A is a bridging fragment selected from the group consisting of: ---(CH2) m ---, where m is an integer with a value between 1 and 6; and X - Halogen, - OAc, - OH or - OCH3; And any dashed line in the formulae represents the bond connecting the substituent to the rest of the molecule.

2. The selective hydrogenation according to claim 1, wherein a starting material containing a carbon-carbon triple bond is selectively hydrogenated.

3. The selective hydrogenation according to claim 1 or 2, wherein the compound of formula (III) is selectively hydrogenated to a compound of formula (IV), in R 2 Is a straight chain or branched C1-C 35 -alkyl; or linear or branched C2-C 35 -alkenyl fragment, wherein the C chain may be substituted; and R 3 is H or a linear or branched C1-C4-alkyl group, wherein the C chain may be substituted; and R 4 is H or a cyclic, linear or branched C1-C6-alkyl group, where the C chain may be substituted; or a C5-C 12 - a cyclic aromatic moiety, which may be substituted; and R 5 is H or OH or OC1-C4-alkyl or O(CO)C1-C4-alkyl.

4. The selective hydrogenation according to claim 1 , wherein the compound of formula (III) is selectively hydrogenated to the compound of formula (IV), in R 2 Is a straight chain or branched C1-C 20 -alkyl; or linear or branched C2-C 20 -alkenyl fragment, wherein the C chain may be substituted; and R 3 is C1-C2-alkyl; and R 4 is H; and R 5 is OH or O(CO)C1-C2-alkyl.

5. The selective hydrogenation according to any one of the preceding claims, wherein A catalyst of formula (I) is used wherein M is Rh.

6. The selective hydrogenation according to any one of the preceding claims, wherein A catalyst of formula (I) is used wherein L is a bidentate phosphine ligand selected from the group consisting of ligands of formula (IIa) to formula (III):

7. The selective hydrogenation according to any one of the preceding claims 1 to 5, wherein A catalyst of formula (I) is used wherein L is a bidentate phosphine ligand selected from the group consisting of ligands represented by the following formula:

8. The selective hydrogenation according to any one of the preceding claims, wherein Using X - Selected from Cl - Br - , I - 、 - OAc, - OH and - OCH3 group consisting of the catalyst of formula (I).

9. The selective hydrogenation according to any one of the preceding claims 1 to 7, wherein Using X - Selected from Cl - and Br - The catalyst of formula (I) is composed of the following:

10. The selective hydrogenation according to any one of the preceding claims, wherein the hydrogenation is carried out without any solvent.

11. The selective hydrogenation according to any one of claims 1 to 9, wherein the hydrogenation is carried out in at least one solvent.

12. The selective hydrogenation according to claim 1, wherein the at least one catalyst of the formula (I) is used in an amount of 0.001 to 1 mol %, based on the moles of the compound of the formula (III).

13. The selective hydrogenation according to claim 1, wherein the hydrogenation is carried out using (pure) H2 gas or a gas comprising H2.

14. The selective hydrogenation according to any one of the preceding claims, wherein the hydrogenation is carried out at a pressure of 1 to 50 bar.

15. The selective hydrogenation according to any one of the preceding claims, wherein the hydrogenation is carried out at a temperature of from -10 to 150°C.