Selective Hydrogenation

Abstract

The present invention relates to the use of certain homogeneous catalysts for the partial (selective) hydrogenation of carbon-carbon triple bonds.

Description

Detailed Description of the Invention

[0001] The present invention relates to the use of certain homogeneous catalysts for the partial (selective) hydrogenation of carbon-carbon triple bonds.

[0002] This catalyst is used for selective hydrogenation, i.e., hydrogenating alkynes to alkenes. Thus, in the case of compounds containing a double bond in addition to a triple bond, only the triple bond is reduced to a double bond.

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

[0004] The purpose of this study was to improve the selectivity of selective hydrogenation reactions using such catalysts.

[0005] It has been found that transition metal catalysts bearing specific bidentate phosphine ligand systems exhibit good hydrogenation efficiency under mild reaction conditions.

[0006] The catalyst used in the selective hydrogenation according to the present invention is a catalyst represented by the following formula (I): [ka] [In the formula, M is Rh or Ir; L is a group represented by formula (II): (R)2-PAP-(R 1 )2(II) (In the formula, R is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl, or isopropyl; R 1 is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl, or isopropyl; A is: [ka] (wherein m is an integer having a value of 1 to 6); [ka] and the cross-linking moiety is selected from the group consisting of is a bidentate phosphine ligand of the formula X - is a halide, - OAc, - OH or - OCH3, Any dotted lines in the formula represent the bond connecting the substituent to the rest of the molecule. It has.

[0007] The catalysts of the present invention are 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.

[0008] Thus, in a first aspect, the present invention provides a compound of formula (I) [ka] [In the formula, M is Rh or Ir; L is a group represented by formula (II): (R)2-PAP-(R 1 )2(II) (In the formula, R is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl, or isopropyl; R 1 is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl, or isopropyl; A is, [ka] (wherein m is an integer having a value of 1 to 6); [ka] and the cross-linking moiety is selected from the group consisting of is a bidentate phosphine ligand of the formula X - is a halide, - OAc, - OH or - OCH3, Any dotted lines in the formula represent the bond connecting the substituent to the rest of the molecule. The present invention relates to the selective hydrogenation (H) of at least one catalyst of the formula:

[0009] Therefore, the present invention also relates to a selective hydrogenation (H), a selective hydrogenation (H1), in which a starting material containing a carbon-carbon triple bond is selectively hydrogenated.

[0010] Therefore, the present invention also relates to a selective hydrogenation (H2), which is a selective hydrogenation (H) or (H1), in which alkynol compounds are selectively hydrogenated.

[0011] Therefore, the present invention also relates to a selective hydrogenation (H2'), which is a selective hydrogenation (H) or (H1), in which an α-alkynol compound is selectively hydrogenated.

[0012] Preferably, the present invention also provides a compound of formula (III) [ka] [In the formula, R 2 is a straight or branched C1 to C 35 -Alkyl moiety; or linear or branched C2-C 35- an alkenyl moiety, the carbon chain of which may be substituted; R 3 is H or a linear or branched C1-C4 alkyl, the carbon chain of which may be substituted; R 4 is H or a cyclic, straight-chain or branched C1-C6 alkyl whose carbon chain may be substituted; or an optionally substituted C5-C 12 - a cyclic aromatic moiety, R 5 is H or OH or OC1-C4-alkyl or O(CO)C1-C4-alkyl] The present invention also relates to a process for the selective hydrogenation of the compound of formula (I).

[0013] The product of the selective hydrogenation is represented by formula (IV): [ka] [In the formula, R 2 , R 3 , R 4 and R 5 has the same meaning as in formula (III). is a compound of

[0014] More preferably, the present invention also relates to a compound of formula (III) [ka] [In the formula, R 2 is a straight or branched C1 to C 30 -Alkyl moiety; straight or branched C2-C 30 - an alkenyl moiety, the carbon chain of which may be substituted; R 3 is C1-C2-alkyl, R 4 is H or cyclic, linear or branched C1-C6-alkyl, the carbon chain of which may be substituted; R 5is OH or O(CO)C1-C2-alkyl] 1. A process for the selective hydrogenation of a compound of the formula Formula (IV) [ka] This relates to a process in which the compound is selectively hydrogenated to the compound of formula (I).

[0015] Even more preferably, the present invention also provides a process for selective hydrogenation comprising reacting a compound of formula (III) [ka] [In the formula, R 2 is a straight or branched C1 to C 20 -Alkyl moiety; or linear or branched C2-C 20 -alkenyl moiety, The carbon chain may be substituted; R 3 is C1-C2-alkyl, R 4 is H, R 5 is OH or O(CO)C1-C2-alkyl] Formula (IV) [ka] This relates to a process in which the compound is selectively hydrogenated to the compound of formula (I).

[0016] The most preferred compounds of formula (III) are of formulae (IIIa) to (IIId): [ka]

[0017] The present invention therefore also provides a selective hydrogenation (H3) of the hydrogenation (H), (H1) or (H2), which is a hydrogenation of formula (III) [ka] [In the formula, R 2 is a straight or branched C1 to C 35 -Alkyl moiety; or linear or branched C2-C 35 -alkenyl moiety, The carbon chain may be substituted; R 3 is H or a linear or branched C1-C4 alkyl, the carbon chain of which may be substituted; R 4 is H or a cyclic, straight-chain or branched C1-C6 alkyl whose carbon chain may be substituted; or an optionally substituted C5-C 12 - a cyclic aromatic moiety, R 5 is H or OH or OC1-C4-alkyl or O(CO)C1-C4-alkyl] is selectively hydrogenated (H3).

[0018] Therefore, the present invention also provides a selective hydrogenation (H3'), which is a selective hydrogenation (H), (H1), (H2) or (H2'), and which is a selective hydrogenation (H3') of formula (III) [ka] [In the formula, R 2 is a straight or branched C1 to C 30 -Alkyl moiety; or linear or branched C2-C 30 - an alkenyl moiety, the carbon chain of which may be substituted; R 3 is C1-C2-alkyl, R 4 is H or cyclic, linear or branched C1-C6-alkyl, the carbon chain of which may be substituted; R 5 is OH or O(CO)C1-C2-alkyl] The compound (H3') is selectively hydrogenated.

[0019] Therefore, the present invention also provides a selective hydrogenation (H3″) of hydrogenation (H), (H1), (H2) or (H2′), which is a reaction of formula (III) [ka] [In the formula, R 2 is a straight or branched C1 to C 20 -Alkyl moiety; or linear or branched C2-C 20 -alkenyl moiety, The carbon chain may be substituted; R 3 is C1-C2-alkyl, R 4 is H, R 5 is OH or O(CO)C1-C2-alkyl] The compound (H3) is selectively hydrogenated.

[0020] Therefore, the present invention also provides a selective hydrogenation (H3'''), which is a hydrogenation (H), (H1), (H2) or (H2'), and which is a hydrogenation of formula (IIIa), (IIIb), (IIIc) or (IIId) [ka] is selectively hydrogenated to a compound of formula (IVa), (IVb), (IVc) or (IVd), respectively. [ka]

[0021] As mentioned above, the selective hydrogenation according to the present invention is carried out using a specific catalyst of formula (I).

[0022] Preferred catalysts of formula (I) are those in which M is Rh.

[0023] It is well known that the catalysts applied generally change between, for example, monomeric, dimeric, and oligomeric species during the catalytic cycle, and therefore the catalyst of formula (I) is the one that is applied initially in the selective hydrogenation reaction.

[0024] The present invention therefore also relates to the selective hydrogenation (H4), which is the hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3") or (H3'"), in which a catalyst of formula (I) in which M is Rh is used.

[0025] Preferred catalysts of formula (I) are The catalyst is one in which L is a bidentate phosphine ligand selected from the group consisting of the following ligands of formulae (IIa) to (IIl): [ka] [ka]

[0026] A more preferred catalyst of formula (I) is A catalyst in which L is a bidentate phosphine ligand selected from the group consisting of ligands of the formula: [ka]

[0027] The present invention therefore also relates to a selective hydrogenation (H5) which is a hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'") or (H4), L is a group represented by the formula (IIa) to (IIl) [ka] [ka] The present invention also relates to a selective hydrogenation (H5) in which a catalyst of formula (I) is used, in which the bidentate phosphine ligand is selected from the group consisting of the ligands

[0028] The present invention therefore also relates to a selective hydrogenation (H5') which is a hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'") or (H4), L is a bidentate phosphine ligand selected from the group consisting of: [ka] It also relates to a selective hydrogenation (H5') in which the catalyst of formula (1) is used.

[0029] The preferred catalyst is X - But Cl -、 Br - , - OAc, - OH or - a catalyst which is OCH3, Halides, - OAc, - OH or - The catalyst is OCH3.

[0030] The more preferred catalyst is X - Cl - or Br - It is a catalyst.

[0031] The most preferred catalyst is X - Cl - It is a catalyst.

[0032] The present invention therefore also relates to a selective hydrogenation (H6) which is a hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5) or (H5'), wherein X - But C l- , Br- , I - , - OAc, - OH and - The present invention also relates to the selective hydrogenation (H6) of a compound selected from the group consisting of OCH3.

[0033] The present invention therefore also relates to a selective hydrogenation (H6') which is a hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5) or (H5'), wherein X - But Cl - and Br - The present invention also relates to the selective hydrogenation (H6') of a compound selected from the group consisting of:

[0034] Therefore, the present invention also provides a selective hydrogenation (H6″) which is a hydrogenation (H), (H1), (H2), (H2′), (H3), (H3′), (H3″), (H3′″), (H4), (H5) or (H5′), wherein X - But Cl - This relates to selective hydrogenation (H6'').

[0035] The catalysts used in the hydrogenation according to the present invention are prepared as disclosed in the prior art.

[0036] The hydrogenation according to the present invention can be carried out without any solvent.

[0037] The present invention therefore also relates to a selective hydrogenation (H7), which is a hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6') or (H6"), wherein the hydrogenation is carried out without any solvent.

[0038] The hydrogenation according to the invention can be carried out in the presence of at least one inert solvent.

[0039] The hydrogenation can be carried out in a solvent (or a mixture of solvents). Suitable solvents are alkanes, esters, carbonates, lactones, ethers, amides, hydrocarbons, halogenated hydrocarbons, water, and alcohols. Preferred solvents are water, hexane, CHCl, toluene, ethyl acetate, THF (= tetrahydrofuran), 2-Me-THF (= 2-methyl-tetrahydrofuran), cyclopentyl methyl ether (= CPME), methanol, ethanol, and isopropanol, and particularly preferred solvents are methanol, water, and hexane.

[0040] The present invention therefore also relates to the selective hydrogenation (H8), which is a 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.

[0041] Therefore, the present invention also relates to a selective hydrogenation (H8') which is a hydrogenation (H8), wherein the solvent is selected from the group consisting of alkanes, esters, carbonates, lactones, ethers, amides, hydrocarbons, halogenated hydrocarbons, water and alcohols.

[0042] Therefore, the present invention also relates to a selective hydrogenation (H8″) which is a hydrogenation (H8), wherein the solvent is selected from the group consisting of water, hexane, CHCl, toluene, ethyl acetate, THF, 2-Me-THF, cyclopentyl methyl ether, methanol, ethanol and isopropanol.

[0043] Therefore, the present invention also relates to a selective hydrogenation (H8''') which is a hydrogenation (H8), wherein the solvent is selected from the group consisting of methanol, water and hexane.

[0044] 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 number of moles of the compound of formula (III)).

[0045] The present invention therefore also relates to the selective hydrogenation (H9), which is the hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8") or (H8'"), in which at least one catalyst of formula (I) is used in an amount of 0.001 to 1 mol % (based on the number of moles of the compound of formula (III)).

[0046] The present invention therefore also relates to the selective hydrogenation (H9), which is the hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8") or (H8'"), in which at least one catalyst of formula (I) is used in an amount of 0.001 to 0.5 mol % (based on the number of moles of the compound of formula (III)).

[0047] The hydrogenation process can be carried out using (pure) H2 gas or using a gas containing H2. Preferably, the hydrogenation according to the present invention can be carried out using (pure) H2 gas.

[0048] The present invention therefore also relates to a selective hydrogenation (H10), which is a hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6'), (H6"), (H7), (H8), (H8'), (H8'), (H8"), (H8'"), (H9) or (H9'), wherein the hydrogenation is carried out using (pure) H2 gas or using a gas comprising H2.

[0049] Therefore, the present invention also relates to a selective hydrogenation (H10') which is a hydrogenation (H), (H1), (H2), (H2'), (H3), (H3'), (H3"), (H3'"), (H4), (H5), (H5'), (H6), (H6"), (H7), (H8), (H8'), (H8"), (H8'"), (H9) or (H9'), wherein the hydrogenation is carried out using H2 gas.

[0050] The hydrogenation process can be carried out at normal pressure or at elevated pressure. Preferably, the hydrogenation process according to the invention is carried out at a pressure of 1 to 50 bar, more preferably 1 to 30 bar. Usually, the reaction is carried out in an autoclave (or any other pressure-resistant vessel).

[0051] The present invention therefore also relates to the selective hydrogenation (H11), which is a 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 is carried out at atmospheric pressure.

[0052] The present invention therefore also relates to a selective hydrogenation (H11') which is a 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 is carried out at a pressure of 1 to 50 bar, preferably 1 to 30 bar.

[0053] The hydrogenation is usually carried out at a temperature of −10 to 150° C. (preferably 10 to 100° C.).

[0054] The present invention therefore also relates to the selective hydrogenation (H12), which is the 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 is carried out at a temperature of from -10 to 150°C.

[0055] The following examples serve to illustrate the invention, temperatures are given in °C and all percentages are by weight.

[0056] [Example] General Catalyst Synthesis (Example 1) Synthesis of [Rh(DPPE)(μ-Cl)] A Schlenk tube was charged with [Rh(cod)(μ2-Cl)]2 (185.6 mg, 0.376 mmol) (cod = 1,5-cyclooctadiene), dissolved in 5 mL of toluene, and heated to 70 °C. DPPE (300.0 mg, 0.753 mmol) dissolved in 5 mL of toluene was added dropwise within 2 h. The reaction mixture was stirred at 125 °C for an additional 3 h. The solvent was then evaporated, and the precipitate was dried under vacuum to obtain the catalyst ([Rh(DPPE)(μ2-Cl)]2). 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. 31 P NMR (121MHz, THF-d8, 297K): δ=72.9(d, J P-RH =198.3Hz) ppm.

[0057] All other catalysts used in the following examples were prepared similarly to the process of Example 1.

[0058] [Hydrogenation Example] [Example 2] An autoclave was charged with 0.5 mmol of dehydroisophytol (compound of formula (IIIb)), 7.5 ml of methanol, and 0.005 mmol of [Rh(DPPE)(μ-Cl)] prepared as disclosed in Example 1. After stirring the mixture, H was added in the form of H gas.

[0059] The autoclave was adjusted to a temperature of 25°C, and the hydrogen pressure was released after 13 minutes to obtain isophytol in a yield of 94.2%.

[0060] [Example 3] An autoclave was charged with 440 mmol of dehydroisophytol (compound of formula (IIIb)), 650 ml of methanol, and 0.044 mmol of [Rh((DPPE)(μ-Cl)] prepared as described in Example 1. The mixture was stirred, and H was added in the form of H gas up to a pressure of 3.5 bar.

[0061] The autoclave was thermostated at 25°C, and the hydrogen pressure was released after 102 minutes to give isophytol in 91.4% yield.

[0062] The following examples were carried out following the same process as in Example 2 (Tables 1-4 list the differences in reaction conditions).

[0063] [Table 1]

[0064] [Table 2]

[0065] [Table 3]

[0066] [Table 4]

Claims

1. Formula (1) 【Chemistry 1】 [In the formula, M is Rh or Ir; L is a group represented by formula (II): (2) ２ ______________________________ １ ) ２ (=) (In the formula, R is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl, or isopropyl; R １ is substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl, or isopropyl; A is, 【Chemistry 2】 wherein m is an integer having a value from 1 to 6; 【Transformation 3】 and the cross-linking moiety is selected from the group consisting of is a bidentate phosphine ligand of the formula X － is a halide, － OAC, － OH or － OCH ３ and Any dotted lines in the formula represent the bond connecting the substituent to the rest of the molecule. Selective hydrogenation using at least one catalyst of

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

3. Formula (III): 【Chemistry 4】 [In the formula, R ２ is a linear or branched C １ ~C ３５ - an alkyl moiety; or a linear or branched C ２ ~C ３５ - an alkenyl moiety, the carbon chain of which may be substituted; R ３ is H or linear or branched C １ ~C ４ - alkyl, the carbon chain of which may be substituted; R ４ is H or a cyclic, straight-chain or branched C １ ~C ６ - alkyl; or optionally substituted C ５ ~C １２ - a cyclic aromatic moiety, R ５ is H or OH or OC １ ~C ４ -Alkyl or O(CO)C １ ~C ４ -alkyl] The compound of formula (IV) 【Transformation 5】 The selective hydrogenation method according to claim 1 or 2, wherein the compound is selectively hydrogenated to a compound of formula (I).

4. Formula (III): 【Transformation 6】 [In the formula, R ２ is a linear or branched C １ ~C ２０ - an alkyl moiety; or a linear or branched C ２ ~C ２０ - an alkenyl moiety, the carbon chain of which may be substituted; R ３ is C １ ~C ２ - alkyl, R ４ is H, R ５ is OH or O(CO)C １ ~C ２ -alkyl] The compound of formula (IV) 【Transformation 7】 The selective hydrogenation method according to any one of claims 1 to 3, wherein the compound is selectively hydrogenated to a compound of the formula:

5. The selective hydrogenation according to any one of claims 1 to 4, wherein a catalyst of formula (I) is used in which M is Rh.

6. A catalyst of formula (I) L is a group represented by the formula (IIa) to (IIl) 【Transformation 8】 【Chemistry 9】 6. The selective hydrogenation according to claim 1, wherein a catalyst of formula (I) is used, wherein the ligand is a bidentate phosphine ligand selected from the group consisting of ligands of formula (I):

7. A catalyst of formula (I) L is a compound of the formula 【Chemistry 10】 6. The selective hydrogenation according to claim 1, wherein a catalyst of formula (I) is used, wherein the ligand is a bidentate phosphine ligand selected from the group consisting of ligands of formula (I):

8. In the catalyst of formula (I), X － But Cl － ,Br － , I － , － OAC, － OH and / or － OCH ３ The selective hydrogenation according to any one of claims 1 to 7, wherein the hydrogen is selected from the group consisting of:

9. In the catalyst of formula (I), X － But Cl － and Br － The selective hydrogenation according to any one of claims 1 to 7, wherein the hydrogen is selected from the group consisting of:

10. The selective hydrogenation according to any one of claims 1 to 9, wherein the hydrogenation is carried out without the use of 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. 12. The selective hydrogenation according to any one of claims 1 to 11, wherein the at least one catalyst of formula (I) is used in an amount of 0.001 to 1 mol % (based on the number of moles of the compound of formula (III)).

13. The hydrogenation is carried out with (pure) H ２ gas or H ２ The selective hydrogenation according to any one of claims 1 to 12, carried out using a gas comprising

14. The selective hydrogenation according to any one of claims 1 to 13, wherein the hydrogenation is carried out at a pressure of from 1 to 50 bar.

15. The selective hydrogenation according to any one of claims 1 to 14, wherein the hydrogenation is carried out at a temperature of from -10 to 150°C.

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