Selective hydrogenation of alkynols to alkenols in the presence of phosphorus compounds

Abstract

The present invention relates to a process for selectively hydrogenating alkynols to alkenols with hydrogen using a hydrogenation catalyst which is palladium supported on a support in the presence of an additive which is an organophosphorus compound bearing either a phosphino group or a phosphine oxide group, provided that when the additive bears a phosphino group, the additive bears two or more phosphino groups.

Description

Detailed Description of the Invention

[0001] [Technical field] The present invention relates to the hydrogenation of alkynols to alkenols.

[0002] [Background of the invention] Alkynes can be hydrogenated to alkenes with hydrogen in the presence of a noble metal catalyst. Palladium catalysts can be used to hydrogenate alkynols to alkenols.

[0003] Alkynols and alkenols, respectively, are substances that are produced on an industrial scale and are particularly important in the fields of vitamins and flavorings. Non-exhaustive examples of such important alkynols and alkenols are 2-methylbut-3-yn-2-ol, 2-methylbut-3-en-2-ol, 3,7-dimethyloct-6-en-1-yn-3-ol, 3,7-dimethylocta-1,6-dien-3-ol, 3,7,11,15-tetramethylhexadec-1-yn-3-ol and 3,7,11,15-tetramethylhexadec-1-en-3-ol.

[0004] There are several problems in the hydrogenation of alkynols. One of the problems is that other chemical groups that are ultimately present next to the carbon-carbon triple bond may also be hydrogenated. This problem can be solved to some extent by using protecting groups. However, this requires additional steps of protection and deprotection, which is inconvenient in terms of additional time, cost, and waste formation.

[0005] Another problem is that the selectivity at high conversions is not high enough. As in any chemical reaction, the goal is to convert as much of the starting material as possible into the desired product. In this case, there is an additional challenge to achieve the highest possible conversion, because the alkynol (i.e., the starting material) and the alkenol (i.e., the product of selective hydrogenation) are extremely difficult to separate. This makes it extremely difficult to separate the unreacted starting material and repeat the reaction after performing the reaction at partial conversion.

[0006] A particularly problematic aspect of the selective hydrogenation of alkynols is overhydrogenation. Overhydrogenation is the effect whereby the hydrogenation of alkynols does not stop at the alkenol stage but continues to produce a significant amount of alkanol, i.e., the hydrogenation reaction not only selectively hydrogenates carbon-carbon triple bonds to carbon-carbon double bonds, but also hydrogenates carbon-carbon double bonds to a significant extent to carbon-carbon single bonds. Overhydrogenated compounds can be extremely difficult to separate from the desired product.

[0007] Lindlar, in US Pat. No. 2,681,938, discloses the selective hydrogenation of alkynes to alkenes using palladium catalysts modified with lead or bismuth.

[0008] US Pat. No. 3,715,404 discloses selective hydrogenation using a palladium catalyst that is partially deactivated by certain specific organosulfur compounds.

[0009] Furthermore, hydrogenation of alkynols leads to the formation of undesirable by-products, such as the formation of dimers or oligomers derived from the alkynols or alkenols.

[0010] [Summary of the Invention] Therefore, the problem to be solved by the present invention is to provide a method for hydrogenating alkynols selectively to alkenols, which method results in high conversion, high selectivity and low overhydrogenation rate.

[0011] Surprisingly, the method according to claim 1 provided a solution to this problem. In particular, the use of additives having two or more phosphino groups has been found to be highly advantageous in providing this desired combination of properties.

[0012] Further aspects of the invention are the subject matter of further independent claims. Particularly preferred embodiments are the subject matter of the dependent claims.

[0013] [Detailed Description of the Invention] In a first aspect, the present invention relates to a method for selectively hydrogenating an alkynol to an alkenol with hydrogen using a hydrogenation catalyst which is palladium supported on a support in the presence of an additive which is an organophosphorus compound bearing either a phosphino group or a phosphine oxide group, wherein when the additive bears a phosphino group, the additive bears two or more phosphino groups.

[0014] For clarity, some terms used in this document are defined below.

[0015] In this document, "C x~y A "-alkyl" group is an alkyl group containing x to y carbon atoms, i.e., for example, C 1~3 An alkyl group is an alkyl group containing 1 to 3 carbon atoms. The alkyl group can be straight or branched. For example, -CH(CH3)-CH2-CH3 is considered a C4-alkyl group.

[0016] Any wavy line in any formula in this document represents a carbon-carbon bond that is in either the Z or E configuration when connected to a carbon-carbon double bond.

[0017] In this document, when the same label for a symbol or group occurs in several formulas, the definition of said group or symbol given in the context of one particular formula also applies to other formulas containing the same label.

[0018] As used herein, an "alkynol" is a compound that has at least one carbon-carbon triple bond and at least one hydroxyl group in its chemical formula. In other words, an alkynol is a hydroxy-functionalized alkyne.

[0019] Similarly, an "alkenol" is a compound that has at least one carbon-carbon double bond and at least one hydroxyl group in its chemical formula. In other words, an alkenol is a hydroxy-functionalized alkene.

[0020] In this document, a "hydrocarbyl" group is formally a monovalent group formed by removing a hydrogen atom from a hydrocarbon.

[0021] [Alkynol] In this process, alkynols are selectively hydrogenated to their respective alkenols.

[0022] An alkynol has at least one carbon-carbon triple bond and at least one hydroxyl group in its chemical formula, while each alkenol has at least one carbon-carbon double bond and at least one hydroxyl group in its chemical formula.

[0023] It is important to the present invention that the hydrogenation reducing the carbon-carbon triple bonds to the respective carbon-carbon double bonds be selective. In other words, any hydroxyl groups and other chemical groups that may be present in the alkynol are not altered by the hydrogenation reaction. In particular, the hydrogenation is selective in the sense that the carbon-carbon double bonds of the alkenol are not, or at least not significantly, further hydrogenated to carbon-carbon single bonds ("overhydrogenation").

[0024] Furthermore, it has been observed that (in addition to reducing the formation of over-hydrogenated products) the formation of other by-products, such as dimers or oligomers derived from the starting materials or products, is also significantly reduced by the above process.

[0025] In one preferred embodiment, the alkynol is an alkynol having a hydroxyl group attached to the carbon alpha to the carbon-carbon triple bond of the alkynol, i.e., the alkynol is preferably an alpha-alkynol.

[0026] The alkynol preferably has the following structural element: [ka] in its structural formula, where * indicates the position of further substituents.

[0027] In an even more preferred embodiment, the alkynol is one in which the carbon-carbon triple bond is a terminal carbon-carbon triple bond.

[0028] In a highly preferred embodiment, the alkynol comprises the following structural element: [ka] in its structural formula, where * indicates the position of further substituents.

[0029] In a highly preferred embodiment, the alkynol is of formula (I): [ka] [In the formula, R 1 represents H or a methyl or ethyl group, preferably a methyl or ethyl group, and R 2represents a saturated or unsaturated, linear or branched or cyclic hydrocarbyl group having 1 to 46 C atoms, optionally comprising at least one chemical functional group, in particular at least one hydroxyl group, or or R 1 and R 2 represents an alkylene group which together form a 5- to 7-membered ring, or Either However, R 1 has the same meaning in formulas (I) and (II), and R 2 has the same meaning in formulas (I) and (II). is an alkynol.

[0030] In formula (I), the preferred substituent R 1 is a methyl group.

[0031] R 2 preferably denotes a saturated, linear or branched or cyclic hydrocarbyl group having 1 to 46 C atoms, optionally comprising at least one chemical functional group, in particular at least one hydroxyl group.

[0032] In formula (I), the substituent R 2 is more preferably a methyl group.

[0033] A highly preferred alkynol of formula (I) is 2-methylbut-3-yn-2-ol (i.e., R 1 =R 2 = methyl).

[0034] In another embodiment, R 1 and R 2 represents alkylene groups which together form a 5- to 7-membered ring. The alkylene groups may be linear or branched, optionally contain at least one chemical functional group, and / or are olefinically unsaturated. Preferably, the alkylene groups are not olefinically saturated.

[0035] Preferably, the alkylene group is a pentylene group.One preferred alkynol of this embodiment is 1-ethynylcyclohexan-1-ol.

[0036] In another preferred embodiment, the substituent R 2 are represented by the formulae (R2-I), (R2-II), (R2-III), (R2-IV), (R2-V), (R2-VI) and (R2-VII) [ka] is selected from the group consisting of wherein the dotted line represents the bond connecting a substituent of formula (R2-I), (R2-II), (R2-III), (R2-IV), (R2-V), (R2-VI) or (R2-VII) to the remainder of a compound of formula (I) or formula (II); dotted line [ka] represent, independently of each other, either a carbon-carbon single bond or a carbon-carbon double bond, preferably a single carbon-carbon bond; each wavy line independently represents a carbon-carbon bond that is in either the Z or E configuration when connected to a carbon-carbon double bond; n represents 1, 2, 3, 4, 5 or 6, in particular 1 or 2 or 3, preferably 3 or 2, most preferably 2.

[0037] The alkynol is preferably 3-methyl-5-(2,6,6-trimethylcyclohex-1-en-1-yl)pent-1-yn-3-ol, (E)-3-methyl-1-(2,6,6-trimethylcyclohex-1-en-1-yl)pent-1-en-4-yn-3-ol, (Z)-3-methyl-1-(2,6,6-trimethylcyclohex-1-en-1-yl)pent-1-en-4-yn-3-ol, (E / Z)-3-methyl-1-(2,6,6-trimethylcyclohex-1-en-1-yl)pent-1-en-4-yn-3-ol, 3-Methyl-5-(2,6,6-trimethylcyclohex-2-en-1-yl)pent-1-yn-3-ol, (E)-3-methyl-1-(2,6,6-trimethylcyclohex-2-en-1-yl)pent-1-en-4-yn-3-ol, (Z)-3-methyl-1-(2,6,6-trimethylcyclohex-2-en-1-yl)pent-1-en-4-yn-3-ol, 3,7-dimethyloct-6-en-1-yn-3-ol, 3,7-dimethyloct-1-yn-3-ol, (E)-3,7-dimethyloct-1-yn-3-ol Methylnon-6-en-1-yn-3-ol, (Z)-3,7-dimethylnon-6-en-1-yn-3-ol, (E / Z)-3,7-dimethylnon-6-en-1-yn-3-ol, 3,7-dimethylnon-1-yn-3-ol, 3,7,11-trimethyldodec-1-yn-3-ol, (E)-3,7,11-trimethyldodec-6-en-1-yn-3-ol, (Z)-3,7,11-trimethyldodec-6-en-1-yn-3-ol, (E / Z)-3,7,11-trimethyldodec-6-en-1-yn-3-ol 3,7,11-trimethyldodec-10-en-1-yn-3-ol, (E)-3,7,11-trimethyldodeca-6,10-dien-1-yn-3-ol, (Z)-3,7,11-trimethyldodeca-6,10-dien-1-yn-3-ol, (E / Z)-3,7,11-trimethyldodeca-6,10-dien-1-yn-3-ol, 3,7,11,15-tetramethylhexadec-1-yn-3-ol, (E)-3,7,11,15-tetramethylhexadec-6-en-1-yn-3-ol, (Z)-3,7,11,15-Tetramethylhexadec-6-en-1-yn-3-ol, (E / Z)-3,7,11,15-tetramethylhexadec-6-en-1-yn-3-ol, (E)-3,7,11,15-tetramethylhexadec-10-en-1-yn-3-ol, (Z)-3,7,11,15-tetramethylhexadec-10-en-1-yn-3-ol, (E / Z)-3,7,11,15-tetramethylhexadec-10-en-1-yn-3-ol, 3,7,11,15-tetramethylhexadec-14-en-1-yn-3-ol , (6E,10E)-3,7,11,15-tetramethylhexadeca-6,10-dien-1-yn-3-ol, (6E,10Z)-3,7,11,15-tetramethylhexadeca-6,10-dien-1-yn-3-ol, (6Z,10E)-3,7,11,15-tetramethylhexadeca-6,10-dien-1-yn-3-ol, (6Z,10Z)-3,7,11,15-tetramethylhexadeca-6,10-dien-1-yn-3-ol, (E)-3,7,11,15-tetramethylhexadeca-10,14-dien-1-yn -3-ol, (Z)-3,7,11,15-tetramethylhexadeca-10,14-dien-1-yn-3-ol, (6E,10E / Z)-3,7,11,15-tetramethylhexadeca-6,10-dien-1-yn-3-ol, (6Z,10E / Z)-3,7,11,15-tetramethylhexadeca-6,10-dien-1-yn-3-ol, (6E / Z,10E)-3,7,11,15-tetramethylhexadeca-6,10-dien-1-yn-3-ol, (6E / Z,10Z)-3,7,11,15-tetramethylhexadeca -6,10-dien-1-yn-3-ol, (6E / Z,10E / Z)-3,7,11,15-tetramethylhexadeca-6,10-dien-1-yn-3-ol, (E)-3,7,11,15-tetramethylhexadeca-6,14-dien-1-yn-3-ol, (Z)-3,7,11,15-tetramethylhexadeca-6,14-dien-1-yn-3-ol, (E / Z)-3,7,11,15-tetramethylhexadeca-6,14-dien-1-yn-3-ol, (E)-3,7,11,15-tetramethylhexadeca-10,14-dien-1-yn-3-ol, (Z)-3,7,11,15-tetramethylhexadeca-10,14-dien-1-yn-3-ol, (E / Z)-3,7,11,15-tetramethylhexadeca-10,14-dien-1-yn-3-ol, (6E,10E)-3,7,11,15-tetramethylhexadeca-6,10,14-trien-1-yn hexadeca-6,10,14-trien-1-yn-3-ol, (6E,10Z)-3,7,11,15-tetramethylhexadeca-6,10,14-trien-1-yn-3-ol, (6Z,10E)-3,7,11,15-tetramethylhexadeca-6,10,14-trien-1-yn-3-ol, (6Z,10Z)-3,7,11,15-tetramethylhexadeca-6,10,14-triene -1-yn-3-ol, (6E,10E / Z)-3,7,11,15-tetramethylhexadeca-6,10,14-trien-1-yn-3-ol, (6E / Z,10E)-3,7,11,15-tetramethylhexadeca-6,10,14-trien-1-yn-3-ol, (6Z,10E / Z)-3,7,11,15-tetramethylhexadeca-6, The alkynol is selected from the group consisting of 10,14-trien-1-yn-3-ol, (6E / Z,10Z)-3,7,11,15-tetramethylhexadeca-6,10,14-trien-1-yn-3-ol, and (6E / Z,10E / Z)-3,7,11,15-tetramethylhexadeca-6,10,14-trien-1-yn-3-ol.

[0038] [Hydrogenation catalyst] The process uses a hydrogenation catalyst which is palladium supported on a carrier.

[0039] Such hydrogenation catalysts are generally known to those skilled in the art. Palladium is a noble metal. In the present invention, the palladium is supported on a support, i.e., the palladium is attached or deposited on a support. The support is a solid material.

[0040] Preferably, the support is carbon or an inorganic support. Preferred inorganic supports are oxides or carbonates. Preferred oxides are oxides of silicon, aluminum, titanium or cerium. Silicon dioxide, alumina, titanium dioxide and ceria are particularly preferred.

[0041] Silicon dioxide can be used as a carrier in the form of pyrogenic silica, precipitated silica, or pulverized silica. Preferably, the silicon dioxide used as a carrier is pyrogenic silica or precipitated silica. Most preferably, the silicon dioxide is substantially pure SiO2. In other words, the silicon dioxide carrier preferably consists of more than 95% by weight of SiO2, more preferably more than 98%, and even more preferably more than 99%.

[0042] Calcium carbonate is the preferred carbonate salt. The preferred calcium carbonate is precipitated calcium carbonate.

[0043] The supports used can be mixed oxides.

[0044] Additionally, supported palladium catalysts can be doped with other metals, such as lead. A well-known catalyst of this type is the "Lindlar catalyst," which is lead-doped palladium supported on calcium carbonate. Such Lindlar catalysts are commercially available, for example, from Sigma-Aldrich, Evonik, Johnson-Matthey, or Hindustan Platinum.

[0045] More preferred hydrogenation catalysts are palladium on carbon, palladium on silica, palladium on alumina, and palladium on carbonate, with palladium on calcium carbonate being even more preferred, and lead-doped palladium on calcium carbonate being most preferred.

[0046] The amount of palladium in the hydrogenation catalyst is preferably in the range of 0.5 to 20 wt %, more preferably in the range of 2 to 5 wt %, and most preferably in the range of approximately 5 wt %, based on the total weight of the hydrogenation catalyst.

[0047] In one embodiment, the hydrogenation catalyst is used in the form of a colloidal suspension.

[0048] Highly suitable hydrogenation catalysts are those disclosed in WO 2009 / 096783 A1 or Peter T. Witte et al., Top Catal (2012) 55:505-511 and commercialized by BASF under the trade name NanoSelect™.

[0049] In another preferred embodiment, the hydrogenation catalyst does not contain any organic quaternary ammonium compounds.

[0050] [Additives] The process is carried out in the presence of an additive which is an organophosphorus compound bearing either a phosphino group or a phosphine oxide group.

[0051] When the additive carries a phosphine oxide group, it is preferred that said additive has one or two, more preferably one, phosphine oxide group.

[0052] A particularly preferred additive that is an organophosphorus compound carrying phosphine oxide is diphenylphosphine oxide.

[0053] When the additive carries phosphino groups, the additive has two or more, preferably two to four, and more preferably two to three phosphino groups.

[0054] In a preferred embodiment, the additive has formula (III) [ka] wherein R is either an alkyl or cycloalkyl or aryl group, in particular a phenyl or tolyl group, and the dotted line represents the bond by which the substituent of formula (III) is attached to the remainder of the additive. The compound has two or more, preferably two, phosphino groups of the above formula.

[0055] The alkyl group is preferably C 1~6 -alkyl group. The cycloalkyl group is preferably C 5~8 -cycloalkyl group.

[0056] In a preferred embodiment, the additive is selected from the group consisting of 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,3-bis(diphenylphosphino)-2-(diphenylphosphino)methyl-2-methylpropane, 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene and bis(2-diphenylphosphinoethyl)phenylphosphine, preferably selected from the group consisting of 1,2-bis(diphenylphosphino)ethane and 1,3-bis(diphenylphosphino)propane.

[0057] The additive can be added to the alkynol by itself, or as a premix or presolution to the alkynol before the start of the hydrogenation reaction, or can be added during the hydrogenation process. In the case of a premix or premix, the additive is dissolved or dispersed in a small amount of an organic solvent, or preferably an alkynol.

[0058] The weight ratio of the additive to the catalyst is preferably in the range of 0.01:1 to 100:1, preferably in the range of 0.1:1 to 10:1, and more preferably in the range of 0.2:1 to 3:1.

[0059] The amount of the hydrogenation catalyst (i.e., the total of palladium and the carrier) is preferably in the range of 0.0001 to 10% by weight, more preferably 0.001 to 1% by weight, and most preferably 0.01 to 0.1% by weight, based on the weight of the alkynol.

[0060] The amount of palladium is preferably 1 to 10% by weight, preferably 3 to 7% by weight, based on the weight of the hydrogenation catalyst.

[0061] The hydrogenation reaction is preferably carried out at a temperature in the range of 10 to 150°C, more preferably at a temperature in the range of 20 to 100°C, and most preferably at a temperature in the range of 40 to 90°C.

[0062] The hydrogenation reaction is preferably carried out at a hydrogen pressure in the range of 1 to 25 bara (absolute pressure bar) hydrogen, more preferably at a hydrogen pressure in the range of 2 to 10 bara hydrogen, even more preferably at a hydrogen pressure in the range of 2 to 6 bara hydrogen, even more preferably at a hydrogen pressure in the range of 2.5 to 4 bara hydrogen, and most preferably at a hydrogen pressure in the range of 2.5 to 3 bara hydrogen.

[0063] The hydrogenation reaction can be carried out without a solvent or in the presence of an organic solvent. The organic solvent is preferably selected from the group consisting of hydrocarbons, halogenated hydrocarbons, alcohols, ethers, esters, carbonates, amides, nitriles and ketones, and mixtures thereof. More preferred are C 4~10 Aliphatic hydrocarbons, C 6~10 Aromatic hydrocarbons, one or more C 1~4 Straight chain alkyl group or C 3~4 C substituted with branched alkyl groups or halogens 6~10 Aromatic hydrocarbons, C 1~4 Linear alcohol or C 3~4 Branched chain alcohols, acyclic and cyclic C 4~10 Ether, C 3~10 Estelle, C 3~10Ketones and mixtures thereof. Particularly preferred organic solvents are selected from the group consisting of hexane, heptane, toluene, methanol, ethanol, n-propanol, 2-propanol, n-butanol, tert-butanol, tetrahydrofuran, 2-methyl-tetrahydrofuran, dioxane, ethyl acetate, isopropyl acetate, ethylene carbonate, propylene carbonate, acetone, and mixtures thereof. The most preferred solvent is heptane.

[0064] Preferably, however, the hydrogenation is carried out without the use of any organic solvent.

[0065] In a preferred embodiment, the hydrogenation is carried out without the use of any organic quaternary ammonium compounds.

[0066] In a very highly preferred embodiment, the hydrogenation is carried out without any organic solvent or any organic quaternary ammonium compound.

[0067] The above process selectively yields respective alkenols, which have the same chemical structure as alkynols, except that the carbon-carbon triple bond in alkenols is replaced by a carbon-carbon double bond.

[0068] In other words, in the preferred case, the compound of formula (I) [ka] is hydrogenated and the alkenol formed by selective hydrogenation is of formula (II) [ka] where R 1 has the same meaning in formulas (I) and (II), and R 2 has the same meaning in formulas (I) and (II).

[0069] The above-described process for selectively hydrogenating alkynols to alkenols has been found to simultaneously provide very high selectivity and very low overhydrogenation at very high conversions.

[0070] In a further aspect, the present invention provides a method for producing a pharmaceutical composition comprising: Formula (I) [ka] [In the formula, R 1 represents H or a methyl or ethyl group, preferably a methyl or ethyl group, and R 2 represents a saturated or unsaturated, linear or branched or cyclic hydrocarbyl group having 1 to 46 C atoms, optionally comprising at least one chemical functional group, in particular at least one hydroxyl group, or or R 1 and R 2 represents an alkylene group that together forms a 5- to 7-membered ring either The compound a hydrogenation catalyst which is palladium supported on a support, and - at least one additive which is an organophosphorus compound carrying either a phosphino group or a phosphine oxide group; A composition comprising: The present invention relates to a composition characterized in that, when the additive carries a phosphino group, the additive carries two or more phosphino groups.

[0071] The compounds of formula (I), the hydrogenation catalyst, and the additives are disclosed and explained in great detail above.

[0072] The composition, as also disclosed above, is highly suitable for being hydrogenated with molecular hydrogen to give, with very high selectivity, a compound of formula (II) [ka] This results in an alkenol of

[0073] [Example] The present invention is further illustrated by the following experiments.

[0074] [Table 1]

[0075] [Selective hydrogenation series 1: Hydrogenation of methylbut-3-yn-2-ol to methylbut-3-en-2-ol] A hydrogenation catalyst (80 mg of palladium-lead-supported calcium carbonate containing 5 wt. % palladium) was placed in a 500 ml pressure reactor. The individual additives were added to the reactor in the amounts listed in Table 1, along with a total of 270 g of 2-methylbut-3-yn-2-ol. The vessel was sealed and purged with nitrogen three times (pressurized to 6 bara and released). The reactor was heated to 70°C and purged with hydrogen three times (pressurized to 4 bara and released). The reactor was pressurized to 2.5 bara, and the mixture was stirred. The mixture was sampled multiple times near the end of the reaction to determine when conversion reached >99.9%. The samples were analyzed by GC (area %) to determine selectivity.

[0076] [Table 2]

[0077] [Selective hydrogenation series 2: Hydrogenation of 3,7-dimethyloct-6-en-1-yn-3-ol to 3,7-dimethylocta-1,6-dien-3-ol] A hydrogenation catalyst (56 mg of palladium-lead-supported calcium carbonate containing 5 wt. % palladium) was placed in a 500 ml pressure reactor. The individual additives were added to the reactor in the amounts listed in Table 2, along with a total of 250 g of 3,7-dimethyloct-6-en-1-yn-3-ol. The vessel was sealed and purged with nitrogen three times (pressurized to 6 bara and released). The reactor was heated to 55°C and purged with hydrogen three times (pressurized to 4 bara and released). The reactor was pressurized to 3 bara, and the mixture was stirred. The mixture was sampled multiple times near the end of the reaction to determine when conversion reached >99.9%. The samples were analyzed by GC (area %) to determine selectivity.

[0078] [Table 3]

[0079] [Selective hydrogenation series 3: Hydrogenation of 3,7,11,15-tetramethylhexadec-1-yn-3-ol to 3,7,11,15-tetramethylhexadec-1-en-3-ol] A hydrogenation catalyst (50 mg of palladium-lead supported calcium carbonate containing 5 wt % palladium) was placed in a 500 ml pressure reactor.

[0080] Each additive was added to the reactor in the amounts listed in Table 3, and a total of 260 g of 3,7,11,15-tetramethylhexadec-1-yn-3-ol. The vessel was sealed and purged with nitrogen three times (pressurized to 6 bara and released). The reactor was heated to 85°C and purged with hydrogen three times (pressurized to 4 bara and released). The reactor was pressurized to 3 bara and the mixture was stirred. The mixture was sampled multiple times near the end of the reaction to determine when conversion reached >99.9%. Samples were analyzed by GC (area %) to determine selectivity.

[0081] [Table 4]

Claims

1. A method for selectively hydrogenating an alkynol to an alkenol with hydrogen using a hydrogenation catalyst that is palladium supported on a carrier in the presence of an additive that is bis(2-diphenylphosphinoethyl)phenylphosphine.

2. 2. The method of claim 1, wherein the alkynol is an alkynol having a hydroxyl group attached to a carbon alpha to a carbon-carbon triple bond of the alkynol.

3. 3. The method according to claim 1, wherein the carbon-carbon triple bond of the alkynol is a terminal carbon-carbon triple bond.

4. The alkynol is a compound of formula (I) 【Chemical 1】 and alkynols of formula (II) 【Chemistry 2】 is an alkenol of During the ceremony, R １ represents H or a methyl or ethyl group, and R ２ represents a saturated or unsaturated, linear or branched or cyclic hydrocarbyl group having 1 to 46 C atoms, optionally comprising at least one chemical functional group, or or R １ and R ２ represents alkylene groups which together form a 5- to 7-membered ring, or Either However, R １ has the same meaning in formulas (I) and (II), and R ２ has the same meaning in formulas (I) and (II) The method according to any one of claims 1 to 3, characterized in that

5. R １ The method of claim 4, wherein is a methyl group.

6. R ２ 6. The method according to claim 4 or 5, characterized in that is a methyl group.

7. R ２ is the formula (R2-I), (R2-II), (R2-III), (R2-IV), (R2-V), (R2-VI) and (R2-VII) 【Chemistry 3】 is selected from the group consisting of wherein the dotted line represents the bond connecting a substituent of formula (R2-I), (R2-II), (R2-III), (R2-IV), (R2-V), (R2-VI) or (R2-VII) to the remainder of the compound of formula (I) or formula (II); dotted line 【Chemistry 4】 represent, independently of each other, either a carbon-carbon single bond or a carbon-carbon double bond; each wavy line independently represents a carbon-carbon bond that is in either the Z or E configuration when connected to a carbon-carbon double bond; n represents 1, 2, 3, 4, 5 or 6 6. The method according to claim 4 or 5.

8. 8. The process according to claim 1, wherein the hydrogenation is carried out without the use of any organic quaternary ammonium compound.

9. 9. The process according to claim 1, wherein the hydrogenation is carried out without the use of any organic solvent.

10. 10. The method according to any one of claims 1 to 9, characterized in that the support is a carbon or inorganic support.

11. 11. The process according to any one of claims 1 to 10, characterized in that the hydrogenation catalyst is in the form of a colloidal suspension.

12. 12. The method according to any one of claims 1 to 11, characterized in that the weight ratio of the additive to the catalyst ranges from 0.01:1 to 100:

1.

13. Formula (I) 【Chemistry 5】 [In the formula, R １ represents H or a methyl or ethyl group, and R ２ represents a saturated or unsaturated, linear or branched or cyclic hydrocarbyl group having 1 to 46 C atoms, optionally comprising at least one chemical functional group, or or R １ and R ２ represents an alkylene group that together forms a 5- to 7-membered ring Either The compound a hydrogenation catalyst which is palladium supported on a support, and - A composition comprising an additive which is bis(2-diphenylphosphinoethyl)phenylphosphine.

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