Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
  • C07B35/00—Reactions without formation or introduction of functional groups containing hetero atoms, involving a change in the type of bonding between two carbon atoms already directly linked
  • C07B35/02—Reduction
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
  • C07C29/17—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by hydrogenation of carbon-to-carbon double or triple bonds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
  • C07C5/02—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by hydrogenation
  • C07C5/08—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by hydrogenation of carbon-to-carbon triple bonds
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/54—Improvements relating to the production of bulk chemicals using solvents, e.g. supercritical solvents or ionic liquids

Definitions

• the invention relates to a method for transferring hydrogen to chemical compounds by catalysis with stabilized metal colloids, and to the use of stabilized metal colloids in a method for transferring hydrogen to chemical compounds.
• Catalysis with metal colloids is usually carried out in conventional solvents.
• DE-A 197 45 904 relates to metal colloid solutions which are stabilized by at least one cation exchange polymer.
• the stabilized metal colloids are described as being soluble in water or an organic solvent.
• the metal colloids disclosed in DE-A 197 45 904 are suitable as catalysts, in particular for fuel cells.
• RU-C 2144020 relates to a process for the hydrogenation of acetylenic alcohols to the corresponding ethylenic alcohols with hydrogen using micellar, palladium-containing catalysts.
• the catalysts are made up of Pd (0), which was applied in the form of palladium acetate to a polystyrene-4-vinylpyridine block copolymer and then reduced. In the final catalyst, the palladium nanoparticles obtained were applied to aluminum oxide.
• DE-A 195 06 113 relates to liquid colloidal metal preparations which contain micelles which consist of a block copolymer which has at least one polymer block which solvates in the solvent and one polymer block which is capable of binding to the colloidal metal, in a liquid organic or inorganic solvent.
• micelles consist of a block copolymer which has at least one polymer block which solvates in the solvent and one polymer block which is capable of binding to the colloidal metal, in a liquid organic or inorganic solvent.
• BESTATIGUNGSKOPIE WO 01/14289 relates to a process for carrying out catalytic reactions in supercritical carbon dioxide, in which a fluid mixture which contains at least one reactant and carbon dioxide is brought into contact with a catalyst which is bound to a polymer and the reactant is in contact with the catalyst Interaction occurs with the formation of a reaction product.
• the polymer used can either be soluble or insoluble in carbon dioxide.
• Polymers with CO 2 -philic groups are mentioned as suitable soluble polymers. Examples of CO 2 -phile groups are silicone-containing groups or polysiloxanes, halogen (in particular fluorine) -containing groups or halogen (in particular fluoro-) carbons as well as branched polyalkylene oxides and fluorinated polyethers.
• the fluorine-containing unit is usually a "fluoropolymer".
• CO 2 -phobic groups include aromatic polymers and oligomers which are composed of styrene, acrylate or vinylpyrrolidone monomers.
• cationic-homogeneous catalysis in supercritical fluid can only be used with fluorinated ligands or with the help of fluorinated cosolvents.
• This object is achieved by a method for hydrogen transfer to chemical compounds, the hydrogen transfer being carried out in the supercritical or subcritical phase using stabilized and dispersed metal particles.
• the metal particles are preferably used in the form of metal clusters or particles of colloidal size.
• Metal colloids are systems in which there are metal particles with a diameter of the order of 1 nm to 1 ⁇ m.
• the extremely fine-particle metal itself is called colloidal metal.
• Metal clusters are understood to mean metal particles which consist of only a few - a few to a few thousand - metal atoms and which are at the lower end of the size scale for colloidal metal (diameter of the metal ponds in metal colloids: lnm to 1 ⁇ ).
• a preferred embodiment of the present invention relates to a method for transferring hydrogen to chemical compounds, in which the chemical compounds are reacted as catalysts in the presence of dispersed metal colloids stabilized by organic compounds or embedded in organic compounds.
• the process according to the invention is then characterized in that the reaction is carried out in the supercritical or subcritical phase.
• the process according to the invention is distinguished by high reaction rates and thus high efficiency. Due to the use of supercritical solvents, no possibly toxic solvent residues remain in the
• heterogeneous catalysis good separability etc.
• homogeneous catalysis catalyst utilization, selectivity etc.
• the hydrogen concentration in the solvent can be selected almost freely and is no longer a limiting factor in the reaction as in liquid solvents in which the solubility of hydrogen is low.
• supercritical refers to the state of the solvent (fluid) used.
• carbon dioxide is in a supercritical state if the temperature is above 31.1 ° C and at the same time the pressure is above 73.8 bar.
• Supercritical fluids show both liquid and gaseous properties, e.g. a liquid-like density and a gas-like viscosity.
• the diffusivity of supercritical fluids lies between the values of gases and liquids. Due to the increased mass transport, gaseous properties are advantageous in the reaction chemistry.
• a particularly important property of supercritical fluids is that they are completely miscible with any type of gas, including hydrogen gas. That is, when the solvent is in the supercritical state, the hydrogen gas used for the reduction can be easily mixed with the solvent.
• the selection of the suitable solvent depends on the type of hydrogen transfer reaction and the used starting products.
• Aromatic and aliphatic hydrocarbons such as benzene, toluene, ethane, propane or butane are particularly suitable; carbon dioxide; Alcohols such as methanol or ethanol; or mixtures thereof.
• the supercritical or subcritical phase very particularly preferably contains carbon dioxide. Carbon dioxide is environmentally friendly, non-toxic, non-flammable, inexpensive, corrosion-resistant and readily available. In the process according to the invention for hydrogen transmission, it can act simultaneously as a solvent and protective gas.
• metal colloids The production of metal colloids has been known for a long time.
• Metal salts in solution are usually reduced to metal in the presence of stabilizers (see e.g. G. Schmid, VCH-Verlag 1994, Clusters and Colloids).
• the stabilizers are substances that are able to form coordinative bonds with the metal, thereby protecting it from agglomeration.
• Organic compounds are used as stabilizers in the process according to the present application. Suitable organic compounds are coordinatable compounds (ligands) or polymers. According to the present application, preferred organic compounds are polymers.
• the metal colloids stabilized by organic compounds or embedded in organic compounds are referred to below as stabilized metal colloids.
• the stabilized metal colloids are preferably metal colloids embedded in organic compounds.
• the stabilized metal colloids are preferably dispersible in the supercritical phase. It is known that the solubility of polymers in a supercritical phase, in particular in supercritical carbon dioxide, is moderate to poor. According to WO 01/14289, polymers containing CO -phile groups are soluble in carbon dioxide. Silicon-containing groups or polysiloxanes, halogen (in particular fluorine) -containing groups or halogen (in particular fluoro-) carbons as well as branched polyalkylene oxides and fluorinated polyethers are mentioned as CO-philic groups.
• block copolymers as stabilizers, preferably block copolymers, in which at least two polymer blocks selected from the group consisting of polystyrene, polyalkylstyrene, polyisoprene, polymethyl (meth) acrylate and polybutadiene, poly-4-vinylpyridine, poly-2-vinylpyridine, polyethylene glycol, polyethylene oxide, poly (meth) acrylic acid, polyhydroxyethyl methacrylate, polyvinyl alcohol, polydimethylsiloxane, Poly-2-dimethylamino-ethyl (meth) acrylate and polyethylene are used, catalysts are obtained which are dispersed in the supercritical phase, in particular in supercritical carbon dioxide, in colloidal form.
• Block copolymers selected from polystyrene-poly-4-vinylpyridine, polystyrene-poly-2-vinylpyridine, polystyrene-poly- (meth) acrylic acid, polystyrene-poly-ethylene glycol, polystyrene-poly-ethylene oxide, polystyrene-poly-hydroxy are particularly preferred as stabilizers -ethyl methacrylate, polystyrene-poly-vinyl alcohol, polydimethylsiloxane-poly-ethylene oxide, poly-2-dimethylamino-ethyl methacrylate-poly-methyl methacrylate and polyethylene oxide-polyethylene used.
• polystyrene from polymethyl methacrylate.
• Polystyrene-poly-4-vinylpyridine block copolymers are very particularly preferably used as stabilizers.
• the preparation of the block copolymers preferably used according to the invention is known to the person skilled in the art. You can e.g. can be obtained by anionic polymerization of the corresponding monomers (M. Antonietti, Chem. Mater. 1997, No. 9, 923-931).
• the polystyrene-poly-4-vinylpyridine block copolymers used with particular preference are prepared according to a method described in Bronstein et al., J. Catal. 196, 302 to 312 (2000).
• the metal colloids are embedded in these polymers, preferably in the block copolymers mentioned.
• Such stabilized metal colloids are e.g. according to M. Antonietti, Chem. Mater. 1997, No. 9, 923-931.
• the metal colloids are metals, metal alloys or non-alloyed metal combinations. These are preferably selected from one or more metals from the group consisting of nickel, cobalt, palladium, platinum, gold, silver, copper, rhodium, ruthenium and iridium; one or more metals are particularly preferably selected from the group consisting of palladium, gold , Platinum, rhodium and ruthenium are used.
• the metal colloids according to the invention very particularly preferably have a core selected from one of the metals mentioned above, in particular gold, which is surrounded by a layer of a further metal selected from the metal mentioned above, preferably palladium, which is different from the metal of the core ,
• a core selected from one of the metals mentioned above, in particular gold
• a further metal selected from the metal mentioned above, preferably palladium, which is different from the metal of the core
• a cosolvent can optionally be used to stabilize and disperse the metal particles.
• a cosolvent is preferably selected from the group consisting of toluene, o-, m-, p-xylene, ⁇ ,, -trifluorotoluene, benzene, ethylbenzene, cyclohexane, hexane, pentane and partially fluorinated alcohols.
• the hydrogen transfer reaction is preferably a reaction selected from the group consisting of hydrogenation, hydroformylation, hydrogenolysis, hydrocarboxylation and hydrosilylation.
• a hydrogenation or hydroformylation is particularly preferably carried out, very particularly preferably a hydrogenation.
• the reagents with which the chemical compounds are reacted in the presence of stabilized metal colloids as catalysts in the supercritical or in the subcritical phase depend on the particular hydrogen transfer reaction and correspond to the reagents used in the corresponding processes known from the prior art.
• the hydrogen transfer reaction is a preferred hydroformylation
• hydrogen and carbon monoxide are used as reagents.
• the process according to the invention can be applied to all common hydroformylation reactions on chemical compounds.
• the chemical compounds used in the hydroformylation carried out in accordance with the process according to the invention are preferably C 2 -C 20 -olefins or alkynes.
• the chemical compounds are reacted with hydrogen as a reagent.
• the process according to the invention can be applied to all common hydrogenation reactions on chemical compounds.
• Chemical compounds preferably used in the hydrogenation carried out according to the process of the invention are selected from the group consisting of alkynes; alkinols; Alkenes, especially unsaturated fatty acids; Nitro compounds; Carboxylic acids, especially fatty acids; Carbonyl compounds and aromatic compounds.
• Particularly preferred chemical compounds are alkynes and alkynols, very particularly preferably 1-hexyne, 3-methylpent-1-yn-3-ol, 3-phenylpropine, 3,3-dimethylbutine and phenylethine.
• the hydrogenation reactions which can be carried out with the process according to the invention are unselective (i.e. complete) and selective hydrogenations.
• An example of a selective hydrogenation is the hydrogenation of alkynes to alkenes.
• the method can be carried out at any pressure / temperature combination, as long as it is ensured that a supercritical or subcritical phase is present.
• the exact pressure and temperature values depend on the corresponding hydrogen transfer reaction and the solvent used.
• the process is carried out in carbon dioxide, it is generally carried out at from 32 to 250 ° C., preferably from 40 to 100 ° C., particularly preferably from 50
• the supercritical or subcritical phase is usually produced by compressing the fluid used as solvent, preferably carbon dioxide, in a reactor at the temperature mentioned to the pressure mentioned, adding the chemical compounds, the catalyst and of the reagent used as a function of the hydrogen transfer reaction and, if appropriate, of further components, can be carried out before or after the compression, preferably first of all by adding the chemical compound, the catalyst, the one dependent on the Hydrogen transfer reaction used reagent, and optionally other components to the fluid used as a solvent and then the compression to the temperature and pressure mentioned to produce the supercritical or subcritical phase.
• a particularly preferred hydrogenation it is preferred to add enough hydrogen to set a hydrogen partial pressure of generally 1 to 100 bar, preferably 2 to 50 bar, particularly preferably 2 to 15 bar (pressure increase based on the previously set internal reactor pressure).
• the amount of the stabilized metal colloid used as a catalyst depends on the hydrogen transfer reaction carried out. In the particularly preferred hydrogenation, the amount is generally 0.01 to 5% by weight, preferably 0.02 to 2% by weight, particularly preferably 0.1 to 1% by weight, based on the chemical compound used.
• reaction time is also dependent on the hydrogen transfer reaction carried out and on the chemical compounds used.
• a reaction time of 1 minute to 1 hour, preferably 1 minute to 10 minutes, is customary.
• Hydrogenation of h in general, 30000 "to 8,000,000 h", preferably 100,000 h "1-4000000 h” 1, more preferably 500,000 h "1-2000000 h” 1 achieved conversion rates.
• the process according to the invention can be carried out continuously, semi-continuously or in a batch process, a continuous procedure being preferred.
• the stabilized metal colloids used as catalysts according to the invention can be recovered after the reaction and used again. Unreacted chemical compounds can also be recovered and reused.
• the solvent is compressed to produce a supercritical phase, so that it is in a supercritical or subcritical phase.
• hydrogen is added in a particularly preferred hydrogenation.
• the chemical compound to be hydrogenated and the stabilized metal colloid used according to the invention as a catalyst are added to this mixture.
• the components can be separated, for example by filtration, ultrafiltration, distillation or sedimentation.
• reactors usually used for reactions in the supercritical or subcritical phase such as stirred kettles or bubble columns, are suitable.
• the metals, metal alloys or non-alloyed metal combinations used, the stabilizers (preferably polymers) used to stabilize the metal colloids optionally by adding further substances as a function of the respective hydrogen transfer reaction, if appropriate by upstream reactions or by physical effects Reactivity and selectivity of the product formation are controlled, the variation preferably taking place in the above-mentioned areas.
• the process according to the invention is characterized in particular by the fact that by using stabilized metal colloids as catalysts in the process according to the invention, a simultaneous, i.e. in pairs, transfer of the two hydrogen atoms of a hydrogen molecule takes place, which is typical for a homogeneous hydrogenation.
• a simultaneous, i.e. in pairs, transfer of the two hydrogen atoms of a hydrogen molecule takes place, which is typical for a homogeneous hydrogenation.
• radical intermediates in the hydrogen transfer are avoided.
• the formation of by-products that can arise from the formation of radical intermediates is avoided.
• Another object of the present application is therefore the use of metal colloids stabilized by organic compounds or embedded in organic compounds as catalysts in a process for the hydrogen transfer to chemical compounds in the supercritical or in the subcritical phase to avoid the formation of radical intermediates during the hydrogen transfer. This reduces the formation of by-products due to side reactions of radical intermediates that are usually formed.
• Substrates and catalyst are placed in a suitable reactor or autoclave, in this case an NMR high-pressure probe.
• Mixed transition metal colloids which consist of gold nuclei surrounded by a palladium layer, serve as the catalyst.
• the colloids used here are stabilized by polystyrene-poly-4-vinylpyridine block copolymers (Bronstein et al. J. Catal. 196, 302-312 (2000)).
• 1-hexyne, 3-methylpent-1-yn-3-ol, 3-phenylpropine, 3,3-dimethylbutine and phenylethine are optionally used as characteristic substrates.
• carbon dioxide is compressed in the reactor at a temperature of 50 ° C.
• each of the specified substrates is hydrogenated at a constant hydrogen pressure (15 bar pressure increase based on the previously set internal reactor pressure of 150 bar CO 2 ).
• the course of the respective reaction is monitored in situ by NMR measurements. The progress of the reaction can be determined by evaluating the signals which change in the course of the reaction, for example the alkyne hydrogen signal. The conversion rates determined for all substrates used are considerably higher than those obtained in organic solvents.
• hydrogenations are also carried out at 2, 4, 8, 10 and 15 bar both of phenylethine and 3-methyl-pent-1-yn-3-ol.

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• 2001
  • 2001-05-25 DE DE10125613A patent/DE10125613A1/de not_active Withdrawn
• 2002
  • 2002-05-24 AU AU2002325219A patent/AU2002325219A1/en not_active Abandoned
  • 2002-05-24 EP EP02758203A patent/EP1404725B1/de not_active Expired - Lifetime
  • 2002-05-24 AT AT02758203T patent/ATE310024T1/de not_active IP Right Cessation
  • 2002-05-24 DE DE50204954T patent/DE50204954D1/de not_active Expired - Lifetime
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  • 2002-05-25 JP JP2003502045A patent/JP4334338B2/ja not_active Expired - Fee Related
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