Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Rhodium catalysts catalysts

An alkene which will give a polar aldehyde product and syn gas are introduced into the reactor containing a non-polar ligand modified rhodium catalyst. Catalyst solution exiting the reactor enters a Flash stage where CO/H2 are purged. The catalyst solution then enters an extractor where it is contacted with a polar solvent. The product aldehyde is captured in the polar solvent in the extractor, then concentrated in the Solvent Removal Column. Polar Solvent is recycled to the Extractor. The Non-Polar catalyst solution is recycled to the reactor (see Figure 2.5). [Pg.17]

Some examples of the use of a temporary additional site of coordination have been published. Burk and Feaster have transformed a series of ketones into hydrazones capable of chelating to a rhodium catalyst (Scheme 4.7). Upon coordination, enanti os elective hydrogenation of the hydrazone is feasible, yielding N-aroylhydrazines in up to 97% ee. Finally, the hydrazines were transformed into amines by treatment with Sml2. [Pg.112]

Similar activation takes place in the carbonylation of dimethyl ether to methyl acetate in superacidic solution. Whereas acetic acid and acetates are made nearly exclusively using Wilkinson s rhodium catalyst, a sensitive system necessitating carefully controlled conditions and use of large amounts of the expensive rhodium triphenylphosphine complex, ready superacidic carbonylation of dimethyl ether has significant advantages. [Pg.193]

On catalytic hydrogenation over a rhodium catalyst the compound shown gave a mixture containing as 1 ten butyl 4 methylcyclohexane (88%) and trans 1 ten butyl 4 methylcyclo hexane (12%) With this stereochemical result in mind consider the reactions in (a) and (b)... [Pg.277]

CO, and methanol react in the first step in the presence of cobalt carbonyl catalyst and pyridine [110-86-1] to produce methyl pentenoates. A similar second step, but at lower pressure and higher temperature with rhodium catalyst, produces dimethyl adipate [627-93-0]. This is then hydrolyzed to give adipic acid and methanol (135), which is recovered for recycle. Many variations to this basic process exist. Examples are ARCO s palladium/copper-catalyzed oxycarbonylation process (136—138), and Monsanto s palladium and quinone [106-51-4] process, which uses oxygen to reoxidize the by-product... [Pg.244]

Process Technology. In a typical oxo process, primary alcohols are produced from monoolefins in two steps. In the first stage, the olefin, hydrogen, and carbon monoxide [630-08-0] react in the presence of a cobalt or rhodium catalyst to form aldehydes, which are hydrogenated in the second step to the alcohols. [Pg.457]

Rhodium Ca.ta.lysts. Rhodium carbonyl catalysts for olefin hydroformylation are more active than cobalt carbonyls and can be appHed at lower temperatures and pressures (14). Rhodium hydrocarbonyl [75506-18-2] HRh(CO)4, results in lower -butyraldehyde [123-72-8] to isobutyraldehyde [78-84-2] ratios from propylene [115-07-17, C H, than does cobalt hydrocarbonyl, ie, 50/50 vs 80/20. Ligand-modified rhodium catalysts, HRh(CO)2L2 or HRh(CO)L2, afford /iso-ratios as high as 92/8 the ligand is generally a tertiary phosphine. The rhodium catalyst process was developed joindy by Union Carbide Chemicals, Johnson-Matthey, and Davy Powergas and has been Hcensed to several companies. It is particulady suited to propylene conversion to -butyraldehyde for 2-ethylhexanol production in that by-product isobutyraldehyde is minimized. [Pg.458]

The acetic anhydride process employs a homogeneous rhodium catalyst system for reaction of carbon monoxide with methyl acetate (36). The plant has capacity to coproduce approximately 545,000 t/yr of acetic anhydride, and 150,000 t/yr of acetic acid. One of the many challenges faced in operation of this plant is recovery of the expensive rhodium metal catalyst. Without a high recovery of the catalyst metal, the process would be uneconomical to operate. [Pg.167]

Other Methods. A variety of other methods have been studied, including phenol hydroxylation by N2O with HZSM-5 as catalyst (69), selective access to resorcinol from 5-methyloxohexanoate in the presence of Pd/C (70), cyclotrimerization of carbon monoxide and ethylene to form hydroquinone in the presence of rhodium catalysts (71), the electrochemical oxidation of benzene to hydroquinone and -benzoquinone (72), the air oxidation of phenol to catechol in the presence of a stoichiometric CuCl and Cu(0) catalyst (73), and the isomerization of dihydroxybenzenes on HZSM-5 catalysts (74). [Pg.489]

This process is one of the three commercially practiced processes for the production of acetic anhydride. The other two are the oxidation of acetaldehyde [75-07-0] and the carbonylation of methyl acetate [79-20-9] in the presence of a rhodium catalyst (coal gasification technology, Halcon process) (77). The latter process was put into operation by Tennessee Eastman in 1983. In the United States the total acetic anhydride production has been reported to be in the order of 1000 metric tons. [Pg.476]

MMA and MAA can be produced from ethylene [74-85-1/ as a feedstock via propanol, propionic acid, or methyl propionate as intermediates. Propanal may be prepared by hydroformylation of ethylene over cobalt or rhodium catalysts. The propanal then reacts in the Hquid phase with formaldehyde in the... [Pg.252]

The search for catalyst systems which could effect the 0x0 reaction under milder conditions and produce higher yields of the desired aldehyde resulted in processes utilizing rhodium. Oxo capacity built since the mid-1970s, both in the United States and elsewhere, has largely employed tertiary phosphine-modified rhodium catalysts. For example, over 50% of the world s butyraldehyde (qv) is produced by the LP Oxo process, technology Hcensed by Union Carbide Corporation and Davy Process Technology. [Pg.465]

Ligand-Modified Rhodium Process. The triphenylphosphine-modified rhodium oxo process, termed the LP Oxo process, is the industry standard for the hydroformylation of ethylene and propylene as of this writing (ca 1995). It employs a triphenylphosphine [603-35-0] (TPP) (1) modified rhodium catalyst. The process operates at low (0.7—3 MPa (100—450 psi)) pressures and low (80—120°C) temperatures. Suitable sources of rhodium are the alkanoate, 2,4-pentanedionate, or nitrate. A low (60—80 kPa (8.7—11.6 psi)) CO partial pressure and high (10—12%) TPP concentration are critical to obtaining a high (eg, 10 1) normal-to-branched aldehyde ratio. The process, first commercialized in 1976 by Union Carbide Corporation in Ponce, Puerto Rico, has been ficensed worldwide by Union Carbide Corporation and Davy Process Technology. [Pg.467]

Other Rhodium Processes. Unmodified rhodium catalysts, eg, 1 14(00)22 [19584-30-6] have high hydroformylation activity but low selectivity to normal aldehydes. [Pg.469]

Meth5l-l,3-propanediol is produced as a by-product. The hydroformylation reaction employs a rhodium catalyst having a large excess of TPP (1) and an equimolar (to rhodium) amount of 1,4-diphenylphosphinobutane (DPPB) (4). Aqueous extraction/decantation is also used in this reaction as an alternative means of product/catalyst separation. [Pg.470]

High enantioselectivities and regioselectivities have been obtained using both mono- and 1,2-disubstituted prochinal olefins employing chiral phosphine phosphite (33,34) modified rhodium catalysts. For example, i7j -2-butene ia the presence of rhodium and (12) (33) gave (3)-2-meth5ibutanal ia an optical yield of 82% at a turnover number of 9.84. ... [Pg.472]

Efficient enantioselective asymmetric hydrogenation of prochiral ketones and olefins has been accompHshed under mild reaction conditions at low (0.01— 0.001 mol %) catalyst concentrations using rhodium catalysts containing chiral ligands (140,141). Practical synthesis of several optically active natural... [Pg.180]

The most common oxidation states, corresponding electronic configurations, and coordination geometries of iridium are +1 (t5 ) usually square plane although some five-coordinate complexes are known, and +3 (t7 ) and +4 (t5 ), both octahedral. Compounds ia every oxidation state between —1 and +6 (<5 ) are known. Iridium compounds are used primarily to model more active rhodium catalysts. [Pg.181]

Alkali moderation of supported precious metal catalysts reduces secondary amine formation and generation of ammonia (18). Ammonia in the reaction medium inhibits Rh, but not Ru precious metal catalyst. More secondary amine results from use of more polar protic solvents, CH OH > C2H5OH > Lithium hydroxide is the most effective alkah promoter (19), reducing secondary amine formation and hydrogenolysis. The general order of catalyst procUvity toward secondary amine formation is Pt > Pd Ru > Rh (20). Rhodium s catalyst support contribution to secondary amine formation decreases ia the order carbon > alumina > barium carbonate > barium sulfate > calcium carbonate. [Pg.209]

A major step in the production of nitric acid [7697-37-2] (qv) is the catalytic oxidation of ammonia to nitric acid and water. Very short contact times on a platinum—rhodium catalyst at temperatures above 650°C are required. [Pg.337]


See other pages where Rhodium catalysts catalysts is mentioned: [Pg.209]    [Pg.953]    [Pg.2]    [Pg.131]    [Pg.5]    [Pg.76]    [Pg.145]    [Pg.239]    [Pg.286]    [Pg.361]    [Pg.555]    [Pg.563]    [Pg.771]    [Pg.788]    [Pg.852]    [Pg.68]    [Pg.471]    [Pg.165]    [Pg.416]    [Pg.280]    [Pg.465]    [Pg.469]    [Pg.469]    [Pg.471]    [Pg.173]    [Pg.180]    [Pg.181]    [Pg.294]    [Pg.73]    [Pg.208]   
See also in sourсe #XX -- [ Pg.143 ]




SEARCH



1- Pentene catalysts, rhodium complexes

1-Hcxenc catalysts, rhodium complexes

1-Octene catalysts, rhodium complexes

2- Pentene, 3-methylhydroformylation catalysts, rhodium complexes

4- Penten catalysts, rhodium complexes

Acetic rhodium carbonyl catalyst

Acetylene, phenylreduction catalysts, rhodium complexes

Achiral rhodium catalyst

Achiral substrates with rhodium catalysts

Activity rhodium catalysts

Alkenes catalysts, rhodium complexes

Alkylation catalysts, rhodium complexes

Alkynes catalysts, rhodium complexes

Alumina-supported rhodium catalyst

Amide-Rhodium Complexes as Catalysts

Amines catalysts, rhodium complexes

Anthracene rhodium complex catalysts

Asymmetric Hydrogenation of Prochiral Olefins by Rhodium-DuPhos Catalysts

Asymmetric hydroformylation, rhodium catalysts

Asymmetric synthesis cyclopropanation, rhodium catalyst

Aziridine catalysts, rhodium complexes

BINAP catalysts rhodium

Bimetallic catalysts platinum-rhodium alloys

By Rhodium and Nickel Catalysts

C-H Amination with Rhodium(II) Catalysts

Carbenoids rhodium catalysts

Catalyst Systems Containing Rhodium

Catalyst grafted 235 - rhodium

Catalyst precursors, butane]rhodium

Catalyst rhodium alloys

Catalyst rhodium chiral

Catalyst rhodium-based

Catalyst rhodium/ceria

Catalysts Other than Cobalt and Rhodium

Catalysts containing rhodium

Catalysts cyclopentadienyl rhodium

Catalysts rhodium black, preparation

Catalysts rhodium carbonyl

Catalysts rhodium systems

Catalysts rhodium-platinum oxide

Catalysts rhodium/zeolite

Cationic rhodium /BINAP complex catalyst

Cationic rhodium catalysts

Cationic rhodium catalysts hydrogenation

Cationic rhodium catalysts with complexes containing

Chiral rhodium catalysts, intramolecular

Cinnamic acid catalysts, rhodium complexes

Cobalt/rhodium catalysts

Cobalt/rhodium catalysts amidocarbonylations

Cyclohexene catalysts, rhodium complexes

Cyclohexene phosphite-modified rhodium catalysts

Cyclopropane catalysts, rhodium complexes

Dendrimers rhodium-based catalysts

Dienes catalysts, rhodium complexes

Diphosphine catalysts, rhodium

Diphosphine-rhodium, chiral catalyst

Dipolar chiral rhodium catalysts

Domino rhodium catalysts

DuPHOS rhodium catalysts

Eight rhodium catalysts

Enamide Hydrogenation with Rhodium Catalysts

Epoxides catalysts, rhodium complexes

Ethanol catalysts, rhodium complexes

Ether, dimethyl catalysts, rhodium complexes

Ethylene catalysts, rhodium complexes

Examples of rhodium catalysts

Formaldehyde catalysts, rhodium complexes

Homobimetallic rhodium catalyst

Homogeneous Rhodium-Chiral Phosphine Catalyst Systems

Hydroacylation rhodium catalysts

Hydroamination rhodium catalyst

Hydroformylation with unmodified rhodium catalysts

Hydrogenation over rhodium catalysts

I-Octcne catalysts, rhodium complexes

IR studies on Ligand-free Rhodium Carbonyl Catalysts

Imprinted rhodium catalyst

Iron-rhodium cluster catalyst

Itaconic acid catalysts, rhodium complexes

Ketones catalysts, rhodium complexes

Limonene phosphite-modified rhodium catalysts

Maleic acid catalysts, rhodium complexes

Mechanism rhodium-based catalysts

Metal catalysts rhodium-on-carbon

Metal supported cobalt-rhodium catalysts

Metal supported rhodium catalysts from

Metal supported rhodium-iron catalysts

Methanol catalysts, rhodium complexes

Methanol rhodium catalysts

Neutral rhodium catalysts

Nitrenoid catalysts rhodium

Nitric oxide rhodium catalysts

Nitriles catalysts, rhodium complexes

Nitro compounds catalysts, rhodium complexes

Olefin hydrogenation rhodium catalysts

Organometallic chiral rhodium catalyst

PAMAM complexes rhodium dendritic catalysts

Phosphane-modified rhodium catalysts

Phosphates, rhodium catalysts

Phosphine anchored rhodium catalyst

Phosphine-modified rhodium catalysts

Phosphine-phosphite rhodium catalysts

Platinum-rhodium catalysts

Pressure Hydrogenation of Phenols over Rhodium Catalysts

Promoters rhodium-ruthenium catalyst

Propan catalysts, rhodium complexes

Propylene catalysts, rhodium complexes

Propylene, 3-phenylhydroformylation catalysts, rhodium complexes

Protein-bound rhodium hydrogenation catalyst

Pyruvic acid catalysts, rhodium complexes

Reflectivity Rhodium hydrogenation catalysts

Rhodium Doyle catalysts

Rhodium Hydroformylation Catalysts with Bidentate Ligands

Rhodium MEPY catalyst

Rhodium MonoPhos catalysts

Rhodium Monsanto catalyst system

Rhodium Rh catalyst

Rhodium Wilkinson’s catalyst

Rhodium acetate catalyst

Rhodium acyclation catalyst

Rhodium allylic oxidation catalyst

Rhodium and Iridium Catalysts

Rhodium and Palladium as Catalysts

Rhodium and Ruthenium Catalysts

Rhodium as catalyst

Rhodium based hydroformylation catalyst

Rhodium black catalysts

Rhodium bulky diphosphite catalysts

Rhodium carbon catalysts

Rhodium carbonyl catalyst, ligand-free

Rhodium carbonyl complexes catalysts

Rhodium carbonyl iodide catalyst, carbonylation

Rhodium carboxylates diazo compound decomposition catalysts

Rhodium catalyst [RhCl

Rhodium catalyst acetic acid production

Rhodium catalyst acetic anhydride production

Rhodium catalyst for hydroformylation

Rhodium catalyst precursors

Rhodium catalysts

Rhodium catalysts (continued

Rhodium catalysts Bonds

Rhodium catalysts Cope rearrangement

Rhodium catalysts Isotherms

Rhodium catalysts Michael addition

Rhodium catalysts Wolff rearrangement

Rhodium catalysts activation

Rhodium catalysts acylation

Rhodium catalysts additions

Rhodium catalysts alkene hydrogenation, chiral

Rhodium catalysts alkoxycarbonylation

Rhodium catalysts alkynes

Rhodium catalysts aromatic rearrangements

Rhodium catalysts asymmetric

Rhodium catalysts asymmetric reactions

Rhodium catalysts bisphosphines

Rhodium catalysts carbenoid

Rhodium catalysts carbon monoxide conversion

Rhodium catalysts carbonylation, effect

Rhodium catalysts carboxylates

Rhodium catalysts colloidal

Rhodium catalysts complexes, triarylphosphine

Rhodium catalysts configuration

Rhodium catalysts conjugate additions

Rhodium catalysts conjugated dienes

Rhodium catalysts containing amphiphilic

Rhodium catalysts containing carboxylated

Rhodium catalysts containing cationic

Rhodium catalysts containing polymer-bound

Rhodium catalysts containing sulfonated

Rhodium catalysts containing sulfonated phosphine

Rhodium catalysts coupling

Rhodium catalysts determination

Rhodium catalysts diphosphites

Rhodium catalysts early studies

Rhodium catalysts enantioselective allylic substitutions

Rhodium catalysts for asymmetric ketone reduction

Rhodium catalysts hydrocarbonylation

Rhodium catalysts hydrogen

Rhodium catalysts hydrogenation, ketones

Rhodium catalysts indole functionalization

Rhodium catalysts insertion into allylic

Rhodium catalysts insertions

Rhodium catalysts lead compounds

Rhodium catalysts ligands

Rhodium catalysts metal leach

Rhodium catalysts organocatalysts

Rhodium catalysts oxidation

Rhodium catalysts phosphine-phosphite ligands

Rhodium catalysts polymer-based

Rhodium catalysts polystyrene-supported

Rhodium catalysts preparation

Rhodium catalysts properties

Rhodium catalysts reactions

Rhodium catalysts rearrangement

Rhodium catalysts regioselectivity effects

Rhodium catalysts review

Rhodium catalysts spectroscopic analysis

Rhodium catalysts sulfide

Rhodium catalysts supported, hydrogen chemisorption

Rhodium catalysts transition metal carbon-hydrogen

Rhodium catalysts with wide-bite-angle

Rhodium catalysts, Wilkinson

Rhodium catalysts, Wilkinson catalyst

Rhodium catalysts, also

Rhodium catalysts, for hydrogenation

Rhodium catalysts, for methanol carbonylation

Rhodium catalysts, hydrosilylation using

Rhodium catalysts, supported

Rhodium catalyzed asymmetric imine hydrogenation catalysts

Rhodium chiral dirhodium catalysts

Rhodium chloride catalyst

Rhodium complex as catalyst

Rhodium complex catalysts

Rhodium complex catalysts asymmetric

Rhodium complex catalysts cationic diene complexes

Rhodium complex catalysts hydroformylation

Rhodium complex catalysts hydrogenation

Rhodium complex catalysts hydrosilation

Rhodium complex catalysts mechanism

Rhodium complex catalysts methanol carbonylation

Rhodium complex catalysts phosphine complexes

Rhodium complex catalysts supported complexes

Rhodium complexes catalyst, cyclization

Rhodium complexes oxidation catalysts

Rhodium complexes, catalysts based

Rhodium dendrimer supported catalysts

Rhodium honeycomb catalyst microstructure

Rhodium honeycomb catalyst microstructure device

Rhodium hydroboration catalyst

Rhodium hydroformylation catalysts

Rhodium hydroformylation catalysts phosphine modified

Rhodium hydroformylation catalysts unmodified

Rhodium hydrogenation catalyst

Rhodium hydrogenation catalysts, enantiomeric

Rhodium hydrogenolysis catalyst

Rhodium isomerization catalyst

Rhodium ligand-modified catalysts

Rhodium oxide-supported metal catalysts

Rhodium phosphine catalyst, hydroformylation

Rhodium phosphine catalysts, chiral

Rhodium phosphine complex catalyst

Rhodium phosphine complexes as catalysts

Rhodium phosphine-free catalyst

Rhodium triphos catalyst

Rhodium(l) Catalysts

Rhodium, active automotive exhaust catalysts

Rhodium, aromatic hydrogenation catalyst

Rhodium, bis catalyst

Rhodium, bis catalyst hydrosilation

Rhodium, chloro catalyst

Rhodium, chloro tris catalyst

Rhodium, chlorotris catalyst

Rhodium, chlorotris catalyst decarbonylation

Rhodium, chlorotris catalyst silane reaction with carbonyl compounds

Rhodium, chlorotris hydrogenation catalyst

Rhodium, chlorotris hydrogenation catalyst alkenes

Rhodium, chlorotris hydrogenation catalyst reduction

Rhodium-BINAPHOS catalyst system, hydroformylation

Rhodium-DlOP catalyst

Rhodium-acetate catalysts, oxidation

Rhodium-alumina catalysts

Rhodium-alumina catalysts reactions over

Rhodium-based catalyst systems

Rhodium-catalyzed hydroformylation catalysts containing

Rhodium-catalyzed hydroformylation water-soluble catalysts

Rhodium-chiral amide catalysts

Rhodium-chiral phosphine catalysts homogeneous

Rhodium-chiral phosphine catalysts imines

Rhodium-cobalt complex catalyst

Rhodium-palladium hydrogenation catalyst

Rhodium-phosphine catalysts

Rhodium-phosphine catalysts achiral

Rhodium-phosphine catalysts asymmetric hydrogenation

Rhodium-phosphite catalysts

Rhodium-ruthenium catalysts

Rhodium-ruthenium catalysts concentrations

Rhodium-ruthenium catalysts groups

Rhodium-ruthenium catalysts product selectivity

Rhodium-ruthenium catalysts studies

Rhodium-ruthenium catalysts temperature-dependence

Rhodium-silica, catalysts, structure

Rhodium-xantphos catalyst system

Rhodium/alumina catalysts, carbon

Rhodium/iodide catalyst

Rhodium/silica catalysts

Rhodium/titania catalysts

Rhodium/titania catalysts hydrogen

Rhodium/titania catalysts preparation

Ruhrchemie water-soluble rhodium catalyst

Selectivity rhodium catalysts

Silane, triethylionic hydrogenation rhodium catalysts

Styrenes, rhodium catalysts

Supported catalysts rhodium complexes

Suzuki-Miyaura reaction rhodium catalysts

The Application of DuPHOS Rhodium(l) Catalysts for Commercial Scale Asymmetric Hydrogenation

The Rhodium Catalyst System

Transition metal catalysts with rhodium

Tris rhodium catalyst

Tris rhodium chloride hydrogenation catalyst

Two-Phase (Water-Soluble) Rhodium Hydroformylation Catalysts

Unsaturaled compounds catalysts, rhodium complexes

Unsaturated compounds catalysts, rhodium complexes

Water-soluble catalyst, rhodium-phosphine

Water-soluble catalyst, rhodium-phosphine complex systems

Water-soluble rhodium catalyst

Water-soluble rhodium hydroformylation catalysts

Wilkinsons catalyst tris rhodium

© 2024 chempedia.info