- Efficient preparation and application of monodisperse palladium loaded graphene oxide as a reusable and effective heterogeneous catalyst for suzuki cross-coupling reaction
-
A homogeneously dispersed graphene oxide supported palladium nanomaterial (Pd?GO) has been successfully synthesized and used as a catalyst in cross-coupling reactions at room temperature. Various analytical techniques such as X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) were used to characterize the monodisperse Pd?GO. Monodisperse Pd?GO nanomaterials were used for the cross-coupling reactions which brought together organic molecules with functional significance. This catalyst showed superior catalytic activity and stability for these coupling reactions. High product yields, short reaction times and mild reaction conditions, obtained by the using of developed catalysts. Importantly, the catalyst can be used at least five experiments successfully without losing its efficiency.
- Diler, Fatma,Burhan, Hakan,Genc, Hayriye,Kuyuldar, Esra,Zengin, Mustafa,Cellat, Kemal,Sen, Fatih
-
-
- Continuous Synthesis of Aryl Amines from Phenols Utilizing Integrated Packed-Bed Flow Systems
-
Aryl amines are important pharmaceutical intermediates among other numerous applications. Herein, an environmentally benign route and novel approach to aryl amine synthesis using dehydrative amination of phenols with amines and styrene under continuous-flow conditions was developed. Inexpensive and readily available phenols were efficiently converted into the corresponding aryl amines, with small amounts of easily removable co-products (i.e., H2O and alkanes), in multistep continuous-flow reactors in the presence of heterogeneous Pd catalysts. The high product selectivity and functional-group tolerance of this method allowed aryl amines with diverse functional groups to be selectively obtained in high yields over a continuous operation time of one week.
- Ichitsuka, Tomohiro,Kobayashi, Shū,Koumura, Nagatoshi,Sato, Kazuhiko,Takahashi, Ikko
-
supporting information
p. 15891 - 15896
(2020/07/13)
-
- Rh-catalyzed selective synthesis of 1,5-dimethylhexahydro-1H-inden-4(2H)-one via hydroformylation of (R)-carvone
-
This work reports domino hydroformylation, hydrogenation and intramolecular keto-aldol condensation reactions for the selective synthesis of 1,5-dimethylhexahydro-1H-inden-4(2H)-one obtained from (R)-carvone and dihydrocarvone under homogeneous hydroformy
- Bhagade, Sachin S.,Bhanage, Bhalchandra M.
-
-
- Highly Selective Hydrogenation of Aromatic Ketones and Phenols Enabled by Cyclic (Amino)(alkyl)carbene Rhodium Complexes
-
Air-stable Rh complexes ligated by strongly σ-donating cyclic (amino)(alkyl)carbenes (CAACs) show unique catalytic activity for the selective hydrogenation of aromatic ketones and phenols by reducing the aryl groups. The use of CAAC ligands is essential for achieving high selectivity and conversion. This method is characterized by its good compatibility with unsaturated ketones, esters, carboxylic acids, amides, and amino acids and is scalable without detriment to its efficiency.
- Wei, Yu,Rao, Bin,Cong, Xuefeng,Zeng, Xiaoming
-
supporting information
p. 9250 - 9253
(2015/08/11)
-
- CATALYTIC HYDROGENATION USING COMPLEXES OF BASE METALS WITH TRIDENTATE LIGANDS
-
Complexes of cobalt and nickel with tridentate ligand PNHPR are effective for hydrogenation of unsaturated compounds. Cobalt complex [(PNHPCy)Co(CH2SiMe3)]BArF4 (PNHPCy=bis[2-(dicyclohexylphosphino)ethyl]amine, BArF4=B(3,5-(CF3)2C6H3)4)) was prepared and used with hydrogen for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (25-60° C., 1-4 atm H2). Nickel complex [(PNHPCy)Ni(H)]BPh4 was used for hydrogenation of styrene and 1-octene under mild conditions. (PNPCy)Ni(H) was used for hydrogenating alkenes.
- -
-
Paragraph 0035; 0053
(2015/12/07)
-
- High catalytic performance of palladium nanoparticles supported on multiwalled carbon nanotubes in alkene hydrogenation reactions
-
The synthesis of Pd nanoparticles (Pd-NPs) supported on multi-walled carbon nanotubes (MWCNTs) and the cataytic performance of the resulting material (Pd-NPs/MWCNTs) in hydrogenation reactions are presented. Facile preparation approaches based on the decomposition of Pd precursors in the presence of MWCNTs lead to homogeneous dispersions of supported Pd-NPs with an average size of 4 nm and Pd loads of about 12%. The catalytic performance of this material was evaluated in hydrogenation reactions of α,β-unsaturated ketones, alkenes, cyclic di-, tri- and tetraenes, aromatic compounds, terpenes and terpenoids, resulting in very high activity offering short reaction times, high conversion rates, notable selectivity, and acceptable recyclability under mild conditions.
- Cano, Manuela,Benito, Ana M.,Maser, Wolfgang K.,Urriolabeitia, Esteban P.
-
p. 1968 - 1972
(2013/10/08)
-
- Continuous flow hydrogenation using an on-demand gas delivery reactor
-
A continuous-flow approach to the hydrogenation of alkenes utilizing Wilkinson's catalyst is reported. The approach relies on a newly developed coil design in which it is possible to load gas and heat the reaction mixture simultaneously. The hydrogenation of various substrates has been performed successfully on small scale and can be scaled up substantially.
- Mercadante, Michael A.,Kelly, Christopher B.,Lee, Christopher,Leadbeater, Nicholas E.
-
supporting information; experimental part
p. 1064 - 1068
(2012/08/27)
-
- Mild and homogeneous cobalt-catalyzed hydrogenation of C=C, C=O, and C=N bonds
-
A cationic cobalt(II)-alkyl complex is an effective precatalyst for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (1-4 atm H2; see scheme). The catalyst shows a high functional-group tolerance across a broad range of substrates. Experiments suggest that the active catalytic species is a cobalt(II)-hydride complex. Copyright
- Zhang, Guoqi,Scott, Brian L.,Hanson, Susan K.
-
supporting information
p. 12102 - 12106
(2013/01/16)
-
- Advantageous heterogeneously catalysed hydrogenation of carvone with supercritical carbon dioxide
-
The hydrogenation of carvone was investigated for the first time in high-density carbon dioxide. The hydrogenation over 0.5 wt% Pd, or Rh, or Ru supported on alumina was found to be generally faster in a single supercritical (sc) phase (fluid reagents) than in a biphasic system (liquid + fluid reactants). The reaction with Pd produced fully hydrogenated products (isomers of carvomenthone) and carvacrol. The Rh catalyst was more selective and favoured carvomenthone isomers with higher selectivity and carvotanacetone as a secondary product. Additionally, the rhodium catalysed reaction exhibited high > 84% selectivity of carvotanacetone with the conversion of > 25% after only 2 min of reaction. The less active Ru catalyst gave significantly lower conversion and the product variety was greater as carvomenthone isomers, carvotanacetone and carvacrol were formed. The conversion and selectivity to carvomenthone within 2 h of the reaction starting followed the order: Pd > Rh > Ru and Rh > Pd > Ru, respectively. High conversion, and diverse and high selectivity accompanied by significant reduction in reaction time depending on the catalyst were achieved in supercritical CO2 compared with hydrogenation occurring in conventional organic solvents.
- Melo, Catarina I.,Bogel-Lukasik, Rafal,Da Silva, Marco Gomes,Bogel-Lukasik, Ewa
-
experimental part
p. 2825 - 2830
(2011/12/05)
-
- A recyclable nanoparticle-supported rhodium catalyst for hydrogenation reactions
-
Catalytic hydrogenation under mild conditions of olefins, unsaturated aldeydes and ketones, nitriles and nitroarenes was investigated, using a supported rhodium complex obtained by copolymerization of Rh(cod)(aaema) [cod: 1,5-cyclooctadiene, aaema-: deprotonated form of 2-(acetoacetoxy)ethyl methacrylate] with acrylamides. In particular, the hydrogenation reaction of halonitroarenes was carried out under 20 bar hydrogen pressure with ethanol as solvent at room temperature, in order to minimize hydro-dehalogenation. The yields in haloanilines ranged from 85% (bromoaniline) to 98% (chloroaniline).
- Dell'Anna, Maria Michela,Gallo, Vito,Mastrorilli, Piero,Romanazzi, Giuseppe
-
experimental part
p. 3311 - 3318
(2010/09/15)
-
- Use of Raman spectroscopy to characterize hydrogenation reactions
-
Raman spectroscopy was used to characterize hydrogenation reactions involving single-step and two-step processes. The Raman technique was shown to be well-suited for endpoint determination as well as process optimization. In this investigation, hydrogenation of cyclohexene to produce cyclohexane was used as a model system. Conditions were varied to determine the effect of catalyst loading, solvent ratios, and reactant concentrations. Four catalysts were evaluated. The kinetic profiles of each reaction process were determined for each of the catalysts. In one case, a side reaction leading to an intermediate was observed for the hydrogenation reaction when run under hydrogen-starved conditions. After these cyclohexene hydrogenations were characterized, Raman spectroscopy was applied to the conversion of carvone to tetrahydrocarvone and the hydrogenation of 2-(4-hydroxyphenyl) propionate. Raman was used to characterize the kinetics of these reactions and was also used to prove that two-step hydrogenation mechanisms occurred in each. Raman was shown to be useful for process understanding, process optimization, process monitoring, and endpoint determination. Accomplishment of these goals leads to better process controls upon transfer of the procedure to a process environment. This ultimately leads, in turn, to the mitigation of risk of making out-of-specification product in manufacturing.
- Tumuluri, Venkat S.,Kemper, Mark S.,Sheri, Anjaneyulu,Choi, Seoung-Ryoung,Lewis, Ian R.,Avery, Mitchell A.,Avery, Bonnie A.
-
p. 927 - 933
(2012/12/23)
-
- Poly(ethylene glycol) (400) as superior solvent medium against ionic liquids for catalytic hydrogenations with PtO2
-
Adams' catalyst in poly(ethylene glycol) (PEG) (400) has been found to be a superior solvent over the ionic liquids by severalfold in promoting the hydrogenation of various functional groups. Both the catalyst and PEG were recycled efficiently over 10 runs without loss of activity, and substrate cross contamination was not observed despite a change in the substrate four times.
- Chandrasekhar, Srivari,Prakash, Samala Jaya,Rao, Chennamaneni Lohitha
-
p. 2196 - 2199
(2007/10/03)
-
- An alternative to the Swern oxidation
-
A variety of alcohols have been oxidized under mild conditions by the DMSO-Ph3P·X2 complexes. The reaction does not produce any Pummerer product. A mechanism for the reaction is proposed.
- Bisai, Alakesh,Chandrasekhar,Singh, Vinod K.
-
p. 8355 - 8357
(2007/10/03)
-
- Catalytic Reaction. 1. Catalytic 1,4-Hydrogenation of α,β-Unsaturated Aldehydes and Ketones using SC-1 Nickel Boride
-
Ex-situ generated Sc-1 nickelboride (SC-1 Ni2B), prepared by refluxing nickel chloride and sodium borohydride in methanol, is used in the selective 1,4-hydrogenation of α,β-unsaturated ketones and aldehydes at one atmospheric pressure.Previous studies of in-situ generated Ni2B have had the disadvantage of the undesirable side reaction of sodium borohydride with the various functional groups.In contrast, our catalyst cleanly gives the corresponding saturated aldehyde or ketone with no detectable amounts of saturated alcohol.Furthermore, the degree of substitution of the double bond plays a significant role in the rate of hydrogenation.While unsaturated carbonyl compounds containing di- and tri- substituted duoble bonds are readily hydrogenated, tetrasubstituted double bond containing carbonyl compounds are highly unreactive.
- Belisle, Christopher M.,Young, Yvette M.,Singaram, Bakthan
-
p. 5594 - 5598
(2007/10/02)
-
- Triethylborane Induced Selective 1,4-Reduction of α,β-Unsaturated Carbonyl Compounds with Triphenyltin Hydride or Tributyltin Hydride
-
Reduction of α,β-unsaturated ketones and esters with triphenyltin hydride or tributyltin hydride in the presence of triethylborane has been studied.Whereas the reaction of α,β-unsaturated ketones (R1CH=CHCOR2) with triphenyltin hydride provided the corresponding saturated ketones (R1CH2COR2), treatment of α,β-unsaturated ester (PhCH=CHCOOMe or CH3CH=CHCOO-n-C6H13) afforded an adduct (PhCH2CH(SnPh3)COOMe or CH3CH(SnPh3)CH2COO-n-C6H13).
- Nozaki, Kyoko,Oshima, Koichiro,Utimoto, Kiitiro
-
p. 2585 - 2587
(2007/10/02)
-
- Selective reduction of hydroxy carbonyl to carbonyl compounds with trialkylborane/trifluoromethanesulfonic acid
-
Triethyl- or triisopropylborane/trifluoromethanesulfonic (triflic) acid is a convenient reagent for the selective reduction of hydroxy substituted carboxylic acids, ketones and aldehydes to yield the corresponding carbonyl compounds. The scope of the reaction, experimental conditions and suggested mechanism are discussed.
- Olah,Wu
-
p. 407 - 408
(2007/10/02)
-
- Electrocatalytic Hydrogenation Using Precious Metal Microparticles in Redox-Active Polymer Films
-
Glassy carbon felt electrodes have been modified by electrodeposition of poly(pyrrole-viologen) films (derived from N,N'-dialkyl-4,4'-bipyridinium salts), followed by electroprecipitation of precious metal (Pt, Pd, Rh, or Ru) microparticles.The resulting electrodes have been proved to be active for the electrocatalytic hydrogenation of conjugated enones (2-cyclohexen-1-one, cryptone, carvone, isophorone), styrene, and benzonitrile in aqueous media (pH 1).Despite low loading of metal catalysts, high electric and product yields and a long term stability of these cathodes have been observed.The influence of the metal loading and the polymer structure on the catalytic efficiency as well as the selectivity obtained according to the metal catalyst used have been studied.Comparision with results previously reported for other catalytic cathodes like Pt/Pt, Pd/C, or Raney nickel electrodes proves the high efficiency of these microparticles within redox polymer film based electrodes.
- Coche, Liliane,Ehui, Bernadette,Limosin, Daniele,Moutet, Jean-Claude
-
p. 5905 - 5910
(2007/10/02)
-
- ELECTROCATALYSE PAR DES FILMS DE POLYPYRROLES FONCTIONNALISES
-
In this paper are rewiewed the possibilities of the utilization of modified electrodes by N-substituted polypyrroles by mediator groups in terms of electrocatalysis.
- Deronzier, Alain
-
-
- Reduction of Organic Compounds with Rare-Earth Intermetallics Containing Absorbed Hydrogen
-
The hydrogenation of organic compounds with rare-earth intermetallic hydrides has been investigated.Alkynes,alkenes,aldehydes,ketones,nitriles,imines, and nitro compounds are hydrogenated in excellent yields with LaNi5H6 or LaNi4.5Al0.5H5 at 0-60 deg C.The present hydrogenation method has the following characteristic features. (1) The intermetallic compounds (alloys) are not poisoned by compounds containing an amino group or a halogen atom. (2) The alloys can be used repeatedly without decrease in activity. (3) The reaction conditions are mild, and selective hydrogenations of some organic functional groups can be achieved.The reaction mechanism of this hydrogenation is briefly discussed in terms of stereochemistry and H/D exchange reactions.
- Imamoto, Tsuneo,Mita, Takeshi,Yokoyama, Masataka
-
p. 5695 - 5699
(2007/10/02)
-
- ULTRASONICALLY IMPROVED REDUCTIVE PROPERTIES OF AN AQUEOUS Zn-NiCl2 SYSTEM - 2. REGIOSELECTIVITY IN THE REDUCTION OF (-)-CARVONE
-
While the previously described reductive system Zn-NiCl2 leads to the non-selective hydrogenation of the two olefinic bonds of (-)-carvone 1, the two selective hydrogenation products (+)-dihydrocarvone 2 and carvotaneacetone 3 are obtained in good yield with the same reagent under modified experimental conditions.
- Petrier, Christian,Luche, Jean-Louis
-
p. 2351 - 2352
(2007/10/02)
-
- REAGENTS ABD SYNTHETIC METHODS-40 HALOSILANES/CHROMIUM TRIOXIDE AS EFFICIENT OXIDIZING REAGENTS
-
Synthetic utility of halosilanes-chromium trioxide reagents as excellent new oxidizing agents is described.They are highly efficient for the oxidation of alcohols to carbonyl compounds, for the oxidative coupling of mercaptans intodisulfides and for a mild cleavage of oximes to carbonyl compounds.Chlorotrimethylsilane-chromium trioxide has been shown to be an efficient oxidizing agent for the conversion of arylmethanes to benzaldehydes.The reagent is applied to the oxidative cleavage of some benzyl esters.A mild procedure for the iodination of organic compounds by means of in situ generated iodonium species from this reagent and molecular iodine is also described.
- Aizpurua, J. M.,Juaristi, M.,Lecea, B.,Palomo, C.
-
p. 2903 - 2912
(2007/10/02)
-
- The Chemistry and Catalytic Properties of Ruthenium and Osmium Complexes. Part 1. Homogenous Catalysis of Organic Reactions by Bromo(carbonyl)hydrotris(triphenylphosphine)osmium(II)
-
The title compound catalyses C=C bond migration, isomerisation of allyl alcohol, hydrogenation of acyclic and cyclic olefins, dienes, acetylenes, aldehydes, ketones, α,β-unsaturated aldehydes and ketones, and hydroformylation of alkenes under moderate reaction conditions.High selectivities have been observed in the hydrogenation of conjugated and unconjugated dienes to monoenes, CC to C=C bonds, α,β-unsaturated aldehydes to unsaturated alcohols, and α,β-unsatuated ketones to saturated ketons; L-carvone may be selectively reduced to 2-methyl-5-(1-methylethyl)cyclohex-2-en-1-one or 2-methyl-5-(1-methylethyl)cyclohexanone depending on the reaction conditions.
- Sanchez-Delgado, Roberto A.,Andriollo, Antida,Gonzalez, Edgar,Valencia, Norma,Leon, Vladimir,Espidel, Jouseff
-
p. 1859 - 1864
(2007/10/02)
-
- PHOTOCHEMICAL TRANSFORMATIONS-IV. OXYFUNCTIONALIZATION OF SOME SATURATED HYDROCARBONS WITH HYDROXYL RADICALS
-
It is shown that hydroxylation of saturated hydrocarbons by hydrogen peroxide occurs under the influence of light.This reaction has been investigated on acyclic, monocyclic and bicyclic hydrocarbons.These reactions were also studied using performic acid as the source of hydroxyl radicals and results compared with those obtained with peracetic acid.As expected, the preferred attack was on tertiary centres, followed by secondary and then primary.
- Sharma, S. N.,Sonawane, H. R.,Dev, Sukh
-
p. 2483 - 2492
(2007/10/02)
-
- HYDROGENOLYSE EN PHASE LIQUIDE SUR Pd/C DES EPOXYDES DU CARVOMENTHENE ET DU LIMONENE
-
Hydrogenolysis over Pd/C of cis and trans epoxides of carvomenthene and limonene give a mixture of hydrocarbons, secondary and tertiary alcohols, and ketones in proportions dependent upon the nature of the starting material.In the limonene epoxides, the extracyclic double bond plays an important role in the opening of the oxirane ring through a common unsaturated tertiary alcohol intermediate by double bond migration, hydrogenation of which leads to the products.For the carvomenthene epoxides the results are similar to those found in the 4-t-butyl series with competition between cis addition and trans addition of hydrogen.The presence of the isopropenyl group leads to slower reaction rates in comparison with t-butyl analogues.
- Accrombessi, G.,Geneste, P.,Olive, J.-L.,Pavia, A. A.
-
p. 3135 - 3140
(2007/10/02)
-
- Silanes in Organic Synthesis. 9. Enesilylation as a Method for 1,2-Carbonyl Migration within Ketones and for Conversion to 1,2-Transposed Allylic Alcohols
-
Vinylsilanes are shown to be valuable synthetic intermediates in useful transformations of ketones.The epoxidation of vinylsilanes followed by lithium aluminium hydride reduction and oxidation with chromic acid and sulfuric acid in a two-phase (ether/water) system often gives high yields of 1,2-transposed ketones.With singlet oxygen and sequential sodium borohydride reduction, 2-trimethylsilyl alcohols are produced in which the α position of the parent ketone has been regiospecifically oxygenated.Fluoride ion promoted desilylation completes the conversion to the migrated allylic alcohol.
- Fristad, William E.,Bailey, Thomas R.,Paquette, Leo A.
-
p. 3028 - 3037
(2007/10/02)
-
- Metalation of 1,3-Dithiolanes. Mercaptan Synthesis and Carbonyl Transposition
-
The reaction of 1,3-dithiolanes with n-butyllithium results in fragmentation to the corresponding thiocarbonyl compound followed by furhter reaction with n-butyllithium.All four types of thiocarbonyl reactions are observed: reduction, S-addition, C-addition, double addition.Synthetic applications of this reaction for the synthesis of secondary mercaptans and 1,2-carbonyl transposition (23 -> 24a-c) are described.
- Wilson, Stephen R.,Georgiadis, Gregory M.,Khatri, Hiralal N.,Bartmess, John E.
-
p. 3577 - 3583
(2007/10/02)
-