Ruthenium on charcoal

A solution of 20 g of estradiol in 500 ml of ethanol containing 1 ml of 40 % sodium hydroxide is hydrogenated over 5 g of ruthenium oxide or 3-5 g of 5% ruthenium-on-charcoal at 65° and 1500 psi. After filtration and evaporation, the residue is recrystallized to give 80% of 5a, 10a-estrane-3j9, 17 -diol. °... 

As described in U.S. Patent 3,025,292, the desired product may be made by hydrogenation of chlorothiazide. Three grams of 6-chloro-7-sulfamyl-1,2,4-benzothiadiazine-1,1-dioxide (chlorothiazide) is suspended in 100 ml of methanol. Then 1.0 gram of a 5% ruthenium on charcoal catalyst is added, and the mixture is reduced at room temperature and at an initial hydrogen pressure of 39 psig. The theoretical amount of hydrogen to form the 3,4-dihydro derivative is absorbed after a period of about 10 hours. 

N-Methyl-2-pyrrolidone Ferric chloride hexahydrate Glycol monomethyl ether Lithium aluminum hydride Ruthenium on charcoal Magnesium ethoxide 4-Toluenesulfonic acid Sodium bicarbonate 1,2,3,4-Tetrafluoro benzene Palladium on charcoal Cyclopropylamine N-benzylimide... 

Both Ru02 and 5% ruthenium-on-charcoal catalyse the aerobic oxidation of activated alcohols such as allylic alcohols [109] and a-ketols [110] (Eq. 27). 

Ruthenium on charcoal and randomly methylated p-cyclodextrin has been used as a recyclable catalyst system to form Qxs in water from benzoin and 1,2-diamines (Scheme 2.12) [88]. Molecular oxygen has been used perhaps to facilitate in situ formation of the 1,2-diketone from the benzoin and the final delydrogenation. 

Although palladium or platinum on charcoal are widely used, there is a preference for homogeneous reactions on both the laboratory and the industrial scale. Complexes of ruthenium (II) and rhodium (I), particularly with phosphine ligands, do have some importance in special applications [4], but... 

RuCNC heterobi metal lie ruthenium/cobalt nanoparticle immobilized on charcoal. 2-Pyridylmethyl formate is used. 

A. Catalysts The catalysts studied consisted of 5 wt. % of metal (rhodium or ruthenium) on either activated alumina powder or activated charcoal. All catalysts were commercial preparations. The metal was present in the reduced form. 

Recently, taking advantage of the very narrow size distribution of the metal particles obtained, microemulsion has been used to prepare electrocatalysts for polymer electrolyte membrane fuel cells (PEMFCs) Catalysts containing 40 % Pt Ru (1 1) and 40% Pt Pd (1 1) on charcoal were prepared by mixing aqueous solutions of chloroplatinic acid, ruthenium chloride and palladium chloride with Berol 050 as surfactant in iso-octane. Reduction of the metal salts was complete after addition of hydrazine. In order to support the particles, the microemulsion was destabilised with tetrahydrofurane in the presence of charcoal. Both isolated particles in the range of 2-5 nm and aggregates of about 20 nm were detected by transmission electron microscopy. The electrochemical performance of membrane electrode assemblies, MEAs, prepared using this catalyst was comparable to that of the MEAs prepared with a commercial catalyst. 

Other ruthenium-based catalysts for the aerobic oxidation of alcohols have been described where it is not clear if they involve oxidative dehydrogenation by low-valent ruthenium, to give hydridoruthenium intermediates, or by high-valent oxoruthenium. For example, both RUO2 and 5% Ru-on-charcoal catalyze the aerobic oxidation of activated alcohols such... 

A water-soluble ruthenium complex, HRu(C0)Cl(TPPMs)3-2H20, was used for hydrogenation of olefins in the biphasic system decalin-water [155], Ruthenium catalyst immobilized on a hydrophilic microporous resin turned out to be more selective for partial hydrogenation of benzene to cyclohexene than the same catalyst immobilized on charcoal. 

As an alternative to palladium and ruthenium catalysts as racemization agents, De Vos and coworkers reported the use of Raney nickel for the DKR of aliphatic amines in toluene and a low pressure of hydrogen (0.01-0.02 MPa) at 70 °C. Its combination with CAL-B and EtOAcMeOAc led to the desired (R)-methoxyacetamides in 64—98% conversion and 80-98% ee [245], The production of optically active amines has been also possible using ketoximes instead of racemic amines as starting materials, and using metal catalysis for the racemization step. Thus, Kim and coworkers reported the asymmetric reductive acylation a system including the use of palladium on charcoal for the reduction/racemization sequence in combination with CAL-B, 2 equivalents of EtOAc, three equivalents of diisopropylethylamine, and 1 Hjatm in toluene at... 

Mossbauer studies of the impregnation of silica with ruthenium chloride solution and subsequently dried at 383 K have reported (59) the presence of a ruthenium surface complex resembling RuC13 xH20. Recent work (128) has shown that Mossbauer spectra of "Ru supported on alumina, silica, activated charcoal, and X- and Y-zeolite are sensitive to the nature of the preparation and treatment of the samples. 

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