Copper catalysts fused

Plot of pMp° - p) against p/p° (r is expressed in cm (stp)). (1) Unpromoted Fe catalyst (2) AljOj-promoted Fe catalyst (3) AI2O3-KjO-promoted Fe catalyst (4) fused copper catalyst (5) chromium oxide gel (6) silica gel. (Courtesy Brunauer, Emmett and Teller.)... 

In contrast to the intermolecular cyclopropanation, the dirhodium tetraprolinates give modest enantioselectivities for the corresponding intramolecular reactions with the do-nor/acceptor carbenoids [68]. For example, the Rh2(S-DOSP)4-catalyzed reaction with al-lyl vinyldiazoacetate 32 gives the fused cyclopropane 33 in 72% yield with 72% enantiomeric excess (Eq. 4) [68]. The level of asymmetric induction is dependent upon the substitution pattern of the alkene cis-alkenes and internally substituted alkenes afford the highest asymmetric induction. Other rhodium and copper catalysts have been evaluated for reactions with vinyldiazoacetates, but very few have found broad utility [42]. 

Other reported syntheses include the Reimer-Tiemann reaction, in which carbon tetrachloride is condensed with phenol in the presence of potassium hydroxide. A mixture of the ortho- and para-isomers is obtained the para-isomer predominates. -Hydroxybenzoic acid can be synthesized from phenol, carbon monoxide, and an alkali carbonate (52). It can also be obtained by heating alkali salts of -cresol at high temperatures (260—270°C) over metallic oxides, eg, lead dioxide, manganese dioxide, iron oxide, or copper oxide, or with mixed alkali and a copper catalyst (53). Heating potassium salicylate at 240°C for 1—1.5 h results in a 70—80% yield of -hydroxybenzoic acid (54). When the dipotassium salt of salicylic acid is heated in an atmosphere of carbon dioxide, an almost complete conversion to -hydroxybenzoic acid results. They>-aminobenzoic acid can be converted to the diazo acid with nitrous acid followed by hydrolysis. Finally, the sulfo- and halogenobenzoic acids can be fused with alkali. 

Zhu and co-workers developed a palladium- and copper-catalyzed procedure for the synthesis of medium- and large-sized ring-fused dihydroazaphenanthrenes and l,4-benzodiazepine-2,5-diones. A distinctly different catal3ffic property of palladium and copper catalysts was uncovered that leads to the development of a divergent synthesis of two... 

Electrolysis of molten NaCl is also carried out on a large scale, yielding sodium metal at the cathode rather than hydrogen. Still other processes involve the electrolysis of fused magnesium chloride (MgCU) or the oxidation of hydrogen chloride by oxygen or air in the presence of a copper catalyst. 

By use of the versatile reactivity of the copper catalysts, the Ohno group expanded their three-component indole formation (Scheme 19.78) to a one-pot synthesis of diazepine-fused indoles [152]. After formation of 2-(aminomethyl)indoles 307 using 2-ethynyl-At-mesylanilines 305, formaldehyde, and 2-bromobenzylamines 288b, addition of NaOMe furnishes removal of Ms group and spontaneous copper-catalyzed N-arylation to produce indole-fused 1,4-diazepines 308 (Scheme 19.82). 

To date, the best results obtained for an iron catalyst in a slurry reactor have been reported by Kolbel with a precipitated iron catalyst promoted with potassium and copper.2 Current efforts in our laboratory have been aimed at developing a catalyst with activity and productivity superior to the catalyst used by Kolbel. Most research efforts have focused on precipitated and fused iron catalysts however, promising results have been reported for... 

Instead of BPA/DC monomer, the corresponding prepolymer was heated with BMI to obtain a binder [62], In a similar composition, p-toluenesulfonic acid was used as the cyanate/maleimide prereaction catalyst. For the crosslinking stage Zn octoate was added [63], Both BPA/DC and BMI can be used in the form of prepolymers. The binder for copper clad laminates contains, moreover, a saturated polyester, Zn octoate and powdered fused quartz [64],... 

Very simple experimental conditions (palladium(II) chloride (catalyst, 0.1 equivalent) copper(II) chloride (oxidant, 3 equivalents) and sodium acetate (buffer, 3 equivalents) in acetic acid under carbon monoxide at normal pressure and temperature) are necessary for this asymmetric route to saturated fused heterocycles with defined stereochemistry. 

Reaction of heteroaromatic thioketones 638 with the carbenoids, generated from phenyliodonium bis(phenylsul-fonyl)methane or bis(arylsulfonyl)diazomethanes in the presence of a copper acetylacetonate catalyst, affords heterocycle-fused [c]thiophenes 639. The reaction involves ring closure of the intermediary thiocarbonyl ylides and elimination of a sulfenic acid (Equation 33) <1995S87>. 

Fused and precipitated iron catalysts are used in the commercial Fischer-Tropsch plants in Sasolburg. These catalysts contain various promoters, such as copper, which facilitates reduction of the catalyst, KjO which enhances activity and oictm selectivity, and Si02 which increases the surface area of the catalyst (15]. Recent literature contains numerous reports aimed at improving catalyst activity and selectivity. 

The alcohol is first vaporized by passing it through coils heated to 80° to 90° C. and through a copper tube containing the catalyst and heated in a bath of fused potassium nitrate. The reaction products then pass through coolers where the water and alcohol are condensed while the ethylene is washed and led into storage vessels. 

Derivation By treatment of naphthalene in a fused state (above 100C) with hydrogen in the presence of a copper or nickel catalyst. 

Butanol is vaporized and passed over a copper catalyst08 for the purpose of dehydrogenation to aldehyde. The aldehyde is separated from the products by fractionation and oxidized to butyric acid in the liquid state with air or oxygen in the presence of a catalyst such as manganese butyrate. With a copper tube yi inch in diameter and packed for 26 inches with fused cupric oxide 240 cc. of butanol per hour may be treated with a 75 per cent conversion per pass.04 At temperatures of 220° to 280° C. the yields of aldehyde are good. At 370° C. only about one-sixth of the aldehyde that forms is decomposed. 

This conversion employs a boronic acid with a copper(ll) catalyst. The method was developed for reactions of heterocycles, including the V-arylation of isatin ° and of pyrazole, imidazole and their benzo derivatives (1,2,3-triazole, 1,2,4-triazole and 5-phenyltetrazole gave only very modest yields). These conditions also apply to the V-arylation of 2-pyridone (and various fused derivatives), 3-pyridazinones, indole-2-carboxylates and pyrrole-2-carboxylates. ... 

A novel ring-opening reaction of oxirans, catalysed by copper and pyridine, generates c/s-diols under mild conditions. The bicyclic epoxides (186 = 1 or 2) yield (187 n = 1) (95%) and (187 = 2) (85%) in neutral, phosphate-buffered, solution. This type of reaction may have some relevance to the metabolic pathways for fused aromatic compounds, which are thought to proceed via arene oxides and diol epoxides. The catalyst system may be used to add OH", Cr, or MeO regiospecifically to the benzylic centre of indene oxide, with proton addition to the oxygen atom of oxiran. 

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