Hydrogenation cyclopentadiene

Coupling of dehydrogenation of isopropyl alcohol and hydrogenation of cyclopentadiene Hydrogenation of acetylene and ethylene... 

Hydrogenation of cyclopentadiene Hydrogenation of nitrobenzene Hydrogenation of naphthalene to tetraline... 

Decomposition of hydroiodic acid Hydrogenation of 1,3-pentadiene, isoprene, cyclopentadiene to corresponding olefines Hydrogenation of ethylene Hydrogenation of 2,4-dinitrophenol to 2,4-diaminophenol Coupling of bomeol dehydrogenation and cyclopentadiene hydrogenation... 

N.N. Michalenko, E.V. Khrapova, and V.M. Gryaznov, Effect of hydrogen transfer through the membrane catalyst from the Pd-Ru alloy on the rate of isopropanol dehydrogenation and cyclopentadiene hydrogenation, Neftekhimiya 18 354 (1978). 

The obtained catalysts showed similar activity in cyclopentadiene hydrogenation. The selectivity data in cyclopentadiene hydrogenation are given in Table I. The selectivity of consecutive reaction was determined as a rate ratio of cyclopentene/cyclopentane formation. On the contrary, the chitosan modification influenced essentially the selectivity of the catalyst on it basis. 

Nevertheless, it is necessary to return to the main point of interest here, which is the effect of deactivat ion and the accumulation of carbonaceous species on the Pt surface on the structure sensitivity or insensitivity exhibited (as inferred from the dependence of K on the platinum surface area)- Turnover numbers so calculated after 10 min reaction time decrease rapidly with increasing platinum surface area in a hyperbolic manner (and increase almost linearly with the mean platinum particle size) for reactions followed at both 3L3K and 295K, in contrast to the results obtained by Boudart over a narrower range of Pt surface area, Such behaviour very unusual but has been reported for structure sensitivity in cyclopentadiene hydrogenation on supported copper. However, the turnover numhers were almost independent of platinum surface area and... 

The solvent effect on the diastereofacial selectivity in the reactions between cyclopentadiene and (lR,2S,5R)-mentyl acrylate is dominated by the hydrogen bond donor characteristics of the solvent... 

Breslow studied the dimerisation of cyclopentadiene and the reaction between substituted maleimides and 9-(hydroxymethyl)anthracene in alcohol-water mixtures. He successfully correlated the rate constant with the solubility of the starting materials for each Diels-Alder reaction. From these relations he estimated the change in solvent accessible surface between initial state and activated complex " . Again, Breslow completely neglects hydrogen bonding interactions, but since he only studied alcohol-water mixtures, the enforced hydrophobic interactions will dominate the behaviour. Recently, also Diels-Alder reactions in dilute salt solutions in aqueous ethanol have been studied and minor rate increases have been observed Lubineau has demonstrated that addition of sugars can induce an extra acceleration of the aqueous Diels-Alder reaction . Also the effect of surfactants on Diels-Alder reactions has been studied. This topic will be extensively reviewed in Chapter 4. 

Both resonance forms of the allylic carbocation from 1 3 cyclopentadiene are equivalent and so attack at either of the carbons that share the positive charge gives the same product 3 chlorocyclopentene This is not the case with 1 3 butadiene and so hydrogen halides add to 1 3 butadiene to give a mixture of two regioisomeric allylic halides For the case of electrophilic addition of hydrogen bromide at -80°C... 

Table 3 provides typical specifications for isoprene that are suitable for Al—Ti polymerization (89). Traditional purification techniques including superfractionation and extractive distillation are used to provide an isoprene that is practically free of catalyst poisons. Acetylenes and 1,3-cyclopentadiene are the most difficult to remove, and distillation can be supplemented with chemical removal or partial hydrogenation. Generally speaking distillation is the preferred approach. Purity is not the main consideration because high quaUty polymer can be produced from monomer with relatively high levels of olefins and / -pentane. On the other hand, there must be less than 1 ppm of 1,3-cyclopentadiene. 

These acids (51) are organic molecules that contain a plurality of cyano groups and are readily ionized to hydrogen ions and resonance-stabilized anions. Typical cyanocarbon acids are cyanoform, methanetricarbonitrile (5) 1,1,3,3-tetracyanopropene [32019-26-4] l-propene-l,l,3,3-tetracarbonitrile (52) 1,1,2,3,3-pentacyanopropene [45078-17-9], l-propene-l,l,2,3,3-pentacarbonitrile (51) l,l,2,6,7,7-hexacyano-l,3,5-heptatriene [69239-39-0] (53) 2-dicyanomethylene-l,l,3,3-tetracyanopropane [32019-27-5] (51) and l,3-cyclopentadiene-l,2,3,4,5-pentacarbonitrile [69239-40-3] (54,55). Many of these acids rival mineral acids in strength (56) and are usually isolable only as salts with metal or ammonium ions. The remarkable strength of these acids results from resonance stabilization in the anions that is not possible in the protonated forms. 

Cyclopentadiene has also been oxidized by singlet oxygen to 4,5-epoxypenten-2-al-l, cis and trans isomers. These compounds and their hydrogenated diol products are claimed as useful intermediates as cross-linking agents, and in the production of pesticides and perfumes (34). 

Dehydrogenation processes in particular have been studied, with conversions in most cases well beyond thermodynamic equihbrium Ethane to ethylene, propane to propylene, water-gas shirt reaction CO -I- H9O CO9 + H9, ethylbenzene to styrene, cyclohexane to benzene, and others. Some hydrogenations and oxidations also show improvement in yields in the presence of catalytic membranes, although it is not obvious why the yields should be better since no separation is involved hydrogenation of nitrobenzene to aniline, of cyclopentadiene to cyclopentene, of furfural to furfuryl alcohol, and so on oxidation of ethylene to acetaldehyde, of methanol to formaldehyde, and so on. 

Subsbtuting vinylic hydrogen in a,P-unsaturated carbonyl compounds with vinylic fluonne does not affect their dienophilic character negatively Indeed, 3,3-difluoroacrylic acid is more reactive toward furan than its nonfluonnated counterpart [95] (equation 81) Consistent with this observation is the fact that tctrafluorobenzoquinone forms only a bis-Diels-Alder adduct m 68% yield in its reaction with cyclopentadiene at room temperature [96, 97 ... 

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