Mechanism of dehydrogenation

The general problem of the mechanism of dehydrogenation in the yohimbine series has been discussed by Janot and Goutarel and by Julian, Magnani, Pikl and Karpel. ... 

The reaction of androst-4-ene-3,17-dione with DDQ in refluxing benzene or dioxane leads to the A -3-ketone as the major product, although small amounts of A -3-ketone and A -3-ketone are also produced. The latter arises from the A -3-ketone, since the A -3-ketone is not dehydrogenated further under the usual reaction conditions. A -3-Ketone production is more favored in benzene than it is in dioxane substituents at C-6 can also influence this selectivity. A recent thorough investigation of the mechanism of dehydrogenation of 3-ketones under neutral and acidic condi-... 

The double-labeling technique is also useful for in vitro studies on the mechanism of dehydrogenative polymerization of monolignols. 

T. Hayashi, M. Kuyama, E. Takizawa, and M. Hata, The mechanism of dehydrogenation of 2,4,5-triphenyl-4,5-dihydroimidazole over solid catalysts. Bull. Chem. Soc. Jpn. 1964, 37, 1702. 

In the discussion of the subject Balandin mentions (15) that Fischer previously postulated that methylene radicals may be produced as an intermediate in the formation of hydrocarbons by his method (116). This mechanism of carbon deposition on platinum supported on oxides of nickel and chromium (oxidized nichrome) through the intermediate formation of methylenes was thought by Balandin to be similar to the mechanism of dehydrogenation over this type of catalyst in that both occur on the boundaries of platinum-nickel and of platinum-chromia and were brought in agreement by him with his multiplet theory (26). 

The mechanism of dehydrogenation of aromatic compounds with dichlorodicyanoquinone (DDQ) is shown in Scheme 7,32. 

The problem all of these, seemingly contradictory views concerning the mechanism of dehydrogenation of cyclohexane was brightened by use of the method of tracers (carbon-14) in our studies together with Isagulyants and Derbentsev (91). 

In order to decide in each particular case which mechanism of dehydrogenation—the sextet or the doublet—takes place, it is evidently necessary to have criteria for both. In addition to the radioactive procedure... 

The mechanism of dehydrogenation and dehydrocyclyzation of alkanes on heterogeneous catalysts is connected with that of isomerization. Thus a study of the initial stages of propane activation over H-ZSM-5 zeolite by NMR, demon-... 

In order to develop pincer complexes into efficacious systems for alkane dehydrogenation, information regarding the mechanism of dehydrogenation within these systems is necessary. Specifically, Goldman, Krogh-Jespersen, and co-workers " " identified key steps in the dehydrogenation process, which include (i) the regioselectivity of... 

Crane, F.L. Beinert, H. (1956) J. Biol. Chem. 218, 717-731. On Ihe mechanism of dehydrogenation of fatty acid acyl coenzyme A the electron transferring flavoprotein. 

The mechanism of dehydrogenation involves the fundamental steps discussed in previous chapters of this book. The reaction mechanism includes oxidative addition of the C-H bond of the alkane, followed by p-hydrogen elimination of the resulting alkyl complex to generate the alkene product. Dissociation of the alkene and either reductive elimination of Hj or transfer of the hydrogen to a hydrogen acceptor regenerates the species that adds the alkane (Scheme 18.8). 

When TPSR was used to study the mechanism of dehydrogenation reaction of n-hexane on Pt/Al203 catalyst, the results showed that the reaction for n-hexane dehydrogenation cyclizating formation benzene may have different courses. 

Crane, F. L., and H. Beinert On the mechanism of dehydrogenation of fatty acyl derivatives of coencyme A. II. The electron-transferring flavoprotein. J. biol. Chem, 218, 717 (1956). 

Scheme 8 Proposed mechanism of dehydrogenative double phosphorylation of alkyne...

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