Hydrogen catalytic functions performed

Although Ru(OCOCH3)2(binap) exhibits excellent catalytic performance on asymmetric hydrogenation of functionalized olefins, it is feebly active for reaction of ketones. This failure is due to the property of the anionic ligands. Simple replacement of the carboxylate ligand by halides achieves high catalytic activity for reaction of functionalized ketones. 

In order to follow the catalytic recovering produced by the burning of coke, partially regenerated catalyst samples were submitted to standard reaction tests for benzene hydrogenation (metallic function) and normal pentane isomerization (acid function). Benzene hydrogenation was done at 423 K, 0.1 MPa, WHSV = 2 h 1, and molar ratio H2/Bz = 20. 200 mg of catalyst were loaded, which was reduced at 533 K with H2 for 2 h before the test. The isomerization of n-pentane was performed at 773 K, 0.1 MPa, WHSV = 2 h 1 and molar ratio H n = 6. 200 mg of catalyst were loaded, and were reduced with hydrogen at 773 K for 2 h before the test. 

Vanadium pentoxide and mercuric oxide were used as catalysts for the hydrogen peroxide oxidation of bis(phenylthio)methane to its monooxide 17a31 (equation 5). From the synthetic point of view, it is interesting to note that vanadium pentoxide, in addition to its catalytic action, functions also as an indicator in this reaction. In the presence of hydrogen peroxide, the reaction mixture is orange while in the absence of hydrogen peroxide a pale yellow colour is observed. Thus, it is possible to perform the oxidation process as a titration ensuring that an excess of oxidant is never present. 

Most catalysts originally developed for C=C bonds show a rather poor performance for the hydrogenation of many ketones. However, this situation changed dramatically when it was found that selected Ru-binap and later Ru-binap-dia-mine complexes achieve excellent enantioselectivities, as well as very high TONs and TOFs, for a variety of ketones [92]. Since then, it has been demonstrated that many a- and yS-functionalized, as well as aromatic ketones, are suitable substrates for hydrogenation with industrially viable catalytic results. For the reduction of various ketones biocatalytic methods are an industrially viable alternative to chemocatalysts [15]. 

When the membrane performs only a separation function and has no catalytic activity, two membrane properties arc of importance, the permeability and the selectivity which is given by the separation factor. In combination with a given reaction, two process parameters are of importance, the ratio of the permeation rate to the reaction rate for the faster permeating component (c.g. a reaction product such as hydrogen in a dehydrogenation reaction) and the separation factors (permselectivities) of all the other components (in particular those of the reactants) relative to the faster permeating gas. These permselectivities can be expressed as the ratios of the permeation rates of... 

Figure 1.33 illustrates asymmetric hydrogenation of a functionalized imine with a XYLIPHOS-Ir catalyst, occurring with a catalyst turnover number of 2,000,000. The presence of I under acidic conditions is crucial to achieve high catalytic performance. (5)-Metolachlor, a herbicide, is industrially produced in a > 10,000-ton quantity per year by this reaction. 

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