Raney nickel, defined

UHV surface analysis, apparatus designs, 36 4-14 see also Ultrahigh vacuum surface analysis mechanisms, 32 313, 319-320 Modified Raney nickel catalyst defined, 32 215-217 hydrogenation, 32 224-229 Modifying technique of catalysts, 32 262-264 Modulated-beam mass spectrometry, in detection of surface-generated gas-phase radicals, 35 148-149 MojFe S CpjfCOlj, 38 352 Molar integral entropy of adsorption, 38 158, 160-161... 

Piperidine-type metacyclophane alkaloids have four chiral carbon atoms C-3, C-5, C-9, and C-ll. With 96 in hand, Fujita et al. hydrogenated its pyridine ring over Adams catalyst and Raney nickel in order to define the relative stereochemistry of C-5 and C-9. They obtained a single crystalline hexahydro derivative in quantitative yield. Catalytic hydrogenation of substituted pyridines generally results in cis products. Therefore, one can assume the cis relationship of C-5 and C-9 hydrogens in the foregoing... 

The N-hydroxy structure (26) was preferred123 to an iV-oxide representation on account of the amphoteric nature of the product and because the derived acetate formed a well-defined hydrochloride salt. Hydrogenation of these N-hydroxyimidazoles over Raney nickel gives imidazoles in 60-94% yields.122 The reaction has been adapted for the preparation of 4-mercaptoimidazoles, using an a-ketothionamide (27) with an aldimine.124... 

Raney Nickel is a good reducing agent, capable of converting a nitro group to an amine (the mechanism is not well defined, but leads to the addition of hydrogen). 

Studies on HOR electrocatalysis have built up a foundation for all modem electrocatalysis. Since the pioneering work of the 1960s, when flie dependence of hydrogen adsorption upon the crystallographic orientation of the platinum surface was discovered, the study of the relationship between electrochemical activity and surface structure has been the main theme of electrochemical research [50]. In this section, we first introduce the electrocatalysis of the HOR on Pt and Pt-alloy electrodes, with detailed discussion of the stmcture-sensitivity of hydrogen adsorption on well-defined Pt surfaces. Then we discuss two types of non-noble catalysts for the HOR carbides and Raney nickels. 

Physicochemical properties (metallic surface area, total surface area) of Raney Nickel catalysts prepared from well defined precursor alloys were related to the metallurgical structures of these alloys. The microstructure of the catalysts was correlated with the physicochemical characteristics and their activities for hydrogenation of acetophenone in the liquid phase. 

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