727. Synthetical applications of activated metal catalysts. Part XV. The catalytic toxicities of the phenyl derivatives of the typical elements of groups V, VI, and VII, and their hydrogenolysis by W-7 Raney nickel

1962 ◽  
pp. 3746 ◽  
Author(s):  
G. D. F. Jackson ◽  
W. H. F. Sasse
Keyword(s):  
Raney Nickel ◽  
Metal Catalysts ◽  
Derivatives Of

Synthetical applications of activated metal catalysts. XXV. The hydrogenolysis of some phenyl derivatives of silicon by Raney nickel

1966 ◽  
Vol 19 (10) ◽  
pp. 1897 ◽  
Author(s):  
WHF Sasse ◽  
KO Wade
Keyword(s):  
Raney Nickel ◽  
Silicon Atom ◽  
Atmospheric Pressure ◽  
Nickel Catalysts ◽  
Metal Catalysts ◽  
Derivatives Of ◽  
Related Compounds ◽  
Raney Cobalt

Tetraphenylsilane and 11 related compounds have been cleaved by treatment at atmospheric pressure with Raney nickel catalysts to give mixtures of benzene and cyclohexane. Yields exceeding 90% are obtained with degassed Raney nickel and silanes. Silanols and siloxanes are less readily spilt. The presence of methanol in the reaction mixtures retards the fission of silicon-phenyl bonds. Tetracyclo-hexylsilane, cyclohexyltrimethylsilane, and hexa(n-hexyl)disiloxane did not react detectably with Raney nickel. Raney cobalt had no effect on tetraphenylsilane. A mechanism for the new reaction is discussed which involves chemisorption via the silicon atom, ejection of a phenyl anion, and hydrogenolysis of the absorbed triphenylsilyl species.

Synthetical Applications of Activated Metal Catalysts. XVI. The Role of Hydrogen in the Formation of 2,2'-Bipyridyl from Pyridine under the Influence of Degassed Raney Nickel

1963 ◽  
Vol 16 (1) ◽  
pp. 14 ◽  
Author(s):  
WHF Sasse ◽  
CP Whittle
Keyword(s):  
Raney Nickel ◽  
Nickel Catalysts ◽  
Nickel Atom ◽  
Metal Catalysts ◽  
Published Data ◽  
Hydrogen Atoms ◽  
Adsorbed Pyridine

The efficiency of W7 Raney nickel catalysts degassed between 30 and 400�C in the preparation of 2,2'-bipyridyl has been examined. The highest activities are observed with catalysts which have been degassed at 200�C, and these catalysts arc up to 20% more efficient than catalysts previously used and degassed at 100�C. The results obtained are compared with published data concerning the hydrogen contents of degassed Raney nickel catalysts (Kokes and Emmett 1959, 1960). This shows that catalysts which are virtually free of hydrogen are only 25% less efficient than catalysts degassed at l00�C (containing 65 to 70% of their original hydrogen). Because of this finding a new mechanism is proposed in which the adsorbed pyridine is activated by the transfer of an electron from the catalyst. On stereochemical grounds it is proposed that meso-2,2'-dihydro-2,2'-bipyridyl with axially disposed hydrogen atoms at the 2,2'-positions and bonded via both nitrogen atoms to one nickel atom is the energetically most favoured intermediate.

SYNTHESES DE LA DL-PROLINE A PARTIR DE L'α-PIPERIDONE

1950 ◽  
Vol 28b (6) ◽  
pp. 245-255 ◽  
Author(s):  
Roger Gaudry ◽  
Louis Berlinguet
Keyword(s):  
Raney Nickel ◽  
Alkaline Solution ◽  
Low Pressure ◽  
Valeric Acid ◽  
Derivatives Of

By treatment of α-piperidone with sulphuryl chloride,β,β′-dichloro-α-piperidone was obtained. It was hydrolyzed to α,α′-dichloro-δ-amino-n-valeric acid, which was simultaneously reduced and cyclized to DL-proline, by low pressure hydrogenation, using Raney nickel, in alkaline solution. All the intermediate compounds were identified and characterized. The over-all yield of DL-proline is 33% calculated from α-piperidone.α-Piperidone was hydrolyzed to δ-amino-n-valeric acid, and the δ-phenylureido-n-valeric and δ-phthalimido-n-valeric acids were prepared. Halogenation of δ-phthalimido-n-valeric acid gave excellent yields of the α-bromo and α-chloro acids. These acids were hydrolyzed to the α-halogenated-δ-aminoacids. On treatment with alkali, they gave DL-proline in 56% and 50% yields respectively, from α-piperidone.Halogenation of δ-phenylureido-n-valeric acid gave the dibromo and the dichloro acids, which ring-close immediately into derivatives of α-piperidone.The different behavior of δ-benzoylamino, δ-phthalimido, and δ-phenylureido derivatives of n-valeric acid with halogens, or halogenating agents is noted.

Isotherme d'adsorption du phénanthrène et de ses dérivés hydrogénés sur du nickel de Raney

1989 ◽  
Vol 67 (3) ◽  
pp. 365-368 ◽  
Author(s):  
François Bossányi ◽  
Chakib Ameziane Hassani ◽  
Hugues Ménard ◽  
Jean Lessard
Keyword(s):  
Raney Nickel ◽  
Adsorption Isotherms ◽  
Hydrogen Atoms ◽  
Position And Orientation ◽  
Derivatives Of

The adsorption isotherms of phenanthrene and its hydrogenated derivatives, of naphthalene, and of tetralin on Raney nickel have been determined by chromatographic studies. The adsorption of these molecules on Raney nickel depends on the number of π electrons and on the position and orientation of hydrogen atoms that can interfere with the interaction of the π electrons with the catalyst. Keywords: adsorption, phenanthrene, chromatographic studies.

Raney metal catalysts: I. comparative properties of raney nickel proceeding from Ni-Ai intermetallic phases

1984 ◽  
Vol 9 (1) ◽  
pp. 69-83 ◽  
Author(s):  
S. Sane ◽  
J.M. Bonnier ◽  
J.P. Damon ◽  
J. Masson
Keyword(s):  
Raney Nickel ◽  
Intermetallic Phases ◽  
Metal Catalysts

Desulfuration of steroidal thians

1982 ◽  
Vol 47 (11) ◽  
pp. 3148-3159 ◽  
Author(s):  
Alexander Kasal
Keyword(s):  
Raney Nickel ◽  
Optimum Conditions ◽  
Unsaturated Esters ◽  
Aprotic Medium ◽  
Derivatives Of ◽  
By Products

The reaction of 4-thia-5-cholesten-3-one (X) with Raney nickel in protic medium affords alcohol III, while A-nor-5β-cholestan-3-one (XXIII), A-bisnor-2,5-secocholestane (XXXI) and the esters of the type XVIII are formed as by-products. When aprotic medium is used compounds XXIII and XXXI are the main products. During desulfuration with a less active Raney nickel the mentioned substances are accompanied by 5-unsaturated derivatives of the type I, XIV and XXIX. Optimum conditions for the preparation of either saturated alcohols of type III or of unsaturated esters of type XIV were found.

Synthetical applications of activated metal catalysts. XXII. The desulphurization of 2,5-Diphenyl-1,4-dithiin

1964 ◽  
Vol 17 (3) ◽  
pp. 353 ◽  
Author(s):  
GM Badger ◽  
P Cheuychit ◽  
WHF Sasse
Keyword(s):  
Raney Nickel ◽  
Hydrogen Content ◽  
Metal Catalysts ◽  
Hydrocarbon Fraction ◽  
Sulphur Atom ◽  
Cis And Trans

The desulphurization of 2,5-diphenyl-1,4-dithiin (II) with a hydrogen-poor Raney nickel (W-7J Raney nickel) has been shown to give 2,4-diphenylthiophen together with three hydrocarbons, viz. cis- and trans-1,3-diphenylbuta-1,3-diene, and 1,3-diphenylcyclobut-1-ene. In another experiment with a Raney nickel having a higher hydrogen content, the hydrocarbon fraction was found to be 1,3-diphenylbut-2- ene. It has been concluded that chemisorption via one sulphur atom leads to 2,4-diphenylthiophen, but that chemisorption via both sulphur atoms leads to the intermediate diradicals (VI) which subsequently react further to give the observed hydrocarbon products.

Chemistry of the Podocarpaceae. L. Conversion of 12-Hydroxypodocarpa-8,11,13-trien-19-oic acid (podocarpic acid) into 19-Hydroxypodocarp-8(14)-en-13-one

1974 ◽  
Vol 27 (11) ◽  
pp. 2413 ◽  
Author(s):  
RC Cambie ◽  
RC Hayward ◽  
AW Missen
Keyword(s):  
Nickel Catalyst ◽  
Raney Nickel ◽  
Raney Nickel Catalyst ◽  
Derivatives Of

Detosylations of derivatives of methyl 12-toluene-p- sulphonyloxypodocarpa-8,11,13-trien-19-oate have been investigated using a modified W-7 Raney nickel catalyst. The final steps in a conversion of podocarpic acid (1) into (+)-19-hydroxypodocarp-8(14)-en- 13-one (21), a useful intermediate for synthesis, have been effected.

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