Stereochemistry of the palladium catalyzed exchange of deuterium with allylic hydrogens. [Cholest-8(14)-en-3. beta. -ol]
Journal Article
·
· J. Catal.; (United States)
OSTI ID:7248986
- Univ. of Arkansas, Fayetteville
The stereochemistry of the palladium catalyzed exchange of deuterium with the allylic hydrogens of cholest-8(14)-en-3..beta..-ol,2, has been examined in a test of the Rooney, Gault, and Kemball hypothesis that a ..pi..-allylic surface intermediate is able to react directly with molecular hydrogen. The test compound was selected from evidence that only one face of the double bond is accessible to a catalytic surface. The correlation of mass, /sup 13/C nuclear magnetic resonance, and infrared spectral data shows that no more than one hydrogen atom in each allylic methylene group is replaced (C-7 and C-15). Because the RGK mechanism would require that both hydrogens should be replaced, it cannot be operating in this system. The isomerization of cholest-7-en-3..beta..-ol to 2 is catalyzed in benzene solutions by PdCl/sub 2/(C/sub 6/H/sub 5/CN)/sub 2/ but not by HRh(PPh/sub 3/)/sub 4/, which lends support to the hypothesis that ..pi..-allylic but not ''half-hydrogenated'' intermediates are involved in the related palladium-catalyzed isomerization and exchange reactions of these steroids.
- OSTI ID:
- 7248986
- Journal Information:
- J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 44:3; ISSN JCTLA
- Country of Publication:
- United States
- Language:
- English
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Tue Feb 04 23:00:00 EST 1997
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OSTI ID:460051
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· J. Catal.; (United States)
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OSTI ID:7147711
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Journal Article
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· J. Biol. Chem.; (United States)
·
OSTI ID:6101234
Related Subjects
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400104 -- Spectral Procedures-- (-1987)
400303* -- Organic Chemistry-- Isotope Exchange & Isotope Separation-- (-1987)
AROMATICS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CONDENSED AROMATICS
DEUTERIUM
ELEMENTS
HYDROGEN ISOTOPES
INFRARED SPECTRA
ISOMERIZATION
ISOTOPES
ISOTOPIC EXCHANGE
KINETICS
LIGHT NUCLEI
MAGNETIC RESONANCE
METALS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PALLADIUM
PLATINUM METALS
REACTION KINETICS
RESONANCE
SPECTRA
STABLE ISOTOPES
STEREOCHEMISTRY
STEROIDS
TRANSITION ELEMENTS
400104 -- Spectral Procedures-- (-1987)
400303* -- Organic Chemistry-- Isotope Exchange & Isotope Separation-- (-1987)
AROMATICS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CONDENSED AROMATICS
DEUTERIUM
ELEMENTS
HYDROGEN ISOTOPES
INFRARED SPECTRA
ISOMERIZATION
ISOTOPES
ISOTOPIC EXCHANGE
KINETICS
LIGHT NUCLEI
MAGNETIC RESONANCE
METALS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PALLADIUM
PLATINUM METALS
REACTION KINETICS
RESONANCE
SPECTRA
STABLE ISOTOPES
STEREOCHEMISTRY
STEROIDS
TRANSITION ELEMENTS