Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Reduction of benzophenone with metal hydrides. Kinetic isotope effect and substituent effect study

Journal Article · · J. Org. Chem.; (United States)
DOI:https://doi.org/10.1021/jo00239a014· OSTI ID:6254471
;

Carbonyl carbon kinetic isotope effects (KIEs) have been determined for the reduction of benzophenone-7-/sup 14/C with various metal hydrides at 25/degrees/C. The observed KIEs are as follows: BH/sub 3//THF, /sup 12/k//sup 14/k = 1.035 /plus minus/ 0.002; AlH/sub 3//Et/sub 2/O, 1.021 /plus minus/ 0.004; 9-BBN/THF, 1.027 /plus minus/ 0.004; DIBAL/hexane, 1.000 /plus minus/ 0.003; LiAlH/sub 4//THF, 1.017 /plus minus/ 0.007. The relative reactivities of ortho-, meta-, and para-substituted benzophenones with these reagents were also determined by the composition experiments. The absence of /sup 14/C KIE, the small sigma value (0.5), and the absence of steric rate retardation due to ortho substituents in the reduction of the ketone with DIBAL suggest that the reaction goes through the rate-determining electron transfer from DIBAL to the ketone. The reactions of other reducing agents showed positive KIE as well as a variable extent of steric effect and are concluded to proceed via a polar mechanism. The difference in the nature of the transition state is discussed on the basis of these results. 32 references, 6 figures, 2 tables.

Research Organization:
Osaka Univ. (Japan)
OSTI ID:
6254471
Journal Information:
J. Org. Chem.; (United States), Journal Name: J. Org. Chem.; (United States) Vol. 53:4; ISSN JOCEA
Country of Publication:
United States
Language:
English

Similar Records

Electron transfer in reactions of ketones with organolithium reagents. A carbon-14 kinetic isotope effect probe
Journal Article · Wed Jul 08 00:00:00 EDT 1987 · J. Am. Chem. Soc.; (United States) · OSTI ID:5890454
Kinetic isotope effect study of reductions of benzophenone with complex metal hydrides
Journal Article · Wed Oct 15 00:00:00 EDT 1986 · J. Am. Chem. Soc.; (United States) · OSTI ID:6995480
$sup 14$C dating by liquid scintillation counting on synthesized methanol and its application on wooden remnants in ejecta of the Fuji volcano
Journal Article · Mon May 01 00:00:00 EDT 1972 · Chishitsugaku Zasshi, v. 78, no. 5, pp. 235-239 · OSTI ID:4407121

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM HYDRIDES
BENZOPHENONE
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BORON COMPOUNDS
BORON HYDRIDES
CARBON 12
CARBON 14
CARBON ISOTOPES
DATA
EVEN-EVEN NUCLEI
EXPERIMENTAL DATA
FURANS
HETEROCYCLIC COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
ISOTOPE EFFECTS
ISOTOPES
ISOTOPIC EXCHANGE
KETONES
LIGHT NUCLEI
LITHIUM COMPOUNDS
LITHIUM HYDRIDES
NUCLEI
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
RADIOISOTOPES
STABLE ISOTOPES
TETRAHYDROFURAN
YEARS LIVING RADIOISOTOPES