71698-86-7Relevant academic research and scientific papers
High-throughput method for determining the enantioselectivity of enzyme-catalyzed hydroxylations based on mass spectrometry
Chen, Yongzheng,Tang, Weng Lin,Mou, Jie,Li, Zhi
supporting information; experimental part, p. 5278 - 5283 (2010/10/19)
(Chemical equation presented) Up to speed: An accurate, sensitive, high-throughput, and simple method for measuring the product ee value of enzyme-catalyzed hydroxylations (see scheme) is based on the use of enantiopure or enantioenriched deuterated substrates and mass spectrometric detection.
Side Chain Hydroxylation of Aromatic Hydrocarbons by Fungi. Part 2. Isotope Effects and Mechanism
Holland, Herbert L.,Brown, Frances M.,Munoz, Benito,Ninnis, Ronald W.
, p. 1557 - 1564 (2007/10/02)
The benzylic hydroxylation of ethylbenzene, p-diethylbenzene, tetralin, indane, and toluene by the fungi Mortierella isabellina, Cunninghamella echinulata, and Helminthosporium species has been investigated by the use of deuterium-labelled substrates.An i
Stereochemical Dynamics of Aliphatic Hydroxylation by Cytochrome P-450
White, Ronald E.,Miller, John P.,Favreau, Leonard V.,Bhattacharyya, Apares
, p. 6024 - 6031 (2007/10/02)
Previous studies on the stereochemistry of hydroxylation by cytochrome P-450 enzymes have been contradictory and confusing.Therefore, the hydroxylation of four isotopically substituted phenylethane substrates has been examined with a single isozyme of rabbit liver microsomal cytochrome P-450.In each case the corresponding 1-phenylethanol was essentially the only product.With ordinary phenylethane, the product was 48percent R-1-phenylethanol and 52percent the S isomer.With (R)-phenylethane-1-d, the product was 42percent R alcohol, while with (S)-phenylethane-1-d the product was 70percent R alcohol.When the substrate was phenylethane-1,1-d2, 50percent R alcohol was produced.The alcohols from the single-deuterium-substituted substrates were highly enriched in deuterium, indicating the operation of a large deuterium isotope effect on hydrogen removal.Most importantly, 23-40percent of the hydroxylation events resulted in alcohol with configuration opposite to that of the original hydrocarbon substrate.These "crossover" events require the intermediacy of a discrete tricoordinate carbon intermediate.These data unambiguously demonstrate that hydroxylation stereospecificity must be enforced by the surrounding protein tertiary structure and is not an inherent feature of the cytochrome P-450 reaction mechanism.
FUNGAL HYDROXYLATION OF ETHYL BENZENE AND DERIVATIVES
Holland, Herbert L.,Carter, Ian M.,Chenchaiah, P. Chinna,Khan, Shaheer H.,Munoz, Benito,et al.
, p. 6409 - 6412 (2007/10/02)
The fungus Mortierella isabellina converts ethyl benzene and a number of para-substituted derivatives to the corresponding optically active 1-phenylethanols with enantiomeric excesses between 5 and 40percent.Hydrogen removal from the substrate preceeds product formation and is stereochemically independent of it.
Occurrence of Electron Transfer in the Reduction of Organic Halides by LiAlH4 and AlH3
Ashby, E. C.,DePriest, R. N.,Goel, A. B.,Wenderoth, Bernd,Pham, Tung N.
, p. 3545 - 3556 (2007/10/02)
A variety of methods have been utilized to detect the occurrence of a single electron transfer pathway in the reduction of alkyl halides by LiAlH4 and AlH3, i.e., (1) product studies of reduction of cyclizable alkyl halides containing the 5-hexenyl group, (2) trapping of intermediate radicals by dicyclohexylphosphine and other trapping agents, (3) direct EPR observation of the trityl radical in the reduction of trityl bromide, and (4) stereochemical studies of the reduction of secondary halides by lithium aluminum deuteride.The extent of electron transfer was found to be a function of the solvent, the substrate, the leaving group, and the hydride reagent.For alkyl iodides, and to a lesser extent bromides, electron transfer was found to be the major reaction pathway; however, no evidence for electron transfer was found for the corresponding chlorides or tosylates.Reduction of (+)-2-octyl iodide by LiAlD4 was found to be much less stereospecific than the corresponding reduction of bromide, chloride, or tosylate, indicating intermediate radical formation in the reduction of the secondary iodide.
