Régiosélectivité et stéréosélectivité de l'hydroxylation homolytique des hydrocarbures par le peracide benzoïque

Fossey, Jacques; Lefort, D.; Massoudi, M.; Nédélec, Jean‐Yves; Sorba, J.

doi:10.1139/v85-111

Cited by 44 publications

(14 citation statements)

References 10 publications

(7 reference statements)

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“…There are a number of chemical systems that will carry out saturated hydrocarbon hydroxylation in the absence of a metal. For example nitrosubstituted perbenzoic acids (Schneider & Müller, 1985), perbenzoic acid (Fossey et al, 1985), ozone and ground state (triplet) oxygen (Zadok & Mazur, 1982), hydrogen peroxide/ trifluoroacetic acid or trifluoroperacetic acid (Deno et al, 1977), dimethyldioxirane and derivatives (Murray et al, 1986;Mello et al, 1989), perfluorodialkyloxaziridines (Des-Marteau et al, 1993), and iert-butylhydroperoxide (Chenier et al, 1978) have all been used to perform this type of oxidation. Perbenzoic acid, triplet oxygen, and ierf-butyl hydroperoxide all utilize the same mechanism, hydrogen radical abstraction at the site of reaction and then recombination of the carbon centered radical and a hydroxyl radical.…”

Section: Discussionmentioning

confidence: 99%

Mechanism of metal-independent hydroxylation by Chromobacterium violaceum phenylalanine hydroxylase

Carr¹,

Balasubramanian²,

Hawkins³

et al. 1995

Biochemistry

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Phenylalanine hydroxylase converts phenylalanine to tyrosine utilizing a tetrahydrobiopterin cofactor. Several key mechanistic questions have yet to be resolved, specifically the identity of the hydroxylating species and the role of the non-heme iron which is present in all of the mammalian PAHs. Recently, we have demonstrated that a bacterial PAH from Chromobacterium violaceum does not require any redox active metal for activity [Carr, R. T., & Benkovic, S. J. (1993) Biochemistry 32, 14132-14138]. To identify the function of iron in the mammalian PAH's, we have undertaken a series of experiments to compare the mechanisms of this metal-independent PAH with the iron-dependent PAH from rat liver. Using [4-2H]phenylalanine as a substrate gave a kinetic isotope effect on hydroxylation of unity for CVPAH which is in agreement with previous values reported for RLPAH. The [4-2H]phenylalanine underwent an NIH shift upon hydroxylation by CVPAH. The extent of deuterium retention at the 3-position of the tyrosine product was identical within experimental error for both RLPAH and CVPAH using [4-2H]phenylalanine and [2,3,5,6-2H]phenylalanine as substrates. This suggests that PAH from either source probably does not directly mediate the NIH shift mechanism. No uncoupled pterin turnover was observed for CVPAH with either L-tyrosine or p-chloro-L-phenylalanine as substrate or tetrahydropterin as cofactor, each of which causes uncoupled turnover with RLPAH. CVPAH readily accepts 4-methylphenylalanine as a substrate giving 4-(hydroxymethyl)phenylalanine as the major product and 3-methyltyrosine as the only other minor product.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussionmentioning

confidence: 99%

Mechanism of metal-independent hydroxylation by Chromobacterium violaceum phenylalanine hydroxylase

Carr¹,

Balasubramanian²,

Hawkins³

et al. 1995

Biochemistry

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“…21 We have now converted the p-ieri-butylcalix[4]arene 2 into tetracarbonate 3 and report here the X-ray crystal and molecular structure of the 1:1 clathrate formed by 3 and acetonitrile. This is the first crystal structure reported of a clathrate of a nonaromatic guest and a p-ferf-butylcalix [4]arene. It is also the first functionalized calixarene to bind a neutral guest in the true clathrate sense.…”

mentioning

confidence: 85%

“…Furthermore, inclusion of aromatic guests was observed only when the para position of the calixarene carried a iert-butyl group, an arrangement believed to provide favorable CH3-7r interaction between the methyl groups and the system of the guest molecule. The iert-butyl groups are unable to bend inwards, thus blocking the entrance to the cavity as appears to be the case with p-(l,l,3,3-tetramethylbutyl)calix [4]arene.18…”

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confidence: 99%

Molecular receptors. Synthesis and x-ray crystal structure of a calix[4] arene tetracarbonate-acetonitrile (1:1) clathrate

McKervey¹,

Seward²,

Ferguson³

et al. 1986

J. Org. Chem.

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“…Molecular oxygen, hydrogen peroxide, tert -butyl hydroperoxides, and peroxyacids were used as oxidants in these oxygenations. Certain complexes of transition metals have been previously reported to oxidize organic compounds including alkanes with meta -chloroperoxybenzoicacid (MCPBA [25]) [25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44] (see, for example, complexes of cobalt [21,24,38], manganese [26,27,34,36,44], iron [28], nickel [30,31,32,33,35,37,39,42,43] and vanadium [40]). Earlier, Nam [15,16] reported that alkane oxidation with MCPBA catalyzed by some cobalt compounds proceeds stereoselectively.…”

Section: Introductionmentioning

confidence: 99%

Stereoselective Alkane Oxidation with meta-Chloroperoxybenzoic Acid (MCPBA) Catalyzed by Organometallic Cobalt Complexes

et al. 2016

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Cobalt pi-complexes, previously described in the literature and specially synthesized and characterized in this work, were used as catalysts in homogeneous oxidation of organic compounds with peroxides. These complexes contain pi-butadienyl and pi-cyclopentadienyl ligands: [(tetramethylcyclobutadiene (10). Complexes 1 and 2 catalyze very efficient and stereoselective oxygenation of tertiary C-H bonds in isomeric dimethylcyclohexanes with MCBA: cyclohexanols are produced in 39 and 53% yields and with the trans/cis ratio (of isomers with mutual trans-or cis-configuration of two methyl groups) 0.05 and 0.06, respectively. Addition of nitric acid as co-catalyst dramatically enhances both the yield of oxygenates and stereoselectivity parameter. In contrast to compounds 1 and 2, complexes 9 and 10 turned out to be very poor catalysts (the yields of oxygenates in the reaction with cis-1,2-dimethylcyclohexane were only 5%-7% and trans/cis ratio 0.8 indicated that the oxidation is not stereoselective). The chromatograms of the reaction mixture obtained before and after reduction with PPh 3 are very similar, which testifies that alkyl hydroperoxides are not formed in this oxidation. It can be thus concluded that the interaction of the alkanes with MCPBA occurs without the formation of free radicals. The complexes catalyze oxidation of alcohols with tert-butylhydroperoxide (TBHP). For example, tert-BuOOH efficiently oxidizes 1-phenylethanol to acetophenone in 98% yield if compound 1 is used as a catalyst.

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Régiosélectivité et stéréosélectivité de l'hydroxylation homolytique des hydrocarbures par le peracide benzoïque

Cited by 44 publications

References 10 publications

Mechanism of metal-independent hydroxylation by Chromobacterium violaceum phenylalanine hydroxylase

Mechanism of metal-independent hydroxylation by Chromobacterium violaceum phenylalanine hydroxylase

Molecular receptors. Synthesis and x-ray crystal structure of a calix[4] arene tetracarbonate-acetonitrile (1:1) clathrate

Stereoselective Alkane Oxidation with meta-Chloroperoxybenzoic Acid (MCPBA) Catalyzed by Organometallic Cobalt Complexes

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