Peracid oxidation of imino ethers

Aue, Donald H.; Thomas, Darryl

doi:10.1021/jo00940a012

Cited by 45 publications

(13 citation statements)

References 37 publications

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“…During the Nef-pathway, the corresponding nitroso-and imineintermediates could not be directly observed due to their inherent instability. 15, 16 However, the corresponding oxime-intermediate could be unambiguously identified using (E/Z)-1-nitro-2-phenyl-1-propene (1) as substrate 15 (Scheme 2).…”

Section: Introductionmentioning

confidence: 99%

Reductive biotransformation of nitroalkenes via nitroso-intermediates to oxazetes catalyzed by xenobiotic reductase A (XenA)

et al. 2011

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A novel reductive biotransformation pathway for β,β-disubstituted nitroalkenes catalyzed by flavoproteins from the Old Yellow Enzyme (OYE) family was elucidated. It was shown to proceed via enzymatic reduction of the nitro-moiety to furnish the corresponding nitroso-alkene, which underwent spontaneous (non-enzymatic) electrocyclization to form highly strained 1,2-oxazete derivatives. At elevated temperatures the latter lost HCN via a retro-[2 + 2]-cycloaddition to form the corresponding ketones. This pathway was particularly dominant using xenobiotic reductase A, while pentaerythritol tetranitrate-reductase predominantly catalyzed the biodegradation via the Nef-pathway.

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Section: Introductionmentioning

confidence: 99%

Reductive biotransformation of nitroalkenes via nitroso-intermediates to oxazetes catalyzed by xenobiotic reductase A (XenA)

et al. 2011

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“…The intermediate, 2, is an oxaziridine IV-oxide which has been proposed as a reactive intermediate in related reactions that approximate the reverse of the mechanism in question. These reactions include the peracid oxidation of imines and oxaziranes to yield nitroso and carbonyl products (31,32). That the nitroso-glyoxylate reaction might proceed via an initial nucleophilic attack of the glyoxylate hydrate on the N-position of the nitroso -bond (Scheme V) is consistent with the known electronic effects of aromatic ring substituents on the kinetics of these reactions (1).…”

Section: Discussionmentioning

confidence: 68%

Studies on the nitroso-glyoxylate reaction. Relative hydroxamic acid production by glyoxylate, pyruvate, and formaldehyde in reactions with 4-nitrosobiphenyl

Corbett¹,

Corbett²

1993

Chem. Res. Toxicol.

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The pH rate profiles for the reactions of 4-nitrosobiphenyl with three carbonyl substrates in aqueous buffers were determined by use of chromatographic and spectrophotometric methods. Glyoxylate and formaldehyde caused the conversion of 4-nitrosobiphenyl to N-(4-biphenyl)-formohydroxamic acid, while pyruvate resulted in the production of N-(4-biphenyl)acetohydroxamic acid. The dramatic effect of pH on the kinetics of these reactions provided considerable information concerning the nature of these reactions. The reactions with pyruvate and formaldehyde displayed similar pH rate profiles and were significant only at acidic pH. Glyoxylate displayed a pH rate profile that differed markedly from those of pyruvate and formaldehyde as the pH was increased beyond 2.0. The ability of glyoxylate to convert 4-nitrosobiphenyl to the hydroxamic acid increased rapidly in the pH range 2.0-4.0, above which the pH dependency was constant. This biphasic appearance of the pH rate profile was unique to glyoxylate, since the reactions of pyruvate and formaldehyde became extremely slow as solution neutrality was approached. A second substrate, 4-chloronitrosobenzene, displayed similar pH rate profiles in its reactions with these carbonyl substrates. For 4-nitrosobiphenyl, hydroxamic acid formation by glyoxylate was 10(4) times faster than that by pyruvate at neutral pH, but only about 3-fold faster at pH 1.0. The appearance of the pH rate profile for glyoxylate suggested that this alpha-oxo acid reacts with nitrosoarenes at neutrality via a pathway that is insignificant for pyruvate or formaldehyde. Thus, the nitroso-glyoxylate reaction is unique to this alpha-oxo acid under physiological pH conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…gave only partial oxidation to the oxaziridine 13 and it was found to be impossible to achieve complete reaction without further oxidation via 16 to give the ring-opened nitroso compound 17 which existed entirely as a mixture of the isomeric oximes 18. 5 When 13 was heated in solution it underwent ring-opening to give the cyclic trimer 15 of the imine 14. Langlois and coworkers have recently examined the synthetic utility of chiral oxazoline Noxides.…”

Section: Results and Discusionmentioning

confidence: 99%