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Oxaziridine ring

In some cases acid amide formation was observed on attempted deprotonation at oxaziridine ring carbon. 2-r-Butyl-3-(4 -nitrophenyl)oxaziridine (67) was converted to the anion of acid amide (68) by sodium amide (69TL3887), while 2-(4 -nitrobenzoyl)-3-phenyl-oxaziridine (69) afforded the diacylimide (70) by addition of cyclohexylamine to its benzene solution at room temperature (67CB2593). [Pg.206]

The oxaziridine ring itself is stable towards alkali there is, for instance, no substitutive ring opening by hydroxyl ions as in oxiranes. 2-r-Butyl-3-phenyloxaziridine (56) is not attacked by methoxide ion in methanol during 12 h at room temperature 3-isopropyl-2-r-octyloxaziridine does not react at room temperature with either solid potassium hydroxide or potassium methoxide solution (57JA5739). [Pg.208]

If, however, hydrogen is present in the a-position of the iV-alkyl substituent, 2-alkyl-oxaziridines are easily decomposed by alkali. Base attack on this H atom effects 1,2-elimination at the C—N bond. From (86) and aldimine (87) forms, and a mixture of ammonia and two carbonyl compounds is finally obtained, one of them containing the carbon atom of the original oxaziridine ring, the other originating from the IV-alkyl group (57JA5739). [Pg.208]

Action of catalytic amounts of vanadium compounds on oxaziridine (52) yields caprolactam almost quantitatively. Reductive opening of the oxaziridine ring and /3-scission yield radical (118), which recyclizes with elimination of the metal ion to form the lactam (63) (77JPR274). [Pg.212]

One-electron cleavage of the oxaziridine ring is especially useful in the case of the oxaziridine (114), easily obtained from cyclohexanone, methylamine and hypochlorite. The radical formed from (114) by uptake of one electron from the iron(II) ion can be trapped, for example, by acrylonitrile to form products derived from radical (297) (68TL5609). [Pg.234]

The oxaziridine ring system has been formed by the oxidation of C=N double bond . The two-step synthesis of iV-phosphinoyloxaziridines 16 from oximes 15 was described (equation 7) . Irradiation of hydroperoxynitrones 18, prepared by dye-sensitized photooxygenation of 2-methoxyfuran in the presence of oximes 17, led to fraw -oxaziridines 19 in yields up to 89% (equation 8) ". ... [Pg.236]

An anomalous reaction of 2-benzenesulfonyl-3-aryloxaziridines (Davis reagents) with indoles has been reported.48 hi this it appears that a re-bond in the indole acts nucleophilically to attack the O of the oxaziridine ring and thereby cleave the O—N bond. [Pg.308]

Whereas several X-ray structural analyses prove the endo orientation of the oxygen atom of the oxaziridine ring, the assumption of an exo oriented hydroperoxy group in 83 is based solely on the opposite sense of asymmetric induction observed for 82 and 83. [Pg.313]

Cu(I)-Cu(II) Catalysis Radical Reactions Triggered by Oxaziridine Ring... [Pg.324]

We have suggested (43) that collapse of the 4a-hydroperoxide via intramolecular nucleophilic attack ofN(5) on the peroxide could generate the three-membered oxaziridine ring (37) (Scheme 12). Should such an oxaziridine prove to be electrophilic, the oxidation of the phenolic substrate would be envisaged proceeding as in Scheme 16. [Pg.87]

Daylight irradiation of an aqueous solution of quinoxaline 1,4-dioxide affords, after two weeks, quinoxalin-2(l//)-one 4-oxide in 40% yield. The reaction proceeds through the intermediate oxaziridine ring. ... [Pg.248]

The nitrone-oxaziridine ring-chain isomerization has attracted theoretical attention.The quantum yield for the reaction has been measured and the reaction has been examined in a rigid polymer matrix. ... [Pg.312]

The stereochemistry of the oxaziridine ring has received considerable attention mainly due to the chirality of the nitrogen atom and the appreciable barrier to its inversion thus, the separation of enantiomers became possible. Optically active oxaziridines have been prepared by the following methods ... [Pg.313]

The fate of the iminal depends upon the reaction conditions. It may cleave in the manner observed by Emmons to yield ammonia and dicarbonyl compounds that aldolize under the alkaline reaction conditions, or it may undergo an S y2 -like substitution to produce the isomeric iminal ether 53. When the a-hydrogen and oxaziridine ring are constrained to a cis relationship, no reaction occurs under these conditions. This mechanism has received further study and has been generally confirmed. ... [Pg.323]

In a variant of this type of reaction in the diazepine system, the oxaziridine ring-opening was followed by reaction of the iminal that led to the destruction of the heterocyclic ring ... [Pg.324]

These calculations on the parent oxaziridine, using double f plus diffuse basis sets and extensive Cl, are consistent with the assumption that the lowest singlet excited state of the oxaziridine ring results from an n >. ajjo excitation and undergoes... [Pg.333]

Treatment of the oxazabicyclohexane 138 with w-chloroperbenzoic acid leads to the oxidation of the pyridine nitrogen, to give the iV-oxide 139 in good yield. However, the oxaziridine ring itself can be oxidized in the absence of another easily oxidizable function the ethoxy oxaziridine 114b is converted by w-chloroperbenzoic acid into the oximino ester 141, via the unstable A -oxide 140. °... [Pg.22]


See other pages where Oxaziridine ring is mentioned: [Pg.198]    [Pg.201]    [Pg.209]    [Pg.228]    [Pg.341]    [Pg.198]    [Pg.201]    [Pg.198]    [Pg.201]    [Pg.223]    [Pg.592]    [Pg.318]    [Pg.320]    [Pg.322]    [Pg.19]    [Pg.198]    [Pg.201]   


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1.2- Oxaziridin

2- oxaziridine

Nitrones oxaziridine ring

Oxaziridination

Oxaziridine ring nitrones, cyclic

Oxaziridine ring synthesis

Oxaziridines ring-opening reactions

Oxaziridines, ring opening

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