4-Oxazoline route to stabilized azomethine ylides.  Controlled reduction of oxazolium salts

Vedejs, E.; Grissom, Janet Wisniewski

doi:10.1021/ja00218a038

Cited by 72 publications

(26 citation statements)

References 2 publications

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“…In addition to C 60 (70 %), the cycloadduct ( 3 ), which resulted from 1,3‐dipolar cyloaddition of the in situ generated azomethine ylide to NPM, was obtained in 19 % yield as a 66:33 endo / exo mixture (Scheme ). The structure of compound 3 was determined by spectroscopic techniques and confirmed by an alternative synthesis from the in‐situ‐generated azomethine ylide and NPM as previously reported in the literature 15…”

Section: Resultssupporting

confidence: 64%

On the Mechanism of the Thermal Retrocycloaddition of Pyrrolidinofullerenes (Retro‐Prato Reaction)

Filippone¹,

Izquierdo²,

Martín‐Domenech³

et al. 2008

Chemistry A European J

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In contrast to N-methyl or N-unsubstituted pyrrolidinofullerenes, which efficiently undergo the retrocycloaddition reaction to quantitatively afford pristine fullerene, N-benzoyl derivatives do not give this reaction under the same experimental conditions. To unravel the mechanism of the retrocycloaddition process, trapping experiments of the in-situ thermally generated azomethine ylides, with an efficient dipolarophile were conducted. These experiments afforded the respective cycloadducts as an endo/exo isomeric mixture. Theoretical calculations carried out at the DFT level and by using the two-layered ONIOM (our own n-layered integrated molecular orbital and molecular mechanics) approach underpin the experimental findings and predict that the presence of the dienophile is not a basic requirement for the azomethine ylide to be able to leave the fullerene surface under thermal conditions. Once the 1,3-dipole is generated in the reaction medium, it is efficiently trapped by the dipolarophile (maleic anhydride or N-phenylmaleimide). However, for N-unsubstituted pyrrolidinofullerenes, the participation of the dipolarophile in assisting the 1,3-dipole to leave the fullerene surface throughout the whole reaction pathway is also a plausible mechanism that cannot be ruled out.

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Section: Resultssupporting

confidence: 64%

On the Mechanism of the Thermal Retrocycloaddition of Pyrrolidinofullerenes (Retro‐Prato Reaction)

Filippone¹,

Izquierdo²,

Martín‐Domenech³

et al. 2008

Chemistry A European J

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“…[94] Certainly, diazo-diazirine isomerism has a great effect on many aspects of chemistry and ranks with other electrocyclic reactions involving isomerism of heterocyclic threemembered rings, including the oxaziridine-to-nitrone, [117] aziridine-to-azomethine ylide, [118] epoxide-to-carbonyl ylide, [119] and azirine-to-nitrile ylide [120] rearrangements. Success in experimental chemistry has initiated the development of a theory.…”

Section: Resultsmentioning

confidence: 99%

Valence Isomerization between Diazo Compounds and Diazirines

Korneev

2011

Eur J Org Chem

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Diazo compounds and diazirines have been separately studied in detail and are widely used in research and for applied purposes. Although the mutual isomerization of these compounds was discovered 50 years ago, it has still been only modestly investigated. Meanwhile, this type of mutual transformation has to be taken into account on every occasion when one of these compounds is used or investigated. This review discusses all main cases of mutual isomerization between diazo compounds and diazirines with the goal of providing an impulse for its rational application, as well as describing the isomerism.

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“…Azomethine ylides have been studied extensively, as they offer an effective method for the construction of nitrogen‐containing heterocycles 16. We began our investigations by using Vedejs' oxazole methodology for mild, low‐temperature azomethine ylide generation (Scheme ) 17,18. Reaction of oxazolium salt 8 with benzaldehyde 7a under reducing conditions yielded oxazolidine 11a 19 in 58 % yield via ylide 10 .…”

Section: Resultsmentioning

confidence: 99%

Addition of Azomethine Ylides to Aldehydes: Mechanistic Dichotomy of Differentially Substituted α‐Imino Esters

2010

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4-Oxazoline route to stabilized azomethine ylides. Controlled reduction of oxazolium salts

Cited by 72 publications

References 2 publications

On the Mechanism of the Thermal Retrocycloaddition of Pyrrolidinofullerenes (Retro‐Prato Reaction)

On the Mechanism of the Thermal Retrocycloaddition of Pyrrolidinofullerenes (Retro‐Prato Reaction)

Valence Isomerization between Diazo Compounds and Diazirines

Addition of Azomethine Ylides to Aldehydes: Mechanistic Dichotomy of Differentially Substituted α‐Imino Esters

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