N-Bromosuccinimide as a Brominating Agent for the Transformation of N-H (or N-Benzyl) Ketoaziridines into Oxazoles

Samimi, Heshmat Allah; Dadvar, Farkhondeh

doi:10.1055/s-0034-1380518

Cited by 18 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Apart from N ‐bromosuccinimide (NBS), which is the most commonly used NBr reagent in organic synthesis, several other NBr reagents that act as electrophilic bromine(I) reagents are known, including the commercially available bis(2,4,6‐trimethylpyridine)bromine(I) hexafluorophosphate, in which a bromonium ion is coordinated with two pyridine units . However, an array of versatile reactions with NBS, spanning the areas of oxidations, rearrangements, and C–H functionalizations, are well known, owing to its ease of availability, economical pricing, and ease of handling (Figure ) , …”

Section: Classical Use Of Halonium Ions and Commercially Availablementioning

confidence: 99%

Role of Lewis‐Base‐Coordinated Halogen(I) Intermediates in Organic Synthesis: The Journey from Unstable Intermediates to Versatile Reagents

et al. 2017

View full text Add to dashboard Cite

The widespread use of halogen‐based reagents in organic synthesis is well known. Hypervalent halogens (oxidation states III and V) have been explored to a significant extent. Among them, hypervalent iodine reagents have found major use and applications. In contrast, understanding of the reactivity of halogen(I) species in the presence of Lewis bases, and their reaction mechanisms, are very limited. This microreview sheds light on the importance of halogen(I) species and their applications in organic synthesis. In commercially available halogen(I) precursors such as N‐halosuccinimides, the halogen atom is attached to the nitrogen atom through a covalent bond with low electrophilicity and thus low reactivity. Interestingly, the reactivity increases if the electrophilic halogen(I) atom is attached to a Lewis base through a polarized covalent bond. The halogen‐bonding interaction between the Lewis base and the halonium ion (or halonium ion equivalent) results in highly reactive and thermodynamically stable halogen(I) intermediates that act as versatile reagents. This microreview unravels the evolution of the unstable halogen(I) intermediates to become versatile reagents.

show abstract

Section: Classical Use Of Halonium Ions and Commercially Availablementioning

confidence: 99%

Role of Lewis‐Base‐Coordinated Halogen(I) Intermediates in Organic Synthesis: The Journey from Unstable Intermediates to Versatile Reagents

et al. 2017

View full text Add to dashboard Cite

show abstract

“…91 Under thermal conditions, N-bromo substituted ketoaziridines 173 are converted into an azomethine ylide 175 via C-C bond cleavage that is followed by the ring-closure of the latter leading to a cyclized intermediate 176, which then undergoes thermal elimination of hydrogen bromide to produce oxazoles 174 (Scheme 52). The authors have also reported that the presence of electron-withdrawing R 1 groups and electron-donating R 2 groups favored the formation of azomethine ylide.…”

Section: Synthesis Of Oxazolesmentioning

confidence: 99%

Recent applications of aziridine ring expansion reactions in heterocyclic synthesis

Singh¹,

Sudheesh²,

Keroletswe³

2017

Arkivoc

View full text Add to dashboard Cite

The inherent reactivity of the aziridine ring due to ring-strain makes it valuable building blocks for the synthesis of other heterocyclic motifs of biological relevance. Of particular significance is the generation of azomethine ylides from them and cycloaddition of ylides with alkenes, alkynes, and heterocumulenes. The ring undergoes opening followed by cyclization with a variety of reagents either in the presence of a catalyst or without any catalyst. This review article discusses the recent applications of aziridines in syntheses of four-to seven-membered heterocycles of biological relevance such as azetidines, 2

show abstract

“…10 N-Bromosuccinimide was reported to successfully promote this transformation in refluxing dioxane. 12 Bromination of the unsubstituted nitrogen atom was assumed to facilitate thermal C-C bond cleavage of the aziridine ring and this effect was also demonstrated for 2benzoyl-1-benzyl-3-phenylaziridine. Heating this aziridine in dioxane afforded only 17% yield of 2,5-diphenyloxazole while addition of NBS increased it to 87%.…”

Section: Short Review Syn Thesismentioning

confidence: 98%

Recent Advances in the Chemistry of 2-Acylaziridines

Pankova

Кузнецов

2017

Synthesis

View full text Add to dashboard Cite

This review highlights recent achievements in the transformations of 2-acylaziridines toward the synthesis of cyclic and acyclic nitrogen-containing compounds. The influence of a carbonyl group on reaction selectivity is discussed.1 Introduction2 Reactions via C–C Bond Cleavage3 Reactions via C–N Bond Cleavage3.1 Reactions Starting with the Aziridine Ring Opening3.2 Reactions Starting at the Carbonyl Group4 Conclusion

show abstract

N-Bromosuccinimide as a Brominating Agent for the Transformation of N-H (or N-Benzyl) Ketoaziridines into Oxazoles

Cited by 18 publications

References 0 publications

Role of Lewis‐Base‐Coordinated Halogen(I) Intermediates in Organic Synthesis: The Journey from Unstable Intermediates to Versatile Reagents

Role of Lewis‐Base‐Coordinated Halogen(I) Intermediates in Organic Synthesis: The Journey from Unstable Intermediates to Versatile Reagents

Recent applications of aziridine ring expansion reactions in heterocyclic synthesis

Recent Advances in the Chemistry of 2-Acylaziridines

Contact Info

Product

Resources

About