5.03 Formation of Four-Membered Heterocycles

Robiette, Raphaël; Marchand‐Brynaert, J.

doi:10.1016/b978-0-08-097742-3.00503-6

Cited by 4 publications

(3 citation statements)

References 261 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ketene chemistry remains a very active area of research worldwide, involving both synthetic and mechanistic studies, and has been extensively reviewed. [3][4][5][6][7][8][9][10][11][12][13][14][15] This review describes the most recent work in the area, which is rich in further opportunities. The organization of this review includes separate headings on ketene preparation and on ketene reactions, but since ketenes are usually short-lived intermediates ketene formation and reactivity are usually inextricably mixed, and examples of one almost invariably contain the other.…”

Section: Introductionmentioning

confidence: 99%

Recent advances in ketene chemistry

Allen¹,

Tidwell²

2016

Arkivoc

View full text Add to dashboard Cite

Recent advances in ketene chemistry are reviewed, including synthetic, mechanistic, and computational studies. Topics include ketene structure determination by experimental and theoretical methods, computational studies of bonding in ketenes, spectroscopic properties of ketenes, preparation and formation of ketenes including photochemical and thermal methods, the discovery and observation of ketenes in space, and ketene reactions. The last category includes decarbonylation, cycloadditions with carbon-carbon, carbon-nitrogen, and carbon-oxygen multiple bonds, addition of oxygen, nitrogen, and carbon nucleophiles, and electrophilic additions.

show abstract

Section: Introductionmentioning

confidence: 99%

Recent advances in ketene chemistry

Allen¹,

Tidwell²

2016

Arkivoc

View full text Add to dashboard Cite

show abstract

“…The [2 + 2] cycloaddition reaction is always a direct way to synthesize four-membered rings, , through which a series of four-membered rings like cyclobutane (C 4 ), azetidine (C 3 N), oxetane (C 3 O), thietane (C 3 S), dioxetane (C 2 O 2 ), and so forth were produced. − However, when more nitrogen atoms are introduced, the four-membered ring becomes unstable. For example, the diazetidine (C 2 N 2 ) obtained by [2 + 2] photocycloaddition between NN and CC is prone to undergo the metathesis reaction and generate two CN groups after heating .…”

Section: Introductionmentioning

confidence: 99%

Arylazo under Extreme Conditions: [2 + 2] Cycloaddition and Azo Metathesis

et al. 2023

View full text Add to dashboard Cite

The four-membered nitrogen ring (N4-ring) is predicted to be a high-energy density moiety and has been the target of chemical synthesis for quite a long time. Here, by compressing the 1:1 co-crystal of trans-azobenzene and trans-perfluoroazobenzene up to ∼40 GPa, the azo groups were restrained closely in parallel in the crystal and underwent two competitive addition reactions. One is [4 + 2] cycloaddition with the azo group as a part of diene and phenyl as dienophile. The other is [2 + 2] cycloaddition between two azo groups, which produced an unprecedented N4-ring structure as evidenced by the metathesis product. The content of the N4-ring structure significantly increases under higher pressure, and we found that it was the external pressure that decreased the kinetic barrier and realized such a high-tensile moiety. Our work shows that high pressure is an alternative synthetic strategy for these high-tensile structures, which can be very effective under the cooperation of crystal engineering.

show abstract

“… − This result surprised us, as [2 + 2] photocycloadditions between the CN bonds of noncyclic imines and CC bonds to afford azetidines have, to the best of our knowledge, not yet been reported. Furthermore, nonphotolytic [2 + 2] cycloadditions between the CN bonds of imines and CC bonds also remain quite rare, with the exception of ketenes in the Staudinger reaction. , Therefore, we further investigated [2 + 2] photocycloadditions between the CN bonds of imines and CC bonds. Subsequently, we attempted the reaction between the N -tosylimine of p -anisaldehyde ( 1b ) and benzofuran.…”

mentioning

confidence: 99%

[2 + 2] Photocycloadditions between the Carbon–Nitrogen Double Bonds of Imines and Carbon–Carbon Double Bonds

et al. 2016

View full text Add to dashboard Cite

In contrast to the well-known [2 + 2] photocycloadditions between C═O and C═C bonds, the participation of C═N bonds in such reactions is relatively rare. In this paper, the unprecedented UV-light-induced [2 + 2] cycloadditions between N-arylsulfonylimines and styrene derivatives or benzofurans are described. This photolytic reaction allows the highly stereoselective construction of azetidine derivatives under ambient conditions.

show abstract

5.03 Formation of Four-Membered Heterocycles

Cited by 4 publications

References 261 publications

Recent advances in ketene chemistry

Recent advances in ketene chemistry

Arylazo under Extreme Conditions: [2 + 2] Cycloaddition and Azo Metathesis

[2 + 2] Photocycloadditions between the Carbon–Nitrogen Double Bonds of Imines and Carbon–Carbon Double Bonds

Contact Info

Product

Resources

About