Preparations and reactions of 2-trifluoromethylketenimines

Katagiri, Toshimasa; Handa, Michiharu; Asano, Hiroyuki; Asanuma, Teppei; Mori, Tomohiro; Jukurogi, Tatsuya

doi:10.1016/j.jfluchem.2009.05.020

Cited by 9 publications

(5 citation statements)

References 25 publications

(10 reference statements)

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“…Treating 28 with various electrophiles, such as hypochlorothioite, Br 2 , and TMSOTf, the more stable ketenimines 29, 30, and 31 can be prepared in 35%, 70%, and 70% yields, respectively (Scheme 8). 10 A similar reaction pattern is also observed in the b-Si-stabilized ketenimines (Scheme 9). 9 When b-Si-stabilized ketenimines 25 are treated with 1 equivalent of sulfanyl chloride, the ketenimine CQC bond undergoes the electrophilic addition.…”

Section: Ketenimine Preparation Via Elimination Reactionssupporting

confidence: 65%

The thriving chemistry of ketenimines

2012

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Ketenimines are an important class of reactive species and useful synthetic intermediates. During the last two decades several practical and versatile approaches to ketenimines have been developed, leading to exhaustive investigations on ketenimine chemistry and the discovery of a variety of highly efficient reactions. Five types of reactions for ketenimines have been reported, including nucleophilic additions (ketenimines can be used as both electrophiles and nucleophiles), radical additions, cycloaddition reactions, electrocyclic ring closure reactions, and σ rearrangements. Furthermore, numerous complex organic compounds, particularly the biologically interesting heterocycles, have been constructed using these methodologies. The review of these accomplishments is presented here.

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Section: Ketenimine Preparation Via Elimination Reactionssupporting

confidence: 65%

The thriving chemistry of ketenimines

2012

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“…The interest in the obtained scaffolds is all the more important given the presence of these structures in biologically active molecules. − In fact, ketenimines bearing fluorinated substituents have been underinvestigated. Apart from F 3 CS-substituted ketenimines, only bis(trifluoromethyl), trifluoromethyl, and bis(difluoro) derivatives have been reported respectively by Knunyants − (1965), Katagiri (2009), and Wang (2019) (Scheme ).…”

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Ketenimines as Intermediates To Access Difluoromethoxylated Scaffolds

et al. 2022

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We report herein the in situ generation of difluoromethoxylated ketenimines. This novel intermediate is readily obtained from the corresponding oxime through a Beckmann rearrangement. The reactivity potential of this species is demonstrated as it easily undergoes addition of various nucleophiles, with a great modularity of the starting oxime. The broad applicability of this transformation leads to a chemical library of original molecules bearing −OCHF2, an Emergent Fluorinated Group (EFG).

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“…Ketenimines are isoelectronic with ketenes and allenes but thermodynamically more stable than them and represent an important class of reactive species, useful synthetic intermediates, and synthons . They can undergo nucleophilic additions, cycloaddition reactions, radical additions, and σ-rearrangements. ,, Classical types of reactions to prepare ketenimines involve the coupling reaction between aza-Wittig reagents and ketenes, the elimination of trifluoropropioimidoyl chloride, and the rearrangement of enolizable nitriles or ynamides . The most efficient method is the copper-catalyzed sulfonyl azide–alkyne cycloaddition/ring cleavage (CuAAC/ring cleavage reaction), ,, which has been applied to synthesize numerous oxygen- and nitrogen-containing heterocyclic compounds. , Traditionally, ketenimines generated by CuAAC in situ act as a dienophile or monoolefine (2π system) to participate in the [2 + 2], [3 + 2], [4 + 2], and [2 + 2 + 2] cycloadditions (Scheme ).…”

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Tandem CuAAC/Ring Cleavage/[4 + 2] Annulation Reaction to Synthesize Dihydrooxazines and Conversion to 2-Aminopyrimidines

Yang

Zhao

et al. 2021

Org. Lett.

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A tandem CuAAC/ring cleavage/[4 + 2] annulation reaction of terminal ynones, sulfonyl azides, and oximes has been developed to synthesize functionalized dihydrooxazines under mild conditions. In particular, intermediate N-sulfonyl acylketenimines are the first example of a 4π-system participating in [4 + 2] cycloadditions, and dihydrooxazines can convert to 2-aminopyridines through ring cleavage under basic conditions.

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Preparations and reactions of 2-trifluoromethylketenimines

Cited by 9 publications

References 25 publications

The thriving chemistry of ketenimines

The thriving chemistry of ketenimines

Ketenimines as Intermediates To Access Difluoromethoxylated Scaffolds

Tandem CuAAC/Ring Cleavage/[4 + 2] Annulation Reaction to Synthesize Dihydrooxazines and Conversion to 2-Aminopyrimidines

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