Chiral Ammonium Betaines as Ionic Nucleophilic Catalysts

Uraguchi, Daisuke; Koshimoto, Kyohei; Miyake, Shuhei; Ooi, Takashi

doi:10.1002/ange.201002315

Cited by 17 publications

(2 citation statements)

References 27 publications

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“…On the other hand, if X−Y is an arene linker the acyl group will be migrated to the nitrogen of the amide (O→N) to generate N ‐acylisoindolinones D . Also, alternative migration leading to product E (O→C) is plausible although less likely because of the sterically congested environment at the reaction center [19b–l] …”

Section: Introductionmentioning

confidence: 99%

Intramolecular Carboxyamidation of Alkyne‐Tethered O‐Acylhydroxamates through Formation of Fe(III)‐Nitrenoids

Su,

Zhang,

Liu

et al. 2023

Chemistry A European J

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We developed intramolecular carboxyamidations of alkyne‐tethered O‐acylhydroxamates followed by either thermally induced spontaneous or 4‐(dimethylamino)pyridine‐catalyzed O→O or O→N acyl group migration. Under iron‐catalyzed conditions, the carboxyamidation products were generated in high yield from both Z‐alkene and arene‐tethered substrates. DFT calculations indicate that the iron‐catalyzed carboxyamidation proceeds via a stepwise mechanism involving iron‐imidyl radical cyclization followed by intramolecular acyloxy transfer from the iron center to the alkenyl radical center to furnish the cis‐carboxyamidation product. Upon treatment with 4‐(dimethylamino)pyridine, the Z‐alkene‐tethered carboxyamidation products underwent selective O→O acyl migration to generate 2‐acyloxy‐5‐acyl pyrroles. Thermal O→N acyl migration occurs during carboxyamidation if the Z‐alkene linker contains an alkyl or an aryl substituent at the β‐position of the carbonyl group. On the other hand, the arene linker‐containing compounds selectively undergo O→N acyl migration to generate N‐acyl‐3‐acylisoindolinones, and the corresponding O→O acyl migration forming isoindole derivatives was not observed.

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Section: Introductionmentioning

confidence: 99%

Intramolecular Carboxyamidation of Alkyne‐Tethered O‐Acylhydroxamates through Formation of Fe(III)‐Nitrenoids

Su,

Zhang,

Liu

et al. 2023

Chemistry A European J

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“…Fortunately, the enantiomeric excess (ee) of anti-4 aa was determined to be 97 %. When the more nucleophilic catalyst 1 b, [13] which lacks a substituent at the 3-position of the aryloxylate moiety (Ar 2 ), was used as a catalyst under otherwise identical conditions, the bond formation occurred sluggishly to afford 4 aa in only 20 % yield with low stereoselectivity (Table 1, entry 2). [14] This intriguing result strongly suggests that 1 functions as an organic base to catalyze the reaction through route B and also reveals the importance of Ar 2 for attaining high reactivity and stereoselectivity.…”

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confidence: 99%

Nitroolefins as a Nucleophilic Component for Highly Stereoselective Aza Henry Reaction under the Catalysis of Chiral Ammonium Betaines

Uraguchi

Oyaizu

Ooi

2012

Chemistry A European J

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Vinylogous nitronate was successfully generated from β,β‐disubstituted nitroolefins for achieving a highly regio‐, diastereo‐, and enantioselective aza Henry reaction under the influence of chiral ammonium betaine of type 1 as an organic‐base catalyst. The present approach greatly expands the synthetic utility of nitroolefins in the development of carbon–carbon bond‐forming reactions (see scheme).

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