Synthesis of Alkynylamines from α‐Halogeno Iminium Salts and Ketene S,N‐Acetals

Buijle, R.; Halleux, André de; Viehe, H. G.

doi:10.1002/anie.196605842

Cited by 14 publications

(5 citation statements)

References 2 publications

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“…In 1964, Gompper and Elser described the first example of synthesis of ketene N , S -acetals from thioamides bearing a secondary amino group by reaction with methyl iodide followed by base-mediated deprotonation, for example, the synthesis of 59 (Scheme , seven examples, no yields were given). Ynamines are synthetically useful. − Treatment of 59g with a strong base enabled the formation of 60 in moderate yield.…”

Section: General Methods For Synthesis Of Functionalized Ketene Ns-ac...mentioning

confidence: 99%

Chemistry of Ketene N,S-Acetals: An Overview

et al. 2016

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Push-pull alkenes, which bear electron-donating and -accepting group(s) at both termini of a C═C double bond, respectively, are of interest not only for their unique electronic properties but also for their importance as versatile building blocks in organic synthesis. In the world of ketene acetals having the push-pull alkene skeleton, ketene N,S-acetal is most likely the biggest family according to the number and types of these compounds. The first ketene N,S-acetal compound was reported in 1956. As a cyclic ketene N,S-acetal compound, nithiazine, the first lead structure of neonicotinoid insecticides, was reported in 1978. The characteristics of ketene N,S-acetals, which have the structural feature of ketene S,S-acetals and enaminones, make them versatile and easy to use, especially in cyclization and multicomponent reactions for the synthesis of various heterocyclic systems and related natural products. There has been an increasing wealth of information about the synthesis and synthetic applications of ketene N,S-acetals, especially, in recent years. This review provides comprehensive knowledge on the chemistry of ketene N,S-acetals.

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Section: General Methods For Synthesis Of Functionalized Ketene Ns-ac...mentioning

confidence: 99%

Chemistry of Ketene N,S-Acetals: An Overview

et al. 2016

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“…Thin-layer chromatography was conducted on aluminum sheets with 0.2 mm silica gel with a fluorescent indicator. Physical and spectral data of alkylideneisoxazolones 1a, 18 1d, 19 1f, 18 1g, 5d 1h, 20 1k, 21 and aminoacetylenes 2a, 22 2b, 23 and 2d−f, 24 prepared according to the published procedures, were in agreement with previously reported values.…”

Section: ■ Experimental Sectionmentioning

confidence: 98%

[2 + 2] Cycloaddition/Retro-Electrocyclization/Decarboxylation Reaction Sequence: Access to 4-Aminopyridines from Methylideneisoxazolones and Ynamines

2023

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4-(1-Aminoallylidene)isoxazol-5-ones were synthesized in good yields by the [2 + 2]cycloaddition–retro-electrocyclization reaction of 4-methylideneisoxazol-5(4H)-ones with ynamines. The reaction mechanism and the absence of hetero-Diels–Alder cycloadducts were investigated by DFT calculations. 4-(1-Aminoallylidene)isoxazol-5-ones were found to be convenient substrates for the preparation of 4-aminopyridines under thermal metal-free conditions. The process proceeds via decarboxylative isomerization with cyclic amino groups and accompanied by partial dealkylation of acyclic amino groups. 4-Aminopyridines can also be prepared directly from 4-methylideneisoxazol-5(4H)-ones and ynamines by the one-pot protocol.

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“…After completion of the reaction, which is indicated by the cessation of hydrogen chloride evolution, the phosphoryl chloride is removed under reduced pressure, and the remaining imidoyl chloride is distilled under vacuum. The reported yield ranges from 41~96 % but generally yields of [80][81][82][83][84][85][86][87][88][89][90] % are obtained. …”

Section: CImentioning

confidence: 98%

“…The elimination of two equivalents of hydrogen chloride from iminium chlorides, which can be accomplished by the use of lithium dialkylamides, yields ynamines CLXXIII (80).…”

Section: CLXVIImentioning

confidence: 99%