A modular 2H-azirine synthesis from ketoximeacetates via Cs2CO3-mediated cyclization has been developed. The reaction utilizes easily available starting materials and provides a general synthetic route to 2,3-diaryl-2H-azirines in good to excellent yields under mild conditions, which is complementary to the conventional approaches for the synthesis of 2H-azirines. A gram-scale reaction was performed
已经开发了由乙酸酮肟通过Cs 2 CO 3介导的环化合成的模块化2 H-叠氮基。该反应利用容易获得的原料,并在温和条件下以良好至优异的产率提供了合成2,3-二芳基-2 H-叠氮基的一般合成路线,这是合成2 H-叠氮基的常规方法的补充。进行了克级反应以证明该合成方法的放大适用性。重要的是,2 H-叠氮基可以有效地转化为各种氮杂杂环。
Antihistaminica II. �ber die Synthese von 1,2-disubstituierten 4-Amino-?2-butenen
作者:W. G. Stoll、Ch. J. Morel、Ch. Frey
DOI:10.1002/hlca.19500330510
日期:——
Es wird die Synthese von 1,2-disubstituierten Δ2-4-Aminobutenen beschrieben, die darauf beruht, dass tertiäre Aminoketone mit Grignard-Verbindungen von substituierten Methylhalogeniden umgesetzt werden und aus den dabei erhaltenen 1,2-disubstituierten tert.-Amino-butanolen Wasser abgespalten wird. An Stelle der direkten Wasserabspaltung erwies sich der Ersatz der Hydroxylgruppe durch Chlor mit anschliessender
An unexpected palladium‐catalyzed carbonylative synthesis of 2,3‐disubstituted chromones has been developed. Starting from 2‐bromofluorobenzenes and ketones, the corresponding chromones were produced in good yields. By control experiments, this transformation was found to proceed through a sequential carbonylation/Claisen–Hasse rearrangement/intramolecular nucleophilic aromatic substitution approach
study, a metal-free synthesis of 2,4,5-trisubstituted thiazoles using 2H-azirines and thioamides is disclosed. Under the catalysis of HClO4, the protocol was realized through a novel chemical bond breaking of 2H-azirine, which is usually achieved using a metal catalyst. It provides an efficient and green route for the synthesis of substituted thiazoles with a broad substrate scope. Preliminary mechanistic