Die 1,4-Diaryl-2-azetidinone 1 werden bei -78°C basenkatalysiert zu 2 sillyliert。Die Titelreaktion der Anionen von 2 führt zur Bildung der dimeren Produkte 4. Die Struktur von 4 wurde mittels Röntgenstrukturanalysis aufgeklärt。在 Gegenwart von Chlortrimethylsilan reagiert das α-Silylcarbanion von 2 mit Mesoxalsäurediester 3 zu den 3-Methylen-2-azetidinonen 8 und 11。
Chemoselective Synthesis of β-Amino Ester or β-Lactam via Sonochemical Reformatsky Reaction
作者:Adam Shih-Yuan Lee、Yu-Ting Chang、Feng-Yi Su
DOI:10.1002/jccs.201300308
日期:2014.2
A series of β‐amino esters were synthesized by the reaction of N‐tosyl aldimine or N‐hydroxy aldimine with bromoacetate by sonochemical Reformatskyreaction. The β‐N‐hydroxyamino ester was obtained and the formed sensitive hydroxylamino functionality was resistant under the reaction condition. The β‐lactam also was synthesized by the reaction of N‐p‐methoxy aldimine as reacting substrate under this
N-甲苯磺酰胺或N-羟醛胺与溴乙酸酯通过声化学Reformatsky反应合成了一系列β-氨基酯。获得了β- N-羟氨基酯,并且在反应条件下形成的敏感羟氨基官能团具有抗性。的β内酰胺也由反应合成Ñ - p -甲氧基醛亚胺作为底这个声化学的Reformatsky反应条件下反应。
Copper‐Catalyzed Oxidative Benzylic C(sp
<sup>3</sup>
)−H Cyclization for the Synthesis of β‐Lactams
oxidative C(sp3 )-H amidation for the synthesis of β -lactams using t BuOO t Bu. This method is based on Kharasch-Sosnovsky amidation and does not require prefunctionalization of C(sp3 )-Hbonds or the installation of a directing group, thereby allowing for the straightforward synthesis of β -lactams. Our intramolecular functionalization protocol can be extended to diverse benzylicC(sp3 )-Hbonds and
β-内酰胺由于在天然产物和药物中普遍存在而成为重要的结构基序。我们在此报告了使用t BuOO t Bu合成β-内酰胺的Cu催化的分子内氧化C(sp 3)-H酰胺化反应。该方法基于Kharasch-Sosnovsky酰胺化,不需要C(sp 3)-H键的预功能化或定向基团的安装,从而可以直接合成β-内酰胺。我们的分子内功能化协议可以扩展到各种苄基C(sp 3)-H键,并显示出色的官能团耐受性。
Indium-mediated facile synthesis of 3-unsubstituted β-lactams
作者:Bimal K. Banik、Anjan Ghatak、Frederick F. Becker
DOI:10.1039/b002833i
日期:——
A simple synthesis of 3-unsubstituted β-lactams was achieved through indium-mediated reaction of imines with ethyl bromoacetate.
通过铟介导的亚胺与溴乙酸乙酯反应,实现了3-未取代β-内酰胺的简单合成。
Synthesis of Exclusively 4-Substituted β-Lactams through the Kinugasa Reaction Utilizing Calcium Carbide
作者:Abolfazl Hosseini、Peter R. Schreiner
DOI:10.1021/acs.orglett.9b01192
日期:2019.5.17
A new Kinugasa reaction protocol has been elaborated for the one-pot synthesis of 4-substituted β-lactams utilizing calcium carbide and nitrone derivatives. Calcium carbide is thereby activated by TBAF·3H2O in the presence of CuCl/NMI. The ease of synthesis and use of inexpensive chemicals provides rapid access of practical quantities of β-lactams exclusively substituted at position 4.
A general and versatile synthesis of 3-phenylthio β-lactams as lead molecules for 3-methyl-2-azetidinones
作者:Seema Kanwar、S. D. Sharma
DOI:10.1002/jhet.5570440523
日期:2007.9
Ketene-imine cycloaddition using phosphorus oxychloride and benzenesulfonyl chloride under the described reaction conditions yielded trans 3-phenylthio 2-azetidinones in good yields. Desulfurization using Raney nickel and alkylation finally afforded trans 3-methyl-2-azetidinones in a stereoselective manner.