On-column N-dearylation of 2-azetidinones by silica-supported ceric ammonium nitrate
摘要:
A modified traditional preparative chromatographic column can be used to achieve quantitative N-dearylation of N-(alkoxyphenyl), N-(alkoxynaphthyl), and N-(alkoxybenzyl)-2-azetidinones under mild conditions. Starting materials are charged on top of the column and the pure N-unsubstituted 2-azetidinones leave the column minutes later without need for other purifications. The yields are good-to-excellent and the reaction condition is mild, easy, efficient, and cheap. (c) 2012 Elsevier Ltd. All rights reserved.
The Vilsmeier reagent: a useful and versatile reagent for the synthesis of 2-azetidinones
作者:Aliasghar Jarrahpour、Maaroof Zarei
DOI:10.1016/j.tet.2009.02.005
日期:2009.4
and oxalyl chloride or thionyl chloride, works as a versatile acid activator reagent for the direct [2+2] ketene–imine cycloaddition of substituted acetic acid and imines in one-pot synthesis under mild conditions. Monocyclic, spirocyclic and 3-electron-withdrawing group β-lactams were synthesized by this method and optimization of conditions were performed.
Electroreduction of 3-bromo- and 3, 3-dichloro-β-lactams 1 carried out at the potential of the first voltammetric peak and in the presence of acetic anhydride gives 3-acetyl-β-lactams 2. The electrosynthesis is highly stereoselective, as only the acetyl derivative with trans configuration is formed.
A Mild and Efficient Route to 2-Azetidinones Using the Cyanuric Chloride-DMF Complex
作者:Aliasghar Jarrahpour、Maaroof Zarei
DOI:10.1055/s-0030-1289517
日期:2011.10
Efficient conversion of Schiff bases and carboxylic acids to β-lactams can be carried out at room temperature in CH2Cl2, using a cyanuric chloride-N,N-dimethyl formamide complex. The complex is easily prepared by reaction of cyanuric chloride and DMF, an inexpensive reagent, at room temperature. Optimization of conditions and comparison of yield with cyanuric chloride were performed.
Cerium(IV) Tetrabutylammonium Nitrate (CTAN): A Mild and Efficient N-dearylation Agent for Synthesis of N-unsubstituted 2-azetidinones
作者:Maaroof Zarei
DOI:10.3184/174751917x14902201357392
日期:2017.4
A simple and efficient protocol for the conversion of N-p-methoxyphenyl, N-p-ethoxyphenyl, N-p-methoxynaphthyl, N-3,4-dimethoxybenzyl and N-p-methoxybenzyl-2-azetidinones to N-unsubstituted 2-azetidinones using cerium(IV) tetrabutylammonium nitrate (CTAN) in dichloromethane is described. The method is compatible with a number of functional groups, and N-unsubstituted 2-azetidinones can be prepared
Synthesis of β‐Lactams: α‐Chloro and α‐Cyano β‐Lactams by Condensation of Imines with Titanium Ester Enolates Derived from Chloro and Cyano Ethyl Acetates
作者:Seema Kanwar、S. D. Sharma
DOI:10.1080/00397910500181947
日期:2005.8.1
Abstract α‐Cyano and α‐chloro β‐lactams are obtained in a one‐step reaction at a temperature of less than −78°C by condensation of imines with ester enolates derived from ethyl α‐cyano and α‐chloro acetates.