A facile and effective synthesis of 2-azetidinones via phosphonitrilic chloride
作者:Maaroof Zarei
DOI:10.1016/j.tet.2013.05.121
日期:2013.8
The Staudinger reaction of imines to β-lactams was successfully achieved with substituted acetic acid and phosphonitrilicchloride in one-pot under mild conditions. Several types of β-lactams, especially 3-electron-withdrawing group β-lactams, can be synthesized by this versatile and efficient method in good to excellent yields. This method is simple, clean, and the by-products were removed by simple
An efficient and green method for the synthesis of 2-azetidinones mediated by propylphosphonic anhydride (T3P®)
作者:Maaroof Zarei
DOI:10.1007/s00706-014-1217-6
日期:2014.9
acids and imines using propylphosphonic anhydride (T3P®) as acid activator under mild and clean conditions. Monocyclic, spirocyclic and 3-electron-withdrawing group β-lactams were synthesized by this method and optimization of conditions were performed. Graphical abstract
Trimellitic anhydride was attached to Merrifield resin and a ketene was generated from polymer-bound phthaloylglycine. Then this polymer reacted with imines in the presence of Vilsmeier reagent and triethylamine to afford the solid-phase-tethered β-lactam products. Selective cleavage of supported β-lactams by trifluoroacetic acid and methylhydrazine gave 4-carboxyphthalimido- and 3-amino-β-lactams, respectively. The trans-stereochemistry was found in all products.
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.
DMF-dimethyl sulfate as a new reagent for the synthesis of β-lactams
作者:Aliasghar Jarrahpour、Maaroof Zarei
DOI:10.1016/j.tetlet.2009.01.092
日期:2009.4
alkoxymethylene-N,N-dimethyliminium salts, the adduct formed from DMF and O-alkylating agents. The advantages of this new method are mild reaction conditions, low cost, avoiding the use of chlorinating agents and easy purification of the products. The best results were obtained when DMF and dimethyl sulfate were used at room temperature.