One-Step Formation of N-Alkenyl-malonamides and N-Alkenyl-thiomalonamides from Carbamoyl Meldrum's Acids
作者:Paweł Punda、Sławomir Makowiec
DOI:10.1080/00397911.2011.634082
日期:2013.5.15
Abstract A one-pot synthesis for the preparation of N-alkenyl-malonamides and N-alkenyl-thiomalonamides was developed. 5-[Hydroxy/mercapto(aryl/alkylamino)methylene]-2,2-dimethyl-1,3-dioxane-4,6-dione act as a source of ketenes that react with the tautomeric form of alkyl-(2-phenyl-propylidene)-amines. A possible [2 + 2] or [4 + 2] cycloaddition product of ketene to imines was not observed. GRAPHICAL
containing a thiomalonamide moiety was developed. Isothiocyanate derivatives of amino acids react smoothly with 2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione (Meldrum'sacid) to yield new thiocarbamoyl derivatives of Meldrum'sacids. Thermal decomposition of these new derivatives leads to thiocarbamoyl ketenes, which acylate amino acid esters to give pseudo‐tripeptides.
Manganese(III)‐promoted cyclization of N‐alkenylmalonamides (=N‐alkenylpropanediamides) gave 3‐(aryl/(alkylamino)carbonyl) β‐lactams as well as 3‐(aryl/(alkylamino)thiocarbonyl) β‐lactams. The relative configuration of the obtained products was unambiguously determined by X‐ray crystallography. The proposed method is very useful for the one‐pot synthesis of a number of 3‐(aryl/(alkylamino)carbonyl)