A Straightforward Approach towards α-Amino-β-keto Esters via Acylation of Chelated Amino Acid Ester Enolates
作者:Uli Kazmaier、Katharina Schultz、Laura Stief
DOI:10.1055/s-0031-1289674
日期:2012.2
Chelated enolates were found to be good nucleophiles for reactions with acyl halides affording α-amino-β-keto esters. In most cases, the reactions are over after a few minutes and preparatively useful yields are obtained, independent of the protecting groups and halides used. Besides acyl halides, also the corresponding imidazolides can be used with similar success. With chloroformates as acylating
A Mild and Efficient Direct α-Amination of β-Dicarbonyl Compounds Using Iodosobenzene and <i>p</i>-Toluenesulfonamide Catalyzed by Perchlorate Zinc Hexahydrate
A direct α-amination of β-dicarbonylcompounds has been achieved by using iodosobenzene (PhIO) as an oxidant and p-toluenesulfonamide (TsNH2) as an aminating reagent in the presence of a catalytic amount of perchlorate zinc hexahydrate. The present amination reaction proceeds quickly at rt (<30 min needed for most tested substrates) to provide the corresponding α-N-tosylamido β-dicarbonyl compounds