beta-carboxylic ester alpha-amino acid derivatives. A series of different beta-keto esters with various ester substituents has been screened as substrates for the catalyticasymmetricdirect Mannich reaction and it was found that the best results in terms of yield, diastereo- and enantioselectivity were obtained when tert-butyl esters of beta-keto esters were used as the substrate. The reaction of different
Catalytic, Highly Enantioselective, Direct Amination of β-Ketoesters
作者:Mauro Marigo、Karsten Juhl、Karl Anker Jørgensen
DOI:10.1002/anie.200390350
日期:2003.3.28
β-Keto Esters Derived from 2-(Trimethylsilyl)ethanol: An Orthogonal Protective Group for β-Keto Esters
作者:Reinhard Brückner、Eva Knobloch
DOI:10.1055/s-2008-1067157
日期:2008.7
esters derived from 2-(trimethylsilyl)ethanol undergo cleavage and decarboxylation when treated with 0.75 equivalents of tetrabutylammoniumfluoride trihydrate in tetrahydrofuran at 50 °C, while P-keto esters derived from methanol, tert-butylalcohol, allyl alcohol, or benzyl alcohol stay intact. Conversely, methyl-, tert-butyl-, allyl-, or benzyl P-keto esters can be cleaved and decarboxylated without