The reaction of lithium enolates of achiral N-protected glycine esters with chiral alkoxyalkenylcarbene complexes of chromium provided the corresponding Michael adducts with either high anti or syn selectivity depending on the nature of the nitrogen protecting group, and high diastereofacial selectivity when carbene complexes containing the (-)-8-phenylmenthyloxy group were employed. Subsequent oxidation
Stereodivergent silver-catalyzed synthesis of pyroglutamic acid esters
作者:Byungjun Kim、Yuna Song、Sarah Yunmi Lee
DOI:10.1039/d1cc04875a
日期:——
We report here a silver-catalyzed method for the enantio- and diastereodivergent synthesis of chiral pyroglutamic acidesters with multiple stereocenters. This process proceeds through asymmetric conjugate addition of glycine imine esters to a broad range of β-substituted α,β-unsaturated perfluorophenyl esters followed by lactamization. By leveraging catalyst control and stereospecificity of the 1
Efficient Asymmetric Synthesis of Novel 4-Substituted and Configurationally Stable Analogues of Thalidomide
作者:Takeshi Yamada、Takuya Okada、Kazuhiko Sakaguchi、Yasufumi Ohfune、Hisanori Ueki、Vadim A. Soloshonok
DOI:10.1021/ol0623668
日期:2006.11.1
conformational stability of these new thalidomide derivatives provides solid experimental evidence for practical feasibility of the approach described here to overcome the inherent problem of configurational instability of thalidomide by introducing an alkyl or aryl group in the C4 position. [reaction: see text].