The invention provides novel compounds and methods to carry out organocatalytic Michael additions of aldehydes to nitroethylene catalyzed by a proline derivative to provide α-substituted-γ-nitroaldehydes. The reaction can be rendered enantioselective when a chiral pyrrolidine catalyst is used, allowing for Michael adducts in nearly optically pure form (e.g., 96-99% e.e.). The Michael adducts can bear a single substituent or dual substituents adjacent to the carbonyl. The Michael adducts can be efficiently converted to protected γ
2
-amino acids, which are essential for systematic conformational studies of γ-peptide foldamers.
该发明提供了新颖的化合物和方法,用于通过脯
氨酸衍
生物催化的醛对
硝基乙烯进行有机催化的迈克尔加成,从而提供α-取代-γ-硝基醛。当使用手性
吡咯烷催化剂时,该反应可以呈现对映选择性,从而使迈克尔加合物几乎以光学纯形式存在(例如,96-99%对映过量)。迈克尔加合物可以在羰基相邻处携带单取代基或双取代基。迈克尔加合物可以有效地转化为受保护的γ2-
氨基酸,这对于γ-肽折叠体系的系统构象研究至关重要。