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 γ2-amino acids, which are essential for systematic conformational studies of γ-peptide foldamers.
本发明提供了新型化合物和方法,以进行有机催化的马克尔加成反应,将醛类化合物加成到由脯
氨酸衍
生物催化的
硝基乙烯中,从而提供α-取代-γ-硝基醛类化合物。当使用手性
吡咯烷催化剂时,反应可以被渲染为对映选择性的,从而可以获得几乎光学纯度的马克尔加成物(例如,96-99% e.e.)。马克尔加成物可以带有一个或两个相邻于羰基的取代基。马克尔加成物可以被有效地转化为受保护的γ2-
氨基酸,这对于γ-肽折叠体的系统构象研究至关重要。