The invention provides compounds and methods, for example, to carry out organocatalytic Michael additions of aldehydes to cyclically constrained nitroethylene compounds catalyzed by a proline derivative to provide cyclically constrained α-substituted-γ-nitro-aldehydes. 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 to >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 cyclically constrained protected γ-amino acid residues, which are essential for systematic conformational studies of γ-peptide foldamers. New methods are also provided to prepare other γ-amino acids and peptides. These new building blocks can be used to prepare foldamers, such as α/γ-peptide foldamers, that adopt specific helical conformations in solution and in the solid state.
US8664356B2
申请人:——
公开号:US8664356B2
公开(公告)日:2014-03-04
US9382291B2
申请人:——
公开号:US9382291B2
公开(公告)日:2016-07-05
US9796660B2
申请人:——
公开号:US9796660B2
公开(公告)日:2017-10-24
New Preorganized γ-Amino Acids as Foldamer Building Blocks
作者:Li Guo、Weicheng Zhang、Ilia A. Guzei、Lara C. Spencer、Samuel H. Gellman
DOI:10.1021/ol3008815
日期:2012.5.18
An asymmetric synthesis of two new diastereomeric γ-amino acids is described. Both molecules contain a cyclohexyl ring to limit conformational flexibility about the Cα–Cβ bond; they differ in having cis vs trans stereochemistry on the ring. Residues derived from the cis γ isomer are shown to support helical secondary structures in α/γ-peptide oligomers.
描述了两种新的非对映体 γ-氨基酸的不对称合成。两个分子都包含一个环己基环以限制 C α -C β键的构象灵活性;它们的不同之处在于环上的顺式与反式立体化学。来自顺式γ 异构体的残基显示支持 α/γ-肽寡聚体中的螺旋二级结构。