A simple approach to several tripeptides consisting of two terminal glycine fragments and a central pipecolic acid derivative was found via a multicomponent reaction starting from tetrahydropyridines. The protected peptides 2a–g were formed in high yields and with different substitution patterns of the central heterocyclic amino acid. In cases where chiral imines were used the target compounds were obtained with remarkable diastereoselectivity. The influence of different substituents attached to the pipecolic acid fragment on N-terminal amide isomerism was investigated using X-ray crystallography and NMR spectroscopic methods.
通过以四
氢吡啶为起点的多组分反应,我们找到了一种简单的方法来制备由两个末端甘
氨酸片段和一个中心
哌啶醇酸衍
生物组成的多种三肽。受保护的肽 2a-g 产量很高,而且中心杂环
氨基酸的取代模式各不相同。在使用手性
亚胺的情况下,获得的目标化合物具有显著的非对映选择性。利用 X 射线晶体学和核磁共振光谱法研究了连接在
哌啶醇酸片段上的不同取代基对 N 端
酰胺异构体的影响。