Regio- and Stereoselective Synthesis of (<i>E</i>)-Alkene <i>trans</i>-Xaa-Pro Dipeptide Mimetics Utilizing Organocopper-Mediated <i>A</i><i>nti</i>-S<sub>N</sub>2‘ Reactions
作者:Akira Otaka、Fumihiko Katagiri、Takayoshi Kinoshita、Yoshihiko Odagaki、Shinya Oishi、Hirokazu Tamamura、Nobuyuki Hamanaka、Nobutaka Fujii
DOI:10.1021/jo025922u
日期:2002.8.1
them. Among such motifs are alkene dipeptide isosteres which mimic cis- or trans-imide using (Z)- or (E)-alkene, respectively. In this report, the first regio- and stereoselective syntheses of (E)-alkene dipeptide isosteres (20, 31, and 35) corresponding to trans-proline dipeptides are described. Key to the synthesis of these mimetics is the anti-S(N)2' reaction of vinyl aziridines such as 15 or vinyl
脯氨酸二肽(Xaa-Pro)以顺式和反式旋转异构体的平衡混合物形式存在,这取决于酰亚胺异构化的能垒。这种构象混合物有助于含有脯氨酸的肽和蛋白质的结构和功能。类似于这些顺式或反式构象异构体的结构基序已成为阐明脯氨酸残基在包含它们的结构的物理化学和生物学特征中的作用的有用工具。在这些基序中,是分别使用(Z)-或(E)-烯烃模拟顺式或反式酰亚胺的烯烃二肽等排体。在该报告中,描述了对应于反脯氨酸二肽的(E)-烯烃二肽等排物(20、31和35)的第一个区域和立体选择性合成。合成这些模拟物的关键是抗S(N)2' 与有机铜试剂“ RCu”(R = CH(2)SiMe(2)(Oi-Pr))与乙烯基氮丙啶(如15)或乙烯基恶唑烷酮(如28和32)反应。衍生自L-丝氨酸的顺式-乙烯基氮丙啶15与有机铜试剂的反应得到反式-L-Ser-D-Pro型烯烃等排体20的前体,伴随有S(N)2副产物。使用这种氮丙啶介导的