Peptide Cyclization and Cyclodimerization by Cu<sup>I</sup>-Mediated Azide−Alkyne Cycloaddition
作者:Reshma Jagasia、Justin M. Holub、Markus Bollinger、Kent Kirshenbaum、M. G. Finn
DOI:10.1021/jo802097m
日期:2009.4.17
Head-to-tail cyclodimerization of resin-bound oligopeptides bearing azide and alkyne groups occurs readily by 1,3-dipolar cycloaddition upon treatment with CuI. The process was found to be independent of peptide sequence, sensitive to the proximity of the alkyne to the resin, sensitive to solvent composition, facile for α- and β-peptides but not for γ-peptides, and inhibited by the inclusion of tertiary
在用 Cu I处理后,通过 1,3-偶极环加成很容易发生带有叠氮基和炔基的树脂结合寡肽的头对尾环二聚化. 发现该过程与肽序列无关,对炔烃与树脂的接近度敏感,对溶剂组成敏感,对 α- 和 β- 肽敏感,但对 γ-肽不敏感,并且受到叔酰胺的抑制联系。短于六聚体的肽主要转化为环状单体。在没有铜催化剂的情况下,低聚甘氨酸和低聚(β-丙氨酸)链通过 1,3-偶极环加成发生低聚反应。这些结果表明,环二聚化取决于叠氮基炔肽在链之间形成框内氢键的能力,以便将反应基团放置得非常接近并降低二聚化的熵损失。树脂和溶剂的特性至关重要,可在溶胀和链间 H 键之间实现高效平衡。