Efficient Kinetic Macrocyclization

作者：Wen Feng, Kazuhiro Yamato, Liuqing Yang, Joseph S. Ferguson, Lijian Zhong, Shuliang Zou, Lihua Yuan, Xiao Cheng Zeng, Bing Gong · 发表于：Journal of the American Chemical Society · 年份：2009 · DOI：10.1021/ja807935y · 被引用次数：131 · 研究领域：Chemical Synthesis and Analysis、Synthetic Organic Chemistry Methods、Supramolecular Chemistry and Complexes

In this article, the highly efficient formation of a series of recently discovered aromatic oligoamide macrocycles consisting of six meta-linked residues is first discussed. The macrocycles, with their backbones rigidified by three-center hydrogen bonds, were found to form in high yields that deviate dramatically from the theoretically allowed value obtained from kinetic simulation of a typical kinetically controlled macrocyclization reaction. The folding of the uncyclized six-residue oligomeric precursors, which belong to a class of backbone-rigidified oligoamides that have been demonstrated by us to adopt well-defined crescent conformations, plays a critical role in the observed high efficiency. Out of two possible mechanisms, one is consistent with experimental results obtained from the coupling of crescent oligoamides of different lengths, which suggests a remote steric effect that discourages the formation of oligomers having lengths longer than the backbone of the six-residue precursors. The suggested mechanism is supported by the efficient formation of very large aromatic oligoamide macrocycles consisting of alternating meta- and para-linked residues. These large macrocycles, having H-bond-rigidified backbones and large internal lumens, are formed in high (>80%) yields on the basis of one-step, multicomponent macrocyclization reactions. The condensation of monomeric meta-diamines and a para-diacid chloride leads to the efficient formation of macrocycles with 14, 16, an...