上海大学李健团队报道了含[6-6-5]或[7-6-5]三环核心骨架的2-异氰苯丙酯多环杂环的化学选择性构建。相关研究成果于2024年8月31日发表在国际知名学术期刊《德国应用化学》。

官能化异氰酸酯化学是有机合成的一个重要研究领域。

该文中，研究人员设计了一种结构独特的结合异氰酸酯和炔丙酯反应性的2-异氰苯基炔丙酯。因此，2-异氰苯基炔丙酯和2-氨基芳族醛亚胺的反应，有助于合成各种多环苯并[b]吲哚并[3,2-h][1,6]萘啶衍生物。

此外，与2-羟基芳族醛亚胺反应能够使上述支架，和另一种具有[7-6-5]核心骨架的结构独特的二氮杂苯并[f]萘并[2,3,4-ij]天青进行发散合成。实验结果和DFT计算表明，这些转变可能是通过原位生成应变环丙烯亚胺物种，然后进行[3+2]环加成反应进行的。接下来，可切换的亲核攻击/扩环/芳构化和亲核加成/扩环-消除解释了观察到的选择性。

附：英文原文

Title: Chemoselective Construction of Polycyclic Heterocycles Containing a [6-6-5] or [7-6-5] Tricyclic Core Skeleton from a 2-Isocyanophenyl Propargylic Ester

Author: Youwen Fei, Zihao Zhou, Zihan Ni, Xin Peng, Lei Cui, Zijun Zhou, Xinyao Li, Chunju Li, Xueshun Jia, jian li

Issue&Volume: 2024-08-31

Abstract: Functionalized isocyanide chemistry represents an important research area in organic synthesis. A structurally unique 2-isocyanophenl propargylic ester has been designed to incorporate the reactivity of isocyanide and propargylic ester. Thus, the reaction of 2-isocyanophenyl propargylic ester and 2-aminoaromatic aldimine facilitates the synthesis of a wide range of polycyclic benzo[b]indolo[3,2-h][1,6]naphthyridine derivatives. Furthermore, reacting with 2-hydroxyaromatic aldimine enables the divergent synthesis of both the aforementioned scaffolds and another structurally distinctive diazabenzo[f]naphtho[2,3,4-ij]azulenes featuring a [7-6-5] core skeleton. Experimental results and DFT calculations suggest that these transformations likely proceed via the in situ generation of a strained cyclopropen-imine species followed by [3+2] cycloaddition. Next, switchable nucleophilic attack/ring-expansion/aromatization and nucleophilic addition/ring-expansion/elimination account for the observed selectivity.

DOI: 10.1002/anie.202414726

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202414726