Hsueh Fang-Che, Tsai Chi-You, Lai Chien-Chen, Liu Yi-Hung, Peng Shie-Ming, Chiu Sheng-Hsien
Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, Taiwan.
Institute of Molecular Biology, National Chung Hsing University and Department of Medical Genetics, China Medical University Hospital, Taichung, Taiwan.
Angew Chem Int Ed Engl. 2020 Jul 6;59(28):11278-11282. doi: 10.1002/anie.202001398. Epub 2020 May 4.
We have prepared NHC-Cu complexes with a rotaxane structure and used them as sterically sensitive catalysts for one-pot sequential copper-catalyzed azide/alkyne cycloadditions in solutions containing all of the coupling partners premixed in unprotected form. Most notably, a photolabile and sterically encumbered complex first catalyzed the coupling of a less bulky azide/alkyne pair; after removing the protective macrocyclic component from the rotaxane structure, through irradiation with light, the exposed dumbbell-shaped NHC-Cu complex catalyzed the second click reaction of a bulkier azide/alkyne pair. Using this approach, we obtained predominantly, from a single sealed pot, a bis-triazole product (84 %) from a mixture of two sterically distinct azides and a diyne.
我们制备了具有轮烷结构的NHC-Cu配合物，并将其用作空间敏感催化剂，用于在含有所有未受保护形式预混合的偶联伙伴的溶液中一锅法连续进行铜催化的叠氮化物/炔烃环加成反应。最值得注意的是，一种对光不稳定且空间位阻较大的配合物首先催化了体积较小的叠氮化物/炔烃对的偶联；通过光照从轮烷结构中除去保护性大环组分后，暴露的哑铃状NHC-Cu配合物催化了体积较大的叠氮化物/炔烃对的第二次点击反应。使用这种方法，我们主要从单个密封罐中，由两种空间结构不同的叠氮化物和一种二炔的混合物得到了双三唑产物（84%）。
