Qian Pu-Fan, Wu Yan-Xuan, Hu Jia-Heng, Chen Jia-Hao, Zhou Tao, Yao Qi-Jun, Zhang Zi-Hang, Wang Bing-Jie, Shi Bing-Feng
Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
College of Material Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou 311121, China.
J Am Chem Soc. 2025 Mar 26;147(12):10791-10802. doi: 10.1021/jacs.5c02428. Epub 2025 Mar 13.
C-N axially chiral compounds represent an important class of atropisomers that are prevalent in bioactive and material molecules. Despite recent advances in synthetic methodologies, the asymmetric construction of atropisomers featuring multiple C-N axes has been rarely explored, significantly limiting their further applications. Herein, we report a novel atroposelective synthesis of diaxially chiral pyridoindolones featuring both six-five and six-six C-N axes through cobalt-catalyzed asymmetric C-H annulation. This approach demonstrates exceptional efficiency, yielding a diverse array of chiral pyridoindolones with excellent yields and atroposelectivities (60 examples, up to >99% yield, >99% ee, and >20:1 dr). Mechanistic studies revealed that the stereochemistry of both C-N axes were generated and fixed simultaneously during the C-H cyclometalation step, along with an unexpected asymmetric amplification effect. The practicality of this protocol is further underscored by successful gram-scale syntheses and various transformations, including the formation of a chiral phosphine ligand. Notably, exceptional photoluminescence quantum yields ( up to 0.99) and positive solvatochromism were observed, coupled with significant chiroptical properties, underscoring the potential applications of these compounds in organic fluorescent materials.
C-N轴手性化合物是一类重要的阻转异构体,广泛存在于生物活性分子和材料分子中。尽管近年来合成方法取得了进展,但具有多个C-N轴的阻转异构体的不对称构建却鲜有探索,这严重限制了它们的进一步应用。在此,我们报道了一种通过钴催化的不对称C-H环化反应,对同时具有六元-五元以及六元-六元C-N轴的双轴手性吡啶并吲哚酮进行新型阻转选择性合成的方法。该方法展现出卓越的效率,能以优异的产率和阻转选择性得到一系列多样的手性吡啶并吲哚酮(60个实例,产率高达>99%,对映体过量值>99%,非对映选择性>20:1)。机理研究表明,在C-H环金属化步骤中,两个C-N轴的立体化学同时产生并固定,同时伴随着意外的不对称放大效应。克级规模的成功合成以及包括手性膦配体形成在内的各种转化进一步突出了该方法的实用性。值得注意的是,观察到了优异的光致发光量子产率(高达0.99)和正溶剂化显色性,以及显著的手性光学性质,这突出了这些化合物在有机荧光材料中的潜在应用。