He Caicai, Song Wei, Wei Dandan, Zhao Wei, Yu Qianfei, Tang Jiaqi, Ning Yongquan, Murali Karunanidhi, Sivaguru Paramasivam, de Ruiter Graham, Bi Xihe
Department of Chemistry, Northeast Normal University, Changchun, 130024, China.
Schulich Faculty of Chemistry, Technion Israel Institute of Technology, Technion City, 3200008, Haifa, Israel.
Angew Chem Int Ed Engl. 2024 Dec 9;63(50):e202408220. doi: 10.1002/anie.202408220. Epub 2024 Nov 7.
Herein we report a general rhodium-catalyzed asymmetric intermolecular dearomative cyclopropanation of indoles using trifluoromethyl N-triftosylhydrazones as carbene precursors. The reaction enables the rapid construction of diverse cyclopropane-fused indolines bearing a trifluoromethylated quaternary stereocenter with high enantioselectivity (up to 99 % ee). This mild method exhibits broad substrate scope, tolerating various functional groups, and can even be utilized for the late-stage diversification of complex bioactive molecules. DFT calculations suggest that the formation of a key zwitterionic intermediate is responsible for the chiral induction. Overall, this approach opens up new possibilities for asymmetric cyclopropanation of challenging aromatic heterocyclic compounds.
在此，我们报道了一种通用的铑催化吲哚的不对称分子间去芳构化环丙烷化反应，该反应使用三氟甲基 N-三氟甲磺酰腙作为卡宾前体。该反应能够快速构建多种带有三氟甲基化季碳立体中心的环丙烷稠合吲哚啉，且对映选择性高（高达 99% ee）。这种温和的方法具有广泛的底物范围，能耐受各种官能团，甚至可用于复杂生物活性分子的后期多样化修饰。密度泛函理论计算表明，关键两性离子中间体的形成是手性诱导的原因。总体而言，该方法为具有挑战性的芳香杂环化合物的不对称环丙烷化开辟了新的可能性。
