Enantioselective Assembly of Ferrocenes with Axial and Planar Chiralities via Palladium/Chiral Norbornene Cooperative Catalysis
Jinxiang Ye, Lisha Li, Yiming You, Chengkang Jiao, Ziyang Cui, Yabin Zhang, Shihu Jia, Hengjiang Cong, Shanshan Liu, Hong‐Gang Cheng, Qianghui Zhou
Abstract
High Resolution Image Download MS PowerPoint Slide The preparation of ferrocenes with both axial and planar chiralities poses a considerable challenge. Herein, we report a strategy for the construction of both axial and planar chiralities in a ferrocene system via palladium/chiral norbornene (Pd/NBE*) cooperative catalysis. In this domino reaction, the first established axial chirality is dictated by Pd/NBE* cooperative catalysis, while the latter planar chirality is controlled by the preinstalled axial chirality through a unique axial-to-planar diastereoinduction process. This method exploits readily available ortho -ferrocene-tethered aryl iodides (16 examples) and the bulky 2,6-disubstituted aryl bromides (14 examples) as the starting materials. Five- to seven-membered benzo-fused ferrocenes with both axial and planar chiralities (32 examples) are obtained in one step with constantly high enantioselectivities (>99% e.e. ) and diastereoselectivities (>19:1 d.r. ).