Enantioselective Assembly of Ferrocenes with Axial and Planar Chiralities via Palladium/Chiral Norbornene Cooperative Catalysis



The preparation of ferrocenes with both axial and planar chiralities poses a considerable challenge. Herein we report a new strategy for the construction of both axial and planar chiralities in a ferrocene system via palladium/chiral norbornene (Pd/NBE*) cooperative catalysis. In this fascinating domino reaction, the firstly established axial chirality is dictated by Pd/NBE* cooperative catalysis, while the latter planar chirality is controlled by the pre-installed axial chirality through a unique axial-to-planar diastereoinduction process. This method exploits readily available ortho-ferrocene-tethered aryl iodides (14 examples) and the bulky 2,6-disubstituted aryl bromides (14 examples) as the starting materials. 5- to 7-membered benzo-fused ferrocenes with both axial and planar chiralities (29 examples) are obtained in one step with constantly excellent enantioselectivities (> 99% e.e.) and diastereoselectivities (> 19:1 d.r.).


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Supporting information of the manuscript, including the detailed optimization of reaction conditions, the preparation of substrates, general procedure for the synthesis of target products and characterization data for products and copies of chiral HPLC chromatogram and NMR spectra, etc.