Dynamic Chirality Beyond Configuration: Reversible Exchange of Chirality Type

Dynamic chirality, wherein chiral parameters readily and reversibly change in response to stimuli, has 5 proven to be a powerful strategy for accessing switchable molecular systems. However, so far dynamic chirality has only been developed based on inversion of chiral configuration. Herein, we show that dynamic chirality can also occur through the exchange of chirality type using enantiopure overcrowded alkenes derived from chiral cyclic(alkyl)(amino)carbenes. Redox-driven π-(de)aromatization drives the reversible exchange of planar for axial chirality. Despite this significant structural rearrangement, the intermediate π-10 chiral radical cations are readily accessible, permitting access to three distinct chiroptical states. By extending dynamic chirality beyond configuration to include chirality type, this work paves the way for new approaches to complex synthetic systems for use in biomedical, catalytic, and materials technologies.