Spatial Assembly of Mechanically Planar Chiral Rotaxanes on Rationally Designed Cavitands

Chirality plays a central role in chemistry, biology, and pharmaceutical sciences. Although covalent chirality is widely studied, stereoselective assembly of mechanically interlocked molecules (MIMs) remains challenging. Herein, we report a spatial assembly strategy for the stereoselective synthesis of mechanically planar chiral (MPC) rotaxanes. Rationally designed inherently chiral cavitands orchestrate the spatial arrangement of macrocycle and axle components during mechanical interlocking. This approach enables high levels of stereocontrol in both active-template and passive-template synthesis of MPC rotaxanes (up to 93:7 e.r.). Our study demonstrates that stereoinduction of MIMs can be made predictable through rational design of chiral auxiliaries, paving the way for applications of the spatial assembly strategy in asymmetric supramolecular synthesis.