Synthesis of Chiral Bowl‐Shaped <i>N</i> ‐Heterocycles via Pd‐Catalyzed Enantioselective Intramolecular C–H Arylation

Abstract

ABSTRACT Chirality arising from curved molecular frameworks represents a unique stereochemical motif with growing importance in materials science and supramolecular chemistry, yet its catalytic asymmetric construction remains highly challenging. Herein, we report a palladium‐catalyzed enantioselective intramolecular C–H arylation strategy for the synthesis of bowl‐shaped tribenzo[ b , d , f ]azepines possessing framework‐defined chirality. Enabled by a P‐chiral monophosphine ligand, this transformation proceeds with high efficiency, delivering a diverse array of bowl‐shaped N ‐heterocycles in excellent yields and enantioselectivities (up to 95% yield, 97% ee). The method accommodates a broad range of substrates and provides direct access to previously inaccessible bowl‐shaped chiral frameworks. Mechanistic studies suggest that C–H activation is turnover‐limiting and that stereocontrol originates from a monoligated palladium species. DFT studies were performed to elucidate the detailed reaction mechanism and the origins of enantioselectivity. This work establishes a general catalytic platform for constructing bowl‐shaped chiral medium‐sized rings and expands the synthetic toolbox for chiral π‐functional molecules.