Enantioselective macrocyclization via catalytic metallic dipole relay

Abstract

Chiral macrocycles play critical roles across medicinal chemistry and materials science, yet their catalytic asymmetric synthesis remains challenging. Existing methods predominantly rely on intramolecular cyclization of linear precursors and asymmetric resolution of racemic macrocycles, often requiring complex synthesis while offering limited structural diversity. Here, inspired by non-ribosomal cyclopeptide biosynthesis, we present a catalytic metallic dipole relay strategy for the construction of axially chiral macrolactones. This approach enables concise enantioselective synthesis through stepwise strain release in biaryl lactones and dynamic kinetic resolution mediated by π-allyl-Pd dipoles. The method demonstrates broad applicability to medium (up to 91% yield with 93% enantiomeric excess) and large (up to 93% yield with 99% enantiomeric excess and >19:1 diastereomeric ratio) ring systems under mild conditions. By establishing stereochemical control during both medium-ring formation and subsequent macrocyclization, this strategy overcomes traditional limitations in the generation of axial chirality while extending the methodology of transition-metal-catalysed asymmetric cyclization.