Enantioselective construction of inherently chiral pillar[5]arenes via palladium-catalysed Suzuki–Miyaura cross-coupling

Abstract

Pillar[n]arenes have broad applications in biological medicine, materials science, and supramolecular gels. Notably, enantiopure pillar[5]arenes are valued for their roles in enantioselective host–guest recognition, chiral sensing, asymmetric catalysis, and related fields. Current methods for obtaining chiral pillar[n]arenes rely heavily on resolution agents or chiral HPLC resolution. However, the synthesis of these compounds via asymmetric catalysis remains challenging. In this study, we develop an asymmetric extended side-arm Suzuki–Miyaura cross-coupling strategy to construct inherently chiral pillar[5]arenes with excellent yields and high enantioselectivities using a palladium catalyst and a Sadphos ligand. The reaction scope extends beyond arylboronic acids to encompass 2-arylvinylboronic acids and other multi-OTf-substituted substrates, all efficiently producing the desired products. Further exploration of the synthetic applications, along with photophysical and chiroptical analyses, confirm the potential of these chiral pillar[5]arenes for diverse applications across multiple disciplines. Enantiopure pillar[5]arenes are valued for their roles in host–guest recognition and chiral sensing, but the current synthesis of these compounds via asymmetric catalysis remains challenging. Here, the authors develop an asymmetric extended side-arm Suzuki–Miyaura cross-coupling strategy to construct inherently chiral pillar[5]arenes.