Palladium has played a pivotal role in the enantioselective construction of inherently chiral pillar[5]arenes through the Suzuki-Miyaura cross-coupling process. These pillar[5]arenes have significant applications in various fields like biological medicine, materials science, and supramolecular gels. Enantiopure pillar[5]arenes are particularly valued for their involvement in enantioselective host-guest recognition, chiral sensing, asymmetric catalysis, and related disciplines.

Traditionally, the synthesis of chiral pillar[n]arenes has been challenging, often relying on resolution agents or chiral HPLC resolution. However, this study introduces a groundbreaking approach using palladium-catalyzed asymmetric extended side-arm Suzuki-Miyaura cross-coupling. This innovative strategy allows for the efficient construction of inherently chiral pillar[5]arenes with exceptional yields and high enantioselectivities by utilizing a palladium catalyst and a Sadphos ligand.

The research extends beyond arylboronic acids to include 2-arylvinylboronic acids and other multi-OTf-substituted substrates, all yielding the desired products efficiently. The synthetic applications, along with photophysical and chiroptical analyses, demonstrate the diverse potential applications of these chiral pillar[5]arenes across multiple disciplines.

The study delves into the historical context of cyclic host molecules, emphasizing the critical role of pillar[5]arenes in supramolecular chemistry. The symmetrical pillar architecture of these macrocyclic arenes offers distinct advantages, making them excellent candidates for constructing molecular aggregates through host-guest complexation. Additionally, the inherent chirality of pillar[5]arenes, characterized by the rotation of dialkoxy benzene units, presents unique opportunities for applications in asymmetric catalysis, chiroptical materials, and chiral supramolecular polymers.

The mechanistic investigations shed light on the stereochemical control process involved in the Suzuki-Miyaura cross-coupling, highlighting the significance of ligand design and the catalytic cycle. Through stepwise control experiments and proposed reaction mechanisms, the study elucidates the key factors influencing the stereoselectivity of the reaction.

In conclusion, the development of this enantioselective palladium-catalyzed Suzuki-Miyaura cross-coupling method represents a significant advancement in the synthesis of chiral pillar[5]arenes. The versatile and practical nature of this approach, coupled with its ability to accommodate a wide range of substrates, underscores its potential for diverse applications in material science, self-assembly systems, and beyond.