Catalytically Four-Fold Asymmetric Sonogashira Coupling for Enantioselective Synthesis of Tetra-functionalized Planar Chiral Pillar[5]arenes^†

Although asymmetric catalytic synthesis via dynamic kinetic resolution has proven to serve as a powerful tool for the efficient preparation of planar chiral pillar[5]arenes, the enantioselective synthesis of highly-functionalized pillar[5]arenes with more than two functional groups remains rarely explored. To tackle with this challenge, here we demonstrate the enantioselective synthesis of tetra-functionalized planar chiral pillar[5]arenes via catalytically four-fold asymmetric Sonogashira coupling, resulting in the successful synthesis of diverse planar chiral pillar[5]arenes with both high functionalization degree and very high enantioselectivities (in most cases, >99% e.e.). Attractively, facile derivatizations of the resultant planar chiral pillar[5]arenes further give access to chiral functional pillar[5]arenes with wide potential applications, making them promising building blocks for practical uses. This work not only enriches the synthetic methods for planar chiral pillararenes with high functionalization degree but also give access to diverse promising chiral building blocks for widespread applications.