Synthesis of axially chiral 5,5′-substituted 2,2′-bipyridine ligands and their application in palladium-catalyzed asymmetric oxidative [2 + 2] annulation

Abstract

A series of axially chiral 5,5′-substituted 2,2′-bipyridine ligands featuring tunable properties have been synthesized. These ligands have been successfully applied to palladium-catalyzed asymmetric oxidative [2 + 2] annulation of arylboronic acids and alkenes, providing a diverse range of chiral benzocyclobutenes in excellent enantioselectivities with a broad substrate scope.