Abstract: Chiral ligands serve as the cornerstone of transition-metal-catalyzed asymmetric synthesis, with their scaffold architectures critically governing the activity and stereoselectivity of the catalytic systems. Planar chiral [2.2]paracyclophane (PCP) represents a class of privileged chiral building blocks featuring a unique rigid framework, in which configurationally stable planar chirality is generated through asymmetric substitution of the benzene rings. Since 2019, this field has undergone explosive advance ment: ligand design has evolved from conventional phosphorus- and nitrogen-containing ligands to innovative π- coordinated catalysts, with applications encompassing asymmetric hydrogenation, C-C bond coupling, cycloaddition, and C-H activation reactions. This review systematically delineates the scaffold structures, stereochemical characteristics, and representative catalytic applications of planar chiral PCP-based ligands. By employing a comparative pedagogical approach with classic chiral skeletons, it addresses two prevalent misconceptions in undergraduate organic chemistry instruction—namely, that “restricted rotation of aromatic rings necessarily confers axial chirality” and that “planar chirality invariably arises from disubstitution of the molecular framework”. This work thus offers an accurate, state-of-the-art, and pedagogically stimulating reference for teaching organic chemistry and asymmetric catalysis.

Key words: [2.2]Paracyclophane (PCP), Planar chirality, Chiral ligand, Asymmetric catalysis, Chirality teaching