Enantioselective Construction of Planar‐Chiral Molecules by Catalytic Asymmetric Late‐Stage Functionalizations

Planar chirality, as one of the most important manifestations of chirality, is frequently employed to constrain three‐dimensional chiral configurations. Recent advancements in the study of planar chirality by chemists have opened up innovative possibilities for designing new catalysts, developing novel drugs, and creating new optical materials. However, the flexible ansa chains present a challenge during the synthesis process of these unique planar‐chiral macrocycles, hindering chemists from achieving high enantioselectivity. In this mini review, we primarily introduce the catalytic asymmetric synthesis methods that have been reported for late‐stage functionalization of planar macrocycles to generate planar chirality. Additionally, we present several recent examples of catalytic enantioselective synthesis of mechanically planar‐chiral rotaxanes through late‐stage functionalization methods. The sources of stereoselectivity are also discussed in this mini review. We aim to inform more researchers about this field and attract chemists to engage in this important and scientifically significant area of research.