Central Chirality via Asymmetric C ( sp 2 )– H Activation Implying Desymmetrization and Kinetic Resolution

Small chiral molecules, presenting a stereogenic atom as a chirality element, are ubiquitous structures in natural products and biologically active scaffolds. Accordingly, the design of new synthetic routes to build up such molecules is a vivid research field. In this context, asymmetric C–H activation is a unique, modern, and sustainable approach. In particular, due to a high reactivity of aromatic compounds toward direct metalation, the last decade has been witnessing an emergence of stereoselective C(sp2)–H functionalization reactions. Asymmetric outcome of such transformations may be expected when using a prochiral substrate, presenting two identical aromatic substituents that may undergo stereoselective desymmetrization. Alternatively, if a racemic substrate is used, a chiral catalyst should be able to distinguish the two enantiomers of a substrate, allowing selective functionalization of a single enantiomer yet implying kinetic resolution. These approaches turned out to be relevant not only to access C-stereogenic molecules but also to synthesize original P-, Si-, and S-chiral scaffolds.