Ligand‐Enabled Enantioselective C sp 3 –H Activation of Tetrahydroquinolines and Saturated Aza‐Heterocycles by Rh I

The first rhodium(I)‐catalyzed enantioselective intermolecular Csp3–H activation of various saturated aza‐heterocycles including tetrahydroquinolines, piperidines, piperazines, azetidines, pyrrolidines, and azepanes is presented. The combination of a rhodium(I) precatalyst and a chiral monodentate phosphonite ligand is shown to be a powerful catalytic system to access a variety of important enantio‐enriched heterocycles from simple starting materials. Notably, the Csp3–H activation of tetrahydroquinolines is especially challenging due to the adjacent Csp2−H bond. This redox‐neutral methodology provides a new synthetic route to α‐N‐arylated heterocycles with high chemoselectivity and enantioselectivity up to 97 %  ee .