Enantioselective Palladium‐Catalyzed Carbene Insertion into the N−H Bonds of Aromatic Heterocycles

C3‐substituted indoles and carbazoles react with α‐aryl‐α‐diazoesters under palladium catalysis to form α‐(N‐indolyl)‐α‐arylesters and α‐(N‐carbazolyl)‐α‐arylesters. The products result from insertion of a palladium‐carbene ligand into the N−H bond of the aromatic N‐heterocycles. Enantioselection was achieved using a chiral bis(oxazoline) ligand, in many cases with high enantioselectivity (up to 99 % ee). The method was applied to synthesize the core of a bioactive carbazole derivative in a concise manner. Pharmacophores made easy: Palladium catalyzes the insertion of α‐arylester carbene ligands into the N−H bonds of heterocycles to afford α‐(N‐indolyl)arylesters and α‐(N‐carbazolyl)arylesters in good yields and up to 99 % ee. The method enables a concise route to the core of a bioactive carbazole derivative.