Ruthenium(II)-Catalyzed CH Bond Activation: An Efficient Route toward Indenamines

An efficient and atom‐economical method for the synthesis of substituted indenamines from N‐tosylarylimines and alkynes via ruthenium(II)‐catalyzed CH bond activation and annulation is described. The catalytic reaction proceeds well with a broad substrate scope and in good yields. A possible mechanism is proposed that involves imine nitrogen chelation‐assisted ortho‐CH bond activation of the substrate, alkyne insertion, and intramolecular insertion of the CN Ts group into the CRu bond. Isotope‐labeling experiments are performed to understand the underlying mechanism of the reaction. Atomic bean counters succeed! An efficient and atom‐economical method for the synthesis of substituted indenamines from N‐tosylarylimines and alkynes via ruthenium(II)‐catalyzed CH bond activation and annulation is described.