Abstract
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=NTs group into the C-Ru bond. Isotope-labeling experiments are performed to understand the underlying mechanism of the reaction. c 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.