**7. Synthesis of** *N***-heterocycles** *via* **Ru(II)-catalyzed C-H/N-H dual activation and alkyne annulation reactions**

Simultaneously activation of C-H and N-H bonds occurs when the nitrogen atom of the directing group possesses an acidic hydrogen atom. The active Ru(II) catalyst first forms a cyclic Ru complex via a concerted deprotonative metalation generally through acetate/carboxylate assisted N-H/C-H activation. A subsequent alkyne insertion and reductive elimination of the ruthenium affords various *N*-hetreocyclic molecules particularly pyrroles, 2-pyridones, indoles, isoquinolines/isoquinolones derivatives, and various others π-conjugated polycyclic *N*-heteroaromatic molecules in a step-economical fashion *via* C-C and C-N bond formation [35–58].
