Ruthenium(II)‐Catalyzed Synthesis of Indolo[2,1‐a]isoquinolines through Double Oxidative Annulation Reaction of Phenyl Isocyanates with Di(hetero)aryl Alkynes

Indole‐containing polycyclic hetero aromatic compounds are synthesized by multistep process, which have wide application in biological activities and organic semi‐conductor materials. Herein we report the one‐pot method for the synthesis of polysubstituted indolo[2,1‐a]isoquinolines by Ru(II) catalyzed double aryl/hetero aryl C(sp2)−H activation through in‐situ installed carbamide of phenyl isocyanate and di(hetero)aryl substituted alkynes in the presence of Cu(OAc)2.H2O as an oxidant and CsOAc as an additive at 120 °C for 3 h in good to excellent yields.