Ru(ii) catalyzed chelation assisted C(sp2)–H bond functionalization along with concomitant (4 + 2) annulation

Ru( ii )-assisted C(sp 2 )–H functionalization along with (4 + 2) annulation leads to coumarin-fused pyridone, highly decorated N-heteroarenes and pyridine- N -oxides; the protocol also induces double C–H activation to the benzimidazole–coumarin conjugates.