Expedient synthesis of new cinnoline diones by Ru-catalyzed regioselective unexpected deoxygenation-oxidative annulation of propargyl alcohols with phthalazinones and pyridazinone

Abstract

Ruthenium-catalyzed simple, cascade and one-pot synthesis of cinnoline-fused diones has been carried out by the C–H activation of phthalazinones/pyridazinones accomplished by the unusual deoxygena- tion of propargyl alcohols. The bond selectivity is accredited to the traceless directing nature of the hydroxyl group of propargyl alcohol. A sequential C–H activation, insertion and deoxy-oxidative annulation hasbeenproposedbasedonthepre liminary mechanistic study.