Silver(I)-Promoted [3 + 3]-Cycloaddition of 2-(2-Enynyl)quinolines with N′-(2-Alkynylbenzylidene)hydrazides

An effective and straightforward Ag(I)-mediated annulation of 2-(2-enynyl)quinolines and N'-(2-alkynylbenzylidene)hydrazides was developed, forging various synthetically challenging 17bH-isoquinolino[2'',1'':1',6']pyridazino[4',5':3,4]pyrrolo[1,2-a]quinolines, including different nitrogen-containing fused rings, in moderate to excellent yields. This one-pot cycloaddition strategy features exclusive regioselectivity, high atom economy, and broad substrate scope under mild conditions. The practicality and reliability of this cycloaddition reaction was demonstrated by a successful scale-up synthesis.