AgOTf/CuI–Co-catalyzed Tandem Alkynylation–Cyclization Reaction of N-Iminoisoquinolinium Ylide

Peng et al. have reported silver triflate and copper(I) iodide co-catalyzed tandem alkynylation–cyclization reaction using N’-(2-alkynylbenzylidene)hydrazide as a starting material. In this reaction, in situ-formed N-iminoisoquinolinium ylides react with bromoalkyne at the α–hydrogen of these ylides. Under mild conditions, the subsequent cyclization reaction proceeds in one pot leading to the corresponding H-pyrazolo[5,1-α]isoquinolines.