Silver Triflate and Palladium Acetate Co-catalyzed Reaction of <i>N</i>′-(2-Alkynylbenzylidene)hydrazide with <i>N</i>-Allyl Ynamide

Abstract

A silver triflate and palladium acetate co-catalyzed reaction of <i>N</i>′-(2-alkynylbenzylidene)hydrazide with <i>N</i>-allyl ynamide is described, which generates 2-amino-<i>H</i>-pyrazolo[5,1-<i>a</i>]isoquinolines in good to excellent yield. The transformation proceeds with high efficiency through 6-<i>endo</i> cyclization, [3 + 2] cycloaddition, 3,3-sigmatropic rearrangement, and aromatization