A Facile Route to H-Pyrazolo[5,1-a]isoquinolines through a Multicomponent Reaction of 2-Alkynylbenzaldehyde, Sulfonylhydrazine, and Benzyne

A facile and efficient route for the generation of H-pyrazolo[5,1-a]isoquinolines via a silver triflate catalyzed three-component reaction of 2-alkynylbenzaldehyde, tosylhydrazine, and benzyne is reported. This reaction proceeds smoothly under mild conditions with high efficiency.