Zinc-Catalyzed Alkyne–Carbonyl Metathesis of Ynamides with Isatins: Stereoselective Access to Fully Substituted Alkenes

A zinc-catalyzed intermolecular alkyne–carbonyl
metathesis
reaction of ynamides with isatins followed by an amide to ester conversion
has been developed, which produces the indolone derivatives with a
fully substituted alkene species in good to high yields. The salient
features of this reaction include the following: mild reaction conditions,
an inexpensive zinc catalyst, a broad substrate scope, the excellent
regiocontrol and stereoselectivity, and amenable to the gram
scale.