Intermolecular Addition of Carbon-Centered Radicals to Ynamides. A Regio- and Stereoselective Route to Persubstituted α‑Iodo-enamides

Rather
surprisingly, C–C bond formation through “intermolecular”
radical addition to internal ynamides has never been reported. Actually,
ynamides are excellent acceptors for “electrophilic”
carbon-centered radicals. These processes enable the introduction
of functionalized alkyl chains at Cβ, groups that have not yet
been introduced via the addition of organometallics. Radical carboiodination
affords persubstituted α-iodo-enamides in moderate to high yield.
The addition is totally stereoselective. Theoretical support to the
mechanism and the scope and limitation of the reaction are discussed.