Preparation of Organozinc Reagents via Catalyst Controlled Three-Component Coupling between Alkyne, Iodoarene, and Bis(iodozincio)methane.
Yukako ShimadaZenichi IkedaSeijiro MatsubaraPublished in: Organic letters (2017)
Three-component coupling between an alkyne, iodoarene, and bis(iodozincio)methane yields allylic zinc with a tetrasubstituted alkene moiety in the presence of a nickel catalyst. The reaction proceeds via aryl nickelation of the alkyne and subsequent cross-coupling with bis(iodozincio)methane. Meanwhile, the same combination in the presence of a palladium and cobalt catalyst gives tetrasubstituted alkenylzinc. The reaction proceeds via a palladium-catalyzed cross-coupling of iodoarene with bis(iodozincio)methane followed by a cobalt-catalyzed benzylzincation of alkyne.