Preparation of Organozinc Reagents via Catalyst Controlled Three-Component Coupling between Alkyne, Iodoarene, and Bis(iodozincio)methane
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.
Investigations on the Suzuki-Miyaura and Negishi couplings with alkenyl phosphates: Application to the synthesis of 1,1-disubstituted alkenes
(Chemical Equation Presented) The development of versatile Suzuki-Miyaura and Negishi cross-couplings with nonactivated alkenyl phosphates and aromatic boronic acids or organozinc reagents was achieved in acceptable to good yields. A series of 1,1-disubst
Hansen, Anders L.,Ebran, Jean-Philippe,Gogsig, Thomas M.,Skrydstrup, Troels