Construction of All-Carbon Quaternary Centers through Cu-Catalyzed Sequential Carbene Migratory Insertion and Nucleophilic Substitution/Michael Addition

A Cu-catalyzed three-component cross-coupling reaction of terminal alkyne, α-diazo ester, and alkyl halide has been developed. This transformation involves sequent migratory insertion of copper-carbene and nucleophilic substitution, in which a C(sp)–C(sp3) bond and a C(sp3)–C(sp3) bond are formed successively on a carbenic center. Michael addition acceptors can also be employed instead of alkyl halides that enable Michael addition to be an alternative way to build C(sp3)–C(sp3) bond. This transformation represents a highly efficient method for the construction of all-carbon quaternary centers.