Ni-Catalyzed (A + 2B)-Type Reductive Coupling of Electron-Deficient Alkenes and Alkynes through a Selective Trimerization/1,6-Reduction Cascade

The first nickel-catalyzed (A + 2B)-type reductive coupling of electron-deficient alkenes with alkynes has been developed. This method provides efficient access to diverse α-skipped dienyl esters in up to 99% yield with high chemo- and stereoselectivity. Synthetic utility is demonstrated in the late-stage modification of bioactive molecules and the development of antibacterial agents. Mechanistic studies indicate a stepwise pathway involving selective trimerization of alkenes with alkynes followed by a nickelacycle-mediated formal 1,6-reduction.