Nickel-Catalyzed Domino Cross-Electrophile Coupling Dicarbofunctionalization Reaction To Afford Vinylcyclopropanes

We
have established a nickel-catalyzed domino reaction that harnesses
sulfonamide, alkyl chloride, and alkyne functionalities in a multistep
sequence to afford vinylcyclopropanes bearing tetrasubstituted olefins.
The starting materials are prepared by iron-promoted aza-Prins reactions
of ynals. This method provides rapid synthetic access to valuable
building blocks with applications in medicinal chemistry. Experimental
and computational results support the initiation of the catalytic
cycle by oxidative addition of the propargylic sulfonamide, and a
key ambiphilic allenylnickel intermediate leads to a bifurcated reaction
pathway that generates olefin isomers.