Nickel-Catalyzed Asymmetric Domino Ring Opening/Cross-Coupling Reaction of Cyclobutanones via a Reductive Strategy.

Herein we demonstrate the successful application of reductive strategy in the asymmetric domino ring opening/cross-coupling reaction of prochiral cyclobutanones. Under the catalysis of a chiral nickel complex, various aryl iodide-tethered cyclobutanones were reacted with alkyl bromides as the electrophilic coupling partner, providing a variety of chiral indanones bearing a quaternary stereogenic center in highly enantioselective manner, which can be further converted to diverse benzene-fused cyclic compounds including indane, indene, dihydrocoumarin, and dihydroquinolinone. The preliminary mechanistic investigations support a mechanism involving Ni(I)-mediated enantiotopic C-C σ-bond activation of cyclobutanones as key elementary step in the catalytic cycle.