Nickel-catalyzed ring-opening alkylative coupling of enone with methylenecyclopropane in the presence of triethylborane.

Nickel-catalyzed alkylative coupling of an enone or enal with methylenecyclopropane in the presence of triethylborane was achieved via stereospecific proximal C–C bond cleavage of methylenecyclopropane. With the use of methylenecyclopropane possessing an acyclic alkyl substituent, this reaction was also accompanied by the β-hydrogen elimination.