“…Treatment of functionalized vinyllithium, 28, with allylmagnesium bromide in the presence of zinc bromide leads to a stereoselectively substituted, metallated cyclopropane, 29, via a tandem metalla-Claisen-cyclization reaction (equation 48) 64 . The produced cyclopropylzinc reagent serves as a unique nucleophilic reagent bearing a quaternary chiral (48) carbon, as exemplified by the conversion into the corresponding bromo-and iodocyclopropanes with bromine and iodine, respectively, and into a copper reagent, via metal-metal exchange, from which a variety of stereoselectively 1,1,2-trialkylated cyclopropanes are prepared.…”