Abstract
We developed new synthetic methods for seven-membered carbocycles by the nickel-catalyzed cycloaddition of electron-deficient alkylidenecyclopropanes with unsaturated hydrocarbons. The selective cycloaddition proceeded in good yields, and the three-component cocyclization was also realized. The chemo- and regioselectivity is controlled by steric and electronic effect of the sub-strates. Electron-deficient alkylidenecyclopropanes are good substrates as three-carbon units, and a variety of unsaturated hydrocarbons such as alkynes, α, w-diynes, 1, 3-diynes, 1, 3-enynes and 1, 3-dienes was applicable to give cycloheptadienes, cycloheptenes and bicyclic compounds.
