The atom-economical synthesis of carbocyclic eight-membered rings from double-and triple- bond systems is a forte of organometallic catalysis. Nickel-catalyzed cyclotetramerizations of alkynes [1] and dimerizations of 1, 3-butadienes with nickel or iron catalysis [2] are among the most common representatives of this class of reaction. One of the limiting aspects of these intermolecular reactions is the required use of identical starting materials. To our ...
