Cobalt-Catalyzed2+2Cycloaddition

摘要

Garbocyclic four-membered rings can be synthesized by cycloaddition reactions through the photochemical conversion of alkenes into cyclobutanes or thermal2+2cycloaddition reactions of acceptor-substituted alkynes with alkenes to give cyclobutenes.Transition-metal-catalyzed reactions of non-activated starting materials,which only undergo thermal cycloaddition under harsh conditions,are usually carried out with ruthenium or rhodium complexes,or alternatively with cobalt or nickel complexes.