[2+2+2] Cycloaddition Reactions Catalyzed by Transition Metal Complexes



Recent progress in the synthesis of benzene and 1,3-cyclohexadiene derivatives, and heterocyclic compounds such as pyridines, pyridones, pyrans, pyrimidine diones, etc, has been reviewed. The general mechanistic aspects of the [2+2+2] cycloaddition reaction are discussed. The asymmetric variants of these reactions are also discussed along with the proposed models of asymmetric induction.