摘要：

The transition-metal-catalyzed cycloisomerizations of α,ω- dienes have been continuously investigated because such cycloisomerization reactions provide atom-economical routes to various carbo- and heterocyclic compounds. Nevertheless, early catalytic systems generally lacked the requisite isomeric selectivity and the general substrate scope. Considerable efforts devoted to the identification of selective and versatile catalyst systems have led to recent developments of late-transitionmetal-catalyzed cycloisomerizations of 1,6-dienes with wide substrate scope and high isomeric selectivity, including asymmetric cycloisomerizations. There is, nevertheless, room for improvement of the substrate scope, the isomeric selectivity, and the enantiomeric selectivity. In addition, by combining the newly developed catalytic systems with state-of-the-art techniques such as a microwave treatment and the use of unique solvent systems, further progress in diene cycloisomerizations is being made possible. For xample, recyclable catalyst systems for the 1,6-diene cycloisomerization have been established using ionic liquids and scCO2 as solvents. Further investigations into the utilization of heterogeneous catalysts and carbophilic Lewis acid catalysts as well as less examined substrates would result in the development of unprecedented modes of cycloisomerization and would increase the synthetic value of α,ω-diene cyclization.

展开