同核铁系双金属络合物及其在均相催化体系中的应用

随着合成化学的不断发展,开发高活性催化剂来活化一些惰性化学键或者惰性分子受到越来越多的关注。双核金属络合物作为一类特殊的催化剂展现出了不同于单核金属催化剂的催化活性。在双核过渡金属催化体系中,因两个金属中心存在协同作用而表现出了独特的催化活性。铁、钴、镍为第四周期第VIII族元素,也称为铁系元素。该类金属廉价易得且参与的催化反应种类繁多,近年来引起了人们的广泛关注。本综述重点介绍了近年来同核双金属铁系络合物的合成及其表征。同时,对相关同核铁、钴以及镍催化剂在均相催化体系中的应用也进行了详细的介绍和总结。

Homodinuclear Ferrous Group Metal Complexes and Their Application in Homogeneous Catalysis

With the development of synthetic chemistry, more and more efficient catalysts are exploited to activate inert chemical bonds and organic molecules. In the synthetic chemistry, catalysts play an important role, scientists are paying more and more attention to the design and synthesis of catalysts. The majority of catalysts in homogeneous catalytic systems belong to mononuclear active species. In addition to the development of catalysis science, major research is also being conducted on the development of the coordination environment for metal centers to increase their catalytic ability and thereby create enhanced catalytic processes. The catalytic activity of dinuclear catalysts varies from those of mononuclear catalysts. Due to the synergistic effect between the two metal centers, the catalytic activity of dinuclear catalytic systems exhibits particular performance characteristics. The first row of elements in group Ⅷ of the periodic table, Fe, Co, and Ni, are also known as the ferrous group. These metals have drawn attention in recent years because of their relatively low price, stable structure, commercial availability, and ability to catalyze various type of reactions. Homodinuclear ferrous group metal complexes are applied in a wide variety of reactions, including hydroboration, hydrosilylation, cross-coupling reactions, asymmetric 1, 4-addition, asymmetric Mannich reactions, CO₂ activation, copolymerization, and alkyne cyclotrimerizations. Compared with mononuclear metal catalytic systems, there are currently relatively few types of homogenous catalytic systems that are catalyzed by bimetal catalysts. However, such catalytic systems possess significant advantages over mononuclear catalytic systems. For example, the catalytic activity and reaction selectivity of dinuclear metal catalytic systems are far superior, the reaction conditions milder, and the operations required simpler. However, research on the mechanisms of dinuclear metal catalytic systems is still insufficient. For example, the interaction between metals and substrates requires further investigation. This review focusses on the synthesis and characterization of homodinuclear bimetallic iron complexes. The application of homodinuclear iron, cobalt, and nickel complexes in homogeneous catalytic systems is introduced and summarized in detail. Finally, the challenges for the future development of homogeneous catalytic systems that utilize homodinuclear bimetallic iron complexes are outlined.