Acta Physico-Chimica Sinica ›› 2019, Vol. 35 ›› Issue (9): 913-922.doi: 10.3866/PKU.WHXB201809036

Special Issue: 碳氢键活化

• Review • Previous Articles     Next Articles

Bimetallic C―H Activation in Homogeneous Catalysis

Yuanyuan HU1,2,Congyang WANG1,2,*()   

  1. 1 Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
    2 University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2018-09-21 Accepted:2018-10-25 Published:2018-10-29
  • Contact: Congyang WANG E-mail:wangcy@iccas.ac.cn
  • About author:WANG Congyang obtained his B.S. degree from Nanjing University in 2000 and his Ph.D. degree from Peking University under the guidance of Prof. Zhenfeng Xi in 2005. After a postdoctoral stay in the same group, he moved to the University of Münster, Germany, working with Prof. Frank Glorius as an Alexander von Humboldt Research Fellow. In 2010, he started his independent research career at Institute of Chemistry, Chinese Academy of Sciences as a professor. In 2015, he became a joint professor at the University of Chinese Academy of Sciences (UCAS). Currently, his research interest focuses on manganese-group-metal catalysis
  • Supported by:
    The project was supported by the National Natural Science Foundation of China(21472194);The project was supported by the National Natural Science Foundation of China(21772202);The project was supported by the National Natural Science Foundation of China(21521002)

Abstract:

The strategy of transition-metal-catalyzed C―H activation has been greatly developed in recent years. Direct transformations of inert C―H bonds undoubtedly provide powerful ways to construct various C―C and C―X (X = heteroatom) bonds, with enhanced atom- and step-economy. Impressive efforts have been devoted to this research all along. However, concerns about reactivity and selectivity remain to be tackled, due to their strong dependence on directing groups and acidic reactive sites. In this regard, more effective catalytic systems are of great importance and therefore in high demand. Bimetallic C―H activation, by virtue of the cooperative effect, has emerged as a promising solution to this issue. The intriguing interactions between two metals with substrates afford exceptional reaction efficiency and selectivity. Intensive interest in both experimental and computational studies has been recently triggered. In this minireview, diverse bimetallic catalytic reactions are summarized into three categories according to the initiator in the C―H activation step, namely, bimetallic catalyses based on palladium, nickel, and other metals. Experimental results as well as density functional theory (DFT) calculations are invoked in the plausible mechanistic considerations. In the first part, collaborative modes based on palladium are described, in which magnesium, chromium, cobalt, and silver are successfully engaged as accessory partners. Most of them stabilize the C―H activation transition states by decreasing the energy, thus facilitating the cleavage of C―H bonds. Notably, some reactions previously reported as examples of monomeric palladium catalysis are now reinvestigated as bimetallic scenarios, in light of computational discussions. In the second part, reactions based on the synergy of nickel, and zinc or aluminum, are generalized, in which zinc or aluminum acts as a Lewis acid to increase the acidity of C―H bonds. It has been shown that the choice of different kinds of Lewis acids and ligands has a great influence on the reaction chemo-, regio-, and stereoselectivity. Gratefully, even enantioselective transformations can be achieved using the cooperation of nickel and aluminum. Moreover, a key reaction intermediate in the bimetallic C―H activation by nickel and aluminum has been isolated, providing guidance for this bimetallic catalytic system in further mechanistic studies and applications. In the last part, synergetic catalysis based on various other metals is presented. Bimetallic regimes of ruthenium/copper, rhodium/bismuth, iridium/aluminum, manganese/zinc, and zirconium/aluminum have been elegantly applied to C―H activation reactions. Multifarious action modes are proposed on account of the mechanistic research.

Key words: Bimetallic synergy, C―H activation, Reaction mechanism, Homogeneous catalysis, Organic synthesis

MSC2000: 

  • O643