DFT Study of the Mechanisms of Transition-Metal-Catalyzed Reductive Coupling Reactions

The mechanism studies of transition-metal-catalyzed reductive coupling reactions investigated using Density Functional Theory calculations in the recent ten years have been reviewed. This review introduces the computational mechanism studies of Ni-, Pd-, Cu- and some other metals (Rh, Ti and Zr)-catalyzed reductive coupling reactions and presents the methodology used in these computational mechanism studies. The mechanisms of the transition- metal-catalyzed reductive coupling reactions normally include three main steps: oxidative addition; transmetalation; and reductive elimination or four main steps: the first oxidative addition; reduction; the second oxidative addition; and reductive elimination. The ratelimiting step is most likely the final reductive elimination step in the whole mechanism. Currently, the B3LYP method used in DFT calculations is the most popular choice in the structural geometry optimizations and the M06 method is often used to carry out single-point calculations to refine the energy values. We hope that this review will stimulate more and more experimental and computational combinations and the computational chemistry will significantly contribute to the development of future organic synthesis reactions.