Theoretical Study of Ni ‐ C atalysis

Ni can easily acquire or lose an electron and thus exists in the form of Ni free radicals. As result, +1 and +3 are also common oxidation states of Ni in some catalytic cycles, which undoubtedly further increases the mechanistic complexity of Ni-catalysis. In this chapter, sections are majorly divided by the corresponding Ni-activated substrates. Many theoretical studies have focused on the mechanism of Ni-mediated C—halogen bond cleavage process, which is discussed in this chapter. In Pd chemistry, a carboxylate-assisted C—H bond activation and functionalization through a concerted metalation–deprotonation mechanism is a very common process; however, as a congener, this type of reaction is less in Ni catalysis. According to the reducibility of Ni(0) species, even stable C—O covalent bonds can be activated by Ni(0), while the formed alkyl or aryl Ni(II) intermediate can be obtained by oxidative addition to break the C—O bonds.