Comprehensive Mechanistic Insight into Cooperative Lewis Acid/Cp*CoIII-Catalyzed C-H/N-H Activation for the Synthesis of Isoquinolin-3-ones.

The mechanism of B(C6F5)3 promoted Cp*CoIII-catalyzed C-H functionalization was investigated in detail employing density functional theory (DFT). The formation free energy of every possible species in the multicomponent complex system was explored and the optimal active catalyst was screened out. The results uncover the role of B(C6F5)3 played in forming active catalyst is from the coordination with OAc-, but not from the formation of [I(C6F5)3B]-, and no acceleration effect is found in C-H activation as well as the formation of CoIII-carbene intermediate. Moreover, present theoretical results elucidate the Cp*CoIII-catalyzed C-H activation is mediated by imine N-coordination other than general proposed the sequence of N-deprotonation directed C-H activation. The metal-controlled C-H/N-H selectivity was then elucidated by insighting into [Cp*CoIIIOAc]+/[Cp*RhIIIOAc]+-catalyzed C-H and N-H activations, respectively.