A theoretical study on the feasibility of 1,4-Copper migration in the Cu-catalyzed formal hydro(borylmethylsilyl)ation of internal alkynes.

The 1,n-metal migration process is distinct from traditional bond-forming pathways and offers a unique approach for constructing complex organic architectures. However, in contrast to the well-documented Pd-, Rh-, Fe-, Co-, and Ni-catalyzed migration coupling reactions, studies on Cu-catalyzed variants are scarce. This report describes density functional theory (DFT) calculations aiming to investigate the mechanism of Cu-catalyzed formal hydro(borylmethylsilyl)ation, which is proposed to occur via 1,4-copper migration. The computational results support a metal non-migration mechanism. The stereoselectivity of the reaction is determined by the energy difference between the proton transfer transition state and the anionic releasing transition state after syn-to-anti isomerization. Additionally, DFT calculations were used to evaluate the effects of various substituents on the internal alkyne. Overall, this study offers a solid theoretical basis for experimental investigations into Cu-catalyzed migration coupling reactions.