DFT Studies on Ligand Controlled Highly Selective Copper‐Catalyzed Borylations of Allenes

Abstract

AbstractThe mechanism of the Cu‐catalyzed borylations of allenes with bis (pinacolato) diboron has been studied by DFT calculations. The possible pathways involve two key steps, borylcupration and γ‐protonolysis. Computed results show that the γ‐protonolysis step is not only the rate‐limiting step but also determines the regioselectivity. When employing monophosphine P(p‐MeOC6H4)3 as the ligand, the electronic and steric effects are both effective in the control of regio‐ and stereoselectivity; however, for sterically hindered bulky bisphosphine ligand BIPHEP, it is the steric hindrance that reverses the regioselectivity of the γ‐protonolysis process.