DFT Studies of Ru-Catalyzed C–O versus C–H Bond Functionalization of Aryl Ethers with Organoboronates

Density functional theory calculations have been performed to investigate how different nucleophiles and directing groups affect the preference of C–H versus C–O bond functionalization in the ruthenium-catalyzed coupling reactions of aryl ethers with organoboronates. Our results indicate that the preference depends on the relative stability of the transition state structures for the C–O bond activation in the C–O bond functionalization pathway and the transmetalation with boronate to form a Ru–C bond in the C–H bond functionalization pathway. When the transition state structure for the transmetalation with boronate lies lower in energy than that for the C–O bond activation, C–H bond functionalization is preferred, and vice versa. How different nucleophiles and directing groups affect the relative stability of the transition structures has been discussed in detail.