Carbon–hydrogen vs. carbon–halogen oxidative addition of chlorobenzene to a cationic iridium(I) system — A density functional theory study

Abstract

Density functional theory (DFT) is used to explore the competitive C−H and C−Cl oxidative additions (OA) of chlorobenzene to the cationic Ir(I) complex: [(PNP*)IrI]+ [PNP* = 2,6-bis((dimethylphosphino)methyl)pyridine]. Consistent with experimental results, the calculated activation barrier for C−H OA (ΔG‡ = 10.7 kcal mol–1) is lower than that for C−Cl OA (ΔG‡ = 19.7 kcal mol–1). However, the C−Cl OA product is calculated to be thermodynamically preferred as its ΔGo is 14.3 kcal mol–1 below that for the most stable C−H OA product.