Effect of the leaving ligand X on transmetalation of organostannanes (vinylSnR₃) with L_nPd(Ar)(X) in stille cross-coupling reactions. A density functional theory study

Density functional theory calculations were carried out to study the effect of different leaving ligands X on transmetalation of organostannanes (vinylSnR₃) with L_nPd(Ar)(X) (X = Cl, Br, I), an important step found in Stille cross-coupling processes. The calculations indicate that the overall activation barriers for the transmetalation process increase in the following order: X = Cl < Br < I. The model phosphine ligands, PH ₃ and PMe₃, were used to investigate this process. It was established that more electron-donating phosphine ligands significantly increase the overall transmetalation barriers.