Theoretical analysis of the catalytic cycle of a nickel cross-coupling process: Application of the energetic span model

The nickel-catalyzed cross-coupling of an anhydride with an organozinc reagent was studied theoretically. The energetic span model (Kozuch, S.; Shaik, S. J. Am. Chem. Soc. 2006, 128, 3355; Kozuch, S.; Shaik, S. J. Phys. Chem. A 2008, 112, 6032) was employed in order to analyze the observed kinetic behavior (Johnson, J. B.; Bercot, E. A.; Rowley, J. M.; Coates, G. W.; Rovis, T. J. Am. Chem. Soc. 2007, 1298, 2718). The computed energy profile, combined with the energetic span model, enables modeling faithfully intriguing experimental findings such as the independence of the rate on anhydride concentration, firstorder kinetics with low organozinc concentration, and zero-order kinetics at high concentration. Two species were identified as being responsible for the overall kinetics of the catalytic cycle: the transition state for the product release and the oxidized NiII complex.