Reductive Elimination or C–C bond Activation with Model Ni, Pd, Pt Complexes? A High-Accuracy Comparative Computational Analysis of Reactivity
The development of Pd- and Ni-catalyzed reactions for C–C bond formation is one of the primary driving forces in modern organic synthesis and the fine chemical industry. However, understanding the role of conformational mobility in reaction mechanisms is a long-standing challenge. We highlight the effect of a multirotamer (multiconformer) system on the effective Gibbs free energy of activation in the key C–C coupling process and promote the use of a simplified version of multiconformer transition state theory that is straightforward to apply. Multivariate regression helped to quantitatively map the effect of coupled organic substituents (their structural and electronic parameters), as well as to determine the relative activity of metals. We provide computational evidence for solvent control of the equilibrium in RE/C–C-bond activation for some model complexes. We also demonstrate that Ni complexes, being unique in the catalysis of sp3-sp3couplings, can be more challenging for machine learning and computational chemistry. The modeling was performed at an exceptionally high level, DLPNO-CCSD(T)/CBS//RIJCOSX-PBE0-D4/def2-TZVP. The Conclusions section contains an infographic summarizing the key findings related to the fields of cross-coupling catalysis, machine learning in catalysis, and computational chemistry.
Reference: Eur. J. Inorg. Chem., 2022, e202200572
