A DFT Study of the Full Catalytic Cycle of the Suzuki−Miyaura Cross-Coupling on a Model System

Abstract

A computational study with the Becke3LYP DFT functional is carried out on the cross-coupling reaction of vinyl bromide H 2 CdCHBr and vinylboronic acid H 2 CdCHB(OH) 2 catalyzed by palladium diphosphine [Pd(PH 3 ) 2 ] in the presence of an excess of base OH -. The full catalytic cycle is computed, starting from the separated reactants and the catalyst and finishing with the cross-coupled product and the regeneration of the catalyst. The different stages in the cycle (oxidative addition, isomerization, transmetalation, reductive elimination) are characterized through calculation of the corresponding intermediates and transition states. Different alternative mechanisms are considered, depending on the number of phosphine ligands at palladium, and on the cis or trans isomery around the metal center. The results indicate the existence of a number of competitive pathways of reasonably low energy.

Enhanced Catalytic Activity of High-Index Faceted Palladium Nanoparticles in Suzuki–Miyaura Coupling Due to Efficient Leaching Mechanism

“…Atom abstraction energies for a 3 nm spherical Pd nanoparticles were calculated to be 45 kcal mol Before reaction oxidative addition of aryl iodides and transmetalation to be 20-25 kcal mol -1 . [52][53] The relatively high activation energies for Pd leaching support the consensus that leaching is the rate-determining step. The surface atomic structure influences the stability and leaching susceptibility of Pd atoms and consequently catalytic activity.…”

Reaction Site Diversity in the Reactions of Titanium Hydrazides with Organic Nitriles, Isonitriles and Isocyanates: TiNα Cycloaddition, TiNα Insertion and NαNβ Bond Cleavage

“…These results are consistent with the experimental observation that pyridine is readily dissociated from 24 in solution. Note that entropy changes (DS) in the gas phase are overestimated with respect to those expected in solution, [40] and therefore, the associated DG values always disfavour the association of molecules.…”

A Quantum-Chemical DFT Approach to Elucidation of the Chirality Transfer Mechanism of the Enantioselective Suzuki–Miyaura Cross-Coupling Reaction

“…The different possibilities of transmetallation reaction that may take place in the second stage of the asymmetric SM reaction were assessed. It has been shown that the transmetallation step in a typical SM coupling reaction does not proceed without the nucleophilic additive, which enhances the electron density at the boron atom through its coordination and formation of boron-ate adduct [20,21,24,65,66]. In an aqueous solution of inorganic bases, the role of this nucleophile may be played by the hydroxyl anion.…”