Theoretical aspects of palladium-catalysed carbon–carbon cross-coupling reactions

Abstract

Palladium-catalysed processes for the formation of carbon-carbon bonds, i.e., coupling reactions of organic halides (R(1)X) and main-group organometallic compounds (R(2)M) are most frequently applied in synthesizing biologically and pharmaceutically important organic molecules. In this article, we provide a critical review on theoretical studies of the palladium-catalysed carbon-carbon cross-coupling reactions, and give an up-to-date summary of the current understanding of the cross-coupling reactions from a theoretical point of view (108 references).

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.…”

CeO2-encapsulated noble metal nanocatalysts: enhanced activity and stability for catalytic application

“…[1][2][3][4][5][6][7][8][9][10] With the help of noble metal catalysts, environmental friendly catalysis resulting in the decreased production of pollutants, waste minimization and new synthetic routes that circumvent modern synthetic techniques such as Sonogashira-, Heck-and Miyaura-Suzuki-type reactions can be easily realized. [11][12][13][14][15] However, for most technologically important chemical processes, noble metal catalysts spontaneously aggregate and grow to reduce the surface energy, which limits the catalysts' lifetime and efficiency. The ultra-high prices of noble metals have also seriously limited their further development.…”

Combined DFT and experimental studies of C–C and C–X elimination reactions promoted by a chelating phosphine–alkene ligand: the key role of penta-coordinate PdII

“…(1') and the transition state TS 1'→2 together with those of the tetra-coordinate complex cis-[PdMe 2 (4)) and corresponding transition states TS 3'→2 , TS 3→2 , TS 4→2 . Selected bond distances (in Å) and bond angles (in degrees).…”

“…Both 3 and 3' are more stable than [PdMe 2 ( 2 -P,C-L1)] (1) by 4.0 and 5.1 kcal mol -1 , respectively, something consistent with stabilisation of the Pd II centre by the σ-donor ligands. 4 On probing the behaviour of 3 and 3' computationally, the transition states for reductive elimination from each complex have been located (Fig. 1, paths B and C), and lie at ΔG ‡ = 25.6 kcal mol -1 from 3' (ΔG ‡ = 20.5 kcal mol -1 from 1) and 22.2 kcal mol -1 from 3 (ΔG ‡ = 18.2 kcal mol -1 from 1).…”

“…Here, experiment has shown that the rate of reductive elimination is intimately linked not only to the nature of the coupling partners (R), but also to the ancillary ligands (L), in particular to their steric and electronic characteristics. [4][5][6] Complexes that possess sterically demanding ligands have achieved particular success. Not only is their bulk believed to enhance the rate of reductive elimination as a result of the relief of steric congestion about the palladium centre upon product formation, but bulky ligands also promote the formation of low coordinate, unsaturated Pd 0 species that show enhanced reactivity in Pd-catalyzed cross-coupling reactions, particularly in the substrate oxidative addition step.…”