Complete Reaction Pathway of Ruthenium-Catalyzed Olefin Metathesis of Ethyl Vinyl Ether: Kinetics and Mechanistic Insight from DFT

摘要: Density functional theory calculations accounting for dispersion, thermochemical, and continuum solvent effects have been applied to study the metathesis of ethyl vinyl ether (EVE) as mediated by ruthenium catalysts L(PCy3)(X)2Ru═CHPh (L = PCy3, IMes (1,3-dimesitylimidazol-2-ylidene), H2IMes (1,3-dimesityl-4,5-dihydroimidazol-2-ylidene); X Cl, Br, I) in toluene. The computational approach has validated against experimental data ruthenium-based olefin is found give acceptable accuracy even weakly bound transition states phosphine dissociation association. All relevant stationary points EVE reaction included study, allowing comparison with kinetic (Sanford, M. S.; Love, J. A; Grubbs, R. H.J. Am. Chem. Soc. 2001, 123, 6543). From active 14-electron complex, barriers both association (at a rate proportional k–1) binding (k2) involve contributions from entropy and...