title: Increased efficiency in cross-metathesis reactions of sterically hindered olefins.
abstract: Efficiency in olefin cross-metathesis reactions is affected upon reducing the steric bulk of N-heterocyclic carbene ligands of ruthenium-based catalysts. For the formation of disubstituted olefins containing one or more allylic substituents, the catalyst bearing N-tolyl groups is more efficient than the corresponding N-mesityl catalyst. In contrast, the formation of trisubstituted olefins is more efficient using the N-mesityl-containing catalyst. A hypothesis to explain this dichotomy is described.
authors.affiliation: The Arnold and Mabel Beckman Laboratory of Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Ian C
authors.initials: IC
authors.lastname: Stewart
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Douglas
authors.forename: Robert H
authors.initials: RH
authors.lastname: Grubbs
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D006571:Heterocyclic Compounds / Q000737:chemistry; D006838:Hydrocarbons / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D000475:Alkenes; D006571:Heterocyclic Compounds; D006838:Hydrocarbons; D009942:Organometallic Compounds; C030011:carbene; D012428:Ruthenium; D008697:Methane