title: Enantioselective olefin metathesis with cyclometalated ruthenium complexes.
abstract: The success of enantioselective olefin metathesis relies on the design of enantioenriched alkylidene complexes capable of transferring stereochemical information from the catalyst structure to the reactants. Cyclometalation of the NHC ligand has proven to be a successful strategy to incorporate stereogenic atoms into the catalyst structure. Enantioenriched complexes incorporating this design element catalyze highly Z- and enantioselective asymmetric ring opening/cross metathesis (AROCM) of norbornenes and cyclobutenes, and the difference in ring strain between these two substrates leads to different propagating species in the catalytic cycle. Asymmetric ring closing metathesis (ARCM) of a challenging class of prochiral trienes has also been achieved. The extent of reversibility and effect of reaction setup was also explored. Finally, promising levels of enantioselectivity in an unprecedented Z-selective asymmetric cross metathesis (ACM) of a prochiral 1,4-diene was demonstrated.
authors.affiliation: Arnold and Mabel Beckman Laboratories of Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: John
authors.initials: J
authors.lastname: Hartung
authors.forename: Peter K
authors.initials: PK
authors.lastname: Dornan
authors.forename: Robert H
authors.initials: RH
authors.lastname: Grubbs
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D003500:Cyclization; D003503:Cyclobutanes / Q000737:chemistry; D008958:Models, Molecular; D009636:Norbornanes / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D056831:Coordination Complexes; D003503:Cyclobutanes; D009636:Norbornanes; D012428:Ruthenium