title: Synthesis of Molybdenum and Tungsten Alkylidene Complexes That Contain Sterically Demanding Arenethiolate Ligands.
abstract: Imido alkylidene complexes of Mo and W and oxo alkylidene complexes of W that contain thiophenoxide ligands of the type S-2,3,5,6-Ph4C6H (STPP) and S-2,6-(mesityl)2C6H3(SHMT = S-hexamethylterphenyl) have been prepared in order to compare their metathesis activity with that of the analogous phenoxide complexes. All thiolate complexes were significantly slower (up to ∼10× slower) for the metathesis homocoupling of 1-octene or polymerization of 2,3-dicarbomethoxynorbornene, and none of them wasZ-selective. The slower rates could be attributed to the greater σ-donating ability of a thiophenoxide versus the analogous phenoxide and consequently a higher electron density at the metal in the thiophenoxide complexes.
authors.affiliation: Department of Chemistry 6-331, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Erik M
authors.initials: EM
authors.lastname: Townsend
authors.affiliation: Department of Chemistry 6-331, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Jakub
authors.initials: J
authors.lastname: Hyvl
authors.affiliation: Department of Chemistry 6-331, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: William P
authors.initials: WP
authors.lastname: Forrest
authors.affiliation: Department of Chemistry 6-331, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Richard R
authors.initials: RR
authors.lastname: Schrock
authors.affiliation: Department of Chemistry 6-331, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Müller
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States.
authors.forename: Amir H
authors.initials: AH
authors.lastname: Hoveyda