title: Experimental investigations of a partial Ru-O bond during the metal-ligand bifunctional addition in Noyori-type enantioselective ketone hydrogenation.
abstract: The transition state for the metal-ligand bifunctional addition step in Noyori's enantioselective ketone hydrogenation was investigated using intramolecular trapping experiments. The bifunctional addition between the Ru dihydride trans-[Ru((R)-BINAP)(H)(2)((R,R)-dpen)] and the hydroxy ketone 4-HOCH(2)C(6)H(4)(CO)CH(3) at -80 °C exclusively formed the corresponding secondary ruthenium alkoxide trans-[Ru((R)-BINAP)(H)(4-HOCH(2)C(6)H(4)CH(CH(3))O)((R,R)-dpen)]. Combined with the results of control experiments, this observation provides strong evidence for the formation of a partial Ru-O bond in the transition state.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takebayashi
authors.forename: Nupur
authors.initials: N
authors.lastname: Dabral
authors.forename: Mark
authors.initials: M
authors.lastname: Miskolzie
authors.forename: Steven H
authors.initials: SH
authors.lastname: Bergens