title: 2-Azanorbornyl alcohols: very efficient ligands for ruthenium-catalyzed asymmetric transfer hydrogenation of aromatic ketones
abstract: 2-Azanorbornyl-derived amino alcohols were prepared and evaluated as ligands in the Ru(II)-catalyzed asymmetric transfer hydrogenation of aromatic ketones. To improve selectivity and rate, the structure of the ligand was optimized. Acetophenone was reduced using 0.5 mol % catalyst in 40 min in 94% ee. This system was also able to reduce a wide range of aromatic ketones to the corresponding alcohols, while maintaining high enantioselectivities and yields. The effects of catalyst loading and the presence of cosolvents in the reaction vessel were examined, and a linearity study was also done.
authors.affiliation: Catalysis Research, Solvias AG, Postfach R-1055.6.17, 4002 Basel, Switzerland.
authors.initials: DA
authors.lastname: Alonso
authors.initials: SJ
authors.lastname: Nordin
authors.initials: P
authors.lastname: Roth
authors.initials: T
authors.lastname: Tarnai
authors.initials: PG
authors.lastname: Andersson
authors.initials: M
authors.lastname: Thommen
authors.initials: U
authors.lastname: Pittelkow