Asymmetric transition metal complexes useful for enantioselective reduction of ketones by hydride transfer

摘要

Asymmetric metal complexes in which the metal is a transition metal. Asymmetric metal complexes in which the metal is a transition metal and the ligand is of formula (I). R = H, 1-12C alkyl optionally interrupted by one or more O or S atoms and optionally substituted by one or more halos, phenyl or benzyl, 2-10C alkenyl or alkenyl optionally interrupted by one or more O or S atoms and optionally substituted by one or more halos, a group SO2R1 or COR1; R1 = 1-12C alkyl, 3-12C cycloalkyl, 6-12C aryl optionally substituted by alkyl, 7-15C aralkyl, these groups being substituted by at least one halo, ether, tertiary amine or thioether, or a halogenated group selected from poly- or perhalogenated 1-10C alkyl or 3-10C cycloalkyl, phenyl substituted by poly- or perhalogenated 1-4C alkyl, or mono-, poly- or perhalogenated phenyl; R2 = 1-12C hydrocarbon which may be acyclic or cyclic, saturated unsaturated or aromatic, and may be substituted and may be interrupted by O or an electroattracting group; A = a mono- or polycyclic aromatic group which may contain one or more heteroatoms Independent claims are also included for: (1) the use of these complexes in the enantioselective reduction of a ketone by hydride transfer; and (2) preparation of an optically-active secondary alcohol.