Crystal structure of chiral binaphthol lanthanide complexes and their catalysis in asymmetric transfer hydrogenation of acetophenone

Heterometallic [(THF) 2 Na] 3 [Ln( R ‐Binolate) 3 (H 2 O)] [Ln = Sm ( 1 ) and Gd ( 2 )] has been synthesized by the reactions of either LnCl 3 or LnBr 3 with 3 equiv. Na( R ‐HBinolate) and characterized by X‐ray crystallographic analysis. Structural analyses proposed that 1 and 2 are isomorphous complexes, crystallizing in the hexagonal space group P6 3 with C 3 symmetry. The coordination geometry of the lanthanide ions in 1 and 2 can be best approximated as a mono‐capped triangle antiprism. When complexes 1 and 2 were employed as catalysts in the Meerwein–Ponndorf–Verley (MPV) reactions of acetophenone, the S ‐phenylethanol was separated in 94 and 85% enantiomeric excess (e.e.) for 1 and 2 , respectively. Copyright © 2005 John Wiley & Sons, Ltd.