Synthesis and structural characterization of a highly effective chiral dipyridylphosphine ligand and its application in the Ru-catalyzed asymmetric hydrogenation of β-ketoesters

摘要

A new chiral dipyridylphosphine ligand Tol-P-Phos has been synthesized and the structure of the complex of (R)-Tol-P-Phos oxide with (-)-dibenzoyl-L-tartaric acid [(-)-DBT] was determined by single crystal X-ray diffraction. The ruthenium complex of Tol-P-Phos, Ru(R-Tol-P-Phos)(C6H6)Cl2, has been found to be a highly active and enantioselective catalyst in the asymmetric hydrogenation of β-ketoesters (up to 98.2% e.e.). The catalyst is also found to be air-stable even in solution.