Aminoquinoline-based Ruthenium catalyst for reduction of ketones by hydrogen transfer

1. Introduction Asymmetric reduction of C=O and C=N bonds to give chiral alcohols and amines is one of the more relevant applications of transition metal catalysis [1]. A striking improvement in hydrogenation or reduction by hydrogen transfer is due to Noyori and more recently to Rigo and co-workers with the development of Ru(II) catalysts bearing chiral diamine ligands [2]. 2. Results and Discussion Here we present our results in hydrogen transfer reduction of aryl ketones with (S)- or (R)-8-amino-5,6,7,8-tetrahydroquinoline (hereafter defined CAMPY). The diphoshines (the counter ligands) used are the achiral triphenylphosphine, DPPB, DPPP and chiral BDPP, BDPH and Zedphos [3]. CAMPY is characterized by the presence of a fused ring; we will discuss the effects of such rigidity on matching/mismatching with the chiral diphosphines and the chirality at the metal centre on both enantioselectivity and activity. 3. References [1] Asymmetric Catalysis on Industrial scale; H.U.Blase, E.Schmidt Eds, Wiley-VCH 2004 [2] P.Rigo, W.Baratta; Eur.J.Inorg.Chem. 2008, 4041. [3] E.Cesarotti, I.Rimoldi, P.Spalluto, F.Demartin; Tetrahedon: Asimmetry, 2007, 1278.