Precious transition metals, such as rhodium, iridium, and ruthenium, play a crucial role in homogeneous catalysis of asymmetric hydrogenation. [1] However, they are expensive rare metals and are anticipated to be limited by the depletion of natural resources in the future. Hence, the investigation and development of sustainable methods using abundant and cheap base transition metals is desirable. [2] Recently, we have developed of homogeneous chiral nickel catalysts for the asymmetric hydrogenation of a chiral, labile a-amino-b-keto esters through dynamic kinetic resolution (DKR). [3][4][5][6] Asymmetric hydrogenation through DKR [7] constitutes one of the most important carbonhydrogen bond forming reactions, in which racemic substrates can be converted into enantiomerically pure products with two or more contiguous stereogenic centers using a single operation. [8][9][10] As an extension of this study, we have investigated the diastereoselective hydrogenation of substituted aromatic a-aminoketone hydrochlorides by using a homogeneous achiral nickel catalyst. During the course of this study, we discovered a novel asymmetric hydrogenation and a remarkable selectivity change, based on the solvent effect. We now describe the asymmetric hydrogenation of substituted aromatic a-aminoketone hydrochlorides through DKR to afford b-aminoalcohols, which are important medicines [11] and chiral modifiers, [12] with anti stereochemistry and high enantio-and diasteroselectivity. Although the enantioselective hydrogenation of a-aminoketones has been extensively investigated, [13,14] studies concerning the diastereoselective hydrogenation of substituted aromatic primary a-aminoketones are still limited. [15,16] We first attempted the screening of achiral ligands for the diastereoselective hydrogenation of an a-aminoketone (S)-1 by employing our developed conditions for the synthesis of aamino-b-ketoester hydrochlorides using nickel acetate (10 mol %) and a phosphine ligand (10 mol %) in the presence of sodium acetate (1 equiv) in trifluoroethanol (TFE) under a hydrogen pressure of 100 atm (Scheme 1). Surprisingly, no reaction took place. However, it was discovered that the presence of sodium tetrakisA C H T U N G T R E N N U N G [bis(3,5-trifluoromethyl)phenyl]borate (NaBArF, 10 mol %) was essential for this hydrogenation. We then carried out preliminary experiments using the above conditions with 10 mol % NaBArF (Table 1).Although most of the bidentate and monodentate phosphines resulted in little or no conversion, we were pleased to find that the hydrogenation using bis(dicyclohexylphosphino)-ethane (dcpe) as the ligand smoothly proceeded at room temperature for 24 h to produce the anti b-aminoalcohol in quantitative yield with a diastereomeric ratio of 95:5 (Table 1, entry 2). The presence of the additives, NaBArF and sodium acetate, were essential for the catalytic activity and smooth reaction (Table 1, entries 7-9). However, the measurement of the optical purity of the product showed complete racemization during the homogene...