Enantioselective Synthesis of Chiral 1,2-Amino Alcohols via Asymmetric Hydrogenation of α-Amino Ketones with Chiral Spiro Iridium Catalysts

Abstract

A highly efficient iridium-catalyzed asymmetric hydrogenation of α-amino ketones for the synthesis of chiral 1,2-amino alcohols is described. With chiral spiro iridium catalyst Ir-(<i>R</i>)-<b>1c</b>, a series of α-amino ketones were hydrogenated to chiral β-amino alcohols in excellent enantioselectivities (up to 99.9% ee) with TON up to 100 000. In addition, with this highly efficient method the chiral drugs (<i>R</i>)-clorpenaline and (<i>R</i>)-phenylephrine were prepared in very high efficiency.