Fast DKR of Amines Using Isopropyl 2‐Methoxyacetate as Acyl Donor

Abstract

Abstract The dynamic kinetic resolution (DKR) of various primary amine substrates was performed using a modified version of the Bäckvall system. A single equivalent of isopropyl 2‐methoxyacetate was used as acyl donor in combination with p ‐MeO Shvo complex as the racemization catalyst and Novozym 435 as the acylation catalyst. A reaction temperature of 100 °C was employed to ensure a high racemization rate. Adding 2,4‐dimethyl‐3‐pentanol (DMP) as hydrogen donor at a concentration of 0.5 M successfully suppressed side product formation. Under these modified DKR conditions, complete conversion was observed for most substrates within 26 h showing both high ee values and good chemoselectivity, whereas the original system required a reaction time of 72 h.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)