Naphthyl-L-α-amino acids via chemo-enzymatic dynamic kinetic resolution

A double catalyst system (protease + base) was applied to the dynamic kinetic resolution (DKR) of isomeric 1- and 2-alpha-naphthyl-glycines and -alanines exploiting the in situ racemization of their thioesters. Due to the different C-acidity of the two sets of compounds, different experimental conditions have been devised to perform the simultaneous resolution/racemization process. In all cases, the racemic N-Boc-thioesters were converted into the aminoacids with an L-configuration almost quantitatively and with complete enantioselectivity. (C) 2012 Elsevier Ltd. All rights reserved.