Synthesis of Aromatic 1,2-Amino Alcohols Utilizing a Bienzymatic Dynamic Kinetic Asymmetric Transformation



The applicability of the recent published bienzymatic protocol for the synthesis of (R)-2-amino-1-phenylethanol was tested using L-threonine aldolase from Pseudomonas putida and l-tyrosine decarboxylase from either Enterococcus faecalis (Efa) or two genes from Enterococcus faecium (Efi1, Efi2). In all 21 benzaldehyde derivatives were applied for an initial TLC screening. On a small scale, octopamine and noradrenaline were obtained as (S)-enantiomers using Efi1. Three protocols were up-scaled yielding enantioenriched (S)-octopamine (yield 99 %, ee 81 %), (R)-2-amino-1-phenylethanol (yield 61 %, ee 62 %) and (S)-noradrenaline (yield 76 %, ee 79 %).