초록
<P><B>Abstract</B></P><P>The biocatalytic synthesis of chiral amines has become a valuable addition to the chemists’ toolbox. However, the efficient asymmetric synthesis of functionalised amines bearing more than one stereocentre, such as 1,3‐amino alcohols, remains challenging. By employing a keto reductase (KRED) and two enantiocomplementary amine transaminases (ATA), we developed a biocatalytic route towards all four diastereomers of 4‐amino‐1‐phenylpentane‐2‐ol as a representative molecule bearing the 1,3‐amino alcohol functionality. Starting from a racemic hydroxy ketone, a kinetic resolution using an (<I>S</I>)‐selective KRED provided optically active hydroxy ketone (86% <I>ee</I>) and the corresponding diketone. Further transamination of the hydroxy ketone was performed by either an (<I>R</I>)‐ or an (<I>S</I>)‐selective ATA, yielding the (2<I>R</I>,4<I>R</I>)‐ and (2<I>R</I>,4<I>S</I>)‐1,3‐amino alcohol diastereomers. The remaining two diastereomers were accessible in two subsequent asymmetric steps: the diketone was reduced regio‐ and enantioselectively by the same KRED, which yielded the (<I>S</I>)‐configured hydroxy ketone. Eventually, the subsequent transamination of the crude product with (<I>R</I>)‐ and (<I>S</I>)‐selective ATAs yielded the remaining (2<I>S</I>,4<I>R</I>)‐ and (2<I>S</I>,4<I>S</I>)‐diastereomers, respectively.</P>