초록
<P>Two independent enzymatic strategies have been developed toward the synthesis of enantioenriched 1-[2-bromo(het)aryloxy]propan-2-amines. With that purpose a series of racemic amines and prochiral ketones have been synthesized from commercially available 2-bromophenols or brominated pyridine derivatives bearing different pattern substitutions in the aromatic ring. Biotransamination experiments have been studied using ketones as starting materials, yielding both the (<I>R</I>)- and (<I>S</I>)-amine enantiomers with high selectivity (91–99% <I>ee</I>) depending on the transaminase source. In a complementary approach, the classical kinetic resolutions of the racemic amines have been investigated using <I>Candida antarctica</I> lipase type B as biocatalyst. Ethyl methoxyacetate was found as a suitable acyl donor leading to the corresponding (<I>S</I>)-amines (90–99% <I>ee</I>) and (<I>R</I>)-amides (88–99% <I>ee</I>) with high selectivity in most of the cases. A preparative biotransamination process has been developed for the synthesis of (2<I>S</I>)-1-(6-bromo-2,3-difluorophenoxy)propan-2-amine in 61% isolated yield after 24 h, a valuable precursor of the antimicrobial agent Levofloxacin.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/joceah/2016/joceah.2016.81.issue-20/acs.joc.6b01828/production/images/medium/jo-2016-01828w_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jo6b01828'>ACS Electronic Supporting Info</A></P>