Development of Biotransamination Reactions towards the 3,4-Dihydro-2H-1,5-benzoxathiepin-3- amine Enantiomers

The stereoselective synthesis of chiral amines is an appealing task nowadays. In this context, biocatalysis plays a crucial role due to the straightforward conversion of prochiral and racemic ketones into enantiopure amines by means of a series of enzyme classes such as amine dehydrogenases, imine reductases, reductive aminases and amine transaminases. In particular, the stereoselective synthesis of 1,5-benzoxathiepin-3-amines have attracted particular attention since they possess remarkable biological profiles; however, their access through biocatalytic methods is unexplored. Amine transaminases are applied herein in the biotransamination of 3,4-dihydro-2H-1,5-benzoxathiepin-3-one, finding suitable enzymes for accessing both target amine enantiomers in high conversion and enantiomeric excess values. Biotransamination experiments have been analysed, trying to optimise the reaction conditions in terms of enzyme loading, temperature and reaction times.Financial support has been received from the Spanish Ministry of Economy and Competitiveness (MINECO, Projects CTQ2013-40855-R and CTQ2016-75752-R), Junta de Andalucía (Project CS2016.1) and Gobierno de Aragon-FEDER (Research group E19_17R)