Bienzymatic Cascade for the Synthesis of an Optically Active O-benzoyl Cyanohydrin

• Published in: Catalysts
• Main Authors: Leemans, Laura, van Langen, Luuk, Hollmann, Frank, Schallmey, Anett
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2019
• Subjects: Article; ddc:57; Veröffentlichung der TU Braunschweig; Publikationsfonds der TU Braunschweig; Enantioselectivity > enzyme cascade > hydroxynitrile lyase > lipase > hydrocyanation > transesterification; Antarc*; Antarctica
• Online Access: https://doi.org/10.3390/catal9060522; https://nbn-resolving.org/urn:nbn:de:gbv:084-2019061413343; https://leopard.tu-braunschweig.de/receive/dbbs_mods_00066693; https://leopard.tu-braunschweig.de/servlets/MCRFileNodeServlet/dbbs_derivate_00045436/Schallmey-catalysts-09-00522.pdf; http://publikationsserver.tu-braunschweig.de/get/66693

A concurrent bienzymatic cascade for the synthesis of optically pure (S)-4-methoxymandelonitrile benzoate ((S)-3) starting from 4-anisaldehyde (1) has been developed. The cascade involves an enantioselective Manihot esculenta hydroxynitrile lyase-catalyzed hydrocyanation of 1, and the subsequent benzoylation of the resulting cyanohydrin (S)-2 catalyzed by Candida antarctica lipase A in organic solvent. To accomplish this new direct synthesis of the protected enantiopure cyanohydrin, both enzymes were immobilized and each biocatalytic step was studied separately in search for a window of compatibility. In addition, potential cross-interactions between the two reactions were identified. Optimization of the cascade resulted in 81% conversion of the aldehyde to the corresponding benzoyl cyanohydrin with 98% enantiomeric excess.