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Hydroxynitrile Lyase in Organic Solvent‐Free Systems to Overcome Thermodynamic Limitations
Author(s) -
von Langermann Jan,
Mell Annett,
Paetzold Eckhard,
Daußmann Thomas,
Kragl Udo
Publication year - 2007
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200700016
Subject(s) - cyanohydrin , chemistry , acetophenone , ketone , enantiomeric excess , organic chemistry , solvent , enantiomer , catalysis , optically active , combinatorial chemistry , enantioselective synthesis
Abstract The overcoming of thermodynamic limitations in the synthesis of optically active ketone cyanohydrins by using organic solvent‐free systems has been investigated. Therefore, substrates with known unfavorable results within hydroxynitrile lyase‐catalyzed reactions were selected for the determination of limitations and bottlenecks in ketone cyanohydrin synthesis. The highly ( S )‐selective hydroxynitrile lyase from Manihot esculenta ( Me HNL) has been chosen for the conversion of acetophenone and the corresponding derivatives, which are substrates that exhibit only low grades of conversion also with several other hydroxynitrile lyases. With organic solvent‐free systems under optimized reaction conditions conversions up to 78 % with>99.0 ee ( S ) were obtained. Finally, 5 mL of ( S )‐acetophenone cyanohydrin with an enantiomeric excess of 98.5 % ee ( S ) were synthesized.