Enzymatic transformations 63.: High-concentration two liquid-liquid phase Aspergillus niger epoxide hydrolase-catalysed resolution:: Application to trifluoromethyl-substituted aromatic epoxides

The aim of this work was to perform different studies allowing us to improve the methodology we had previously described to realise the Aspergillus niger epoxide hydrolase-catalysed resolution of eight trifluoromethyl-substituted styrene oxide derivatives. A two liquid-liquid phase methodology was developed, for the first time with such an enzyme, using iso-octane as a co-solvent. Different experimental parameters like the global volume substrate concentration, the substrate over enzyme ratio, the agitation rate and the purity of the enzyme were also optimised. This allowed us to set up very efficient bioreactors allowing performance of the hydrolytic kinetic resolution of the different substrates by operating at room temperature (27 degrees C), within a few hours only and at a very high global volume substrate concentration, i.e., 360 g/L (1.8M). ne efficiencies of the Aspergillus niger epoxide hydrolase toward the different epoxides studied were compared and the productivity of the practical process was evaluated. These results amply demonstrated that, without contest, the biocatalysed hydrolytic kinetic resolution of epoxides is nowadays to be considered as a very efficient, mild, cheap and easy-to-use green chemistry methodology applicable for cost effective preparative (i.e., industrial) scale implementation.