Efficient Chemo-Enzymatic Epoxidation Using silcoat-Novozym®435: Characterizing the Multiphase System

Abstract

Silicone composites of Novozym®435 (silcoat-NZ435) demonstrate improved leaching and mechanical stability compared to native Novozym®435 (NZ435). Here, the application scope of this novel enzyme preparation has been broadened significantly by the transfer from single-phase esterification to a complex chemo-enzymatic epoxidation reaction in a three-phase system. The reaction gave up to 80 % yields with almost 100 % selectivity in 50 h when operated in the absence of mass transfer limitations. Characterization of the system revealed that octanoic acid inhibited the reaction at concentrations around 6 M. The silcoat-NZ435 catalyst could be reused over five days with less than 50 % loss in activity when 5 M H₂O₂ was present. H₂O₂ was also identified as the component which deactivates the enzyme at high concentration (17.5 M) demanding spatial separation of the silcoat-NZ435 for optimal operation.

silcoat-NZ435 was successfully applied to biocatalyze a solvent-free chemo-enzymatic epoxidation reaction of a model alkene 1-dodecene in a multiphase system. The system was operated without mass transfer limitations and provided yields of up to 80 % and excellent selectivity of almost 100 % for the reaction.