Supported Ionic Liquid-Like Phases (SILLPs) for enzymatic processes: Continuous KR and DKR in SILLP–scCO2 systems

Abstract

The immobilisation of Candida antarctica lipase B (CALB) onto SILLPs has been studied in order to obtain the maximum activity, selectivity and stability of the resulting supported biocatalyst for the KR of rac-1-phenylethanol by flow processes using scCO₂. This involves the use of hydrophilic SILLPs (chloride anion) with high loadings of IL moieties and CALB. The combination of the immobilized biocatalyst with an acidic zeolite has allowed us to carry out DKR processes. Excellent results in terms of yield (92%) and enantioselectivity (>99.9% ee) are obtained by the use of a “one-pot” reactor containing a mixture of both catalyst particles under scCO₂ flow conditions (50 °C, 10 MPa), resulting in an environmentally friendly process with high productivity and enantioselectivity.