Covalent Immobilization of Pseudomonas stutzeri Lipase on a Porous Polymer: An Efficient Biocatalyst for a Scalable Production of Enantiopure Benzoin Esters under Sustainable Conditions

The immobilization of lipase from Pseudomonas stutzeri (lipase TL) by covalent bonding to a porous polymer is described for the first time. The immobilized enzyme was characterized in terms of optimal pH and thermal stability, and its catalytic efficiency was tested in the kinetic resolution (KR) of symmetrical and unsymmetrical benzoins (1,2-diaryl-2-hydroxyethanone structures). Reactions were performed in the green solvent 2-MeTHF, reaching maximum conversion and enantiomeric excess, with a significant increase of productivity due to the possibility of reuse of the catalyst. Moreover, the immobilization allowed the development of an adequate scaling up of this KR process permitting a further rise in the catalytic efficiency. Finally, the dynamic kinetic resolution of benzoin (DKR) was carried out by the combination of the immobilized lipase and a ruthenium catalyst (Shvo’s catalyst) in 2-MeTHF, reaching conversions up to 90%, maintaining its excellent enantioselectivity during six catalytic cycles.