Highly efficient one pot dynamic kinetic resolution of benzoins with entrapped Pseudomonas stutzeri lipase

The immobilisation of lipase from Pseudomonas stutzeri (Lipase TL®) by different entrapment protocols (sol–gel, static emulsion-silicone and direct entrapment in silicone spheres) is described for the first time. As this not very common commercial lipase has been recently reported as able to catalyse the dynamic kinetic resolution of benzoins (1,2-diaryl-2-hydroxyethanone structures) combined with a transition metal catalyst, although suffering a deactivation at high temperatures, the different immobilisation methodologies were tested with the aim of enhance lipase activity and stability in the above mentioned process. The enzyme immobilisation by silicone spheres entrapment was the most appropriate method, resulting in a considerable activation of this lipase. Furthermore, the high stability of this immobilised lipase at 60 °C, allowed the development of a “one pot” benzoin DKR process, reaching high conversions in short time, with a 30-fold increase of the productivity of the process due to the possibility of recycling and reuse of the catalyst.