Recent papers estimates that about 40 % of drugs present chiral amines in their structure and their synthesis in a sustainable and cost-competitive way is still a challenge for the industry. Kinetic resolution is one of the most applied method to produce these desired compounds where the association with lipase as a catalyst is a good alternative. However, the use of separate racemization catalyst and enzymes in the reaction medium still limits recovery, recycling and can occasionally be responsible for decreasing in selectivity for the desired product. In this work we proposed the synthesis and characterization of a hybrid magnetic catalyst composed containing lipase CaL B and Pd immobilized on the same recovered nanometric magnetic support for the application on Dynamic Kinetic Resolution of (rac)-1-phenylethylamine both in batch and continuous flow conditions. As results it was possible to achieve 99 % of conversion, with 95 % of selectivity and 93 % of enantiomeric excess after 12 h in batch. For a continuous flow system, it was possible to achieve 95 % of conversion with 71 % of selectivity and ee > 99 % after 60 min of reaction. The hybrid catalyst had around 50−100 nm with nanoparticulated Pd (5−10 nm) on its surface, presented a superparamagnetic behavior without remaining magnetization and 22 emu/g of saturation magnetization.
Synthesis and characterization of a magnetic hybrid catalyst containing lipase and palladium and its application on the dynamic kinetic resolution of amines
Molecular Catalysis, vol. 493, pg. 111106 (2020)