Dynamic Kinetic Resolution of Diarylmethanols with an Activated Lipoprotein Lipase

We explored the kinetic resolution of 31 different diarylmethanols with an activated lipoprotein lipase (LPL-D1) which was about 3000-fold more active than its native counterpart in organic solvent. Most of the substrates tested were accepted by LPL-D1 with good to high enantioselectivity in the kinetic resolution. Next, we explored the dynamic kinetic resolutions (DKRs) of these substrates (24 out of 31) using LPL-D1 and a ruthenium-based racemization catalyst in combination, which provided satisfactory yields (71-96%) and high enantiopurities (90-99% cc). As an illustrative example for the synthetic applications of the DKR procedure, we synthesized L-cloperastine, an antitussive drug, from phenyl-(p-trimethylsilylphenyl)methanol via DKR.