Chemoenzymatic Synthesis of Rivastigmine Based on Lipase-Catalyzed Processes

A straightforward chemoenzymatic synthesis of enantiomerically pure rivastigmine has been efficiently carried out under mild reaction conditions, with Candida antarctica lipase B responsible for the stereoselective acetylation of the corresponding (R)-alcohol or amine. An exhaustive enzymatic study has been developed exploring the possibilities of carry out enzyme recycling, scaling tip the enzymatic process and development of a dynamic kinetic resolution procedure for the production of adequate enantiomerically pure precursors of rivastigmine. Total chemoenzymatic synthesis of this pharmaceutical has been performed in good overall yield from commercially available 3-methoxyacetophenone.