A Novel Synthesis of Rasagiline via a Chemoenzymatic Dynamic Kinetic Resolution

A novel synthetic route for preparing rasagiline mesylate is presented using a dynamic kinetic resolution (DKR) as the key step, catalyzed by Candida antarctica lipase B (CALB) and a Pd nanocatalyst. The chiral intermediate (R)-2,3-dihydro-1-indanamine was obtained through the DKR of the racemic aminoindan rac-1 in high yield (>90%) and excellent enantioselectivity (>99% ee). The process could be conducted on a 73 g scale at 200 g/L. Rasagiline mesylate was synthesized in 25% overall yield and excellent enantioselectivity (99.9% ee) over 7 steps.