A dynamic kinetic resolution method for the preparation of enantiopure 1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (R)-2 was developed involving the CAL-B-catalyzed enantioselective hydrolysis of the corresponding ethyl ester (±)-1 in toluene/acetonitrile (4:1) containing 1 equiv of added water and 0.25 equiv of dipropylamine. This method allowed the preparation of (R)-2 (ee = 96%) with 80% isolated yield. The kinetic resolution of (±)-1 in diisopropyl ether at 3 °C afforded both enantiomers with ee ≥92%.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry