Enantiomerically pure 2-piperazinemethanols as novel chiral ligands of oxazaborolidine catalysts in enantioselective borane reductions

Article abstract of DOI:10.1016/S0040-4039(99)01031-X

Novel enantiomerically pure 2-piperazinemethanols (3-5) were synthesized from 2-piperazinecarboxylic acid 1. The asymmetric reduction of aromatic ketones, ketimine and oxime ether has been performed with reagents prepared from 2-piprazinemethanol and borane to yield enantiomerically enriched alcohols and amines, respectively. The preferred absolute configuration of the product was dependent on the structure of the sulfonyl substituent in the chiral ligand.