Highly enantioselective borohydride reductions of 2-phenacylpyridine catalyzed by optically active β-ketoiminato cobalt(II) complexes

The highly enantioselective reduction of 2-phenacylpyridine catalyzed by optically active β-ketoiminato cobalt(II) complexes with pre-modified sodium borohydride was achieved affording in high enantiomeric excess 1-phenyl-2-(2-pyridyl)ethanol, a precursor of sedamine derivatives. The enantioselective sense in the present reduction is discussed and compared to the asymmetric reduction catalyzed by other complex catalysts. Copyright (C) 2000 Elsevier Science Ltd.