Reductive desymmetrization of 2-alkyl-1,3-diketones catalyzed by opticallyactive beta-ketoiminato cobalt complexes

[GRAPHICS] The reductive desymmetrization of acyclic 1,3-diketones was achieved for th e first time by catalytic borohydride reduction in the presence of opticall y active beta -ketoiminato cobalt(II) complex catalysts. In this reaction, various 2-substituted-1,3-diaryl-1,3-propanediones were converted into the corresponding optically active 2-substituted-1,3-diaryl-3-hydroxypropanone in good-to-high yields with excellent diastereo- and enantioselectivities a nd high catalytic efficiencies.