Abstract 'Semicorrin'cobalt complexes, prepared in situ from cobalt (II) chloride and the corresponding ligands, are efficient catalysts for the enantioselective reduction of electrophilic C [DOUBLE BOND] C bonds with NaBH 4. The best selectivities (> 90% ee) are achieved with α, β-unsaturated carboxamides and carboxylates. Analogous α, β-unsaturated nitriles, sulfones, and phosphonates afford enantiomeric excesses of 50–70%. ...
