A NEW ASYMMETRIC-SYNTHESIS OF TRICARBONYLCHROMIUM COMPLEXES OF ORTHO-SUBSTITUTED BENZALDEHYDES

ortho-Substituted [Cr(CO)3(benzaldehyde)) complexes are obtained via nucleophilic addition of alkyl- and aryllithium reagents to a [Cr(CO)3(phenylmethaneimine)] complex followed by endo-hydride abstraction with triphenylmethyl cation. This sequence, when carried out with a [Cr(CO)3(benzaldehyde SAMP hydrazone)] complex affords substituted derivatives (Me, Bu, Ph, vinyl) with high ( greater-than-or-equal-to 97 %) diastereoselectivity and, after hydrolysis, ortho-substituted [Cr(CO)3(benzaldehyde)] ((S)-1) complexes of high enantiomeric purity.