POLYFUNCTIONAL, STRUCTURALLY DEFINED CATALYSTS FOR THE ENANTIOSELECTIVE ADDITION OF DIALKYLZINC REAGENTS TO ALDEHYDES

: Two new chiral catalysts, 9 and 14, have been developed for the enantioselective addition of dialkylzinc reagents to aromatic aldehydes, as exemplified by the reaction of benzaldehyde and diethylzinc in the presence of 10 mol % of 9 to form (S)-(-)-1-phenylpropanol (>95% yield, 94% enantioexcess). Catalysts 9 and 14 were prepared by the reaction of equimolar amounts of diethylzinc and diamino alcohols 7 and 8, respectively. A short synthesis of 7 and 8 from ethyl (S)-N-(ethoxycarbonyl)pyro-glutamate (2) via intermediates 3–6 is described. © 1990, American Chemical Society. All rights reserved.