Enantioselective Addition of Chiral Organotitanium Derivatives to Aldehydes

Abstract

Alkoxy‐ and aryloxy‐organotitanium compounds 2–4 derived from (S)‐2‐methyl‐1‐butanol, (R)‐2‐butanol, (‐)‐menthol, quinine, cinchonine, and (S)‐1.1′‐binaphthol are added to aromatic aldehydes to give optically active alcohols 5–10 in enantioselectivities of up to 88% e. e., with nucleophilic transfer of methyl, phenyl, and 1‐naphthyl groups. The Tables 1–3 list the effects of varying the reagents, the substrates, and the reaction conditions of the new asymmetric synthesis.