Enantioselective Trimethylsilylcyanation of Some Aldehydes Catalyzed by Chiral Schiff Base-Titanium Alkoxide Complexes

Article abstract of DOI:10.1021/jo00058a037

A variety of aldehydes (aromatic, heteroaromatic, α,β-unsaturated, and nonconjugate aliphatic aldehydes) has been trimethylsilylcyanated in highly enantiomeric excess (ee) with a catalyst prepared in situ from titanium tetraisopropoxide and chiral Schiff bases.A remarkable rate enhancement was brought about by the addition of the Schiff base into the titanium alkoxide mediated silylcyanation of aldehydes.The chemical structure of chiral Schiff base-titanium alkoxide complexes is discussed based on their 13C NMR spectra, field desorption (FD) mass spectra, and molecular weights.