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New chiral phosphoramide ligands derived from cinchona alkaloids were developed, which react with diethylzinc to form chiral phosphoramide‐Zn(II) complexes containing two Lewis bases and one Lewis acid. These trifunctional complexes can serve as highly efficient chiral catalysts for triple activation of enantioselective addition reactions of diethylzinc with aldehydes to give desired alcohol products...
The use of the `pseudoenantiomeric pair' of cinchonine and cinchonidine as ligands for the addition of diethylzinc to N-diphenylphosphinoylimines has been investigated. With 1equiv of cinchonidine as ligand, a series of chiral amines was prepared in good yield and enantiomeric excesses of up to 94%. The use of 2.0equiv of methanol as an achiral additive was found significantly to improve the selectivity...
The use of cinchona alkaloids to promote the addition of diethylzinc to P,P-diphenyl-N-(phenylmethylene)phosphinic amide has been examined. Using cinchonine and cinchonidine as ligands, the S and R enantiomers of N-(1-phenylpropyl)-P,P-diphenylphosphinic amide were prepared in good yield with up to 93% ee. The reaction was shown to proceed with catalytic amounts of ligand.
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