Cinchona Derivatives as Bifunctional Organocatalysts for the Direct Asymmetric Nitroaldol (Henry) Reaction

Abstract

Bifunctional Cinchona derivatives are asymmetric catalysts for the nitroaldol reaction. Enantiomeric excesses up to 45% have been achieved with activated aromatic aldehydes.

Key words

asymmetric organocatalysis - bifunctional catalysis - Cinchona alkaloids - nitroaldol reaction - nitroalcohols

References

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12

In ref. 5 the ee reported for 1a is 81% in the preliminary studies and 78% for a preparative run after work-up and chromatography. This corresponds approximately to the same loss of optical purity we experienced.