SYNTHESIS OF THREE NEW BIFUNCTIONAL GLUCOSE-THIOUREA ORGANOCATALYSTS AND THEIR APPLICATION IN ASYMMETRIC MICHAEL ADDITION

Abstract

Three new glucose-based asymmetric bifunctional organocatalysts containing a 6-aminopyridyl or a 6-methylpyridyl or a cinchona unit were synthesized. Asymmetric Michael addition of pentane-2,4-dione to β-nitrostyrene was catalyzed successfully by these catalysts. In case of the cinchona based glucose-thiourea derivate the S enantiomer of the corresponding Michael adduct was formed with moderate enantiomeric excess in three different solvents.

Keywords

• organocatalyst, carbohydrates, cinchona alkaloids, Michael addition, asymmetric syntheses