Organocatalytic asymmetric Mannich reactions: New methodology, catalyst design, and synthetic applications

The direct, asymmetric Mannich reaction catalyzed by small organic molecules offers a facile route to optically active alpha-or beta-amino acid derivatives and 1,2- and gamma-amino alcohols. One-pot reactions of unmodified carbonyl donors with preformed or in situ generated imines can be stereochemically controlled with Organic catalysts such as proline, chiral pyrrolidines, chiral Bronsted acids, and Cinchona alkaloids. The generated Mannich adducts can be further functionalized towards a variety of bioactive molecules. In this Microreview, recent contributions are discussed to present the methodology and synthetic advantages achieved so far in the asymmetric Mannich reaction. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)