Aqua-organocatalyzed direct asymmetric aldol reaction with acyclic amino acids and organic bases with control of diastereo- and enantioselectivity

An effective aqua-organocatalytic direct aldol reaction is described. Aromatic amino acids can be a bifunctional catalyst system, which demonstrate excellent reactivity, diastereoselectivity, and enantioselectivity (up to 96% ee) in water without the addition of organic solvents. Furthermore, the present study demonstrates that both diastereo and enantioselectivity can be easily modulated by the appropriate combination of an organocatalyst together with an organic base as a co-catalyst. (c) 2007 Elsevier Ltd. All rights reserved.