Studies in Organocatalyzed Direct Aldol Reactions under Solvent-Free Conditions

The aldol reaction is one of the most powerful synthetic tools for carbon–carbon bond formation, with a large application in stereoselective synthesis. In this area, organocatalysis is a strategy that recently has attracted a great deal of attention and become an intensively active research topic. After the pioneering work reported by List et al. published in 2000 new organocatalysts proline derivatives have been designed for asymmetric direct aldol reactions. More recently, efforts have also been dedicated to asymmetric organocatalytic reactions using water as solvent to develop greener reaction media. Following our studies involving application of organocatalyst 6 under mild condition reactions, herein we reported the results obtained in the aldol reaction promoted under solvent-free conditions.