α-Amino Acids, β-Amino Alcohols and Related Compounds as Chiral Auxiliaries, Ligands and Catalysts in the Asymmetric Aldol Reaction

The aldol reaction is regarded as one of the most powerful tools in organic synthesis for the formation of carbon-carbon bonds. Besides, this reaction allows the generation of many stereocenters in the final product, which makes it even more interesting from the synthetic organic chemist point of view. Consequently, an extensive number of methodologies for performing stereoselective aldol reactions have been developed over the last years. In this context, enantiopure α-amino acids, β-amino alcohols or closely related compounds have very often played successfully the role of chirality sources either as auxiliaries, ligands or catalysts in order to exert efficient stereocontrol in the addition step. In this review the use of such chiral reagents in asymmetric aldol reactions will be presented and the most important applications in the field of organic synthesis will be highlighted.