2-Hydroxy-3-[(S)-prolinamido]pinanes as novel bifunctional organocatalysts for asymmetric aldol reactions in aqueous media
作者:Dmitry E. Siyutkin、Alexander S. Kucherenko、Larisa L. Frolova、Alexander V. Kuchin、Sergei G. Zlotin
DOI:10.1016/j.tetasy.2011.07.013
日期:2011.6
Novel (S)-prolinamides with stereoisomeric 2-hydroxy-3-aminopinane units have been synthesized. In the presence of (1R,2R,3S,5R)-2-hydroxy-3-[(S)-prolinamido]pinane (5 mol %) cyclic ketones reacted with (hetero-)aromatic aldehydes in aqueous media to afford chiral aldols in high yields. The reaction had moderate to high diastereo- (dr up to 91/9) and enantioselectivities (up to 83% ee). (C) 2011 Elsevier Ltd. All rights reserved.
Sterically and Electronically Tunable and Bifunctional Organocatalysts: Design and Application in Asymmetric Aldol Reaction of Cyclic Ketones with Aldehydes
tunable and bifunctional organocatalysts have been developed and evaluated in the direct aldolreaction of heterocyclic ketones. Catalysts with different substituents showed variablecatalytic efficiency for analogous substrates, indicating the importance of fine-tuning the strength of the hydrogen bonding in the two NH groups. The reactions all proceeded in good to high yield and with excellent enantioselectivities