The first example of a crystallization-induced asymmetric transformation (CIAT) in the Mannich reaction
摘要:
The novel synthesis of highly enantioenriched N-substituted alpha-amino-gamma-alkyl(aryl)-gamma-oxoutanoic acids is described The process involves the combination of a crystallization-induced asymmetric transformation (CIAT) and the Mannich reaction The role of retro-Mannich and retro-Michael reactions in the mechanism of the highly stereoselective transformation is also discussed. (c) 2009 Elsevier Ltd All rights reserved
base-catalyzed cascade nucleophilic/aza-Michael addition reaction of N-alkoxy β-oxo-acrylamides with isocyanates has been developed to afford various highly functionalized hydantoin derivatives in 80–98% yields under mild reaction conditions. The intriguing features of this method include metal-free reaction conditions, low catalyst loading, broad substrate scope and short reaction time.
An asymmetrichydrogenation of aroylacrylic acidscatalyzed by RuPHOX-Ru catalyst has been developed, affording the corresponding chiral γ-lactones in high yields and with up to 93% ee. The methodology has the advantage of utilizing easily accessible substrates and has therefore expand the scope of the resulting chiral γ-lactones. Furthermore, high catalytic efficiency was achieved in that the reduction
The novel synthesis of highly enantioenriched N-substituted alpha-amino-gamma-alkyl(aryl)-gamma-oxoutanoic acids is described The process involves the combination of a crystallization-induced asymmetric transformation (CIAT) and the Mannich reaction The role of retro-Mannich and retro-Michael reactions in the mechanism of the highly stereoselective transformation is also discussed. (c) 2009 Elsevier Ltd All rights reserved