Synthesis of a chiral artificial receptor with catalytic activity in Michael additions and its chiral resolution by a
Luis Simón1, Francisco M Muñiz, Angel Fuentes de Arriba
1Organic Chemistry Department, University of Salamanca, 37008, Salamanca, Spain. lsimon@usal.es
Abstract:
Xanthone derivatives were tested as organocatalysts for the Michael addition of pyrrolidine to an alpha,beta-unsaturated lactam. The receptors combine a double H-bond donor pattern that resembles the oxyanion hole in natural enzymes, with a sulfone or sulfoxide that acts as a proton-transfer group. Since these compounds cannot be obtained enantiomerically pure from natural sources, chiral resolution was necessary to study their enantioselectivity. For the most promising receptor, this was accomplished using a new methodology that exploits its supramolecular interactions with a chiral guest and that is inspired in dynamic combinatorial chemistry. The success in the resolution of the racemic mixture indicates that this new method offers an alternative to kinetic resolution.
Related Concept Videos
Prochirality
Racemic Mixtures and the Resolution of Enantiomers
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Conjugate Addition of Enolates: Michael Addition
Sharpless Epoxidation
Molecules with Multiple Chiral Centers


