L-proline's Derivates Catalyzed Asymmetric Michael Addition

The Michael addition reaction is one of the most important carbon-carbon bond-forming reactions in organic synthesis. Asymmetric organocatalytic Michael addition has attracted intense interests in the recent few years due to its environmental friendliness, stability, cheapness and the generation of multiple chiral centers in a single step. Recently, quite a number of small chiral organic molecules have been developed as stereoselective catalysts for asymmetric Michael reactions.In this thesis, we designed and synthesized a series of chiral amides 31, 33, 35 and 41 as stereoselective organocatalyst for the asymmetric Michael addition of cyclohexanone to trans-beta-nitrostyrene. In the presence of TFA, the chiral amides catalysts catalyzed the reaction of cyclohexanone to trans-beta-nitrostyrene in DMSO with moderate yields(up to 65.70%) and lower enatioselectivities(up to 28.03% ee). The amides'catalytic activity and stereoselectivity is lower than that have been reported in this area. We argue that the structure of carboxyl group have negative effect on the enantioselectivity.