The highly enantioselective bifunctional organocatalysts for the Michael addition of сyclohexanone to titroolefins

Resumo

A new family of organocatalyst derived from proline has been developed and shown to be an efficient catalyst for asymmetric Michael addition of cyclohexanone to nitroolefins with high diastereo- and enanthio -selectivities. (syn: anti ratio up to 99:1, ee. up to 95%.). The result of computational studies at the B3LYP/6-31G* level indicate that both the hydrogen bonding and the stereo hindrance play the crucial role in the activation of the nitro alkene and help to discriminate between the two diastereofacial approaches.