RESUMEN
A new type of pyrrolidine-based organocatalyst, which was developed earlier in our lab, has been found to be very effective for the Michael addition reaction in aqueous solvents involving a wide range of α,ß-unsaturated aldehydes and malonate derivatives. For the reactions studied, good to excellent yields (73%-96%) and high to excellent enantioselectivities (up to 97%) were obtained using this catalyst. In addition, the catalyst could be recycled up to four times with gradual reductions in yields and enantioselectivity observed after the second cycle.
Asunto(s)
Aldehídos/química , Malonatos/química , Agua/química , Catálisis , Estructura Molecular , Pirrolidinas/química , EstereoisomerismoRESUMEN
A new class of ionic liquid supported (ILS) (S)-pyrrolidine sulfonamide organocatalyst has been developed and shown to be a very effective catalyst for the asymmetric Michael addition reactions of ketones and aldehyde to nitroolefins with high enantio- and diastereoselectivities. This ILS organocatalyst is also easily recycled and could be reused at least five times without significant loss of its ability to affect the outcome of the asymmetric reactions.