| Firstly, recent advances in asymmetric reactions catalyzed byL-proline-based organocatalysts were reviewed in this dissertation.Secondly, a novel class of pyrrolidine-pyridinium conjugations IPC 1-5as task-specific, ionic organocatalysts were designed and synthesizedfrom L-proline. Their structures were characterized by IR, MS, 1H NMR,13C NMR and X-ray crystallographic analysis. These organocatalystshave never been reported in literatures. Finally, organocatalytic propertiesof IPC 1-5 in asymmetric Michael addition and Mannich reactions wereinvestigated.Investigation results revealed that: (1) the organocatalyst IPC 3a orIPC 3b performed excellent catalytic ability in the Michael additionreaction. In the presence of 10 mmol％of IPC 3a or IPC 3b,nitrostyrenes reacted with cyclohexanones smoothly to give desired Michael adducts in up to 95％yield, 96/4 diastereoselectivity and～100％enantioselectivity after 20h at room temperature with ionic liquid[BMIm]BF4 as reaction media. Moreover, IPC 3a/BMImBF4 systemcould be conveniently recycled and subsequently reused at least 5 cycleswithout a significant loss of catalytic performance; (2) In the direct,one-pot, three-component Mannich reaction of cyclohexanones,formaldehyde and aniline or analogs, 10 mmol％of IPC 3a led toMannich products in up to 98％yield and 78％ee value after 24-72h atroom temperature. IPC 3a behaved the catalytic performance much betterthan L-proline; (3) based on the enamine-catalytic mechanism and theobtained stereo-structure of IPC 3a, the configuration of the finalproducts must be strongly controlled by steric hindrance of thepyridinium moiety on the organocatalyst.
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