Popis: |
Organocatalysis is represented by a set of broadly applicable and efficient synthetic tools for the preparation of many types of enantiomerically enriched molecules. In this regard, L-proline and related derivatives have risen to prominence since List, Barbas and Lerner rediscovered that these small molecules could stereoselectively catalyze reactions without the requirement of transition metals. Chiral organocatalysts used in stereoselective reactions are usually nontoxic, highly efficient and selective and readily available. However, the preparation of more complex organocatalysts may involve several steps. Therefore, in an economic and environmental perspective, the easy recovery and recycling of the catalyst remain a significant challenge. One of the most widely used strategies for this purpose consists in immobilizing the homogeneous catalyst on silica. This hybrid material, have the advantages of easy handling, recovery and reuse of the catalyst. [1] In connection with our ongoing research program into the design of new class of organocatalyst, we recently developed a new prolyl pseudo-peptide by a multicomponent approach. Inspired by these results, we further employed this strategy for the synthesis of a supported organocatalysts. |