The Study Of Asymmetric Mannich Reaction Catalyzed By Bifunctional Organocatalysts

Mannich reaction was considered as one of the most important reactions for the formation of carbon-carbon bond and carbon-nitrogen bond. In recent years, asymmetric Mannich reaction catalyzed by chiral small-molecule organocatalyst has been studied widely and thoroughly. In this thesis, we have designed and synthesized series of thiourea and sulfonic acid amide catalysts start from (L)-4-hydroxylproline and applied them in asymmetric Mannich reaction. We have screened those catalysts and found that good reactivity and enantioselectivity could be obtained when the reaction catalyzed by the pyrroline thiourea 12a. The influence of solvent,reaction temperature and catalyst load on the reaction was further investigated and found that good result could be obtained when the reaction proceeded at - 20℃, 1, 2-dichloroethane as solvent and 5 mmol% catalyst load was used. We have enlarged the reactive substrate under the optimal condition.