Design And Synthesis Of Supported Small Molecular Organocatalysts And Their Application In Michael Addition Reaction

In this dissertation,two kinds of novel supported bifunctional organocatalysts which derived from 4-hydroxylproline were designed and synthesized.These bifunctional organocatalysts containing thiourea or sulfonylamide functionality supported by a macropore polystyrene resin were synthesized for the first time.And the synthetic methods of those supported organocatalyst were also studied and explored for their further applications.It was found that the best catalyst was the immobilized sulfonylamide when these synthetic immobilized bifunctional small organocatalysts were used to catalyze the asymmetric Michael addition reaction of cyclohexanone toβ-nitrostyrene.The optimal reactive conditions were obtained by systematically study the influence of solvent,additive, temperature and etc on the reactivity and enantioselectivity.The experimental results demonstrated that excellent yield(up to 100%),high diastereoselectivity(up to 97:3) and enantioselectivity(up to 93%) were achieved when the reaction proceeded in 0.5 mL water at room temperature for 48 h in the scale of cylcohexanone(2.5 mmol) andβ-nitrostyrene(0.25 mmol) with 10 mol%catalyst 65b and 10 mol%p-nitrobenzoic acid.When the immobilized sulfonylamide catalyst was used in the Michael reaction at room temperature in water,the catalyst could be reused for six consecutive trials without significant loss of activity and enantioselectivity.