Studies On The Synthesis And Asymmetric Catalytic Behaviors Of Novel Isosteviol

In recent years,organocatalysisgets the attention of many chemical workersbecause of its unique advantages.Among the many chiral organocatalysts,primary amine thiourea catalyst is widely used in different series of reactions.In this paper,we transform the structure of the inexpensive readily availableisostiviol by separately introducing the primary amine thiourea groups and the tertiary amine thiourea groupsin the four carbon,we finally get4kinds of different structures of primary amine thiourea catalysts and4kinds of different structures of tertiary amine thiourea catalysts.In the following study,we described the efficient oaganocatalytic asymmetric Michael additions of aldehyde to N-substituted maleimides promoted by novel isosteviol-derived primary amine thiourea catalyst.After screening of differentreaction conditions,we get the optimum reaction conditions:toluene as solvent,1.0mol%catalyst, room temperature, N-phenyl maleic imide and isobutyl aldehyde weight ratio is2to1.We study the different substrates and get satisfactory catalytic effect:58-96%of the catalytic yield and60-99%ee in the optimum reaction conditions.Finally we examine catalytic effect and get ideal resultin the case of the amount of amplification reaction substrate.