Developing New Transformations Via Electrophilic Trapping Of Active Zwitterionic Intermediates Generated From Diazoamides

The thesis includes two parts of research work. The first part is to introduce a method to build 3-substituted oxindole derivatives via trapping active zwitterionic intermediates generated from diazoamides by glyoxylate ester imide; and the second part of this thesis is to trap the active zwitterionic intermediates by ethyl glyoxalate.Many bioactive natural compounds and drug molecules contain oxoindole skeletons, so developing more efficient methods to build structurally diversoxoindole derivatives is of great importance. On the basis of our group’s methodology, we realized the trapping of active zwitterionic intermediates generated from diazoamides with aldehyde ester imide, getting a series of compound which contains three substituted oxindole derivativesIn chapter one, firstly we discuss basic concepts and knowledge about diazo chemistry, and ylide carbene chemistry, as well as some types of chemical reactions of ylide; Secondly we introduce the background about trapping zwitterionic intermediates, then propose the specific research work of the thesis.The second chapter of the thesis, the main work is to develop a method of trapping zwitterionic intermediates from diazoamides by aldehyde ester imide. We tried different kinds of chiral phosphoric acid:finally we got a new series of 3-substituted oxindole skeleton with moderate yield, moderate diastereoselectivity and high enantioselectivity.In the third chapter we discuss the preliminary study about trapping zwitterionic intermediates from diazoamides with the aldehyde ester. After trying different conditions, we got the aldol-type product with high yield. At the same time, we also independently synthesized several types of "thiourea" chiral organocatalysts for potential asymmetric control of this transformation. However, we have not yet achieved good results, and this part of work needs further studies.