Studies On Immobilization Of Isosteviol Derivatives Chiral Ligand Based On Novel Method And Application

A novel method was established in the thesis to immobilize chiral ligand catalyst to the silica sphere. And application of the immobilize chiral ligand catalyst and its intermediate in the chiral synthesis was carried out. Isosteviol-prione was selected as our template substrate.Firstly, pre-reaction was carried out with the cheap raw materials which had similar structure of our template substrate in order to determine a good reaction condition to link them with hexamethylene diamine. Then our target template substrate was coupled with hexamethylene diamine under the optimization condition.Secondly, aminopropyl silica sphere activated by1,1’-Carbonyldiimidazole (CDI) was prepared by a sequence of reaction. Then hexamethylene diamine derivative of isosteviol-prione was immobilized to the surface of the silica sphere by the reaction of the two products above-mentioned in a mild condition. The immobilization amount of our target template substrate was about0.29mmol/g on the silica gel.Finally, stereoselectivity for the asymmetric aldol reaction catalyzed by hexamethylene diamine derivative of isosteviol-prione and its immobilization of silica sphere was evaluated with different solvents, different aldehydes and ketones as the reaction substrate material, different amount of the catalysts. Compared with literature data, the stereoselectivity were decreased, and the reasons for the decrease of the activity of the catalysts were explained.In general, a novel method for the immobilization of the low weight molecules to the solid particles is established in the paper, and there will be a widen application in the research field of catalyzing asymmetric reaction and etc.