The Synthesis And Application Of Ionic Liquid Immobilized Imidazolethiones And The Application Of Gaussian In Fragmentation Pathways Of Pyrrole Derivatives

This thesis consists of two parts: the synthesis and application of ionic liquid immobilized imidazolethiones and the application of Gaussian in fragmentation pathways of pyrrole derivatives.In the past few years,imidazolidinone,imidazolethiones,ionic liquid immobilized imidazolethiones had been successfully used in asymmetric synthesis as efficient organocatalysts.Herein,we described an efficient synthetic route to the synthesis of ionic liquid immobilized imidazolethiones.(S)-3-(3-(1H-imidazol-1-yl)propyl)-5-benzyl-2,2-dimethylimidaz olidin-4-one was synthesized from L-phenylalanine via 5 steps with using the commercially available L-phenylalanineas starting material and followed by HOBt/EDC-mediated coupling with N-(3-aminopropyl)imidazole.Then it was followed the sulfurated reaction with using Lawesson reagent as sulfuration agent and immobilized by 1-iodobutane.The application of ionic liquid immobilized imidazolethiones catalysts in enantioselective α-arylation of aldehydes with iodonium salt was performed which showed that ionic liquid immobilized imidazolethiones was a potential useful catalyst.Gaussian is a kind of quantum chemical calculation technique with higher accuracy and efficiency and has been applied in organic synthesis and mechanism research.In this paper,we study the fragmentation of protonated 2-substituted pyrrole derivatives in electrospray ionization mass spectrometry by using the Density Functional Theory(DFT)B3LYP method with 6-31G(d,p)basis set.Based on the calculation data,the speculated machanisms were proposed.