The Synthesis Of Carbazole Texaphyrin And Indoleporphyrin

Containing four pyrrolic units and four methylene groups,porphyrin is a type of aromatic heterocycle with 18-πelectrons.Due to their important role in biological processes,porphyrins have been widely studied.Inspired by the structure of porphyrins,researchers have developed expanded porphyrins with larger conjugated systems.Expanded porphyrins have potential and important applications in fields such as magnetic resonance imaging（MRI）or photodynamic therapy（PDT）.Therefore,two new porphyrin analogues based on Texaphyrin and porphyrin,namely carbazole texaphyrin and indoleporphyrin,are designed and their synthesis are explored in this thesis.This thesis includes the following aspects:（1）The research background including their history and synthesis methods of porphyrins and expanded porphyrins were briefly reviewed.The medical applications as radiation sensitizers in magnetic resonance imaging and photosensitizers in photodynamic therapy were also summarized.The mechanism and development history of sensitizers also were introduced in detail.（2）A novel expanded porphyrin,"carbazole-taxephyrin",was designed and successfully synthesized by Vilsmeier-Haack and Suzuki coupling reactions from tert-butyl carbazole.The structure of carbazole-taxephyrin was characterized by ¹H NMR and X-Ray single crystal diffraction.The ultraviolet-visible absorption spectra of carbazole-taxephyrin was also tested and found that there was no absorption in visible light region.In addition,the oxidation of carbazole-taxephyrin and its coordination with Gd³⁺and other metal ions were also explored.（3）In order to extend the conjugated system of porphyrin,indole unit was designed to replace the pyrrole unit into the scaffold of porphyrin.The synthesis routes of indoloporphyrin were explored.Three different precursors（compound 3-2,compound 3-3 and compound 3-7）were prepared through multiple steps including Suzuki coupling reaction from indole and pyrrole.However,the crucial step of the ring-closing reaction was not successful.The reaction conditions for synthesis of indoloporphyrin are still being explored.