The Synthesis Of Novel Heterocycle-embedded Porphyrinoids

Porphyrin is an aromatic macrocycle containing an 18?-electron conjugated system.Porphyrin exist in nature widely and play important biological roles.The structure of a porphyrin is highly modifiable.Besides introducing different groups at the meso-position and?-position,the macrocyclic skeleton of the porphyrin can be modified as well to gain porphyrinoids,such as expanded porphyrin,porphycene and benzoporphyrin.Compared with normal porphyrin,these porphyrinoids have different properties and functions,such as anion recognition and near-infrared absorption,etc.They have potential applications in the fields of biomedicine,optical materials,and molecular recognition.Realization of the regulation of aromaticity and complexation of actinide metal ions through novel porphyrinoids by introducing heterocyclic rings into the porphyrin has always been a hot topic in porphyrin chemistry.This thesis focuses on the synthesis of novel heterocycle-embedded porphyrinoids and includes three parts:1.the types,synthesis methods and aromaticity of porphyrins are reviewed.First,the types of porphyrinoids reported in literature were briefly introduced.Second,the common synthesis methods of porphyrins,such as acid-catalyzed condensation,oxidation coupling and Suzuki coupling,were described.Then,the study on the regulation of the aromaticity of expanded porphyrins was briefly sketched,and the differences of the UV-Vis absorption spectrum,electron cloud density and current path between the aromatic and anti-aromatic expand porphyrins were compared.At last,the types of porphycenes and the research progress of quinoxaline-embedded porphycenes are summarized.2.the synthetic exploration of quinoxaline-embedded expanded porphyrin 2-3 and porphycene 2-2 is described.Dipyrrolylquinoxaline 1-60 and tetrapyrrolylquinoxaline2-1 were synthesized by acylation,condensation,halogenation and Suzuki coupling reaction,etc.Octaphyrin 2-3 was obtained from tetrapyrrole quinoxaline 2-1 by oxidative coupling,and its macrocyclic structure was characterized by ¹H NMR,¹³C NMR,combined high resolution mass spectrometry and X-ray single crystal diffraction.The UV-Vis spectrum of the macrocycle shows that there is an absorption peak at 650nm.Combined with the analysis of single crystal structure and ¹H NMR spectra,we found that the macrocycle is non-aromatic.In addition,the synthesis of porphycene 2-2 embedded with dipyrrolylquinoxaline 1-60 was explored by oxidation coupling,Mc Murry coupling and Suzuki coupling,etc.3.we designed and synthesized the furan-embedded orangarin with the goal of regulating its aromaticity.Through boride,Vilsmeier-Haack reaction,Ullmann coupling reaction and decarboxylation reaction,precursors such as the pyrrole-furan-pyrrole subunit 3-12,the aldehyde-substituted pyrrole-furan-pyrrole subunit 3-17,the ketone-substituted pyrrole-furan-pyrrole subunit 3-23,bipyrrole 1-10,the aldehyde-substituted bipyrrole 3-5,and the hydroxyl-substituted pyrrole-furan subunit 3-26 were obtained,respectively.Finally,using 3-12 and 3-26 as precursors,orangarin 3-25embedded with two furan units was successfully achieved by[3+2]acid-catalyzed condensation.According to the UV-Vis absorption spectrum of 3-25,the macrocycle is antiaromatic.Its properties are still under further study.