Synthesis of Chiral Polyphenylenes through Bergman Cyclization of Enediynes with Pendant Chiral Amino Ester Groups  

作　　者：Shiyuan Sun Binlei Huang Fei Li Depeng Song 胡爱国 

机构地区：[1]Shanghai Key Laboratory of Advanced Polymeric Materials,School of Materials Science and Engineering,East China University of Science and Technology

出　　处：《Chinese Journal of Polymer Science》2015年第5期743-753,共11页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.21474027,91023008);Ph.D.Programs Foundation of Ministry of Education of China(No.20100074110002);the Fundamental Research Funds for the Central Universities,and Shanghai Leading Academic Discipline Project(No.B502)

摘　　要：Chiral enediynes with pendant chiral amino ester groups are synthesized through Sonogashira reactions and subjected to thermal triggered Bergman cyclization at elevated temperatures either in bulk or in solvents to produce chiral polyphenylenes. The disappearance of enediyne monomers are evidenced by FTIR and NMR spectroscopies. The formation of polyphenylenes is further confirmed by UV-Vis and MALDI-TOF mass spectroscopies（MS）. Isotope pattern analysis of the MS spectra shows that the polymers prepared in solvents are terminated by the solvent molecules, whereas the chain ends of the polymers prepared in bulk consist of considerable amount of unmasked free radicals, which is further confirmed by EPR analysis. Circular dichroism（CD） spectra of the chiral polymers show blue shifts of the Cotton peaks, indicating the occurrence of the cycloaromatization reaction. A new set of peaks mirrored at the horizontal axis show up in the long wavelength range, which are assigned to main chain chirality of the polyphenylenes.Chiral enediynes with pendant chiral amino ester groups are synthesized through Sonogashira reactions and subjected to thermal triggered Bergman cyclization at elevated temperatures either in bulk or in solvents to produce chiral polyphenylenes. The disappearance of enediyne monomers are evidenced by FTIR and NMR spectroscopies. The formation of polyphenylenes is further confirmed by UV-Vis and MALDI-TOF mass spectroscopies（MS）. Isotope pattern analysis of the MS spectra shows that the polymers prepared in solvents are terminated by the solvent molecules, whereas the chain ends of the polymers prepared in bulk consist of considerable amount of unmasked free radicals, which is further confirmed by EPR analysis. Circular dichroism（CD） spectra of the chiral polymers show blue shifts of the Cotton peaks, indicating the occurrence of the cycloaromatization reaction. A new set of peaks mirrored at the horizontal axis show up in the long wavelength range, which are assigned to main chain chirality of the polyphenylenes.

关 键 词：Enediyne Bergman cyclization Chiral polyphenylene MALDI-TOF/MS 

分 类 号：O631.5[理学—高分子化学]