1453107-46-4Relevant articles and documents
Synthesis of Selenium and Tellurium Core-Modified Azuliporphyrinogens and Benziporphyrinogens and Corresponding Carbaporphyrinoids
Ahmad, Sohail,Singhal, Anchal,Nisa, Kharu,Chauhan
, p. 11333 - 11340 (2018)
The synthesis of selenium and tellurium core-modified carbaporphyrinogens was carried out by the reaction of functional selenophene/tellurophene diols with azulene or a benzitripyrrane in the presence of acid. The products were obtained in moderate yields and were characterized by using 1H and 13C NMR, UV-vis, FT-IR, CV, and HRMS spectroscopic techniques. Further, oxidation of the obtained core-modified carbaporphyrinogens in the presence of DDQ in CHCl3 afforded the corresponding carbaporphyrins in good yields. Benziporphyrins showed no indication of a ring current or macrocyclic aromaticity as confirmed by using proton NMR spectroscopy, but the addition of TFA gave rise to the formation of weakly diatropic dications.
Synthesis of Nonaromatic and Aromatic Dithia Benzisapphyrins
Sengupta, Rima,Thorat, Kishor G.,Ravikanth, Mangalampalli
, p. 11794 - 11803 (2018/09/27)
A series of [24?€] dithia meta-benzisapphyrins and [22?€] dithia para-benzisapphyrins were synthesized by 3 + 2 condensation of appropriate benzitripyrrane with bithiophene diol under mild acid catalyzed conditions. The dithia m-benzisapphyrins and dithia p-benzisapphyrins were thoroughly characterized by HR-MS, 1D and 2D NMR, absorption, and electrochemical techniques. Our studies showed that dithia m-benzisapphyrins are nonaromatic, whereas the dithia p-benzisapphyrins are aromatic in nature. Thus, we demonstrated here that the dithiabenzisapphyrins can be made aromatic by replacing the m-phenylene moiety of the benzisapphyrin macrocycle with a p-phenylene unit. Furthermore, the studies also indicated that the aromaticity of the dithia p-benzisapphyrins was relatively more compared to the reported heterosapphyrins. The structural and spectral characteristics including aromaticity of the m-benzisapphyrins and p-benzisapphyrins were also discussed with the help of DFT, NICS, and TD-DFT studies.
