Selenosartans: Novel selenophene analogues of milfasartan and eprosartan
摘要:
A series of selenophene analogues of the thiophene-containing anti hypertensives milfasartan and eprosartan were prepared and tested for AT(1) receptor antagonist properties. All four selenophene compounds proved to be potent AT(1) receptor antagonists, with pK(B) estimates indicating that these selenides are at least as effective as the thiophene parent compounds at blocking AT(1) receptor mediated responses. These results reveal that replacement of sulfur with selenium in thiophene-containing sartans does not interfere with sartan activity. (C) 2007 Elsevier Ltd. All rights reserved.
Synthesis and Characterization of <i>N</i>-Methylporphyrins, Heteroporphyrins, Carbaporphyrins, and Related Systems
作者:Alissa N. Latham、Timothy D. Lash
DOI:10.1021/acs.joc.0c01737
日期:2020.10.16
shifted UV–Vis absorptions compared to their core unsubstituted congeners. However, protonNMR spectroscopy demonstrated that these derivatives retained strong diamagnetic ring currents and the presence of the internal alkyl substituents had little effect on the global aromatic characteristics. Nevertheless, the UV–Vis spectra of N-methyl-oxybenzi- and N-methyl-oxypyriporphyrins were dramatically altered
Extended porphyrinoid chromophores: heteroporphyrins fused to phenanthrene and acenaphthylene
作者:Timothy D. Lash、Patrick J. Rauen
DOI:10.1016/j.tet.2021.132481
日期:2021.11
Fusion of aromaticsubunits onto porphyrin chromophores produces variable results and in some cases only minor bathochromic shifts are observed. In order to extend these observations, a series of oxa-, thia- and selenaporphyrins with fused acenaphthylene or phenanthrene units have been synthesized. Phenanthro[5,6-b]porphyrins were previously prepared via conventional ‘2 + 2’ MacDonald condensations
Synthesis, structural characterization and reactivity of heteroazuliporphyrins
作者:Timothy D. Lash、Jessica A. El-Beck、Gregory M. Ferrence
DOI:10.1039/c3ob41992d
日期:——
A series of hetero-azuliporphyrins have been prepared by the “3 + 1” variant on the MacDonald condensation. Azulitripyrranes with tert-butyl and phenyl substituents reacted with thiophene or selenophene dialdehydes in the presence of TFA to give, following an oxidation step, thia- and selena-azuliporphyrins in 45–55% yield. Two of these compounds gave crystals suitable for X-ray crystallographic analysis and the data were consistent with the presence of a 17-atom delocalization pathway. The hetero-azuliporphyrins have significant diatropic character that is enhanced by the presence of an electron-donating tert-butyl substituent. The aromatic character is further increased in polar solvents such as DMSO, which are believed to stabilize dipolar resonance contributors with 18π electron delocalization pathways. Protonation also greatly increases the diatropic characteristics of these macrocycles. The porphyrinoids underwent an oxidative ring contraction with t-BuOOH–KOH to give moderate yields of benzoheterocarbaporphyrins. Reaction of azulitripyrranes with 2,5-furandicarbaldehyde afforded oxa-azuliporphyrins, a class of carbaporphyrinoids that had previously been inaccessible. These “missing links” in the study of heteroazuliporphyrins were isolated as the dihydrochloride salts. Protonated oxa-azuliporphyrins are stable aromatic compounds, but the free base forms underwent rapid decomposition in solution.
Synthesis of a Series of Tropone-Fused Porphyrinoids
作者:Emma K. Cramer、Timothy D. Lash
DOI:10.1021/acs.joc.1c02063
日期:2022.1.21
greatly altered, showing shifts to longer wavelengths and the appearance of strong Q bands between 600 and 800 nm. The proton nuclearmagneticresonance spectra were also very unusual, as the internal protons were strongly shifted upfield, in some cases giving rise to resonances that approached −10 ppm. However, the external protons showed reduced downfield shifts compared to porphyrinoids that do not