Synthesis of 12-Membered Tetra-aza Macrocyclic Pyridinophanes Bearing Electron-Withdrawing Groups
作者:Akop Yepremyan、Magy A. Mekhail、Brian P. Niebuhr、Kristof Pota、Nishanth Sadagopan、Timothy M. Schwartz、Kayla N. Green
DOI:10.1021/acs.joc.0c00188
日期:2020.4.3
electron-withdrawing groups CN, Cl, NO2, and CF3 are introduced. Potentiometric titrations were used to determine the protonation constants of the new pyridinophanes. Further, the influence of such modifications on the chemical behavior is predicted by comparing the potentiometric results to previously reported systems. X-ray diffraction analysis of the 4-Cl substituted species and its Cu(II) complex are also
Synthesis and Structural Studies of 5,12-Dioxocyclams Capped by 4-Substituted Pyridines Across the Amine Nitrogens
作者:Michal Achmatowicz、Louis S. Hegedus、Scott David
DOI:10.1021/jo0301393
日期:2003.10.1
A series of 4-substituted pyridine-capped 5,12-dioxocyclams was synthesized and fully characterized. The 4-substituent varied from electron-withdrawing groups (NO2, NO, CN) to electron-donating groups (NHCbz, NH2). The most versatile substituent was the 4-bromo group, which could be replaced by a variety of groups using Stille, Sonogashira, or Buchwald-Hartig palladium-catalyzed chemistry. Copper complexes of a majority of these capped dioxocyclams were synthesized and characterized as well.