Acetoxylation of 6,7-dialkoxy-substituted 1,4-dihydroquinoxaline-2,3-diones (Qxs) using fuming nitric acid in acetic acid: A facile synthesis of 5-acyloxy-6,7-dialkoxy QXs
摘要:
Treatment of 6,7-dialkoxy-1,4-dihydroquinoxaline-2,3-diones 3 with fuming nitric acid in acetic acid at 25 degrees C resulted in an acetoxylation reaction, giving 5-acetoxy-6,7-dialkoxy-1,4-dihydroquinoxaline-2,3-diones 4 in moderate yields. A mechanism involving ipso attack of nitronium ion as the first step is proposed.
Synthesis, Structure, and Computational Studies of Soluble Conjugated Multidentate Macrocycles
作者:Amanda J. Gallant、Joseph K.-H. Hui、Federico E. Zahariev、Yan Alexander Wang、Mark J. MacLachlan
DOI:10.1021/jo050742g
日期:2005.9.1
Conjugated, shape-persistent macrocycles based on [3 + 3] Schiff-base condensation are of interest for supramolecular materials. In an effort to develop new discotic liquid crystals based on these compounds, a series of macrocycles with peripheral alkoxy groups of varying length have been prepared. The synthesis and mechanism of formation have been probed by isolation of oligomeric intermediates. A
The Influence of Linker Geometry in Bis(3-hydroxy-N-methyl-pyridin-2-one) Ligands on Solution Phase Uranyl Affinity
作者:Géza Szigethy、Kenneth N. Raymond
DOI:10.1002/chem.201002372
日期:2011.2.7
unsubstituted reference ligands. Uranylaffinity was found to follow no discernable trends with incremental geometric modification. The butyl‐linked 4 li‐Me‐3,2‐HOPO ligand exhibited the highest uranylaffinity, consistent with prior in vivo decorporation results. Of the rigidly‐linkedligands, the o‐phenylene linker imparted the best uranylaffinity to the bis‐Me‐3,2‐HOPO ligand platform.
Tautomerization in Naphthalenediimines: A Keto-Enamine Schiff Base Macrocycle
作者:Amanda J. Gallant、Michael Yun、Marc Sauer、Charles S. Yeung、Mark J. MacLachlan
DOI:10.1021/ol051511z
日期:2005.10.1
[GRAPHICS]A new [3 + 3] Schiff base macrocycle incorporating naphthalene groups has been prepared. By examination of its properties, X-ray crystallography of model compounds, and calculations, it has been determined that the macrocycle exists predominantly as the keto-enamine tautomer. This unexpected tautomerization presents an unusual hexaketo interior in the macrocycle.