Dearomatization−Bis-alkylation of Aromatic and Heteroaromatic Diesters Promoted by Me<sub>3</sub>SnLi via a Stanna−Brook Rearrangement
作者:Pablo Monje、Paula Graña、M. Rita Paleo、F. Javier Sardina
DOI:10.1021/ol053130r
日期:2006.3.2
Reaction of Me3SnLi with aromatic and heteroaromatic diesters proceeds through a fast stanna-Brook rearrangement that generates an stable bis-enolate which can be regioselectively alkylated and cyclized, in one step, to bicyclic compounds containing 6,5-, 6,6-, and 6,7-fused ring systems.
Primary coloured electrochromism of aromatic oxygen and sulfur diesters
作者:Xiuhui Xu、Richard D. Webster
DOI:10.1039/c4ra02523g
日期:——
Eleven aromatic diesters and thioic S,S′-diesters were synthesized and investigated using electrochemical (cyclic voltammetry and controlled potential electrolysis) and UV-vis spectroscopic techniques over a range of temperatures. Nine of the compounds exhibited vibrant colour changes from a colourless state in their neutral forms to brightly coloured upon one-electron electrochemical reduction in acetonitrile. The compounds were found to display either red, green or blue colours in their one-electron reduced states. The electrochromic properties of 3 of the compounds that displayed the most vibrant colour changes were examined in solution using a gold micro-mesh electrode laminated inside a polymer film.
作者:Timothy J. Donohoe、Andrew J. McRiner、Peter Sheldrake
DOI:10.1021/ol0065930
日期:2000.11.1
[GRAPHICS]The partial reduction of electron-deficient pyridines is described herein. Mono- and disubstituted pyridines can be transformed into functionalized dihydropyridines using either Birch reduction conditions or sodium/naphthalene in THF. The compounds formed by these high-yielding reductive alkylation protocols have potential as synthetic intermediates, and we have shown that bicycle compounds containing 6,5, 6,6, and 6,7 ring systems can be prepared in one step via a base-promoted cylization.
Use of dissolving metals in the partial reduction of pyridines: formation of 2-alkyl-1,2-dihydropyridines
作者:Timothy J. Donohoe、Andrew J. McRiner、Madeleine Helliwell、Peter Sheldrake
DOI:10.1039/b101662h
日期:——
The partial reduction of a series of electron deficient pyridines to give both 1,2- and 2,5-dihydropyridines is described. The factors that lead to formation of such dihydropyridines are discussed and it was found that, generally, the presence of two activating groups on the pyridine nucleus is optimal. A series of 2-alkyl-1,2-dihydropyridines was prepared using either Birch or sodium naphthalenide reducing conditions and some preliminary derivatisation chemistry has been examined. The identity of three relevant nitrogen containing heterocycles was proven by X-ray crystallography.
A New Family of Insulin-Mimetic Vanadium Complexes Derived from 5-Carboalkoxypicolinates
作者:Jessica Gätjens、Beate Meier、Tamás Kiss、Eszter M. Nagy、Peter Buglyó、Hiromu Sakurai、Kenji Kawabe、Dieter Rehder
DOI:10.1002/chem.200305019
日期:2003.10.17
physiological pH, with citrate being the most effective competitor for picolinate. All of the complexes trigger glucose uptake and degradation by simian virus modified mice fibroblasts at non-toxic concentrations (<100 microM), with 2 a, [VO(2)(pic)(2)](-) and [VO(2)(dipic)](-) being at least as effective as insulin. Vanadium uptake by the cells is most effective in the case of 2 a. 2 a also effectively inhibits