نتایج جستجو برای: pyridines
تعداد نتایج: 6741 فیلتر نتایج به سال:
Various N-heteroaromatic compounds, including pyridines, quinolines and isoquinoline, react with arynes and nitrile-containing solvents to give N-arylated 1,2-dihydro-2-pyridinyl, -2-quinolinyl and -1-isoquinolinyl nitriles in excellent yields.
RCM can be used to make aromatic heterocycles, namely pyridines and, for the first time, pyridazines; the key step after RCM involves elimination of sulfinate to provide the aromatic system.
We report a new, simple and air-stable iron(II) complex pre-catalyst for the synthesis of substituted pyridines via a [2+2+2] cycloaddition between diynes and nitrile derivatives.
The first synthesis of 3-methoxalylchromone was described. The reaction of the latter with electron-rich aminoheterocycles afforded a set of heteroannelated pyridines bearing a CO(2)Me substituent located at the α-position of the pyridine core.
Cyclodehydration of Bohlmann-Rahtz aminodienone intermediates using N-iodosuccinimide as a Lewis acid proceeds at low temperature under very mild conditions to give the corresponding 2,3,6-trisubstituted pyridines in high yield and with total regiocontrol.
The pyridine heterocycle continues to play a vital role in the development of human medicines. More than 100 currently marketed drugs contain this privileged unit, which remains highly sought after synthetically. We report an efficient means to access di- and trisubstituted pyridines in an efficient and highly controlled manner using transient 3,4-pyridyne intermediates. Previous efforts to emp...
The reactivity of the 7-chloro-8-iodo- and 8-chloro-7-iodoimidazo[1,2-a]pyridines 1a-e diversely substituted on the 2 position, towards Suzuki-Miyaura, Sonogashira, and Buchwald-Hartwig cross-coupling reactions as well as cyanation was evaluated. Various methodologies are proposed to introduce aryl, heteroaryl, alkyne, amine or cyano groups in the two positions depending on the nature of the su...
Transition-metal-catalyzed [4+2] heteroannulation of α,β-unsaturated oximes and their derivatives with alkynes has been developed into a powerful strategy for the synthesis pyridines. It nevertheless lacks regioselectivity when unsymmetrically substituted are used. We report herein unprecedented polysubstituted pyridines by formal [5+1] two readily accessible building blocks. A copper-catalyzed...
A series of chiral linear and macrocyclic bridged pyridines has been prepared starting from pyridine-2,6-dicarbonyl dichloride (2). The coupling of 1 with D-alanyl methyl ester gave 2,6-bis-D-alanyl pyridine methyl ester (3). Hydrazinolysis of 3 with hydrazine hydrate afforded bis-hydrazide 4. The latter was reacted with thiophene-2-carbaldehyde, phthalic anhydride or cyclohexanone to afford bi...
Four models of halogen bonds were used to quantify this bond using the DFT B97D/6-311+G(d) computational level: para-substituted iodobenzenes, paraand meta-substituted bromobenzenes complexed with three simple Lewis bases (NH3, NCH and CNH), 1-bromo-4-substituted-bicyclo[2.2.2]octanes with NH3 and 3and 4-substituted pyridines complexed with BrCl and BrF. In addition, the combination of the para...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید