Metal-Free-Mediated Oxidation Aromatization of 1,4-Dihydropyridines to Pyridines Using Visible Light and Air
作者:Xiaojing Wei、Lin Wang、Wenliang Jia、Shaofu Du、Lizhu Wu、Qiang Liu
DOI:10.1002/cjoc.201400521
日期:2014.12
A metal‐free and environmentally friendly aerobic aromatization photosensitized by organic dye eosin Y bis(tetrabutyl ammonium salt) (TBA‐eosinY) has been developed. With the aid of K2CO3, the aerobic catalytic system converts 1,4‐dihydropyridines to their corresponding pyridine derivatives efficiently under visiblelight irradiation (λ=450 nm) at room temperature.
已经开发了一种无金属且环保的需氧芳香化方法,该方法通过有机染料曙红Y双(四丁基铵盐)(TBA-曙红Y)进行光敏。借助于K 2 CO 3,好氧催化系统在室温下在可见光照射下(λ = 450 nm)将1,4-二氢吡啶有效地转化为其相应的吡啶衍生物。
NaI readily mediated oxidative aromatization of Hantzsch 1,4-dihydropyridines with hydrogen peroxide at room temperature: A green procedure
作者:D. Shahabi、M. A. Amrollahi、A. A. Jafari
DOI:10.1007/bf03246562
日期:2011.12
The oxidative conversion of 1,4-dihydropyridines to give the corresponding pyridine derivatives in excellent yields was easily effected using the catalytic amount of NaI in combination with H2O2 (30%) as a green external oxidant. The process is highly green wherein the solid products are easily filtered out after the addition of ice-water to the reaction mixture. This non-transition metal catalyst
使用催化量的NaI和H 2 O 2(30%)作为绿色外部氧化剂,可以轻松实现1,4-二氢吡啶的氧化转化,从而以优异的收率得到相应的吡啶衍生物。该方法是高度绿色的,其中在将冰水添加到反应混合物中之后,容易将固体产物滤出。这种非过渡金属催化剂具有成本效益,提供了简单的后处理和易于分离的产物。
Hydride, Hydrogen, Proton, and Electron Affinities of Imines and Their Reaction Intermediates in Acetonitrile and Construction of Thermodynamic Characteristic Graphs (TCGs) of Imines as a “Molecule ID Card”
作者:Xiao-Qing Zhu、Qiao-Yun Liu、Qiang Chen、Lian-Rui Mei
DOI:10.1021/jo902332n
日期:2010.2.5
A series of 61 imines with various typical structures were synthesized, and the thermodynamic affinities (defined as enthalpy changes or redox potentials in this work) of the imines to abstract hydride anions, hydrogen atoms, and electrons, the thermodynamic affinities of the radical anions of the imines to abstract hydrogen atoms and protons, and the thermodynamic affinities of the hydrogen adducts of the imines to abstract electrons in acetonitrile were determined by using titration calorimetry and electrochemical methods. The pure heterolytic and homolytic dissociation energies of the C = N pi-bond in the imines were estimated. The polarity of the C = N double bond in the imines was examined using a linear free-energy relationship. The idea of a thermodynamic characteristic graph (TCG) of imines as an efficient "Molecule ID Card" was introduced. The TCG can be used to quantitatively diagnose and predict the characteristic chemical properties of imines and their various reaction intermediates as well as the reduction mechanism of the imines. The information disclosed in this work could not only supply a gap of thermodynamics for the chemistry of imines but also strongly promote the fast development of the applications of imines.