the N2Cl3 coordination sphere around copper(II) is distorted square pyramidal in nature in 2-OCH3. Isolated 2-R complexes, on dissolution in methanol, are found to undergo facile reduction of the metal center to generate the corresponding 1-R complexes. The 1-R and 2-R complexes show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry on the 1-R and 2-R complexes shows both
摘要1,4-二氮杂丁二烯(p-RC6H4N = C(H)(H)C = NC6H4R-p; R = OCH3,CH3,H和Cl;缩写为LR)在环境温度下于甲醇中与CuCl2·2H2O反应25°C)提供一组[CuI(LR)Cl} 2]类型的双氯桥联双铜配合物,命名为1-R。在乙腈中进行的类似反应提供了一种类型为[CuII(LR)Cl2} 2]的双氯桥联双铜络合物,称为2-R。1-OCH3和2-OCH3的分子结构已经通过X射线晶体学确定。虽然铜(I)在1-OCH3中具有接近四面体的N2Cl2配位球,但铜(II)周围的N2Cl3配位球在2-OCH3中实际上是扭曲的方形锥体。分离的2-R配合物,溶于甲醇后,被发现容易地还原金属中心以生成相应的1-R配合物。1-R和2-R配合物在可见光和紫外线区域显示出强烈的吸收。1-R和2-R配合物的循环伏安法显示了以金属为中心和以配体为中心的氧化还原反应。发现
Nitroaldol-reaction of aldehydes in the presence of non-activated Mg:Al 2:1 hydrotalcite; a possible new mechanism for the formation of 2-aryl-1,3-dinitropropanes
Commercially available, non-activated 2:1 Mg:Al hydrotalcite catalyzes the nitroaldol reaction between a variety of aromatic and aliphatic aldehydes and simple nitroalkanes such as nitromethane and nitroethane. A new mechanism is proposed for the formation of the 1,3-dinitropropanes. The threo/erythro diastereoselectivity of the nitroethane-adducts was determined by 1H NMR spectroscopy and was found
study of dynamic nitroaldol systems aided the discovery of a diastereoselective crystallization process through amplification of 2-nitro-1-(pyridine-4-yl)propan-1-ol. The phenomenon was further developed into an effective procedure for asymmetic synthesis of pyridine-nitroalcohols and several substrates were screened to this end. These results demonstrate how work with larger dynamicsystems facilitates
Henry reactions of nitroalkanes call be initiated with diethylzine in the presence of catalytic amounts of 1,2aminoethanol or 1,2-diaminoethane. (C) 2002 Elsevier Science Ltd. All rights reserved.