alpha-Acylaminophosphonates possessing an epoxyisoindolone moiety were prepared with good stereoselectivity (de >= 80%) by a tandem acylation/[4+2]-cycloaddition reaction between maleic anhydride and alpha-aminophosphonates derived from a furfurylamine. The cycloaddition products have an opposite orientation of epoxy and phosphonate groups, which was confirmed by NMR spectroscopy and X-ray crystal structure analysis. (c) 2007 Elsevier Ltd. All rights reserved.
Phenylphosphonic acid is an efficient, friendly and reusable heterogeneous catalyst for the synthesis of α-aminophosphonates through a ‘one-pot’ three-component reaction of amines, carbonyl compounds and dialkyl phosphites undersolvent-freeconditions. This methodology illustrates a very simple procedure, with wide applicability, extending the scope to aliphatic and aromatic amines, aliphatic and
acceleration in the Kabachnik–Fieldsreaction in an externalmagneticfield has been observed. The phenomenon is explained by the proper orientation of substrate molecules forced by externalmagneticfield. Diamagnetic dipoles are repulsed to the center by both electromagnet poles, being simultaneously arranged. This phenomenon may then promote the acceleration of the reaction.
Effects of a Constant Magnetic Field on the Electrochemical Reactions of Quercetin
作者:Marek Zieliński、Barbara Burnat、Ewa Miękoś
DOI:10.1002/open.202000066
日期:2020.12
constant magneticfield (CMF) on the basic processes of quercetin electrochemical reactions. According to the observation made in previous studies, the presence of a double bond in the C‐ring of quercetin enhances the antioxidant properties of that compound, whereas the presence of −OH groups also affects the antioxidant properties. Using cyclic voltammetry it was found that the constant magnetic field
本文研究了恒定磁场 (CMF) 对槲皮素电化学反应基本过程的影响。根据先前研究中的观察,槲皮素 C 环中双键的存在增强了该化合物的抗氧化性能,而 -OH 基团的存在也会影响抗氧化性能。使用循环伏安法发现,恒定磁场提高了槲皮素电氧化的效率,尤其是该过程的第三阶段,即。e. A环中OH基团氧化最困难的阶段。HPLC 的使用证实了电化学测量和循环伏安法研究的结果。
alpha-Aminophosphonates are synthesized by three-component condensation of aldehydes, amines, and trimethylphosphite in acetonitrile by using TiCl4 as catalyst. Compared to conventional methods, this new method consistently has advantages, including excellent yields, short reaction times, and mild reaction conditions.