5-Nitroisoxazoles in S<sub>N</sub>Ar reactions: access to polysubstituted isoxazole derivatives
作者:Dmitry A. Vasilenko、Sevastian E. Dronov、Dzianis U. Parfiryeu、Kirill S. Sadovnikov、Kseniya N. Sedenkova、Yuri K. Grishin、Victor B. Rybakov、Tamara S. Kuznetsova、Elena B. Averina
DOI:10.1039/d1ob00816a
日期:——
functionalization of the isoxazole ring via the reactions of aromatic nucleophilic substitution of the nitro group with various nucleophiles has been elaborated. The method features excellent chemical yields, easy operability of the reaction, mild reaction conditions and a broad scope of both 5-nitroisoxazoles and nucleophiles. A synthetic approach to 3,5- and 3,4,5-substituted isoxazoles via the sequential
Synthesis and biological evaluation of novel 5-hydroxylaminoisoxazole derivatives as lipoxygenase inhibitors and metabolism enhancing agents
作者:Elena B. Averina、Dmitry A. Vasilenko、Yulia A. Gracheva、Yuri K. Grishin、Eugene V. Radchenko、Vladimir V. Burmistrov、Gennady M. Butov、Margarita E. Neganova、Tatyana P. Serkova、Olga M. Redkozubova、Elena F. Shevtsova、Elena R. Milaeva、Tamara S. Kuznetsova、Nikolay S. Zefirov
DOI:10.1016/j.bmc.2015.12.040
日期:2016.2
A versatile synthesis of novel 5-hydroxylaminoisoxazoles bearing adamantane moieties has been accomplished using the heterocyclization reactions of readily available unsaturated esters by the treatment with tetranitromethane in the presence of triethylamine and subsequent reduction of resulting 5-nitroisoxazoles by SnCl2 with the participation of THF. A number of obtained isoxazole derivatives were evaluated for their antioxidative activity, inhibition of lipoxygenases and impact on the rat liver mitochondria. The majority of tested compounds demonstrated moderate antiradical activity in DPPH test (up to EC50 16 mu M). The same compounds strongly inhibited soybean lipoxygenase (up to IC50 0.4 mu M) and Fe2+- and Fe3+-induced lipid peroxidation (LP) of rat brain cortex homogenate (up to IC50 0.3 mu M). All tested isoxazole derivatives promoted the phosphorylating respiratory activity simultaneously with maximal stimulated respiratory activity of mitochondria and do not reveal any toxicity towards the primary culture of rat cortex neurons. (c) 2015 Elsevier Ltd. All rights reserved.
Chemoselective Reduction of Functionalized 5-Nitroisoxazoles: Synthesis of 5-Amino- and 5-[Hydroxy(tetrahydrofuran-2-yl)amino]isoxazoles
Reduction by using SnCl2 of easily accessible 5-nitroisoxazoles substituted with an electron-withdrawing group (EWG) has been studied. Whereas the reaction in ethanol yielded 5-aminoisoxazoles, performing the reaction in tetrahydrofuran gave previously unknown 5-[hydroxy(tetrahydrofuran-2-yl)amino]isoxazoles. Both reduction procedures were optimized to afford the corresponding products in good to excellent yields. Some mechanistic details concerning the inclusion of the tetrahydrofuranyl moiety into the reaction product are discussed