作者:Thomas D. Svejstrup、Alessandro Ruffoni、Fabio Juliá、Valentin M. Aubert、Daniele Leonori
DOI:10.1002/anie.201708693
日期:2017.11.20
structural motifs from simple building blocks is desirable but still challenging. We demonstrate that protonated electron-poor O-aryl hydroxylamines give aminiumradicals in the presence of Ru(bpy)3 Cl2 . These highly electrophilic species undergo polarized radical addition to aromatic compounds in high yield and selectivity. We successfully applied this method to the late-stage modification of chiral catalyst
Cycloaddition of 5-substituted 1- pyrroline 1-oxide and conversion of the nitrone cycloadducts into cis-and trans- 2,5-disubstituted pyrrolidines
作者:Sk.Asrof Ali、Mohammed I.M. Wazeer
DOI:10.1016/s0040-4020(01)85751-3
日期:1993.1
carried out. The mechanism of the peracid induced ring opening reaction of isoxazolidines (5) is now firmly established. Second cycloaddition reaction of 5-substituted 1- pyrroline1-oxide (6) provides an efficient and stereoselective entry into the trans- (24) as well as cis-2,5- disubstituted pyrrolidines (28).
Poly(4-vinylpyridine)/methylrhenium trioxide (MTO) compounds IIII and microencapsulated polystyrene/MTO systems IVV are efficient catalysts for the oxidation of secondary hydroxylamines to the corresponding nitrones with H2O2. Complete conversions of substrates and quantitative yields of products are obtained under environmentally friendly experimental conditions and with the use of simple work-up
聚(4-乙烯基吡啶)/三氧化二甲基methyl(MTO)化合物IIII和微囊化的聚苯乙烯/ MTO系统IVV是将仲羟胺氧化为相应的H 2 O 2硝酮的有效催化剂。在环境友好的实验条件下并使用简单的后处理程序即可获得底物的完全转化和定量的产品收率。对称取代的羟胺,以及非对称的3-取代和2-取代的羟基吡咯烷酮,用于生物碱和生物活性同类物合成的硝酮的前体,被认为是底物。该非均相催化剂在反应条件下是稳定的,并且可以被回收和再循环至少五次而没有任何明显的效率损失。
Inexpensive and Environmentally Friendly Oxidation of Hydroxylamines to Nitrones with Bleach
作者:Stefano Cicchi、Massimo Corsi、Andrea Goti
DOI:10.1021/jo990417r
日期:1999.9.1
Manganese dioxide oxidation of hydroxylamines to nitrones
Several structurally differentiated N,N-dialkylhydroxylamines were oxidised to the corresponding nitrones using MnO2. Manganese dioxide revealed an efficient and mild reagent for oxidation of hydroxylamines, showing a level of regioselectivity comparable to HgO. Its non-toxicity makes MnO2 the reagent of choice for replacing HgO in this oxidation. (C) 2001 Elsevier Science Ltd. All rights reserved.