Metal ions and complexes in organic reactions. Part XI. Reactions in pyridine between copper species and aryl halides, in particular between copper(<scp>I</scp>) oxide and 2-bromonitrobenzene
作者:R. G. R. Bacon、Seetar G. Pande (née Seeterram)
DOI:10.1039/j39700001967
日期:——
The main result of reaction between 2-bromonitrobenzene and copper(I) oxide in boiling pyridine was Ullmanntype coupling, giving up to 70% of 2,2′-dinitrobiphenyl; other products were 2-nitrophenol (0–40%), nitrobenzene (0–70%), and bis-2-nitrophenylamine (ca. 1%), formed via 2-nitroaniline resulting from opening of the pyridine ring. Brief reaction of 1-bromo- or 1-chloro-2,4-dinitrobenzene under similar
2-溴硝基苯与氧化铜(I)在沸腾的吡啶中反应的主要结果是Ullmann型偶联,最多可产生70%的2,2'-二硝基联苯。其他产物为2-硝基苯酚(0–40%),硝基苯(0–70%)和双-2-硝基苯胺(约1%),它们是通过吡啶环开环通过2-硝基苯胺形成的。1-溴-或1-氯-2,4-二硝基苯在相似条件下的简短反应可生成2,4-二硝基苯胺。其他一些邻-硝基取代的芳基溴化物或碘化物,以及邻-碘代苯甲酸甲酯显示出类似于2-溴硝基苯的反应。如果将适当的元素添加到反应混合物中,则会形成联芳基(ArHal →为了形成芳基衍生物Ar 2 Hg,Ar 2 Se 2(或Ar 2 Se)和Ar 2 Te ,抑制了ArAr)。通过使用铜金属或硫化铜(I)(也产生Ar 2 S)代替氧化物,而不是卤化铜(I),可以生产出高收率的联芳基。报告了各种添加剂的作用,并提出了一种机械方案。
Catalytic Antioxidant Activity of Bis-Aniline-Derived Diselenides as GPx Mimics
作者:Giancarlo V. Botteselle、Welman C. Elias、Luana Bettanin、Rômulo F. S. Canto、Drielly N. O. Salin、Flavio A. R. Barbosa、Sumbal Saba、Hugo Gallardo、Gianluca Ciancaleoni、Josiel B. Domingos、Jamal Rafique、Antonio L. Braga
DOI:10.3390/molecules26154446
日期:——
diselenides present GPx-mimetic properties, showing better antioxidant activity than the standard GPx-mimetic compounds, ebselen and diphenyl diselenide. DFT analysis demonstrated that the electronic properties of the substituents determine the charge delocalization and the partial charge on selenium, which correlate with the catalytic performances. The amino group concurs in the stabilization of the selenolate
A One-Pot Access to Benzo[b][1,4]selenazines from 2-Aminoaryl Diselenides
作者:Stefano Menichetti、Antonella Capperucci、Damiano Tanini、Antonio L. Braga、Giancarlo V. Botteselle、Caterina Viglianisi
DOI:10.1002/ejoc.201600351
日期:2016.6
Different 2-sulfonylaminoaryl diselenides substituted with electron-withdrawing or -donating groups are transformed in one pot into benzo[b][1,4]selenazines. The reaction uses a substoichiometric amount of Cu(OTf)2, and the mechanism involves a base-mediated 1,4-elimination at selenium with the generation of an o-iminoselenoquinone and a 2-sulfonylaminoselenolate anion. The former is a dienic species