An Exceptionally Stable Ti Superoxide Radical Ion: A Novel Heterogeneous Catalyst for the Direct Conversion of Aromatic Primary Amines to Nitro Compounds
作者:Gajanan K. Dewkar、Milind D. Nikalje、Iliyas Sayyed Ali、Abhimanyu S. Paraskar、H. S. Jagtap、A. Sudalai
A matrix-bound superoxide radical anion, generated by treating Ti(OR)4 (R=iPr, nBu) with H2 O2 , is a selective heterogeneous catalyst for the oxidation of anilines to the corresponding nitroarenes with 50 % aqueous H2 O2 [Eq. (1)]. Yields of 82-98 % are obtained, even with anilines bearing electron-withdrawing substituents (R=NO2 , COOH).
通过用H 2 O 2处理Ti(OR)4(R = iPr,nBu)生成的与基质结合的超氧自由基阴离子是一种选择性多相催化剂,用于用50%H 2 O水溶液将苯胺氧化为相应的硝基芳烃2 [式 (1)]。即使具有带吸电子取代基的苯胺(R = NO 2,COOH),也可得到82-98%的产率。
Oxygen as moderator in the zinc-mediated reduction of aromatic nitro to azoxy compounds
作者:Faiz Ahmed Khan、Ch. Sudheer
DOI:10.1016/j.tetlet.2009.02.122
日期:2009.7
A simple and useful protocol for the reduction of nitro arenes to their corresponding azoxy derivatives by employing zinc and NH4Cl in a mixture of [bmim][BF4] and water is described. The selectivereduction of nitro to azoxy is attributed to the hitherto unknown moderating effect of oxygen on zinc metal.
Tandem selective reduction of nitroarenes catalyzed by palladium nanoclusters
作者:Ziqiang Yan、Xiaoyu Xie、Qun Song、Fulei Ma、Xinyu Sui、Ziyu Huo、Mingming Ma
DOI:10.1039/c9gc03957k
日期:——
borohydride (NaBH4) in aqueous solution under ambient conditions, which can selectively produce five categories of nitrogen-containing compounds: anilines, N-aryl hydroxylamines, azoxy-, azo- and hydrazo-compounds. The catalyst is in situ-generated ultrasmall palladium nanoclusters (Pd NCs, diameter of 1.3 ± 0.3 nm) from the reduction of Pd(OAc)2 by NaBH4. These highlyactivePd NCs are stabilized by
Unexpected observations during the total synthesis of calothrixin B–sodium methoxide as a source of hydride
作者:Shrikar M. Bhosale、Aadil A. Momin、Shrikant Kunjir、P.R. Rajamohanan、Radhika S. Kusurkar
DOI:10.1016/j.tetlet.2013.10.140
日期:2014.1
During the total synthesis of calothrixin B, various novel and unexpected results were noticed such as cleavage of C–N bond in imine using sodium cyanoborohydride, sodium methoxide as a hydride source for reduction, deformylation in the presence of bromine, and deacylation using ceric ammonium nitrate (CAN). A detailed mechanism has been proposed for the unexpected results and a few of them are generalized
A Green Chemoenzymatic Process for the Synthesis of Azoxybenzenes
作者:Fengjuan Yang、Zhi Wang、Xiaowen Zhang、Liyan Jiang、Yazhuo Li、Lei Wang
DOI:10.1002/cctc.201500720
日期:2015.11
efficient chemoenzymaticprocess for the synthesis of azoxybenzenes was developed. A peracid was generated in situ by Novozym 435, and then a range of anilines were oxidized by the produced peracid to afford azoxybenzenes in yields ranging from 63.1 to 94.1 %. This method expands the application of lipase in organic synthesis and provides an alternative method for the synthesis of azoxybenzenes.