1815-14-1Relevant academic research and scientific papers
Method for preparing azobenzene and azobenzene compound by electro-catalysis
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Paragraph 0053-0057, (2021/09/04)
The invention relates to a method for preparing azobenzene and azoxybenzene compounds through electrocatalysis. Under the conditions of room temperature and inert gas, an aromatic nitro compound is reduced and coupled with an aromatic amino compound to be oxidized through electro-catalysis, and an azoxybenzene compound is obtained. The method has the advantages of mild conditions, high efficiencyand selectivity, and high universality, and can realize the synthesis of asymmetric azobenzene and azoxybenzene compounds.
TEMPO catalyzed oxidative dehydrogenation of hydrazobenzenes to azobenzenes
Fan, Baomin,Laishram, Ronibala Devi,Li, Jiayan,Luo, Yang,Lv, Haiping,More, Sagar,Su, Zhimin,Xu, Dandan,Yang, Yong,Zhan, Yong
supporting information, p. 3471 - 3474 (2020/05/25)
A metal-free direct oxidative dehydrogenation approach for the synthesis of azobenzenes from hydrazobenzenes has been developed by using TEMPO as an organocatalyst for the first time. The reaction proceeded in open air under mild reaction conditions. A wide range of hydrazobenzenes readily undergo dehydrogenation to give the corresponding azobenzenes in excellent yields.
Photocatalyzed oxidative dehydrogenation of hydrazobenzenes to azobenzenes
Lv, Haiping,Laishram, Ronibala Devi,Li, Jiayan,Zhou, Yongyun,Xu, Dandan,More, Sagar,Dai, Yuze,Fan, Baomin
supporting information, p. 4055 - 4061 (2019/08/07)
Visible light mediated oxidative dehydrogenation of hydrazobenzenes under an ambient atmosphere using an organic dye as a photocatalyst was reported for the first time. The reaction provides an environmentally benign method for the preparation of azobenzenes in excellent yields with good functional group tolerance.
Synthetic method for aromatic azo compound based on cyclohexanone aromatization
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Paragraph 0069-0073, (2019/03/28)
The invention provides a synthetic method for an aromatic azo compound based on cyclohexanone aromatization, and belongs to the technical field of organic chemistry. The method provided by the invention comprises the step of using iodine and DMSO to promote a cyclohexanone compound and arylhydrazine to condensation and dehydrogenation aromatization, and generating the aromatic azo compound. The synthetic method provided by the invention is capable of conveniently synthesizing the asymmetrical aromatic azo compound, and moderate in condition, wide in substrate applicability, simple and convenient in operation, lower in cost, high in product purity, convenient for separation and purification, and is suitable for large-scale preparation without using acid and transition metal.
Photocatalysis Enabling Acceptorless Dehydrogenation of Diaryl Hydrazines at Room Temperature
Sahoo, Manoj K.,Saravanakumar, Krishnasamy,Jaiswal, Garima,Balaraman, Ekambaram
, p. 7727 - 7733 (2018/07/25)
Aromatic azo compounds are privileged structural motifs, and they exhibit a myriad of pharmaceutical as well as industrial applications. Here, we report a catalytic acceptorless dehydrogenation of diarylhydrazine derivatives to access a wide variety of aryl-azo compounds with the removal of molecular hydrogen as the sole byproduct. This distinctive reactivity has been achieved under dual catalytic conditions by merging the visible-light active [Ru(bpy)3]2+ as the photoredox catalyst and Co(dmgH)2(py)Cl as the proton-reduction catalyst. The reaction proceeds smoothly under very mild and benign conditions and operates at ambient temperature. This dual catalytic approach is highly compatible with many different functional groups and has a broad substrate scope. We have also demonstrated the reversible hydrogen storage and release phenomenon on hydrazobenzene/azobenzene couple to show the utility of these compounds as hydrogen storage materials. Further diversification of azobenzene was shown by a transition-metal-catalyzed azo-group-directed ortho-C-H bond functionalization.
Dehydrogenation of the NH?NH Bond Triggered by Potassium tert-Butoxide in Liquid Ammonia
Wang, Lei,Ishida, Akiko,Hashidoko, Yasuyuki,Hashimoto, Makoto
supporting information, p. 870 - 873 (2017/01/14)
A novel strategy for the dehydrogenation of the NH?NH bond is disclosed using potassium tert-butoxide (tBuOK) in liquid ammonia (NH3) under air at room temperature. Its synthetic value is well demonstrated by the highly efficient synthesis of aromatic azo compounds (up to 100 % yield, 3 min), heterocyclic azo compounds, and dehydrazination of phenylhydrazine. The broad application of this strategy and its benefit to chemical biology is proved by a novel, convenient, one-pot synthesis of aliphatic diazirines, which are important photoreactive agents for photoaffinity labeling.
Convenient Electrocatalytic Synthesis of Azobenzenes from Nitroaromatic Derivatives Using SmI2
Zhang, Yu-Feng,Mellah, Mohamed
, p. 8480 - 8486 (2017/12/08)
The synthesis of azobenzenes has been a long-standing challenge. Their current preparation at a preparative or industrial scale requires stoichiometric amounts of environmentally unfriendly reactants. Herein, we demonstrate that the catalytic use of electrogenerated samarium diiodide (SmI2) could promote, in one-step synthesis, the reduction of nitrobenzenes into azobenzenes in high yields under mild reaction conditions. This catalytic procedure contains many elements satisfying a sustainable chemical process for the preparation of one of the most widely wanted family of chemical compounds. The easy synthetic procedure, and the absence of precious metals, bases, and nonhazardous substances, already makes our catalytic procedure a serious alternative to currently available methods. This is a promising method for the efficient synthesis of both symmetrical and asymmetrical azo compounds with a high functional group tolerance.
Structure requirements for anaerobe processing of azo compounds: Implications for prodrug design
Gavin, Jason,Ruiz, Juan F. Marquez,Kedziora, Kinga,Windle, Henry,Kelleher, Dermot P.,Gilmer, John F.
, p. 7647 - 7652 (2013/02/21)
This Letter generalizes the metabolism of the azo class of compounds by Clostridium perfringens, an anaerobe found in the human colon. A recently reported 5-aminosalicylic acid-based prednisolone prodrug was shown to release the drug when incubated with the bacteria, while the para-aminobenzoic acid (PABA) based analogue did not. Instead, it showed a new HPLC peak with a relatively close retention time to the parent which was identified by LCMS as the partially reduced hydrazine product. This Letter investigates azoreduction across a panel of substrates with varying degrees of electronic and steric similarity to the PABA-based compound. Azo compounds with an electron donating group on the azo-containing aromatic ring showed immediate disproportionation to their parent amines without any detection of hydrazine intermediates by HPLC. Compounds containing only electron withdrawing groups are partially and reversibly reduced to produce a stable detectable hydrazine. They do not disproportionate to their parent amines, but regenerate the parent azo compound. This incomplete reduction is relevant to the design of azo-based prodrugs and the toxicology of azo-based dyes.
