61653-40-5Relevant academic research and scientific papers
Construction of 1,2,3-Benzodiazaborole by Electrophilic Borylation of Azobenzene and Nucleophilic Dialkylative Cyclization
Imamatsu, Masaya,Ishida, Shintaro,Kai, Yusuke,Kiriyama, Moe,Kondo, Yoshinori,Nozawa-Kumada, Kanako,Shigeno, Masanori
supporting information, p. 8023 - 8027 (2021/10/25)
1,2,3-Benzodiazaboroles can be conveniently prepared from azobenzenes by a two-step protocol involving electrophilic ortho-borylation with BBr3 and dialkylative cyclization with the Grignard reagent. The methodology provides a diverse range of products equipped with functionalities from azobenzenes containing substituents (Me, t-Bu, F, Cl, Br, I, and OCF3) and a series of Grignard reagents (alkyl- and arylmagnesium reagents). Moreover, this study displays the moderate aromaticity of the B-N-N-containing five-membered ring and mechanistic investigations of the cyclization reaction.
Chemoselective Hydrogenation of Nitroarenes Using an Air-Stable Base-Metal Catalyst
Zubar, Viktoriia,Dewanji, Abhishek,Rueping, Magnus
supporting information, p. 2742 - 2747 (2021/05/05)
The reduction of nitroarenes to anilines as well as azobenzenes to hydrazobenzenes using a single base-metal catalyst is reported. The hydrogenation reactions are performed with an air-and moisture-stable manganese catalyst and proceed under relatively mild reaction conditions. The transformation tolerates a broad range of functional groups, affording aniline derivatives and hydrazobenzenes in high yields. Mechanistic studies suggest that the reaction proceeds via a bifunctional activation involving metal-ligand cooperative catalysis.
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.
The 4.4′-benzidine rearrangement of 4-alkyl substituted hydrazobenzenes
Bouillon, Marc E.,Meyer, Hartmut H.
supporting information, p. 3151 - 3161 (2016/05/24)
When treated with dilute inorganic acids N,N′-diarylhydrazines (hydrazobenzenes) with an alkyl substituent in the 4-position undergo [5,5]-sigmatropic rearrangement reactions to furnish 4-(4′-aminophenyl)-4-alkylcyclohexa-2,5-dienimines (ipso-benzidines) in moderate to excellent yields. Steric bulk of the 4-alkyl substituent in the starting material decreases the yield of the respective ipso-benzidine. Additional electron-donating alkyl substituents in the ortho- and/or meta-positions on both rings generally promote the reaction and consequently increase the yield of the 4.4′-benzidine rearrangement product. Described herein are our findings regarding the scope and limits of this unusual benzidine rearrangement.
Cu(I) mediated one-pot synthesis of azobenzenes from bis-Boc aryl hydrazines and aryl halides
Kim, Kyu-Young,Shin, Jeong-Taek,Lee, Kang-Sang,Cho, Cheon-Gyu
, p. 117 - 120 (2007/10/03)
N,N′-bis-Boc aryl hydrazines underwent Cu(I) catalyzed couplings with aryl halides to provide N,N′-bis-Boc diaryl hydrazines. The resulting N,N′-bis-Boc diaryl hydrazines are readily oxidized to the azobenzenes in the presence of Cu(I) and a base. A prolo
Single Electron Transfer as Rate-Determining Step in an Aliphatic Nucleophilic Substitution
Lund, Torben,Lund, Henning
, p. 470 - 485 (2007/10/02)
The rate of transfer of an electron between electrochemically generated anion radicals and alkyl halides has been measured by cyclic voltammetry and the dependence of the rate on the redox potential of the electron donors found.From this dependence, the rate of electron transfer from an electron donor with reorganization energy about 10 kcal mol-1 to a given alkyl halide can be calculated if the reversible oxidation potential of the donor is known.The method has been applied to show that the rate of the aliphatic nucleophilic substitution of the enolate ion of 4-methoxycarbonyl-4-methyl-1,4-dihydropyridine on t-butyl bromide, neopentyl bromide and adamantyl bromide is the same as that expected for a SET reaction for a donor with the same oxidation potential as the enolate ion.Primary alkyl halides react somewhat faster than expected for a pure SET reaction.The dianion of dihydroperylene reacts with t-butyl chloride and s-butyl bromide at the same rate as would be expected for a SET reaction with a donor with the same oxidation potential as the dianion.The model for the aliphatic nucleophilic substitution is discussed.
