T:Toxic;
99-08-1Relevant articles and documents
Photoinduced Iron-Catalyzed ipso-Nitration of Aryl Halides via Single-Electron Transfer
Wu, Cunluo,Bian, Qilong,Ding, Tao,Tang, Mingming,Zhang, Wenkai,Xu, Yuanqing,Liu, Baoying,Xu, Hao,Li, Hai-Bei,Fu, Hua
, p. 9561 - 9568 (2021/08/06)
A photoinduced iron-catalyzed ipso-nitration of aryl halides with KNO2 has been developed, in which aryl iodides, bromides, and some of aryl chlorides are feasible. The mechanism investigations show that the in situ formed iron complex by FeSO4, KNO2, and 1,10-phenanthroline acts as the light-harvesting photocatalyst with a longer lifetime of the excited state, and the reaction undergoes a photoinduced single-electron transfer (SET) process. This work represents an example for the photoinduced iron-catalyzed Ullmann-type couplings.
Method and device for preparing methylnitro-benzene by channelization
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Paragraph 0043; 0044; 0045; 0046, (2019/02/04)
The invention discloses a method and a device for preparing methylnitro-benzene by channelization. The device comprises a storage tank, a nitrogen dioxide cylinder, an ozone generator, a flow pump, agas flowmeter, a reaction pipeline filled with a catalyst, a mixing pipeline, two T-shaped mixed joints, a cooling system, a heating system, a back pressure valve and a receiving tank. The method specifically comprises the following steps: opening the cooling system and the heating system; opening the ozone generator; arranging the flow pump and the gas flowmeter; and mixing raw materials liquid methyl benzene and nitrogen dioxide through the first T-shaped mixing joint and feeding the mixture into the mixing pipeline, then mixing the mixture with ozone in the second T-shaped mixing joint, feeding the mixture into the reaction pipeline filled with the catalyst for a nitrifying reaction, and post-treating a reaction liquid to obtain methylnitro-benzene. The method is controlled precisely and automatically, and is simple to operate, mild in reaction condition, simple in post treatment, quick to transfer mass and heat, high in safety and good in economical benefit.
Niobium oxide prepared through a novel supercritical-CO2-assisted method as a highly active heterogeneous catalyst for the synthesis of azoxybenzene from aniline
Tao, Yehan,Singh, Bhawan,Jindal, Vanshika,Tang, Zhenchen,Pescarmona, Paolo P.
, p. 5852 - 5864 (2019/11/11)
High-surface area Nb2O5 nanoparticles were synthesised by a novel supercritical-CO2-assisted method (Nb2O5-scCO2) and were applied for the first time as a heterogeneous catalyst in the oxidative coupling of aniline to azoxybenzene using the environmentally friendly H2O2 as the oxidant. The application of scCO2 in the synthesis of Nb2O5-scCO2 catalyst resulted in a significantly enhanced catalytic activity compared to a reference catalyst prepared without scCO2 (Nb2O5-Ref) or to commercial Nb2O5. Importantly, the Nb2O5-scCO2 catalyst achieved an aniline conversion of 86% (stoichiometric maximum of 93% with the employed aniline-to-H2O2 ratio of 1?:?1.4) with an azoxybenzene selectivity of 92% and with 95% efficiency in H2O2 utilisation in 45 min without requiring external heating (the reaction is exothermic) and with an extremely low catalyst loading (weight ratio between the catalyst and substrate, Rc/s = 0.005). This performance largely surpasses that of any other heterogeneous catalyst previously reported for this reaction. Additionally, the Nb2O5 catalyst displayed high activity also for substituted anilines (e.g. methyl or ethyl-anilines and para-anisidine) and was reused in consecutive runs without any loss of activity. Characterisation by means of N2-physisorption, XRD, FTIR and TEM allowed the correlation of the remarkable catalytic performance of Nb2O5-scCO2 to its higher surface area and discrete nanoparticle morphology compared to the aggregated larger particles constituting the material prepared without scCO2. A catalytic test in the presence of a radical scavenger proved that the reaction follows a radical pathway.
Ipso-nitration of arylboronic acids with copper nitrate and trifluoroace-tic acid
Wang, Zhu-Qing,Guo, Meng-Ping,Wen, Yong-Ju,Shen, Xiu-Li,Lv, Mei-Yun,Zhou, Xiu-Ling
, p. 891 - 894 (2018/11/06)
An efficient and novel nitrating reagent has been developed for ipso-nitration of arylboronic acids. By using inexpensive and commercially available Cu(NO3)2/CF3COOH as nitrating reagent, various nitroarenes are produced in moderate to excellent yields (51-96%). Advantages of this procedure are the operational simplicity and no need of extra catalyst.
A Predictive Model for the Decarboxylation of Silver Benzoate Complexes Relevant to Decarboxylative Coupling Reactions
Crovak, Robert A.,Hoover, Jessica M.
, p. 2434 - 2437 (2018/02/28)
Decarboxylative coupling reactions offer an attractive route to generate functionalized arenes from simple and readily available carboxylic acid coupling partners, yet they are underutilized due to limitations in the scope of carboxylic acid coupling partner. Here we report that the field effect parameter (F) has a substantial influence on the rate of decarboxylation of well-defined silver benzoate complexes. This finding provides the opportunity to surpass current substrate limitations associated with decarboxylation and to enable widespread utilization of decarboxylative coupling reactions.
Pd-poly(N-vinyl-2-pyrrolidone)/MCM-48 nanocomposite: a novel catalyst for the Ullmann reaction
Mosaddegh, Neda,Yavari, Issa
, p. 2013 - 2021 (2018/07/29)
Abstract: Homocoupling of aryl halides (Ullmann-type reaction) promoted by a Pd-poly(N-vinyl-2-pyrrolidone)/MCM-48 (Pd–PVP/MCM-48) nanocomposite catalyst is described. In situ polymerization method was employed to prepare composite poly(N-vinyl-2-pyrrolidone)/MCM-48 (PVP/MCM-48) which was used as a support for palladium nanoparticles obtained by reducing Pd(OAc)2 with hydrazine hydrate. FT-IR, XPS, XRD, UV–Vis, SEM, and BET techniques were used to study the chemical and physical properties of the catalyst. The catalytic performance of this heterogeneous catalyst was specified for Ullmann-type reaction between aryl halies in DMF. The catalyst was good with regard to its stability and it can be reused up to six times without significant loss of its activity.
Convenient, metal-free ipso-nitration of arylboronic acids using nitric acid and trifluoroacetic acid
Shen, Guodong,Zhao, Lingyu,Liu, Wanxing,Huang, Xianqiang,Song, Huina,Zhang, Tongxin
supporting information, p. 10 - 14 (2016/12/30)
A feasible protocol for the direct ipso-nitration of arylboronic acids using trifluoroacetic acid and nitric acid as nitration reagent has been developed. Various aromatic nitro compounds are produced in moderate to good yields under the metal-free conditions. The method is operationally simple and regioselective, and might have potential application in industry.
Sulfated SO4 2?/WO3 as an efficient and eco-friendly catalyst for solvent-free liquid phase nitration of toluene with NO2
Jiao, Yinchun,Zhu, Man,Deng, Renjie,Jian, Jian,Yin, Yi,You, Kuiyi
, p. 3961 - 3974 (2017/06/20)
With the increase in environmental awareness, developing a highly efficient and environmentally benign nitration process has very important academic and applied industrial values in the synthesis of nitro-compounds. Towards this goal, we have developed an efficient and environmentally friendly approach for solvent-free liquid phase nitration of toluene by employing NO2 as a nitrating agent and sulfated SO4 2?/WO3 as a catalyst replacing traditional nitric acid–sulfuric acid under mild conditions. The results indicate that SO4 2?/WO3 as an effective and eco-friendly catalyst exhibits excellent catalytic activity and reusability for the nitration of toluene with NO2. In addition, the possible pathway for liquid phase nitration of toluene with NO2 over sulfated SO4 2?/WO3 catalyst was suggested. The present method makes this nitration process safe and environmentally friendly, and has the potential to enable a sustainable production of nitro-compounds from the liquid phase nitration of aromatic hydrocarbon with NO2 in industrial applications.
Organocatalytic oxidation of substituted anilines to azoxybenzenes and nitro compounds: Mechanistic studies excluding the involvement of a dioxirane intermediate
Voutyritsa, Errika,Theodorou, Alexis,Kokotou, Maroula G.,Kokotos, Christoforos G.
supporting information, p. 1291 - 1298 (2017/06/06)
An organocatalytic and environmentally friendly approach for the selective oxidation of substituted anilines was developed. Utilizing a 2,2,2-trifluoroacetophenone-mediated oxidation process, substituted anilines can be transformed into azoxybenzenes, while a simple treatment with MeCN and H2O2 leads to the corresponding nitro compounds, providing user-friendly protocols that can be easily scaled up. Various substitution patterns and functional groups were tolerated leading to products in high to excellent yields. Mechanistic studies utilizing HRMS provide clear evidence for the distinct mechanistic intermediates that are involved. This study constitutes an indirect proof excluding the involvement of a dioxirane intermediate in the green organocatalytic oxidation, utilizing 2,2,2-trifluoroacetophenone as the catalyst.
NH4I/tert-butyl hydroperoxide-promoted oxidative C–N cleavage of tertiary amines leading to nitroaromatic compounds
Shao, Ying,Zheng, Hao,Wu, Zhuhong,Huang, Lei,Tong, Jingjing,Wu, Ming,Sun, Xiaoqiang
, p. 504 - 508 (2017/10/03)
A NH4I/tert-butyl hydroperoxide-promoted oxidation of tertiary N-aryl-N,N-dialkylamines in DMSO has been developed to access nitroaromatic compounds. This methodology involves sequential N-dealkylation reactions in one-pot and a radical pathway is proposed.
