609-73-4Relevant articles and documents
Nitration of Phenylboron Dichloride with Nitronium Tetrafluoroborate. Attempted Nitration of Iodobenzene and Phenylphosphorous Dichloride
Olah, George A.,Piteau, Mark,Laali, Khosrow,Rao, Chandra B.,Farooq, Omar
, p. 46 - 48 (1990)
Electrophilic nitration of phenylboron dichloride with nitronium tetrafluoroborate and N-nitro-2,4,6-collidinium tetrafluoroborate was investigated in nitromethane solution.The reactions give 10 - 18 percent ortho, 67 - 69 percent meta, and 15 - 21 percent para isomer.NMR studies of the sytem als show the formation of PhBFCl and PhBF2 by fluoride exchange as well as their intermediate complexes with the BF4- anion.The high meta content is attributed to the nitration of uncomplexed phenylboron dihalides with the -BX2 group exhibiting an -I effect which directs the nitration significantly to the meta position.High para isomer content was obtained when phenylboron dihalides were mostly complexed by the BF4- anion, thereby reducing the -I effect of -BX2 group.The nitration of iodobenzene dichloride gave esentially only nitroiodobenzenes due to dissociation of PhICl2 and the much faster nitration of PhI as compared to PhICl2.Attempted nitration of PhPCl2 with NO2+BF4- in CH3NO2 led only to oxidation.The oxidation could not be prevented even when trimethyl phosphate was used as solvent or the milder nitrating agent MeONO2/BF3.
Low-temperature and highly efficient liquid-phase catalytic nitration of chlorobenzene with NO2: Remarkably improving the para-selectivity in O2-Ac2O-Hβ composite system
Deng, Renjie,Liu, Pingle,Luo, He'an,Ni, Wenjin,You, Kuiyi,Zhao, Fangfang
, (2020/02/26)
In this work, we developed a low-temperature and efficient approach for the highly selective preparation of valuable p-nitrochlorobenzene from the liquid-phase catalytic nitration of chlorobenzene with NO2 in O2-Ac2O-Hβ composite system. The results demonstrated that the introduction of molecular oxygen remarkably enhanced the chlorobenzene conversion and the cooperation catalysis of Hβ zeolite and Ac2O envidently improved the selectivity to para-nitro product. Under the optimized reaction conditions, 93.6 % of the selectivity to p-nitrochlorobenzene with 84.0 % of chlorobenzene conversion was obtained, and the ratio of p-nitrochlorobenzene to o-nitrochlorobenzene could reach up to 20.3. Furthermore, the selectivity distribution of nitration products was reasonably explained by the density functional theory (DFT) calculation. Finally, the possible nitration reaction pathway of chlorobenzene with NO2 was suggested in O2-Ac2O-Hβ composite catalytic system. The present work affords a new and mild nitration approach for highly selective preparation of valuable para-nitro products, and has potential industrial application prospects.
Arene diazonium saccharin intermediates: A greener and cost-effective alternative method for the preparation of aryl iodide
Ghaffari Khaligh, Nader,Rafie Johan, Mohd,Shahnavaz, Zohreh,Zaharani, Lia
, p. 535 - 542 (2020/06/01)
In the current protocol, the arene diazonium saccharin derivatives were initially produced from various substituted aromatic amines; subsequently, these intermediates were treated with a greener organic iodide for the preparation of the aryl iodide. We tried to choose low-cost, commercially available, biodegradable, recoverable, ecofriendly, and safe reagents and solvents. The arene diazonium saccharin intermediates could be stored in the liquid phase into a refrigerator for a long time with no significant loss activity. The outstanding merits of the current protocol (a) included the partial recovering of saccharin and tetraethylammonium salt, (b) reduce the use of solvents and the reaction steps due to eliminating separation and purification of intermediates, (c) good yield of the sterically hindered substrates, and (d) avoid the generation of heavy metal or corrosive waste.
Two-Phase Electrochemical Generation of Aryldiazonium Salts: Application in Electrogenerated Copper-Catalyzed Sandmeyer Reactions
Goljani, Hamed,Tavakkoli, Zahra,Sadatnabi, Ali,Nematollahi, Davood
supporting information, p. 5920 - 5924 (2020/08/12)
The electrochemical generation of aryldiazonium salts from nitroarenes in a two-phase system (ethyl acetate/water) was reported for the first time. Some compounds including azo, azosulfone, and arylazides were prepared in good yields with good purity. Cathodically generated aryldiazoniums and anodically produced copper(Ι) ions were used to perform Sandmeyer reactions. To improve the method, an H-type self-driving cell equipped with a Zn rod as an anode was introduced and used for two-phase aryldiazonium production.
Dehydroxyalkylative halogenation of C(aryl)-C bonds of aryl alcohols
Liu, Mingyang,Zhang, Zhanrong,Liu, Huizhen,Wu, Tianbin,Han, Buxing
supporting information, p. 7120 - 7123 (2020/07/14)
We herein report Cu mediated side-directed dehydroxyalkylative halogenation of aryl alcohols. C(aryl)-C bonds of aryl alcohols were effectively cleaved, affording the corresponding aryl chlorides, bromides and iodides in excellent yields. Aryl alcohols could serve as both aromatic electrophilic and radical synthetic equivalents during the reaction.
A new hypervalent iodine(iii/v) oxidant and its application to the synthesis of 2: H -azirines
Zhang, Guangtao,Wang, Yuanxun,Xu, Jun,Sun, Jiyun,Sun, Fengxia,Zhang, Yilin,Zhang, Chenglin,Du, Yunfei
, p. 947 - 953 (2020/02/11)
The reaction of o-nitroiodobenzene and mCPBA in acetic acid was found to afford a novel hypervalent iodine compound, in the structure of which both iodine(iii) and iodine(v) moieties coexist. The nitro groups at the ortho phenyl positions were found to be crucial in stabilizing this uncommon structure. This novel hypervalent iodine(iii/v) oxidant is proved to be effective in realizing the synthesis of 2-unsubstitued 2H-azirines via intramolecular oxidative azirination, which could not be efficiently achieved by the existing known hypervalent iodine reagents.
ipso-Bromination/iodination of arylboronic acids: Poly(4-vinylpyridine)-Br2/I2 complexes as safe and efficient reagents
Fu, Fang,Gurung, Laxman,Czaun, Miklos,Mathew, Thomas,Prakash, G.K. Surya
supporting information, (2019/08/26)
Poly(4-vinyl pyridine) supported bromine/iodine complexes were prepared and probed for ipso-bromination/iodination of arylboronic acids. These solid complexes with catalytic amount of additive are found to be safe and efficient reagent system for the ipso-bromination/iodination. The reaction occurs under mild conditions and tolerates various functional groups resulting in products with high selectivity and yields.
Mechanism of Cu-catalyzed aryl boronic acid halodeboronation using electrophilic halogen: Development of a base-catalyzed iododeboronation for radiolabeling applications
Molloy, John J.,O'rourke, Kerry M.,Frias, Carolina P.,Sloan, Nikki L.,West, Matthew J.,Pimlott, Sally L.,Sutherland, Andrew,Watson, Allan J. B.
supporting information, p. 2488 - 2492 (2019/04/10)
An investigation into the mechanism of Cu-catalyzed aryl boronic acid halodeboronation using electrophilic halogen reagents is reported. Evidence is provided to show that this takes place via a boronate-driven ipso-substitution pathway and that Cu is not required for these processes to operate: General Lewis base catalysis is operational. This in turn allows the rational development of a general, simple, and effective base-catalyzed halodeboronation that is amenable to the preparation of 125I-labeled products for SPECT applications.
Base promoted peroxide systems for the efficient synthesis of nitroarenes and benzamides
Gupta, Sampa,Ansari, Alisha,Sashidhara, Koneni V.
supporting information, (2019/09/07)
A useful and efficient approach for the synthesis of nitroarenes from several aromatic amines (including heterocycles) using peroxide and base has been developed. This oxidative reaction is very easy to handle and afforded the products in good yields. Formation of benzamides from benzylamine was also successfully carried out with this metal-free catalytic system in good to excellent yields.
An efficient gram scale synthesis of aryl iodides from aryl diazofluoroborates in water under mild conditions
Gholap, Somnath S.
, p. 594 - 599 (2018/06/26)
Transition metal-free synthesis of synthetically valuable aryl iodides from aryl diazofluroborates in water under mild conditions has been described. Majority of synthesized aryl iodides are obtained in quantitative yields (>99%) under present reaction conditions. The structural effects due to the substituents present on aryl diazofluoroborates did not show any satisfactory effect on the yields of the aryl iodides. Hence, the methodology presented here was found to be adventitious for the quantitative production of synthetically valuable aryl iodides.
