Xn:Harmful;
106-39-8Relevant articles and documents
Mild chlorination of aromatic compounds with tin(IV) chloride and lead tetraacetate
Muathen, Hussni A.
, p. 8863 - 8866 (1996)
SnCl4/Pb(OAc)4 acts as a safe source of Cl2 for the chlorination of aromatic compounds. A variety of aromatic compounds are effectively chlorinated with SnCl4/Pb(OAc)4 under mild conditions. The mixture is a selective chlorinating agent, particularly with polyalkylbenzenes, polycyclic aromatic compounds and anisoles.
Eco-compatible zeolite-catalysed continuous halogenation of aromatics
Losch,Kolb,Astafan,Daou,Pinard,Pale,Louis
, p. 4714 - 4724 (2016)
A completely eco-compatible halogenation reaction of arenes has been developed allowing high conversions (>95%) of iodobenzene with nearly 100 kg iodobenzene converted per kgcat in one day. Several solid acids, zeolites being the most promising, have been successfully tested in the chlorination reaction of iodobenzene by using trichloroisocyanuric acid (TCCA), a green chlorination agent. H-?BEA zeolites were found to be the most active catalysts for this model halogenation reaction. A strong structure-activity relationship could be established by thorough characterisation (SEM, BET, XRD, FTIR) of various synthetic zeolites. Indeed, nano-sized ?BEA zeolites and more specifically nanosponge-like ?BEA crystals exhibited the highest catalytic performance with a conversion up to 100% and a selectivity toward monochlorinated products up to 98%. Finally, the gained knowledge was applied to set-up an eco-compatible continuous flow halogenation process of different aromatics catalysed by H-?BEA zeolites.
Highly para-Selective Mono-Chlorination of Aromatic Compounds Under Mild Conditions by t-Butyl Hypochlorite in the Presence of Zeolites
Smith, Keith,Butters, Michael,Nay, Barry
, p. 1157 - 1158 (1985)
t-Butyl hypochlorite supported on H(1+), Na(1+) faujasite X (zeolite X) produces para-selective monochlorination of alkyl-, phenyl-, and halobenzenes under mild conditions; for example, chlorobenzene in acetonitrile (at 40 deg C) is chlorinated in high yield of isolated product (92percent) to give dichlorobenzene with an isomer ratio 97percent para/3percent ortho.
Decarboxylative Ipso Halogenation of Mercury(II) Pyridinecarboxylates. Facile Formation of 3-Iodo- and 3-Bromopyridines
Uemura, Sakae,Tanaka, Sakuya,Okano, Masaya,Hamana, Masatomo
, p. 3297 - 3301 (1983)
Treatment of mercury(II) nicotinate with iodine and bromine in nitrobenzene at 180-185 deg C for 2 h afforded 3-iodo- and 3-bromopyridines in 44percent and 27percent yields, respectively, without any regioisomers and dihalopyridines.From mercury(II) picolinate only 2-3percent of 2-bromopyridine was obtained under similar reaction conditions, while the reaction using mercury(II) isonicotinate did not give any products.When a mixture of nicotinic acid and HgO was used in place of mercury(II) nicotinate, the halodecarboxylation occurred with similar ease.An ionic pathway involving the initial attack of electrophilic Hg(II) species on the ring-C bearing carboxyl group to afford a 3-pyridylmercury(II) compound and the subsequent replacement of the Hg(II) moiety by electrophilic iodine and bromine was proposed for this reaction.
Poly-N-bromosulfonamide-melamine as a novel brominating reagent for regioselective ipso-bromination of arylboronic acids
Alavinia, Sedigheh,Ghorbani-Vaghei, Ramin
, p. 1269 - 1276 (2021/08/27)
A practical synthetic method for the synthesis of aryl bromide was developed through regioselective bromination of boronic acid in the presence of poly-N-bromosulfonamide-melamine (PBBSM). In this regard, a novel heterogeneous support, cross-linked poly sulfonamide-melamine, has been successfully synthesized to stabilize bromine with high surface functional group density (6.6?mmol Br+/g). The prepared reagent is a novel brominating reagent that combines the effective functions of N-bromosulfonamide, N-bromosulfonamide-melamine, and melamine groups. The structure of PBBSM was characterized using XRD, FT–IR, 1H NMR, TGA, FE-SEM, EDX, and TGA analysis. Graphic abstract: [Figure not available: see fulltext.]
The graphite-catalyzed: ipso -functionalization of arylboronic acids in an aqueous medium: metal-free access to phenols, anilines, nitroarenes, and haloarenes
Badgoti, Ranveer Singh,Dandia, Anshu,Parewa, Vijay,Rathore, Kuldeep S.,Saini, Pratibha,Sharma, Ruchi
, p. 18040 - 18049 (2021/05/29)
An efficient, metal-free, and sustainable strategy has been described for the ipso-functionalization of phenylboronic acids using air as an oxidant in an aqueous medium. A range of carbon materials has been tested as carbocatalysts. To our surprise, graphite was found to be the best catalyst in terms of the turnover frequency. A broad range of valuable substituted aromatic compounds, i.e., phenols, anilines, nitroarenes, and haloarenes, has been prepared via the functionalization of the C-B bond into C-N, C-O, and many other C-X bonds. The vital role of the aromatic π-conjugation system of graphite in this protocol has been established and was observed via numerous analytic techniques. The heterogeneous nature of graphite facilitates the high recyclability of the carbocatalyst. This effective and easy system provides a multipurpose approach for the production of valuable substituted aromatic compounds without using any metals, ligands, bases, or harsh oxidants.
Metal- and base-free synthesis of aryl bromides from arylhydrazines
Phuc Tran, Dat,Nomoto, Akihiro,Mita, Soichiro,Dong, Chun-ping,Kodama, Shintaro,Mizuno, Takumi,Ogawa, Akiya
supporting information, (2020/05/08)
An efficient method was developed to synthesize brominated aromatic compounds from arylhydrazine hydrochlorides by using BBr3 in DMSO/CPME (cyclopentyl methyl ether) under air at 80 °C for 1 h without the use of bases or metal catalysts. In particular, this method could be carried out satisfactorily using electron-withdrawing groups to afford aryl bromides in a moderate to excellent yields.
Orthogonal Stability and Reactivity of Aryl Germanes Enables Rapid and Selective (Multi)Halogenations
Deckers, Kristina,Fricke, Christoph,Schoenebeck, Franziska
supporting information, p. 18717 - 18722 (2020/08/25)
While halogenation is of key importance in synthesis and radioimaging, the currently available repertoire is largely designed to introduce a single halogen per molecule. This report makes the selective introduction of several different halogens accessible. Showcased here is the privileged stability of nontoxic aryl germanes under harsh fluorination conditions (that allow selective fluorination in their presence), while displaying superior reactivity and functional-group tolerance in electrophilic iodinations and brominations, outcompeting silanes or boronic esters under rapid and additive-free conditions. Mechanistic experiments and computational studies suggest a concerted electrophilic aromatic substitution as the underlying mechanism.
Amplification of Trichloroisocyanuric Acid (TCCA) Reactivity for Chlorination of Arenes and Heteroarenes via Catalytic Organic Dye Activation
Rogers, David A.,Bensalah, Adam T.,Espinosa, Alvaro Tomas,Hoerr, John L.,Refai, Fares H.,Pitzel, Amy K.,Alvarado, Juan J.,Lamar, Angus A.
supporting information, p. 4229 - 4233 (2019/06/17)
Heteroarenes and arenes that contain electron-withdrawing groups are chlorinated in good to excellent yields (scalable to gram scale) using trichloroisocyanuric acid (TCCA) and catalytic Brilliant Green (BG). Visible-light activation of BG serves to amplify the electrophilic nature of TCCA, providing a mild alternative approach to acid-promoted chlorination of deactivated (hetero)aromatic substrates. The utility of the TCCA/BG system is demonstrated through comparison to other chlorinating reagents and by the chlorination of pharmaceuticals including caffeine, lidocaine, and phenazone.
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.
