Efficient,Rapid, and Regioselective Bromination of Phenols and Anilines with N-Bromosaccharin Using Tungstophosphoric Acid as a Heterogeneous Recyclable Catalyst

A simple, efficient, and rapid method for high-yielding regioselective mono bromination of phenols and anilines has been achieved by treatment with N-bromasaccharin in the presence of a catalytic amount of tungstophosphoric acid.     

Bromination of Some Aromatic Compounds with Potassium Bromide in the Presence of Benzyltriphenylphosphonium Peroxodisulfate

A simple, efficient, and mild method for selective bromination of some activated aromatic compounds using potassium bromide in the presence of benzyltriphenylphosphonium peroxodisulfate in nonaqueous solution is reported. The results obtained revealed good to excellent selectivity between ortho and para positions of phenols and methoxyarenes.     

Regioselective Bromination of Aromatic Amines and Phenols Using N-Benzyl-DABCO Tribromide

N-Benzyl-DABCO tribromide, a stable, solid organic ammonium tribromide, has been used as a bromine source for the regioselective and high-yielding bromination of aromatic amines and phenols. Mono-bromination proceeds well in the presence of a stoichiometric amount of bromine source at room temperature.     

芳香胺和酚溴化的新工艺

研究了在室温下,N-溴丁二酰亚胺对芳香胺和酚的溴化工艺,在CHCl3、EtOH或EtOH/CHCl3溶剂中,用等摩尔的N-溴丁二酰亚胺可将某些芳香胺和酚(考察了5种反应底物)选择性地一溴化,产率92%~98%,N-溴丁二酰亚胺和反应底物摩尔比为2∶1;某些芳香胺和酚被专一地二溴化(考察了5种反应底物),产率90%~97%。 反应无须催化剂,投料后室温搅拌,反应条件温和,产品只需过滤洗涤即可纯化,操作简便。     

Oxidative Bromination of Aromatic Compounds Using O-Iodoxybenzoic Acid with Tetraethylammonium Bromide

A mild and selective procedure for the bromination of activated arenes using o-iodoxybenzoic acid and tetraethylammonium bromide is presented. The reactions were carried out at room temperature and gave moderate to excellent yields.     

Regioselective Synthesis of Para‐Bromo Aromatic Compounds

Reaction of substituted benzene rings with N‐bromophthalimide, under neutral conditions, gave the corresponding bromo derivatives with a preference for the formation of the para bromo isomer over the ortho isomer. The simple work‐up procedure minimizes loss of product and the yields are good.     

Regioselective Bromination of 3,4—Dimethoxytoluene with N—Bromosuccinimide

The selective brominationsd of 3,4-dimethoxytoluene with N-bromosuccinimide were reported.The nuclear and side-chain brominated products were obtained under different reaction conditions.The mechanism was also discussed.     

Facile Bromination of Aromatic Ethers with Quaternary Ammonium Bromide and Iodosylbenzene

Thedirectintroductionofbromineintotheringsofaromaticethersisawell-establishedprocedure,withbromineinasuitablesolventsuchascarbontetrachloride'oraceticacid2.Recently,quatemaryammoniumsaltswerefoundtobeusedasco-catalystforthedirectbrominationofanilinederivatives3.Thus,quaternaryammoniumtribro-mide,acomplexofquatemaryammoniumbromideandbromine4couldbeappliedforbrominationofaromaticethers5'6.However,theproceduresareverytroublesomeandunsafe.RozenandBrand'reportedthatbrominefluoridecouldbeappliedasa…     

Regioselective Photochemical and Microwave Mediated Monobromination of Aromatic Compounds using 2,4,4,6–Tetrabromo‐2,5‐cyclohexadienone

Bromination of different aromatic substrates have been described using 2,4,4,6‐tetrabromo‐2,5‐cyclohexadienone in conjunction with microwave and ultraviolet radiations. Important features of the work include high regioselectivity obtained in very short to moderate reaction time, atom economy, and recyclability of the reagent.     

Regioselective bromination of activated aromatic substrates with a ZrBr4/diazene mixture

A regioselective method for the bromination of phenols, ethers and anilines using a ZrBr₄/diazene mixture is described. The reaction takes place under mild reaction conditions and the bromine atom adds first at the para unsubstituted position with respect to the OH, OR or NR₂ group of the activated aromatic substrate. Less reactive compounds such as toluene, phenyl acetate, benzonitrile and trifluoromethylbenzene remain intact under the same conditions.     

Ionic Liquid Iodinating Reagent for Mild and Efficient Iodination of Aromatic and Heteroaromatic Amines and Terminal Alkynes

Hexamethylene bis(N-methylimidazolium) bis(dichloroiodate) (HMBMIBDCI), an ionic liquid iodinating reagent, have been prepared and characterized. Its ability to perform iodination reactions with a variety of substrates has been explored. In general, iodination reactions of aromatic and heteroaromatic amines proceed with good yields in the absence of solvent. Reactions of terminal alkynes in the presence of 1,8-diazabicyclo [5.4.O] undec-7-ene and tetrahydrofuran have been investigated as well.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]     

Bromination of porphyrins (Review)

Methods for the bromination of porphyrins and their derivatives at the meso and β-positions are examined. The dependence of the course of the reactions on the conditions and on the structure of the initial compounds is discussed. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 323-353, March, 2009.     

焦脱镁叶绿酸-a甲酯的溴化反应

以焦脱镁叶绿酸-a甲酯为起始原料,通过与各种溴化剂的加成和取代反应,在3-位和meso-位上引进溴原子,分别得到单取代、三取代和四取代的溴化卟吩;其3-位乙烯基与溴化氢的加成则分别生成正常溴代产物和水解产物及其酯化产物.用四氧化锇和高碘酸钠将焦脱镁叶绿酸甲酯的3-位乙烯基氧化成醛,进而与四溴化碳和三苯基磷反应,生成3-位偕二溴取代焦脱镁叶绿酸衍生物.所合成的叶绿酸溴代衍生物均经UV, IR, 1H NMR及元素分析证明其结构.     

α‐Bromination of 1,3‐Dicarbonyl Compounds Using Dess–Martin Periodinane (DMP) and Tetraethylammonium Bromide (TEAB)

A mild and expeditious method for α‐bromination of 1,3‐dicarbonyl compounds using Dess–Martin periodinane and tetraethylammonium bromide is described.     

4-苄基氨甲酰苯基苯胺三氟甲磺酸盐(BCPPAT)：一种新型高效Friedel-Crafts苄基化和环己基化反应的催化剂

首次报道了一种新型高效、可循环使用的Friedel-Crafts反应催化剂——4-苄 基氨甲酰苯基苯胺三氟甲磺酸盐(BCPPAT)，它能够有效地催化芳烃的苄基化和环己 基化反应。     

Regioselective Bromination and Functionalization of Dibenzo[hi,st]ovalene as Highly Luminescent Nanographene with Zigzag Edges

Dibenzo[hi,st]ovalene (DBOV) is a nanographene with a combination of zigzag and armchair edges, consisting of 38 sp² carbons. Excellent optical properties with strong red emission have been demonstrated. Here we report the regioselective bromination of DBOV bearing two mesityl groups ( DBOV‐Mes ) by treatment with N‐bromosuccinimide (NBS) under mild conditions. The dibrominated DBOV was further subjected to transition‐metal‐catalyzed cross‐coupling reactions, that is, Suzuki and Sonogashira coupling, demonstrating the edge‐decoration of DBOV with different functional groups. Notably, DBOVs arylated at the bay regions showed intense red emission and enhanced fluorescence quantum yields of up to 0.97. Amphoteric reduction and oxidation behavior were observed by cyclic voltammetry (CV) measurements. Chemical oxidation to stable radical cation species was also demonstrated, followed by reduction back to their neutral species.     

Gram‐Scale Synthesis and Highly Regioselective Bromination of 1,1,9,9‐Tetramethyl[9](2,11)teropyrenophane

An improved synthetic pathway to the nanobelt‐like 1,1,9,9‐tetramethyl[9](2,11)teropyrenophane has been developed, and enables the synthesis of gram quantities of material. Key innovations are the development of a sequential chlorination/Friedel–Crafts alkylation reaction, a sequential iodination/Wurtz coupling reaction, and a room‐temperature teropyrene‐forming reaction. The teropyrenophane was found to form a very stable radical cation and undergo a completely regioselective fourfold bromination reaction.